Aquatic therapy for children with Duchenne muscular dystrophy: a pilot feasibility randomised controlled trial and mixed-methods process evaluation

Epidemiology

Duchenne muscular dystrophy (DMD) is a genetic disease mainly affecting boys. It affects between 1 in 3600 and 1 in 6000 live male births;1–3 the prevalence is 5 in 100,000. 4

Aetiology

Duchenne muscular dystrophy is caused by deletions, duplication or point mutations in a gene on the X chromosome. 5 The gene codes for a protein, dystrophin, that links the cell’s cytoskeleton to a transmembrane complex. Absence of this protein causes disease in muscle cells and brain neurons. The precise mechanism is still uncertain.

Pathology

In muscle, pathological studies show a ‘dystrophic’ picture in which there are dying muscle cells and regenerating muscle cells, together with inflammatory cells and excess amounts of fat and connective tissue. 6,7 Clinically, this manifests as weakness, first of the larger skeletal muscles around the shoulders and hips, and later of all skeletal muscles in the limbs and trunk. With increasing age, this causes a progressive loss of functional abilities that affect mobility (going up stairs, walking, standing, sitting and transferring between objects such as a chair or bed), activities of daily living (dressing, bathing and eating) and eventually breathing. As the disease progresses, muscles and tendons become shorter. These ‘contractures’ then prevent the joints they operate from moving through their full range, because the muscle can no longer stretch as completely as it should. The calf and long finger muscles are often involved by the age of 5 years, causing an inability to bend the foot fully up towards the shin (dorsiflexion) or straighten the fingers back. If untreated, contractures become more severe with time. Later, weakness of the trunk muscles causes scoliosis or curvature of the spine. The heart muscle is increasingly affected with age, eventually leading to impaired function and cardiac failure. The smooth muscle of the bowel deteriorates, affecting bowel function. The lack of dystrophin subtypes in the brain increases the risk of non-progressive cognitive dysfunction, which is associated with communication difficulties. 8

Prognosis

Untreated, half of boys will lose independent ambulation by the age of 9 years, and all will do so by the age of 12 years. Scoliosis and impaired heart function start in early adolescence, whereas breathing difficulty develops later in adolescence. In the 1960s, survival beyond mid-adolescence was unusual. With better therapies, survival increased to late adolescence in the 1970s to the 1990s. In the past two decades, the introduction of more effective respiratory support and heart treatment has increased survival into the early 30s, or longer. The more widespread use of corticosteroids from a young age has slowed disease progression; in those taking daily steroids, the average age at loss of ambulation has increased to 14 years. 9

Significance in terms of ill health

Health-related quality of life for boys with DMD and their carers is lower than for the general population. 10,11 Although physical and psychosocial domains of health-related quality of life are comparatively low in boys with DMD, psychosocial quality of life is sometimes higher in adolescents than in school-age children, indicating the development of coping strategies. 12–14 The psychosocial well-being of parents is greatly impacted, particularly around the time of a boy’s transition to wheelchair use. 15,16 Parents, especially mothers, report high levels of anxiety, depression and guilt. 17,18 Early diagnosis and the resilience of the family unit, expressed as their commitment and control, were associated with improved psychological adjustment by the parent, resilience on the part of the boy and response from siblings. 18–22 Parents, and mothers in particular, report care activities, such as including help for bathing and toileting, as time-intensive and contributing to social isolation. 23

Health-care costs are associated with access to specialist paediatricians/physicians in neurology, respiratory, cardiac and endocrine fields, orthopaedic surgeons, psychologists, physiotherapists and occupational therapists. Boys will sometimes have care co-ordinators or advisors, dietitians or nutritionists, or speech/language/swallowing therapists. Young men older than most of those in our study are likely to make increased use of emergency and respite care. Outside the health services, older boys may access home help, personal assistants and transportation services. From around 8 years of age, the median age of boys entering our study, families will typically make investments in and reconstructions of the home, for instance making adaptations for wheelchair accessibility. 24 Adaptations may also be required to educational facilities. A systematic review of the cost of illness4 noted only three studies that reported cost-impact data, all of which were > 20 years old. 25–27 However, a questionnaire study24 involving people with DMD in Germany, Italy, the UK and the USA provided per-patient annual costs of DMD in 2012 in international dollars. The questionnaire elicited information about hospital admissions, visits to health-care professionals, tests, assessments, medications, non-medical community services, aids, devices, alterations to the home and informal care. Mean per-patient annual direct cost was $23,920–54,270, which is between 7 and 16 times higher than the mean per-capita health expenditure. The total societal costs were $80,120–120,910 per patient per annum, increasing sharply with disease progression. Mean household costs were estimated at $58,440–71,900. 24

Pharmacological management and multidisciplinary care excluding physiotherapy

At diagnosis, a boy and his family will typically be seen by a paediatrician at their local hospital, often a district general hospital. They will then be referred to a specialist muscle clinic, usually involving a paediatric neurologist, in their regional teaching hospital. 28 Regular review and ongoing medical care is provided by these services. The boy and his family will also be seen by the regional genetics service. As part of this service provision they will also be referred to the local paediatric physiotherapy team for assessment and management (see Physiotherapy). If needed, they may be referred for occupational therapy advice as well. Educational services will also be involved. Some children and their families may also benefit from psychological support.

From the age of 3–4 years, most boys will start treatment with corticosteroids, which requires 6-monthly monitoring visits. If complications develop, extra visits and referrals may be needed. One frequent early complication is excess weight gain, which would lead to referral to dietetic services. Approximately one-third of the current population of ambulant boys is eligible for trials of newer treatments designed to increase the amount of the missing dystrophin protein in muscle cells, leading to a milder disease course. If successful, these treatments are likely to become generally available, and additional products are likely to be designed to expand the number of boys who could benefit.

Physiotherapy

Although physiotherapy has been a mainstay of treatment since the 1960s, there is relatively little evidence for its efficacy. There have been no generally accepted guidelines on what type or dose of physiotherapy intervention should be provided. 29,30 Many recommendations are based on animal studies in which contraction-induced muscle injury was observed in dystrophinopathy. 31 A Muscular Dystrophy Campaign workshop29 agreed that the main aims of physiotherapy in neuromuscular disease should be to:

1. maintain or improve muscle strength by exercise

2. maximise functional ability through the use of exercise and the use of orthoses

3. minimise the development of contractures by stretching and splinting.

The prevention of joint contractures is a multidisciplinary effort, involving specialist hubs and community spokes. 32 Regional consultant neurologists and specialist neuromuscular physiotherapists review disease progress and treatment regimens at clinic visits, typically twice a year, and offer management suggestions to community physiotherapists. 28 While a boy is still able to walk, a community paediatric physiotherapist will monitor him for hip and ankle contractures until he becomes wheelchair dependent. 33 The community physiotherapist is responsible for tailoring a programme of stretches and exercises to the boy’s individual needs and tolerance levels,28 and for training parents, carers, school staff or, occasionally, other health and social care staff to deliver the stretches. 33

Management should consist of a variety of treatment options aimed at maintaining the length and extensibility of affected muscle groups. 34 Although evidence to support interventions aimed at improving the range of movement is lacking, there are generally recognised principles that should be carried out to delay or, where possible, prevent the development of contractures. 35 These include the prescription of a regular targeted stretching regime and the use of specific orthotics (e.g. resting or night splints are generally recommended). Stretches are typically prescribed to be performed at home, in school or occasionally in community clinics, on a minimum of 4–6 days per week. 28 They are intended to maintain dorsiflexion and hip flexion range, among other targets, with a view to postponing the onset of contractures and prolonging the length of time the child can walk independently. 33 There are no clear guidelines to specific exercise prescription, but regular submaximal exercise is recommended to maintain existing muscle strength and avoid secondary disuse atrophy,36,37 along with general advice on regular activity such as walking, cycling and swimming. Although there is still the need for further research, there is general agreement that exercise that contains a substantial eccentric component (such as trampolining, stair descending) should be avoided because of the risk of exacerbating muscle damage. 38

Physiotherapy plays its part in the holistic, multidisciplinary management of children with DMD, providing specialist assessment, physiotherapy prescription and ongoing monitoring and evaluation of a complex and progressive condition. 28 Liaison with other specialist services, such as orthotics, wheelchair services, social and housing services, and schools to ensure the provision of appropriate equipment and support in a timely manner to maximise function and independence wherever possible is key. Hyde et al. 39 recommend the use of night splints. Resting or night splints, generally ankle–foot orthoses, are provided for use in combination with a regular stretching regime to optimise the length of the tendo-Achilles complex and maintain ankle dorsiflexion at night. 28,33,39 Children who are losing the ability to walk may be provided with knee–ankle–foot orthoses and may have surgical intervention to release tendons with a view to maintaining joint motion and independent ambulation. 28,33 Postponing wheelchair use may also defer the more or less inevitable associated onset of spinal scoliosis. 33

Introduction

Exercise that is safe and controlled but still sufficiently intense to maintain physical function is a challenge for children with altered muscle tone, balance or motor control problems and severe contractures. 40 Warm water allows children with DMD to perform targeted stretches, exercises and function-based and play activities that are progressively lost to them on dry land. 33 An aquatic therapy (AT) pool may be the only setting in which these children can learn new postures or skills and maintain fitness without damaging their joints.

Although definitions sometimes overlap, common usage distinguishes hydrotherapy and ‘aquatic therapy’ and, especially, ‘aquatic exercise’, from ‘balneotherapy’, which denotes seated immersion or spa therapy without exercise. 41–43 The Aquatic Therapy Association of Chartered Physiotherapists (ATACP) defined aquatic physiotherapy as:

A physiotherapy programme utilising the properties of water, designed by a suitably qualified Physiotherapist. The programme should be specific for an individual to maximise function which can be physical, physiological, or psychosocial. Treatments should be carried out by appropriately trained personnel, ideally in a purpose built, and suitably heated pool.

ATACP43

They permit the use of the term ‘aquatic therapy’ for water-based programmes, designed by a suitably qualified physiotherapist, but carried out by non-specialist physiotherapists, or by carers and teaching assistants without specialist knowledge of anatomy and physiology.

Theoretical basis

In addition to the theories underpinning land-based therapy (LBT) (see Physiotherapy), the theoretical bases for AT are our understanding of the physical properties of water and a learning theory that accounts for developmental aquatic readiness, a model of systematic desensitisation44 and the biomechanical principles of the floating human body,45 as encapsulated in the Halliwick Concept. 46

The physical properties of water that are relevant to physiotherapy are density and specific gravity, hydrostatic pressure, buoyancy, viscosity and thermodynamics. 47 For DMD, a musculoskeletal condition, immersion brings the following benefits. First, warm water may increase cardiac output away from the splanchnic beds to the skin and musculature. 48–50 Blood flow to the muscles may be enhanced at rest51 and during exercise. 52 Second, body weight is offloaded with immersion, with the desired amount of loading variable by depth. 53 In musculoskeletal conditions, then, it is hypothesised that the hydrostatic effects and the warmth of the water, compared with cooler water in community swimming pools, make muscles more supple. The buoyancy and antigravity effects relieve pressure on joints, leading to a reduction in pain and an increase in joint mobility compared with strengthening and stretching exercises performed on dry land. 47 The metacentric or rotational effects, caused by altering the amount of the body that is immersed or the shape of the body in water so that the body is displaced requiring postural adjustments, are used to develop balance, core/proximal stability (stomach, shoulder and hip muscles) and to simulate function (transitions between positions – sit to stand, rolling over, going up steps, lying to sitting).

Systems such as Halliwick, which teach people with disabilities to return to a safe breathing position in water,46 thereby producing confidence and safety, are essential for an AT/physiotherapy programme. 54 They combine two elements: first, the ‘Ten Point Program’, which covers aspects of mental adjustment (including water confidence and breath control), balance control and movement; and, second, a protocol for ‘Water Specific Therapy’, involving assessment and objective setting, based on which the therapist chooses appropriate exercise patterns and treatment techniques. 46

Intervention methods and materials

Aquatic therapy pools typically operate at temperatures of 32–36 °C, higher than the 28 °C of conventional swimming pools, with a greater level of disinfectant and more frequent microbial sampling. 55 Pool size varies, with a recommended minimum space of 2.5 m × 2.25 m per patient and a typical depth of 1–1.2 m, often on a gradient. The provision of changing rooms with adequate space and wide entrances is optimal, along with hoists, both in the changing rooms and to get in and out of the pool. An ATACP foundation programme for chartered physiotherapists is necessary for safe and effective treatment. 56 Subjective, Objective, Assessment and Plan (SOAP) record keeping is recommended. 33

Evidence for effectiveness

In an overview,42 three systematic reviews evaluating aquatic exercise against controls in adults with musculoskeletal conditions showed small post-intervention improvements in function [n = 648, standardised mean difference 0.26, 95% confidence interval (CI) 0.11 to 0.42], quality of life (n = 599, standardised mean difference 0.32, 95% CI 0.03 to 0.61) and mental health (n = 642, standardised mean difference 0.16, 95% CI 0.01 to 0.32). 57–59 They also found a 3% absolute reduction and a 6.6% relative reduction in pain, measured on a visual analogue scale (n = 638, standardised mean difference 0.19, 95% CI 0.04 to 0.35). The meta-analyses identified no differences for walking ability or stiffness.

Although annotated bibliographies on the use of AT in disabled children exist,60,61 we are aware of only one relevant systematic review of aquatic interventions for children with neuromotor or neuromuscular impairments. 62 It included one randomised controlled trial (RCT) and 10 observational studies. Only three studies, all with low levels of evidence, investigated neuromuscular disorders. Seven articles indicated improvements in physical function and activity level, and two out of four articles investigated levels of participation-indicated improvements. The review concluded that there was a lack of quality evidence on the effects of AT in this population.

Current aquatic therapy provision in the UK

Although many health professionals believe that AT can improve mobility, strength, flexibility and cardiopulmonary fitness,63 and although AT is a routine part of care in other countries, access is uneven and restricted in the UK. 64 At the end of 2015, the charity Muscular Dystrophy UK (MDUK) identified 179 AT pools in the UK that people with muscle-wasting conditions could potentially use, but highlight that:

1. many hydrotherapy pools are based in schools and are only open during school hours and terms

2. privately-owned hydrotherapy pools can be expensive to access – often more than £75 for a half-hour session

3. people have to travel long distances to get to a pool, and this is not sustainable

4. hydrotherapy pools do not always have hoists, or accessible changing facilities.

Reproduced with permission from MDUK, Hydrotherapy in the UK: The Urgent Need for Increased Access64

Muscular Dystrophy UK asserts that NHS-funded AT ‘is often restricted to patients whose improvements can be demonstrably measured’;64 as such, functional improvements are difficult to demonstrate in degenerative conditions and funding is often absent or limited. In MDUK’s report, a young person with DMD is quoted as saying:

We have an ongoing need for hydrotherapy, which is not fulfilled by just being given a block of sessions for six weeks. This does not allow us to continue to maintain our condition because once our block of six sessions is over we struggle to be able to access hydrotherapy treatment anywhere else.

Reproduced with permission from MDUK, Hydrotherapy in the UK: The Urgent Need for Increased Access64

The aspiration to access AT throughout the year, rather than in 4- to 6-week blocks, is confirmed by our patient and public involvement (PPI) author, James Parkin, who notes ‘If you have AT regularly, it improves self-esteem; self-esteem improves how you deal with self-management’. A long hiatus between sessions can decrease water confidence and result in a loss of skills. Our qualitative research (see Chapter 5, Environmental factors and Operational work) confirms that, where publicly funded AT is available, it often comes in blocks of 4 or 6 weeks, ≥ 6 months apart, and is not necessarily routine but may be contingent on a successful application. MDUK end their report by arguing that access to AT helps people with muscle-wasting conditions ‘to manage their condition and improve their quality of life by reducing pain and increasing mobility’. 64 They make an appeal to equity, proposing that access should not depend on where a person lives or their disposable income. 64

Rationale

The National Institute for Health Research (NIHR) published a commissioning brief (commissioning brief HTA 12/144) requesting a ‘feasibility study’ to evaluate the addition of ‘manualised hydrotherapy’ to ‘optimised land-based exercise’ for children and young people with DMD who still have some mobility. There are several ways in which we might have interpreted and responded to this brief so, at this point, it is worth taking the reader through the choices we made and why we made them. First, confusion about the definition of feasibility studies, which has since been widely acknowledged,65,66 meant that a decision had to made on the primary objective of this study. The request for a control group, and the focus on the ability to recruit and randomise, led us to interpret the brief as requiring an external pilot RCT, sometimes defined as ‘a version of the main study run in miniature to determine whether the components of the main study can all work together’. 66 In other words, we interpreted the brief primarily as a study to understand the feasibility of a research protocol for a full-scale RCT, rather than of the feasibility of delivering manualised AT per se. As the reader will see, an understanding of both issues is likely to be important for future clinical decision-making and the commissioning of further research.

Primary objective

A future full-scale trial would test the hypothesis that AT in addition to LBT is more effective than LBT alone for the maintenance of functional, participation or quality-of-life outcomes. The primary objective of this external pilot RCT was to determine the feasibility of a full-scale trial, defined in terms of participant recruitment.

Secondary objectives

Secondary objectives were the identification of:

1. the best primary outcome for a full-scale trial

2. the consent rate among eligible boys with DMD who were approached about the study

3. why boys with DMD refuse consent

4. the proportion of boys who provide valid outcome data 6 months after entering the trial

5. reasons for attrition from the trial

6. the views of participants and their families on the acceptability of the research procedures and the AT intervention

7. the robustness of the intended data collection tools

8. the willingness of participating centres to provide an AT service and to recruit participants

9. the ability of participating physiotherapists to deliver the AT intervention faithfully in accordance with a manualised protocol

10. therapist views on the feasibility of the AT intervention and the acceptability of the research protocol.

Overview

None of the team’s specialist physiotherapists knew of intervention manuals tailored to the needs of boys with DMD, as per the NIHR brief. As they would be interventions ‘with several interacting components’, we followed the steps recommended by the Medical Research Council Framework in developing them in parallel with the grant application process. 68 The first step, identification of the evidence base, has been discussed: there is no standard approach to LBT or AT for boys with DMD based on evidence for improvement in function, participation and emotional well-being. Either may help children with DMD maintain physical function but certain types of exercise are thought to be dangerous (see Chapter 1, Physiotherapy and Evidence for effectiveness). The second step, identifying/developing intervention theory, is addressed in The development of treatment manuals and theory. The third and final step is modelling the process and outcomes of implementation, culminating in the development of a programme theory (see Modelling process: developing programme theory). As researchers do not always have the same vision of what theory is supposed to be or do,69 to clarify, then:

1. The function of a pilot RCT is not to test physiological treatment theory, but to determine whether a future full-scale RCT would be capable of doing so. 70,71

2. Initial testing of the programme theory, using linear logic modelling, is one subject of this report.

3. We also access theory to consider why patterns of observations may have occurred. We use general theories and conceptual frameworks, concerning disability and participation, the burden and implementation of services and the character of AT service delivery traditions, to better understand how the social context mediates programme delivery.

The development of treatment manuals and theory

Key stakeholders attended an all-day meeting on 27 March 2013, 4 hours of which were set aside to inform the design of the study intervention (Table 1).

Specialist physiotherapists proposed a set of exercises appropriate to manage the development of DMD in the target population group (see Figure 1 and Interventions). They also agreed that there should be free play at the end of the session, that disease progression should be monitored throughout the study with exercise prescription adapted accordingly and that, in the context of this study, it was worth experimenting with a twice-weekly programme that continued for as long as possible. Members of the team felt that, with no reliable ‘dose–response’ data available for the use of AT in people with DMD, maximising the dose would improve the chances of detecting a treatment effect, if one existed, in any future, full-scale trial. After the meeting, Heather Epps modified an AT manual created for the management of junior idiopathic arthritis,73 Marion Main adapted an existing LBT manual for the management of DMD,34 and the physiotherapists agreed that the manual was suitable for testing. The intervention protocols are described in Interventions.

At successive meetings we developed a treatment theory that hypothesises links between ingredients (observable measurable actions, chemicals, devices or forms of energy), mechanisms of action (processes through which the ingredients bring about change) and targets (measurable aspects of the individual’s functioning that is predicted to be directly changed). 74,75 Figure 1 shows the treatment theory, with ingredients 1 and 2 applying to LBT and all three ingredients applying to the AT intervention. Stretches (ingredient) provide mechanical traction for,76 and relax,37 muscles (mechanisms), which tend to tighten with the progression of DMD, thereby maintaining muscle length and soft tissue structure, while deferring the development of contractures (target). 37 Muscle training and general aerobic, submaximal exercises (ingredients) create biochemical adaptations that increase muscle mass by means of muscle fibre hypertrophy37 and maintained stroke volume77 (mechanisms) to prevent disuse atrophy and maintain or improve skills such as sit to stand, getting up from the floor and stair climbing (targets). Warm water (ingredient) creates haemodynamic changes78 and offers properties such as buoyancy and turbulence (mechanisms)47 that are not available in land-based physiotherapy, thereby reducing mechanical stress during muscle strengthening and allowing activation of muscles in ways not possible on land (target). The mental adjustment and disengagement stages of the Halliwick Concept46 (ingredients) may use mechanisms (e.g. reciprocal inhibition,79 systematic desensitisation80 and extinction81) that psychologists associate with exposure with graded support to achieve water confidence and participation (targets).

FIGURE 1.

Treatment theory for AT programme. VO₂, oxygen consumption.

Modelling process: developing programme theory

A treatment theory is essentially physiological and, in this project, limited in scope to the prescribed exercises performed in the pool. Around these exercises is a ‘programme’, that is, a ‘set of planned activities directed toward bringing about specified change(s)’82 in boys with DMD through prescribed exercises. A programme theory recognises that, around the AT exercises, there is a complex series of contracts, actions, interactions and emergent relationships between people and organisational units. For many researchers, the purpose of evaluating a programme is to develop or test a theory about how it works, rather than merely evaluating whether it works. 83 If the programme is successful, then the evaluation can identify essential elements for replication; if the programme is unsuccessful, then it can identify whether or not this was through failures of implementation, translation to unsuitable contexts or treatment theory. 84 A programme theory, then, is broader than a treatment theory; it focuses on assumptions about background behavioural, social and economic mechanisms that operate if the treatment is to be delivered as scheduled. 85 Programme theory was developed iteratively: (1) deductively, through a review of the literature, (2) by articulating mental models, through discussions at stakeholder meetings, and (3) inductively through interviews with participants and professionals. 86

We searched the literature to inform an initial thematic framework about how children with neurological or musculoskeletal problems, their parents and physiotherapists respond to physical therapy programmes. We used Medical Subject Headings, such as ‘musculoskeletal diseases’, ‘nervous system diseases’, ‘children’, ‘adolescents’ and ‘physical therapy modalities’, as well as free-text terms such as ‘qualitative’ and ‘themes’ in a MEDLINE search to find papers. We found four relevant qualitative research studies on the acceptability of physiotherapy in children with neuromuscular conditions, consisting mainly of inductive thematic analyses. 87–89 One study90 drew on two social science theories. The themes of social model theory, distinguishing impairment from disability and eliminating discrimination and removing barriers to access91,92 have been incorporated into the International Classification of Functioning, Disability and Health – Children and Youth version (ICF-CY)93 (see Modelling process: developing programme theory), which is recommended for understanding context in evaluative studies. 94 The theory of psychosocial development95 was used to understand how changes brought on by adolescence affect adherence to therapy and adaptation to illness. Our population was younger and more compliant than that in that study. As neither theory seemed suited to this population, we constructed an initial framework by which to understand responses to the interventions from themes observed in the four studies. Table 2 shows the key themes of the a priori framework.

We later employed a number of conceptual frameworks and models to ‘make sense of or shed light on’69 the empirical data we gathered, to better understand the implementation and acceptability of the AT programme and to consider how processes could be improved.

The ICF-CY is a conceptual framework used to define disability, which has widespread appeal and acceptance among physiotherapists, one target audience of this work. 93 It describes functioning in terms of body structures and function, desired activity or activity limitations, and participation restrictions (the inclusion of the young person in social situations). The ICF-CY Environmental factors component views disability as the outcome of interactions of these factors with other contextual factors, both environmental and personal.

The way in which participation is understood has developed rapidly since this work was commissioned. 96–99 The conceptual framework developed through an integrative review by Kanagasabai et al. 100 suggests contextual conditions under which participation is reduced or maintained (Figure 2). Another review, by Kang et al. ,101 proposes that participation is optimised with physical, social and self-engagement. Social engagement refers to interpersonal interactions during activities, feelings of being included or belonging. Self-engagement refers to feelings of enjoyment, self-determination and how a person thinks about themselves, especially in the setting and achievement of goals.

FIGURE 2.

Conceptual framework of association between motor functioning and leisure participation. Reproduced with permission from Kanagasabai et al. , Association between motor functioning and leisure participation of children with physical disability: an integrative review, Developmental Medicine & Child Neurology,100 John Wiley and Sons © 2014 Mac Keith Press.

A range of child-, family- and environment-related attributes affect participation. Personal factors covered later in Figure 23 relate to how children adapt to keep engaging with peers or to cope with rejection. 102,103 Age, gender and preferences for particular activities or experiences also play a part in the extent of participation. 104–106 Family socioeconomic status,104 functioning,105 mental well-being,107 orientation towards physical activity105,106 and other factors108 also contribute. A physical environment, societal attitudes and supportive services can provide physical assistance, guidance and broader opportunities for activity. 109–112

Often, the strategies that we develop to manage chronic disease created additional burdens of work for patients, leading to poor adherence and clinical outcomes, as well as wasted resources. 113,114 Minimally disruptive medicine should identify this burden, encourage improved co-ordination of care and design, or prioritise care from the patient perspective. 115 Burden of treatment theory provides a way of understanding the relationship between health-care users, their social networks and the health services they use, with a view to redesigning those services to make them minimally disruptive. 113,116 As burden of treatment theory has been developed around the adult service user, it is useful to consider it in tandem with a conceptual model of parental work of care for children with special health-care needs (Figure 3 and Table 3). 117

FIGURE 3.

The burden of health care in chronic conditions: two conceptual models. a, See Table 3. Adapted from Tran et al. ,114 Hexem et al. 117 and Eton et al. 118 All articles are distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. CSHCN, children with special health-care needs.

Burden of treatment theory helps us to understand the response of patients and carers to complex interventions. To understand the perspectives of physiotherapists delivering AT, we draw on normalisation process theory (NPT), a general theory of how complex interventions become routinely embedded in health services. 119,120 NPT categorises the different kinds of work that people do when they implement a new practice as sense-making, relational, operational and appraisal. Problems in any of the categories can result in implementation failure.

Finally, we draw on themes identified by a systems analysis of problems encountered in aquatic programmes for disabled children (Figure 4). 121 The author describes a split between recreational and therapeutic approaches that existed in both practice and the literature of the early 1980s. 121,122 She identified problems in this division of philosophy, principles, staff composition, roles and training (Figure 5), and described an integrated approach to aquatic intervention for disabled children. Retrospectively, we find this theory useful to interpret the responses of some participating physiotherapists to manualised AT.

FIGURE 4.

Dulcy’s systems analysis of problems in aquatic programmes for disabled children. Copyright 1983 from Aquatic programs for disabled children by Faye H. Dulcy. 121 Reproduced by permission of Taylor & Francis, LLC (www.tandfonline.com). Tx, treatment.

FIGURE 5.

Dulcy’s vicious cycle of problems in aquatic programmes. Copyright 1983 from Aquatic programs for disabled children by Faye H. Dulcy. 121 Reproduced by permission of Taylor & Francis, LLC (www.tandfonline.com).

Based on the above literature and through team discussions, we developed the programme theory, which could be briefly described as follows:

Boys, parents, specialist physiotherapists will be willing and able to conduct twice-weekly AT and tertiary centres will allocate resources for this (inputs and activities). This will be manageable within the existing roles, interactions and relationships that characterise the management of DMD (context). Delivery of the programme per protocol (immediate outcomes) will bring about physiological benefits described in the treatment theory (intermediate outcomes).

We developed a logic model to illustrate how chains of events over time were to bring about the desired outcomes, in accordance with the programme theory (Figure 6). 123,124 Contextual factors that can influence and be influenced by implementation are included.

FIGURE 6.

Logic model (initial).

Most elements of the logic model are self-explanatory, but some are worth unpacking. First, there are a number of definitions of ‘case management’ containing functions that also appear in definitions of ‘programme management’. 125,126 Although we acknowledge this overlap, we use the term to mean a micro-level episode of health-care management in a health-care setting in which one is accountable for service user outcomes. To simplify, by ‘case management’, we mean everything that a physiotherapist does with a boy with DMD and their notes, from identifying a boy as suitable for AT to discharging them from the service. By ‘programme maintenance’, we mean everything that the physiotherapist, his or her colleagues and organisation do to sustain (continue and institutionalise) an AT service beyond case management. 127–130

The programme theory and the logic model form the starting point for a process evaluation, which investigates what is delivered and how, mechanisms of impact (broadly defined) and how context affects implementation and outcomes. 131 In the standard format of a process evaluation, there is an imperative to evaluate implementation fidelity,131–134 which is typically interpreted as the consistency with which intervention components are delivered. 135 However, insofar as front-line physiotherapy often involves making sense of rapidly changing and ambiguous phenomena to revise treatment plans, it is not the kind of work that benefits from standardisation. 136 A body of theoretical literature suggests that the standardisation of function, that is, being faithful to the intervention theory, is more important than standardising the form of an intervention. 137–139 In this study, standardisation would not meet the physical and psychological needs or capabilities of individual children. For these reasons, we evaluate treatment optimisation to the child’s needs and capabilities, adjudicated by an independent physiotherapist, rather than fidelity to intervention components. We define optimisation as good adherence to a good-quality prescription (see Optimisation of prescription).

Trial design

This was a parallel-group, open-label, randomised external pilot trial with a 1 : 1 allocation ratio (Figure 7). Consolidated Standards of Reporting Trials guidelines are observed. 140 Important changes to the methods after trial commencement are reported in Appendix 1.

FIGURE 7.

Pilot RCT summary. 6MWD, Six-Minute Walk Distance; ACTIVLIM, Activity Limitations Measure; CarerQol, Care-related Quality of Life; CHU-9D, Child Health Utility 9D Index; FVC, forced vital capacity; NSAA, North Star Ambulance Assessment.

Participants

Interventions

Outcomes

Outcomes are summarised in Table 5.

Sample size

The sample size was based on a recommended minimum of 30 participants (15 per group) for feasibility objectives involving parameter estimation. 151 Assuming a dropout rate at 6 months of 20%, we set a target of randomising at least 40 participants (20 per group).

Feasibility criterion

This pilot aimed to recruit 40 children in 6 months and to deliver AT to 20 of them. If this objective success criterion was met, then a full-scale study would be deemed feasible.

Generation of the random allocation sequence

The randomisation schedule was computer generated prior to the study by the clinical trials research unit (CTRU) in accordance with standard operating procedures. It was stratified by centre with randomly permuted blinded block sizes to ensure that enough patients were allocated evenly.

Allocation concealment

The allocation schedule was concealed through the use of the centralised web-based randomisation service.

Implementation

After eligibility and written consent were confirmed, patient details were entered into the randomisation system by good clinical practice- and protocol-trained site staff (physiotherapists), and the treatment allocation was returned.

Blinding

Although the physiotherapists, physicians and participants were not blinded, the data analysts remained blind to treatment allocation until after the statistical analysis plan was finalised, the database was locked and the data review was completed. Initially, blinded data were delivered to the statistician by the data manager to define analysis sets and to test statistical programs. Any queries were communicated to the study and data manager prior to database lock. The database was locked after agreement between the statistician, data manager and study manager. No changes were made once the data had been locked. Database freeze and lock were conducted in accordance with CTRU standard operating procedures.

Statistical methods

Ethical aspects

The study received a favourable opinion from the National Research Ethics Committee, East of England – Cambridge South, on 4 July 2014 (reference 14/EE/0204).

Patient and public involvement

James Parkin, a young man with DMD, and Victoria Whitworth, his mother and former carer, were involved in the design of the intervention, the study, the qualitative research analysis and the drafting of the report. They reviewed, made changes to and approved the final lay summary.

Introduction

Physiotherapists are legally obliged to record treatments given in a patient’s record at each intervention session. Participating physiotherapists collected standardised information on the type of exercises, number of repetitions and the time spent on each exercise, in a log based on the AT manual. Parents did the same for LBT. These data were entered onto a web-based data capture system and validated through on-site source data verification. An independent physiotherapist (JS), who was not a co-applicant, acted as an independent reviewer. She assessed whether or not prescribed treatment was ‘optimal’ given the treatment need and capacity of the boy concerned. We tabulated and charted summary data completeness. Missed/cancelled sessions were attributed to provider, patient or unknown factors. In attendance calculations we assumed that when the reasons for a missed session were unknown, then they were due to provider factors; the sum of sessions attended and sessions missed for family reasons were used as the denominator for attendance statistics.

Optimisation of prescription

The assessor made an assessment of whether AT or LBT prescriptions were optimised based on treatment logs and baseline data (NSAA, ACTIVLIM, medical/social history and schooling). The NSAA score was assessed as above or below average depending on the participant’s age and steroid regime. 9 The AT attendance was assessed as good if > 70% of available sessions were attended. The quality of the AT/LBT prescription was classified as ‘good’ if it was individualised to patient’s needs and focused on priorities, as ‘varied’ if the prescription was inconsistent, less focused or too extensive, or as ‘poor’ if it was unfocused and had too much content. In addition, prescriptions were classified as achievable if the exercises were appropriate and could be completed in a half-hour session. The LBT was also classified as realistic if it was clinically appropriate and achievable for the child’s level of ability, contractures and functional score (NSAA). This accepts that prescriptions may need to change with time, loss of function and loss of range of movement.

Adherence to the prescription

As a result of the shortfall in recruitment, sampling was unnecessary and all completed records were evaluated. Full LBT adherence would be demonstrated by completed logs, demonstrating that all prescribed exercises were performed, for each of the seven 4-week periods throughout the 26-week study. Full AT adherence would also be demonstrated by completed logs.

The number of exercises prescribed for AT and LBT is sometimes provided as a range when prescriptions changed during the trial period. Weekly (LBT) or by session (AT) percentage compliance with the prescription was described using mean, median and range values. Prescription compliance of > 50% was assessed as good for both AT and LBT. For both the AT and LBT data, Jennie Sheehan assessed whether or not priority stretches were prescribed according to baseline joint range, NSAA score and knowledge of natural history of DMD. In addition, Jennie Sheehan assessed if any changes in the LBT prescription appeared to affect compliance.

Assessment of overall treatment optimisation

To summarise, the independent reviewer was asked to assess the following:

1. Was the quality of the prescription ‘good’, ‘varied’ or ‘poor’?

2. Was adherence with the prescription ‘good’ or ‘poor’?

If the answer to both (a) and (b) was good, then we considered treatment to be optimised. We considered attendance as a separate variable, but note that it is possible for treatment to be optimised but for there still to be poor receipt of the treatment (see Figure 6). Physiotherapists were given the chance to respond to detailed feedback from the independent rater. Only two took up the opportunity.

Interviewer characteristics

All interviews were conducted by Daniel Hind, a male graduate anthropologist, with 10 years’ experience of qualitative research, employed as a senior research fellow at the University of Sheffield.

Relationship with participants

No relationship was established with interviewees prior to commencement of the qualitative substudy. Participants were informed of the purpose of the research and the professional identity of the interviewer via the information sheet, and reminded, immediately before the interview, that he was an employee of the university, not of their care provider.The interviewer is a health services researcher with no motivational interest in either the population or the success of either intervention.

Theoretical and thematic framework

Participant selection

Convenience samples of children/parents and interventionists were taken. The consent of children and their parents was sought by the site principal investigators at the same time as RCT consent, but was not a precondition of the trial entry. Interventionists were informed at site initiation and approached for consent by a member of the research team directly. We interviewed all of the seven families whose boys (n = 8) received AT. In one case, the child was unavailable on the day and only the parent was interviewed. We interviewed seven physiotherapists who had delivered the intervention at five NHS trusts and a consultant paediatric neurologist at a sixth trust where the only participant had been randomised to the control arm (total health professional interviews, n = 8). None of the families approached declined an interview; one physiotherapist declined an interview, without giving a reason. Once recruited, no-one dropped out. All interviewed physiotherapists (n = 7) had experience of delivering AT prior to this project. Using the NHS Agenda for Change paygrade system,169 two physiotherapists we interviewed were band 6 (the most junior), three were band 7 and two were band 8. To put this in context, all those interviewed would have specialised in a particular condition (whereas it is typical that grade 5 physiotherapists rotate around specialties). Band 8 is usually an indicator that the individual is a physiotherapy service manager.

Setting

Semistructured interviews took place between 22 September 2015 and 14 January 2016 for participants and between 17 September 2015 and 29 January 2016 for physiotherapists. Parents chose the setting for data collection: most parent and child dyads were interviewed in their own home, in person; one dyad was interviewed by Skype^TM (Microsoft Corporation, Redmond, WA, USA); and one parent was interviewed by telephone after the failure of a Skype call. In general, interviews were conducted in quiet and private settings to reduce distractions; one interview was somewhat disrupted by the unavoidable presence of a younger child, otherwise, parents aside, no non-participants were present at interviews. All health professionals were interviewed by telephone around the time of site closure.

Data collection

In addition to the a priori themes identified in Table 2, semistructured interview guides for participants contained questions about the acceptability of intervention and research protocols. Interview guides were piloted with interventionist and patient/carer members of the study management group. The interview guide for health professionals adapted questions suggested by the NPT developers166 and was not piloted. No repeat interviews were undertaken. All interviews were recorded on an encrypted digital recorder and fully transcribed, with transcriptions anonymised. Field notes were taken after interviews as required. Participant/parent interviews lasted a median of 32 minutes (range 20–42 minutes), with durations typically related to the responsiveness of the child; the researcher’s sensitivity and judgement were used to determine the length of the interview. 170 Physiotherapist interviews took a median of 52 minutes (range 44–81 minutes). Formal assessment of whether or not saturation has occurred or of stopping criteria for qualitative data collection was not employed. 171 Although fewer than planned (because of the trial’s recruitment shortfall), some researchers would consider 16 interviews with families and professionals adequate for thematic172 (if not other sorts173,174 of) saturation. There was, for the most part, great consistency in messages from both groups. Transcripts were not returned to participants for correction.

Data analysis

We used the National Centre for Social Research ‘Framework’ approach to analysis, with its five ‘key stages’: (1) familiarisation, (2) identifying a thematic framework, (3) indexing, (4) charting and (5) mapping/interpretation. 175 ‘Framework’ analysis allows sufficient flexibility for analysts to pre-specify themes of anticipated importance as coding categories and to combine them with others that are identified during inductive analysis, allowing the reformulation of ideas during the progress of the analytical process. 176 Transcripts were imported into NVivo version 11 (QSR International, Warrington, UK). Daniel Hind, James Parkin and Victoria Whitworth read and re-read transcripts (familiarisation), considering them in light of the initial thematic framework (see Table 2), NPT and the logic model (Figure 8; see also Figure 6), with notes being taken on new categories inductively derived from the data. We did not develop subthemes because of the number of different theoretical approaches that we were interested in accommodating. Daniel Hind, James Parkin and Victoria Whitworth independently coded a sample of the transcripts (indexing), before conferring with each other with regard to the coded transcripts for items relating to the thematic framework (see Table 2). Daniel Hind also coded within the NPT166 and against items in the logic model. Further literature reviews were conducted to understand emergent themes (see Modelling process: developing programme theory). New frameworks were added to NVivo, where necessary transcripts were recoded and categories refined or merged. We summarised coded data using NVivo matrices, linked to the relevant quotations (charting). Completed charts (available on request) were compared within and between participants.

FIGURE 8.

Coding framework.

We noted if a participant held strong views on a subject and if there was considerable agreement or disagreement between participants. Emerging ideas were mapped out on paper to aid interpretation (mapping). In addition to the involvement of patient representatives, protection against the researcher’s own views and prejudices were minimised by involving a specialist physiotherapist (ES) in three discursive debriefing sessions in which we reviewed coding and discussed interpretations. We actively sought discrepant and divergent views to combat confirmatory bias and to avoid overly simplistic interpretations of phenomena. 177 Participants were not asked to provide feedback on the findings.

Reporting

Before the main results, we provide an exploration of context, which critical interpretivists define as more than the physical environment,178,179 factors, variables and causal relationships,180 but as something sociorelational, which incorporates settings, ‘roles, interactions and relationships’;178 ‘people’s social connectedness, their social locations, or their affinity with the intervention itself’;179 and conflicts, ‘perspectives, relationships, and trust’. 180 As proposed elsewhere,181 to add greater insight,182 participant quotations are sometimes supplemented with accounts from PPI representatives. We provide quotations for major and some minor themes.

Rationale

The rationale for using different methods and informants in this study, and a formal framework to compare their findings, was to address different aspects of the overall research question, making the study more comprehensive, increasing confidence in findings and providing a platform for feedback by professionals and patient representatives. 183

Design

Quantitative and qualitative methods described above were used concurrently, with no priority granted to either, to assess the feasibility of a research protocol and an intervention. We used a modified version of the protocol proposed by Farmer et al. 184 to compare quantitative and qualitative findings (methodological triangulation of data sets), with the following stages: sorting, convergence coding, convergence assessment, completeness assessment and feedback (researcher comparison was not undertaken because of resource constraints).

We reviewed the various data sets to identify key components of the intervention logic model (see Figure 6) to compare for presence and examples (‘sorting’). A convergence coding matrix summarised similarities and differences between data sets for each of the 17 logic model components in the Resources (n = 6), Activities (n = 3), Immediate outcomes (n = 4) and Intermediate outcomes (n = 4) categories. We compared the prominence of logic model components in the data sets, selecting examples to support or explain how each component had contributed to the success or failure of the intervention (‘convergence coding’). We applied the following convergence coding scheme: ‘agreement’ – full agreement between data sets in terms of the interpretation, partial agreement (some disagreement within or between either data sets), silence (only one set of results covers a logic mode component) and dissonance (disagreement between data sets). We quantified the level of agreement between the data sets (‘convergence assessment’) and highlighted differences in the contribution to the research question (‘completeness comparison’). We shared the triangulated results with team members and other selected stakeholders at a face-to-face meeting on 13 April 2016 for ‘feedback’, allowing points of disagreement to be discussed and changes in interpretation to be incorporated if supported by the data.

Implementation summary

Overall, 17 sites were approached to participate in the study: six sites opened and 11 were unable to do so. Of the six sites involved in the grant application, four opened between October 2014 and December 2014, one was unable to proceed because of difficulties securing treatment costs and another because of pool access. Ten sites approached between December 2014 and May 2015 either declined or were unable to gain the relevant approvals in time. Reasons for non-involvement included treatment costs, a lack of eligible participants within travelling range, lack of AT pool availability, organisational change (e.g. moving premises) and therapists being on maternity leave. In April 2015, two additional sites were initiated. The duration between site initiation and the first participant consent was 30–40 days for two sites, 50–60 days for another two sites, 90 days for one site and 169 days for another site.

NHS treatment costs as a cause of centre attrition

Considerable problems were encountered in accessing treatment costs for the research. Where the cost of an experimental treatment is greater than the cost of usual care, in the UK this cost falls on health-care commissioners rather than grant-awarding bodies. 185 Although at the time at which the trial was run most NHS commissioning was devolved, local commissioners recognised that the commissioning of services for rare disease groups was the responsibility of NHS England, an executive non-departmental public body of the Department of Health, established in 2013. However, NHS England responded that they did not have a process in place to support the alignment of commissioning priorities and research needs and refused to meet the treatment costs. After negotiating for several months with local commissioners, one of the original sites withdrew from participation in the study because they could not meet the treatment costs for the trial locally [minutes, Trial Management Group (TMG), 19 January 2015]. Neither local commissioners nor the participating trusts effectively met the treatment costs at other trusts, with physiotherapy teams absorbing the costs within their units or, more usually, participating physiotherapists delivering the intervention and trial procedures in their own time (see Chapter 5, Therapist views of the service, Operational work and Chapter 5, Comments on the trial procedures, Operational work). This was possible only because of the low levels of recruitment and the goodwill of research enthusiasts in research-active trusts.

Specialist centres and distance from the target population

The use of highly specialist physiotherapists from tertiary centres to deliver the AT intervention proved problematic. The eligible patients who were approached for participation in a RCT, which could see them come into the centre twice per week, would have to travel for long distances. Eligible participants at Leeds lived as far afield as Hull and York; Great Ormond Street Hospital, London, drew its patients from as far as Watford and Guildford. At other centres, the majority of study candidates lived > 20 miles away. Unlike in a previous paediatric AT trial, in which usual care involved a 2-week inpatient stay in a specialist centre, at the beginning of which children could be randomised, the contemporary DMD treatment pathway was wholly based on outpatient visits. The team at Great Ormond Street Hospital planned to deliver the intervention not on their own premises, but at AT suites in east and north-west London, which were closer to, and more accessible for, the target population (minutes, TMG, 7 July 2014). However, on investigation, the costs proved prohibitive (minutes, TMG, 3 November 2014). The inability to reimburse travels costs for travel to intervention sessions caused some consternation (minutes, TMG, 7 July 2014).

The idea of subcontracting delivery of AT to therapists at satellite centres, nearer to participants’ homes was discussed (minutes, TMG, 7 July 2014, 19 January 2015). However, given that the population is small and geographically dispersed, we have had to contract with almost as many community trusts as participants would, not to mention agree treatment costs (see previous paragraph) for interventionist training and the delivery of the intervention. The team’s perception was that less research-active community trusts were less likely to tolerate implementation of the study and intervention without access to treatment costs. All trusts had intended to run AT as a group intervention with two or more children in the pool, something that was prevented by under-recruitment. All the trusts were limited to providing AT sessions in office hours because of staffing requirements for safety and evacuation procedures and lone-working policies (minutes, TMG, 3 November 2014).

Participant recruitment and the prohibition on co-enrolment

The general prohibition on co-enrolment of patients,186 especially those deemed to be vulnerable, considerably reduced the pool of candidates available to the study. For instance, at Great Ormond Street Hospital, the children with the best cardiac function tended to be already enrolled in the DMD Heart Protection Study (ISRCTN50395346), meaning that the potential sample could have poor external validity. In addition, there were concerns that many parents were anticipating the opening of well-advertised drug studies (NCT02383511, NCT02369731, NCT01957059, NCT01826474) and would withhold their children from the AT trial, or enrol and then drop out, in the hope of access to a disease-modifying drug therapy (minutes, TMG, 7 July 2014). Although the NIHR urged us to co-enrol patients who had already consented to drug trials (Emma Catlin, NIHR, 2013, personal communication), the research ethics committee refused our request to do so (Leslie Gelling, NRES Committee East of England-Cambridge South 2014, personal communication).

Problems with the delivery of land-based therapy

The commissioning brief required that LBT be ‘optimised’. Normally, community physiotherapists see families between once every 6 weeks and once every 6 months to give an exercise prescription (the minority of patients that are at special schools have therapists who come into school to deliver exercises two or three times per week). Specialist physiotherapists on the team felt that the delivery of LBT would be variable between participants in between seeing community physiotherapists. In routine practice, specialist physiotherapists can recommend problems to work on and specific techniques to community physiotherapists, but varying degrees of co-operation between specialist and community physiotherapists were reported. The reorganisation of services in 2013, when this research was commissioned, following the Health and Social Care Act 2012,187 resulted in complexity and a lack of uniformity of services previously hosted by primary care trusts, including community physiotherapy. 188 As we anticipated difficulties finding out with whom to engage and approach, in order to gain the appropriate NHS Research and Development permissions to implement the study, we asked physiotherapists at participating specialist centres to prescribe LBT for the duration of the trial (minutes, TMG, 15 September 2015). We then relied on parents to capture the weekly delivery of LBT on a log.

Problems with data collection

The ability to deliver the 6MWD, which requires a 30-m corridor,189 was a source of great anxiety in the set-up period. Some hospital sites, where the NSAA would normally have been conducted, did not have passageways of this length (minutes, TMG, 7 July 2014, 15 September 2014, 3 November 2014). It was also posited that, in trusts that were not research active, training would have to be given regarding the administration of the 6MWD (minutes, TMG, 15 September 2014). Although the costs of data capture and entry were adequately funded, this money did not translate into extra resource for the units in terms of a data entry clerk at any of the sites. Instead, relatively expensive physiotherapists ended up entering data, with the CTRU personnel team making on-site visits to help out as the trial advanced (minutes, TMG, 3 November 2014).

Protocol non-compliances

Table 6 shows protocol non-compliances. In general, these were to do with the timing of assessments not being within acceptable ‘windows’. Issues with consent included getting verbal but not written assent at the same time as consent and using superseded versions of consent/assent forms.

Losses and exclusions after randomisation

Table 7 shows the pilot trial completion rate by site. One of the 13 boys for whom the study team received parental consent withdrew from the study before randomisation; his family could not be contacted to confirm the reason, which was, according to a physiotherapist, to enter a drug industry trial. Two participants formally withdrew from the study before completing, both from the control arm: one gave the reason as ‘burden of attending the trial procedure for child’ (R06/001), the other was ‘accepted onto another trial’ (R01/001). One participant was lost to follow-up in the control arm (R07/002). No patients were excluded by the study team.

Decision on the primary end point and sample size for a full-scale trial

Although the 6MWD is the most popular primary outcome in drug trials for ambulant children with DMD, the study raised concerns about its feasibility (see Problems with data collection). Such concerns would be magnified if, as seems likely, any future study involved community trusts, which are more likely to lack the necessary 30-m corridors for the shuttle walk or staff already trained in assessment. For this reason, the NSAA, which is routinely collected for all boys with DMD in the UK, seems like the most feasible outcome for any future full-scale trial. Not only could data collection costs be minimised through its use, but, given the small number of DMD patients available, it is essential that we minimise any loss of information – especially in the control arm – as a result of patient attrition.

Table 10 lists the maximum sample sizes and expected sample sizes on termination required by three-stage ρ-family error spending tests of H₀. We fix the power to detect a minimum important difference of 9 points at 0.8, and take the response SD to be 15 points, which looks sensible given the results of Mayhew et al. 190 We consider designs for a range of values for the type I error rate; given the small sample sizes available, we may be willing to conduct a trial at higher than conventional significance levels, acknowledging the increased risk of a false-positive conclusion when interpreting the trial results.

To interpret the numbers listed in Table 10, please note that once a patient enters the trial, there will be a 6-month delay before their primary response to treatment can be measured. As a result of this delay, when the trial is conducted, at each interim analysis there will be patients in the pipeline who have not yet been followed up for their 6-month response. Conservatively, this external pilot indicates that a future trial might recruit up to 16 boys per year, which implies that approximately eight boys would be in the pipeline at an interim analysis. The standard group sequential designs summarised in Table 10 make stopping decisions using only those data available at an interim analysis. However, the expected sample sizes listed are the expected numbers of patients recruited on termination, incorporating those who are in the pipeline when a stopping decision is made.

From Table 10 we see that the maximum sample sizes needed to conduct a definitive trial with a conventional type I error rate of α = 0.025 are likely to be prohibitive in the context of a national UK trial, which could recruit up to 16 boys with DMD per year. At this rate of recruitment, it would take > 6 years to reach the maximum sample size in the absence of early stopping. If we relax the type I error constraint to test at the 10% significance level, we would expect to take around 2.5 years to come to a conclusion and, in the absence of early stopping, just under 4 years to recruit the maximum sample size.

Table 11 summarises the findings of a simulation study, listing the percentage of trials satisfying the proposed success criterion for various sample sizes when prior distributions are as previously defined. The frequentist type I error rate at θ = 0 is approximately 10%, which is much higher than the conventional 2.5% significance level permitted for one-sided tests of superiority. Under the assumptions of the simulation study, we estimate that a future Bayesian trial would have frequentist power of ≥ 0.7 to detect a clinically relevant treatment effect if ≥ 40 patients could be recruited and followed up for their primary response at 6 months.

Results are based on 10,000 simulations. N is the total sample size divided equally between interventions. Data are simulated according to the model θ^ ∼ N(θ, 4σ²/N) and s² ∼ (σ²/N) χ_N − 2² setting σ = 15 and δ = 9.

Delivery and receipt of the aquatic therapy and land-based therapy interventions

If eight participants allocated to AT attended all 52 AT sessions, there would be 416 session reports. In fact, several participants did not have their first AT session until some time after randomisation (Table 12). The median time between randomisation and commencement of AT was 47 days (range 7–211 days); the mean was 63 days. As a result, not all 416 sessions were possible, especially for those randomised late in the project because the 6-month assessment is anchored to the randomisation date. Of the 349 scheduled sessions for which we have data, 203 (58.2%) expected sessions took place and 146 (41.8%) did not. Reasons for aggregate non-attendance are reported in Table 13 (for individual non-attendance, see Chapter 4, Attendance). Where reasons for session cancellation were discernible (10% of sessions were unaccounted for), there was an even split between participant/family factors (43%) and health-care provider factors (47%).

Of the 12 participants who were randomised, only five returned any LBT data, and for one of those there was only 1 week’s worth of data (Table 14). The other four participants returned more or less full sets of data. The median duration between randomisation and the first date on a LBT parent-completed data collection form was 25 days (range 11–52 days); the mean was 28 days. The LBT adherence data completion summary is shown in Table 15.

Number of missing values/incomplete cases

Data completeness is described in Tables 16 and 17.

Frequentist group sequential trial

In the following, we refer to optimised LBT and LBT plus AT as interventions C and E, respectively. We assume that transformed NSAA scores at 6 months would be analysed by fitting a general linear model adjusting for baseline NSAA score and other relevant baseline covariates. Therefore, the 6-month response of the ith patient would be modelled as:

where X_Ei is an indicator variable that takes the value 1 if patient i is randomised to the intervention, and 0 otherwise; X_Bi is the NSAA score at baseline; and ε_i is an independent random-error term with ε_i ∼ N(0, σ²). We interpret θ as the adjusted difference between expected transformed NSAA scores at 6 months on E versus C; positive values indicate that E is superior to C.

Our first proposal is to conduct a future trial according to a group sequential test of H₀: θ ≤ 0 against H₁: θ > 0 with type I error rate α at θ = 0 and type II error rate β at θ = δ. We take δ = 9 as the minimum important difference we wish to detect. We shall consider group sequential designs, which permit early stopping either for futility (i.e. to abandon a lost cause) or for success (i.e. to declare E superior to C). By testing the H₀ group sequentially, we reduce the expected number of patients needed to conduct the trial, which is particularly desirable in this context when sample sizes are small. We consider one-sided, rather than two-sided, tests of null hypotheses as AT would be adopted in practice only if it can be shown to be superior to standard care.

We propose group sequential tests of H₀ following error spending designs, so called because stopping rules are derived such that certain probabilities of making a type I or type II error are ‘spent’ at each interim analysis. The advantage of this type of design is that it can accommodate unpredictable group sizes, which are likely to occur if recruitment rates are unpredictable and Data Monitoring and Ethics Committee meetings are scheduled at fixed calendar times. We consider designs spending error probabilities according to the ρ-family of functions:

where t, 0 ≤ t ≤ 1, represents the fraction of the test’s maximum information level that has been accrued. Here, f and g stipulate the cumulative type I and type II error probabilities to be spent by the time information fraction t has been accrued. The error-spending parameter, ρ, governs how rapidly error probabilities are spent as a function of the statistical information available for θ: smaller values of ρ imply more aggressive stopping rules with greater opportunity for very early stopping.

Bayesian design

We could shift the aim of a future trial from reaching definitive conclusions on the relative merits of interventions E and C to increasing our understanding of these merits. A future trial would then proceed by recruiting as many patients as possible over a reasonable time frame; based on the HydroDMD pilot study, we believe that 32 patients could be recruited over 2 years. The accumulated data would then be analysed using Bayesian methods to quantify our current thinking about treatment benefits.

Before the future trial begins, the Bayesian approach would start with a thorough evaluation of what is already known about probable patient responses on interventions E and C. For simplicity, we shall take µ_E and µ_C to represent the average change from baseline to 6 months in the linearised NSAA score on interventions E and C, respectively. Furthermore, let σ² denote the common variance of the change from baseline scores. We propose that our prior understanding of the relative merits of interventions E and C could be summarised by placing the following independent prior distributions on θ = µ_E – µ_C and σ:

The prior for θ summarises the findings of the HydroDMD pilot study: the mean is equal to the observed sample mean difference while we set the prior SD equal to twice the estimated standard error of the sample mean. This inflation is made in order to downweight the contribution of the pilot information to a future efficacy trial and reflects our uncertainty about the estimated standard error. An independent and vague prior is used for σ to reflect our uncertainty about the response variance. We could seek to incorporate into the stated prior distributions data from other relevant historical controlled trials; however, the natural history of DMD is known to have changed markedly in recent years with the introduction of glucocorticoid therapy and the standardisation of usual care (Ricotti et al. 72). Therefore, it is unlikely that the average responses seen in historical trials would be commensurate with those seen in contemporary studies.

The next step would be to conduct the Bayesian trial, recruiting as many patients as possible across a network of UK centres. Patients would be randomised in a 1 : 1 ratio between interventions E and C. On termination of the trial, once all recruited patients have been followed up for their 6-month outcome, the new trial data would be summarised by the pair of sufficient statistics for θ and σ, that is, the maximum likelihood estimate of θ and the sample variance. A Bayesian analysis would then be performed, using Bayes’ theorem to update the priors to derive posterior distributions incorporating the trial data. A provisional decision to introduce intervention E would be made if the posterior probability that θ > 0 exceeds 0.9.

Figures 17 and 18 show the OMNI after the session and change for each intervention participant, respectively.

FIGURE 17.

OMNI score after the session.

FIGURE 18.

OMNI score change.

Figures 19 and 20 show the Wong–Baker visual analogue scale after the session and change for each intervention participant, respectively.

FIGURE 19.

Wong–Baker visual analogue scale after the session.

FIGURE 20.

Wong–Baker change.

Attendance

Aquatic therapy attendance (Table 22 and Figures 21 and 22) overall was assessed as good for six of the eight participants. The actual number of sessions attended by participants varied between 16 and 30 sessions overall, and the actual number of sessions not attended ranged between 10 and 34 sessions overall. Patient and pool factors for non-attendance were equal for three participants, pool factors were higher for three participants and patient factors were higher for two participants. Two participants had overall attendance of < 40%, one had overall attendance of between 40% and 50% and five participants had attendance levels of between 50% and 60%.

FIGURE 21.

Number of AT sessions completed.

FIGURE 22.

Timing of AT sessions.

The aquatic therapy prescription

The NSAA score was assessed by the independent rater as above expected for age for three participants and below expected for five participants. Between the consent and baseline assessments (a gap of 1 month), five participants improved, one maintained function and two declined on the NSAA. Seven of the participants had contractures and all participants had a reduced range of movement (Table 23). Note the rapid decline in NSAA score for participants R04/001 and, in particular, R07/001, during the 6-month trial period.

The prescription overall was assessed as good for three participants, variable by session for two and poor for three participants. The independent assessor assessed the AT prescriptions as realistic and achievable for four of the eight participants. The prescription was assessed as unachievable for four participants at two centres. The independent assessor stated that the number of exercises prescribed per session ranged from 4 to 27 exercises across all participants who contributed data. In relation to overall prescription compliance, three participants were assessed as poor and five as having good levels of compliance. Overall prescription compliance was between 20% and 30% for one participant, 30% and 40% for two participants, 70% and 80% for two participants, and 80% and 90% for three participants. The prescription compliance per session ranged from 9% to 100% across participants. One physiotherapist, who was deemed to have optimised treatment based on the data given to the independent rater, commented that her participant (participant R07/001) encountered significant fatigue and dissatisfaction (see Chapter 5, Fatigue and pain and Appraisal work). She explained that, although the prescription remained the same, the actual number of exercise repetitions was adjusted depending on the participant’s fatigue, which the independent assessor agreed was appropriate.

Five of the eight participants had additional non-prescribed exercises completed during sessions with no explanation provided. The independent rater considered exercises not to be appropriately prioritised in three cases: with R01/002, she would have prioritised hips in addition to ankles; with R01/004 she would have prioritised more hip and trunk exercises, and fewer wrist exercises; with R07/001 she would have prioritised iliotibial band exercises in addition to ankles. The independent rater felt that too much emphasis was placed on wrist exercise in a number of prescriptions (R01/002, R01/005, R01/004 and R05/001). Although wrist stretching was appropriate, it did not require the properties of water and, with limited time, other exercises that do benefit from the properties of water (particularly lower limb exercises) could have been prioritised. The independent rater remarked that wrist exercises were placed first on the manual menu of exercises and that this may have led to overprescription.

Impairment and activity limitation

The children in our study were already starting to have problems walking (d450) and moving around as a result of increasing muscle weakness and secondary joint contractures (b710). Many had already transitioned into a phase involving adaptive equipment to improve mobility and quality of life. Some were using canes, walkers or power wheelchairs for parts of the day to maintain independence of mobility. One interview took place as an occupational therapist was inspecting the participant’s house for modifications. To assist with care, one child’s bedroom had recently been moved to the ground floor. Modified vans and ramps were often in evidence as aids to assist with care. Several children were falling frequently (d455), and some were using motorised wheelchairs for portions of the day.

Yeah, playing in the street, he walk, and when he walking, he fell down very easily . . . now he can’t walk maybe more than hundred metre, something like that.

Parent R05/001

Participation restriction

Predictably,100,191 some parents reported that their boys were increasingly frustrated at the loss of function (see Perceived improvement in confidence, independence or participation) and consequent withdrawal from sport, play (d880) and their peer group (d7500).

Personal factors

Typically for the age group, most participants were on steroid therapy with the anticipation of prolonging ambulation,9,192 sometimes with attendant weight gain and behavioural issues (b152, d310). 193 We are not aware that any of our participants had substantial learning difficulties (b117, b164), which are sometimes associated with DMD. 193 With life expectancy now much longer as a result of improved disease management,194 the prospect of further education and profession was likely to be an important goal for many families. However, at an average age of 9 years, a child’s awareness of possible futures is somewhat limited.

We are now having a population that lives to go on to university and, in that case, academia is very important . . . the ones that are cognitively good, you know, that’s really important.

Physiotherapist S07/001

I have a 14-year-old son and obviously [his brother and participant] is 8 . . . now. [Participant] knows he’s got poorly muscles, he knows he’s got something called DMD; he knows that he’ll need a wheelchair more and more. But, for him, it’s the day by day. I think, as a parent, you keep it as normal as possible for as long as possible . . . we’ve also got to think about the 14-year-old who can go on Google [Google Inc., Mountain View, CA, USA] and see all the worst case and the future . . . we’re pumping [participant] full of steroids every day so, emotionally, that changes him, gives him high and lows . . . When he’s tired he becomes quite emotional he can laugh uncontrollably at the slightest thing or cry uncontrollably at the slightest thing.

Parent R02/001

Environmental factors

Perceived improvement or decline in physical function

In five cases, parents or boys perceived some improvement (R01/005, R01/004, R01/002, R02/001, R07/001), although in one case the child and physiotherapist disagreed. In two cases (R02/001 and R01/005) this was based on specific observations:

I actually think his range on his heels improved.

Parent R02/001

The next morning [after the AT], his legs were like really, really good. They weren’t stiff and they didn’t feel heavy . . . it keeps him flexible and it stops the cramps. On the assessment that [the physiotherapist] did at the hospital [at the 6-month assessment] he actually had to step up . . . without holding onto anything. He didn’t do it the first time . . . then he did. We were all amazed. He did absolutely fantastic.

Have you been able to do that before?

Not as high as what it were, no.

So it’s actually improved over the last 6 months you think?

Oh definitely . . .

And I couldn’t jump either. I couldn’t jump and now I can.

Parent and child R01/005

In some cases, the perceived benefits were less specific, but still valued:

They’re seeing a difference to what it was before and we think it’s helping . . . They’re more active, more active in the water that’s for sure.

Parent R01/002 and R01/004

It makes his muscles relax and then when I bring him home to massage him after the hydro[therapy] session you know he’s much more looser and I can tell the difference . . . I think he benefited from it . . . I mean the calf muscle is definitely something that was tight always before anyway and it’s much looser now. And I find that I can stretch him a bit further . . . I can see the difference.

Parent R07/001

In another case, a parent felt that function had remained the same, but also commented on the beneficial morning-after effect, also observed in child R01/005 previously mentioned:

His mobility, his strength, everything stayed where it was, even if it has not improved much, but it’s not going down . . . he was more relaxed, had a nice sleep at night when he does the [AT] exercises and the next day the body is more refreshed actually . . . it was nice way to start the day.

Parent R04/001

One parent perceived that his son’s condition had deteriorated despite the AT:

Unfortunately, I couldn’t find any, any kind of good positive result from hydrotherapy . . . I expected you know hydrotherapy would have more, er . . . stopped progressing in his symptom . . . but recently I found that [participant] quite often fell quite easily when he was playing or when he’s walking.

Parent R05/001

Perceived improvement in confidence, independence or participation

Some parents discussed fewer physiological benefits when asked about benefits, volunteering that they perceived improvements in confidence and participation. Sometimes, as with child R01/005, this related to a sense of achievement linked to a goal of maintaining or improving function:

The step up, me and [the physiotherapist], we were gobsmacked . . . You were happy weren’t you? You were buzzing.

Parent and child R01/005

For others, the outcomes might be less tangible, but the psychosocial response was nonetheless appreciable.

He really did come out of himself and be excitable in the pool and actually chat to the physiotherapists . . . rather than being the reserved [child’s name] he often is in public . . . he’s incredibly competitive, and [the physiotherapists] were able to fetch that out of him . . . a lot of the time when [child’s name] does physical activity he’s, he’s the slow one, he’s behind the standard, he’s the one being specially accommodated for. Whereas, this being one on one, it was just at his own ability to be able to push that. He goes swimming at school now, no matter how hard he tries, he’s not going to keep up with the other children so it becomes a negative. So to be able to do this physical, fun thing without any kind of peer pressure or benchmark it may be why [he] enjoyed it so much.

Parent R02/001

Patient representative and coauthor, James Parkin, confirms the importance of swimming and, therefore, water confidence as DMD progresses in terms of cardiovascular exercise, self-esteem and enjoyment: ‘When every other sport or exercise is taken away from you with Duchenne, that’s what you’re left with’. As something you can do as a family, it can be incredibly important. In that sense, AT can be about more than just stretching muscles for the assessment of function in 6 months’ time, it is about longer-term outcomes (see Chapter 2, Methods Modelling process: developing programme theory and Figure 4 on the views of Faye Dulcy,121,122 and physiotherapist S01/001 on water confidence in Appraisal work below). Here, another parent describes the importance of a perceived improvement in water confidence at a time when the child is beginning to be marginalised in participation terms:

In school he’s not involved in any sports because, if he was hit by other kids then he’ll just fall . . . I could see what [the physiotherapists] are doing and that, from day one until the last session, he knows how to swim. So yeah it’s really amazing what it [the AT] did.

Parent R02/002

Fatigue and pain

Fatigue was not generally a concern for either parents or children. In general, descriptors for how children felt after the session ranged from ‘not tired at all’ (R02/002) to ‘a bit tired’ (R05/001), with some indicating that it depended on the pressures of the school day when AT sessions immediately followed school (R001/002 and R001/004). One parent maintained that the child’s energy levels had decreased since the AT programme stopped:

After he stopped [the 6-month AT programme] he feel more tired.

Parent R04/001

In one case, the child, mother and physiotherapist expressed concerns about pain and, particularly, fatigue arising from sessions delivered before the school day, with school missed as a result of fatigue:

Well I get really exhausted I feel like I wanna go to bed, but obviously I can’t go to bed because I have to go to school . . . when I get in class my legs are in a little bit of pain but then, when it’s the afternoon my legs feel better.

Between the trip from the hospital to school it’s about half hour in the car so [participant] then sits in the car and has a good rest . . . some of those days [the school] would call and say ‘he is extra tired, could you come and pick him up?’.

Child and parent R07/001

We had huge issues with fatigue . . . it was too much with the burden for the patients . . . and I also think the community teams had a bit of a panic about it, and were wanting to do different exercises and we ended up cutting them back because they were too tired. I also think that we didn’t get involved in what they were doing at school, we kept them doing the same things at school but obviously with each new school term the physio[therapist] goes in and changes things and then I think by the time they did [LBT exercises] at school, then parents felt they need to do [LBT exercises] as well . . . the fatigue was way too much, our patient that did do the hydro[therapy] was constantly fatigued: we ended up stopping all the land exercises except the stretches; we’ve ended up cancelling a lot of the hydro[therapy]; the fatigue was a real issue.

Physiotherapist S07/001

No other child receiving AT complained of pain. Two parents volunteered information about back injuries brought on by the delivery of LBT exercises to their children in the home (see Environmental factors).

Quality of the therapist–family relationship and communication

Parents and children were almost universally effusive about their physiotherapists. Only in two interviews did parents distinguish between physiotherapists who had delivered AT to their sons, and then only to highlight the difference in their skill at making physiotherapy fun, which they perceived as crucial to maintain their children’s engagement (see Chapter 2, Modelling process: developing programme theory and Figure 4):

It’s a testament to the team there for understanding his learning style . . . and adapting to it. They build rapport . . . they all got to know him as an individual and were able to kinda trigger conversations about the things he likes doing, like splashing me at the side of the pool or whatever that might be . . . you’d hope to get a good physio[therapist] to be concerned about his journey . . . rather than just being about physical [function].

Parent R02/001

We thought they were amazing, because they had the skills to deal with children. So they treated [participant] as how he should be treated at his age and made it fun in the pool.

Parent R07/001

This conscious effort to engage children in what could be fairly unpalatable exercises was summed up by one physiotherapist as follows:

[Children] don’t really see it as exercising; they see it as a fun thing to do . . . It’s the therapist’s skill, isn’t it, in making the exercises into a game so they don’t even really realise what they’re doing.

Physiotherapist S02/001

Balancing the demands of the programme with work, school and family life

There was general agreement on the burden of a twice-weekly programme. Universally, this related to travel time to the AT sessions, often through rush hour traffic to make slots at the beginning and end of the day. Even those with strong relational networks, for example, extended family who could help with sibling child care, said that ‘it takes a lot of organisation’ and felt that ‘it would be better if it was a bit closer to home’ (parent R01/005). Two mothers had given up full-time work during the last year for reasons related to the burden of care for their sons; one stated unequivocally that this had happened before involvement with the trial, in the other case, the mother had moved to casual work as a response to being allocated twice-weekly AT. Some parents had employers who were fairly inflexible about working arrangements or whose self-employment made for an uncomfortable choice:

New business, not having a wage and having to turn down work due to attend is, is something I’m more than willing to do and I’ll do every single time but obviously a challenge . . . It was probably only 15 miles each way, but via the school and then rush hour traffic. Bear in mind my session was at 4 o’clock so sometimes it was an hour and a half on the way back, not a challenge unless you’ve got a 5-month-old screaming baby in the back.

Parent R02/001

Mother (via translator): There was no other option, no other choice but to attend. It was really important for the boys . . . we’ve got five children . . .

Father (via translator): Sometimes there were child [care] problems and I finish my work at 8 p.m.

Family R01/002 and R01/004

No parent highlighted that the programme had created any problems with school. For some children, this was because the session was after the working day. Even those who had attended 4 p.m. sessions remarked that it had not been a problem to miss the last 30 minutes to 1 hour of the day. Only one parent mentioned concern that the programme might compromise his son’s education, a concern that had been allayed by the school:

[School] were happy, because they said like most of the work is done by 1 o’clock, with respect to the main studies. After 2 o’clock is more like activities, fun things, so it’s OK. And they normally give him homework before 1.

Parent R04/001

The two boys whose therapy took place before school found this particularly difficult and, although the parents reported that the schools were co-operative, the therapists were concerned (see Fatigue and pain and Appraisal work):

He did miss a fair few sessions . . . he’s now said that he can’t do the Wednesday [morning] because it’s just too early for him because that’s all we could offer him was an early appointment . . . Basically it’s not as convenient a time that we were offering him.

Physiotherapist S05/001

Summary

Notwithstanding the burden of treatment and the fact that some boys experienced functional decline while receiving AT, there was a widespread enthusiasm for continuing to access AT, more locally, once per week, for reasons of participation and the hope of maintenance of function:

A lot of them did sort of say, ‘Oh, what’s next? Is there any way we can continue?’ or ‘Will the service be continuing?’. The feedback that I’ve had is that they’re dying [for] it to be continued or to, to access more if there’s the opportunity.

Physiotherapist S01/001

Sense-making

Unsurprisingly, physiotherapists distinguished the AT intervention from standard LBT (differentiation). Many specified that the properties of water, particularly buoyancy, which were unavailable on dry land, were highly relevant and helpful to people with muscle conditions who wished to exercise. There was a shared sense of the aims of physical therapy (communal specification), but differing understandings about the desired objectives (deliverables) (individual specification), for which the research team must take some responsibility:

We were confused . . . we didn’t realise we were supposed to go through the exercises and decide at the beginning which ones we were going to do and then each week tick them off. So we . . . didn’t quite get it right at the beginning. So I don’t know whether that was explained quite clearly enough.

Physiotherapist S05/002

The collective understanding within some centres was as specified in the training, that the manual formed a ‘menu’ of exercises that could be selected to address specific, emerging problems. However, some centres, which had sent physiotherapists on face-to-face training, characterised the manual as prescriptive and prescribed exercises from most categories in the manual, regardless of relevance. This was not the intended message of the training, which asked for focus and realism (see Chapter 2, Interventions). At other centres, physiotherapists who did optimise treatment delivery (see Chapter 4, The aquatic therapy prescription) nonetheless perceived the manual as prescriptive and questioned whether certain types of exercises or intensive AT in general were necessary:

I know the purpose of physio[therapy] for this type of condition, but . . . I’m not convinced that stretching in the pool is a better way of stretching than stretching out of the pool.

Physiotherapist S05/002

I think just putting somebody in hydrotherapy all the time just as an extra form of therapy I don’t think is a purpose . . . I think you can make hydrotherapy have a purpose in specific.

Physiotherapist S07/001

All but one participating physiotherapist constructed some sort of potential value of the AT intervention for their work (internalisation). Part of this value included ensuring that stretches were actually being conducted:

People used to go for physiotherapy, but that doesn’t happen now: stretches are done by parents or carers . . . the benefit of hydro[therapy] is that . . . you can tell it’s happening because you’re in the pool.

Physiotherapist S02/001

Relational work

Several centres were unable to set up the service because of problems accessing treatment costs (see Chapter 3, NHS treatment costs as a cause of centre attrition). At all centres that eventually participated in the study, key individuals drove the intervention forward (initiation). In each case, the site principal investigator was charged with setting up systems and procedures, as well as engaging with others to make the intervention happen. Once a senior physiotherapist got agreement from a service manager, then there was no problem getting others’ implementation as part of their work (enrolment), at least at the scale required by and for the duration of the study:

I have to go to a manager to say ‘Right, this is what we want to do, this is how long it’s going to take, this is how many staff I’m going to need’ . . . and the staff then have to agree to take it on.

Physiotherapist S02/001

Although the majority of physiotherapists thought that increased access to AT was beneficial for boys with DMD, none believed that it was right for them, as specialist physiotherapists in tertiary centres, to be involved in its delivery (a problem of ‘legitimation’). They also questioned if it was a sound use of scarce resources, with some explicitly addressing the issue of opportunity cost, that is, the benefits other populations could have received by diverting resources to them:

My role is mainly assessment and communication with the community services, who communicate with the physiotherapist who provides the treatment, so [delivery of AT] is in addition to what I would normally do.

Physiotherapist S05/001.

You’re having to look at it and say, ‘where am I going to pull staff from?’. If you’ve got the resources, then it’s quite straightforward to set it up. What’s difficult is if everybody’s saying, ‘well hang on a minute, where are we going to find people to do it?’, because they’d be pulling them from other work.

Physiotherapist S02/001

Thinking of costs, you’ve got to think, ‘what is the point of hydrotherapy over and above land[-based therapy]?’.

Physiotherapist S07/001

The physiotherapists continued to support the intervention (activation), but stressed that this could be done only for the duration of the study and because of the scale required by the low participant study consent rate:

So we are willing to invest the time but the problem is . . . we said originally we said we could probably take five hydro[therapy] people [participants who were allocated to do AT] and we only ended up having one, which was jolly lucky because actually in reality I don’t think we could have fitted five in . . . we haven’t got the staffing numbers, we haven’t got the pool availability, you know, it just doesn’t work.

Physiotherapist S07/001

It’s not really very sustainable to be able to offer two sessions a week for 6 months to a family, that’s certainly over and above what would be sustainable to be able to offer on a regular basis.

Physiotherapist S01/001

Operational work

Most physiotherapists described a process of translating or adapting instructions from the AT manual in order to get participants to perform a particular procedure in the pool (interactional workability):

Yeah it seemed like the right thing to be doing but we also applied our own assessment and clinical reasoning. We spent quite a bit of time looking at our patients and what their needs were, and modifying it a little bit to address their problems.

Physiotherapist S02/002

As more than one physiotherapist was involved at each trust, this knowledge work was a communal process and helped to maintain confidence in the intervention and in each other (relational integration):

At the beginning when we first started doing it we had to really think, sit down and write down what our treatment plans for our two children in the pool, looking at the manual and then saying, ‘Right so we want to do that exercise, how are we going to get it done? How are we going to do it? How are we going to deliver it?’. I’ve got our treatment plan that we came up with . . . we used the manual to do it, but we needed to streamline it to make it more user friendly for the sessions.

Physiotherapist S02/001

Other staff were involved in the delivery of AT, and their availability was among the factors that affected delivery:

The staffing’s got to be there to run it safely . . . you need some experienced physio[therapist]s but you also need some of the junior staff . . . who are very capable of delivering the service, but there’s training and supervision issues. And then you need your pool-side assistant who is usually a physio assistant or a technical instructor . . . then we also had to have three other people in the department in case of pool rescue . . . Then you need all your maintenance people who keep the pool up and running . . . I mean we had our pool closed for a lot of sessions because we had some building work that had to be done.

Physiotherapist S02/001

Although the work of delivering AT was not always considered appropriate to the role, physiotherapists were consistently confident that they had the expertise to enact it (skill set workability). This was not just based on their technical knowledge of physiotherapy technique (intervention) but also because, as physiotherapists who were highly specialised in musculoskeletal conditions, they understand how to apply it given the complicated changing needs of the condition (which would not apply to community physiotherapists):

The complexity of deciding on the treatment plan, knowing the boys well enough to know how to do their treatment plan and then how to deliver it just wasn’t something that could just be handed out.

Physiotherapist S02/001

Critically, there was no participating NHS trust in which the delivery of the intervention was adequately supported by a host organisation (absence of ‘contextual integration’). Although all physiotherapists reported that their NHS trusts were enthusiastic about participating in the research study, this did not extend to backfilling their posts so that they could deliver the study intervention after NHS England declined to pay excess treatment costs (see Chapter 3, NHS treatment costs as a cause of centre attrition):

We’ve done this over and above what we normally do . . . we’ve ended up having to do this on our non-working days . . . By the time we’re doing it all on extra hours and fitting it around our child care and home life and everything else . . . it’s a non-viable service.

Physiotherapist S07/001

No participating physiotherapist believed that a twice-weekly, ongoing AT service delivered from a tertiary centre was viable (programme maintenance), with some indicating that their organisation’s commitment to AT more generally was wavering in a period of fiscal constraint:

It’s not really very sustainable to be able to offer two sessions a week for 6 months to a family . . . But you know, more blocks of hydro[therapy] to try and show them activities so they can go away and do [them], is a good idea.

Physiotherapist S01/001

I know that they would love to shut the pool . . . because of the financial drain.

Physiotherapist S05/001

Even those physiotherapists who believed that AT was a useful intervention for boys with DMD thought that it should be delivered elsewhere in the health-care system:

I just see the patients when they come to clinic, do the assessments and provide advice. So I don’t provide any treatment, I don’t go to the schools, I don’t go to the homes, whereas the community physio[therapist]s do that and set up their treatment programmes . . . where there is a pool, they will have a designated physio or physio team, that provide the hydrotherapy.

Physiotherapist S05/001

Appraisal work

All highly specialised physiotherapists who see boys with DMD enter their physical function data on to the North Star database every 6 months and so are keenly aware of changing rates of disease progression. However, with the disease progression being so unpredictable and treatment effects being confounded by concomitant therapies, especially steroids, physiotherapists were sceptical that they could attribute objective clinical outcomes to AT:

Most of the boys that had the therapy maintained their function which, for those boys, is a goal . . . maintenance is part of the battle. But, then again, it’s hard to know whether they would have maintained [that level of physical function] over that 6-month period without the hydro[therapy] . . . so it is quite difficult to say explicitly that they’ve been able to maintain [physical function] because of that input.

Physiotherapist S01/001

However, there are other effects of AT that physiotherapists were able to access (systematisation), both positive, such as perceived small physical gains, water confidence and ‘carryover’ (‘the extent to which treatment gains are maintained and used functionally between treatment sessions’212), and negative, in particular fatigue:

[The family] perhaps don’t always see a lot of the small gains that you might be able to get in the water in terms of a bit of extra range or a bit of activation in muscles that they might not necessarily have used in that way on land . . . the one boy in particular he had never really been in water before, he’d never done activity in water, he was quite water cautious and was quite fearful of coming in the pool, and by the end of the intervention he was very water confident and was able to independently float and swim in the water . . . I think it’s definitely helped to encourage families to carry that over into what they’re doing at home in terms of like recreation err and sort of sport and extracurricular activities.

Physiotherapist S01/001

All he’s done is get progressively worse and had more and more issues at school with fatigue, and I think we’ve affected his quality of life very negatively.

Physiotherapist S07/001

The majority of participating physiotherapists contributed to the triangulation exercise detailed in Chapter 7, Convergence assessment (communal appraisal). Although most of them assessed the AT intervention to be worthwhile in principle (with some dissent), they were united in their agreement that it was too costly as currently implemented and that AT interventions should be delivered in community settings. Those who believed that the intervention was worthwhile thought that the manual represented a good starting point for treatment but that it should be used as a menu of options from which exercises could be selected and adapted to the individual patient and available materials (reconfiguration; see Sense-making). This flexible implementation of complex interventions to local circumstances is often held to be inevitable, desirable and an indicator of sustainability. 137,213 It is also, to some extent, a normal, if arduous, part of physiotherapy case management, manifested through SOAP note keeping (see Chapter 1, Intervention methods and materials):33

You do need to think about planning the treatment programme and then you need to reassess it and modify it and try different things . . . and you need time to do that and then time obviously to reflect and evaluate on it afterwards. So it’s not just about being in the pool, it’s the time before and after the sessions and time to document it all. Because it all has to be documented, even though we were filling in the forms for the [RCT]; we had to write patient notes and a patient treatment plan each time as well . . . It is, again, quite resource heavy.

Physiotherapist S01/001

Some participating physiotherapists did individually assess the AT programme’s effects on themselves and their work contexts in terms other than those already discussed (individual appraisal). These reflections were generally positive:

I definitely benefited from additional training to help skill me up more, into delivering a more pure sort of hydrotherapy-based activity [where you use the properties of the water] as opposed to what you would describe as exercises or activity in water.

Physiotherapist S01/001

To actually be able to see one child over that length of time is extremely unusual in tertiary referral and I think it’s been a positive experience for me in terms of, not only [because] I enjoyed it, but also that I really feel that this is something that I would advocate even more than I was already doing. I mean I’ve often said ‘this child needs hydro[therapy]’ but I think I would be even more dogmatic now and say ‘look it really is a good intervention’.

Physiotherapist S04/001

Summary of therapist views within normalisation process theory

Normalisation process theory is a framework for understanding how new complex interventions are implemented and embedded in health service contexts. 119,120 When we used NPT to analyse the views of seven specialist physiotherapists who delivered the AT programme in their tertiary centres, we found that the roll-out of the intervention had not been successful. Although the intervention made sense to all, not everybody thought it to be of value and there were different perceptions about how flexible their use of the AT manual should be, with those who took the most flexible approach being most satisfied with the intervention. Although participating physiotherapists implemented the intervention energetically, they believed that community settings, not tertiary settings, were the right place for the intervention, and their organisations permitted its delivery, with sometimes indifferent support, only for the duration of the trial (programme maintenance). Case management was arduous and is unlikely to be feasible at scale. Nevertheless, most of the physiotherapists were pleased with the new skills that they had acquired and felt that they would advocate the use of frequent and intensive AT in other, more patient-convenient, settings where resources permitted. Figure 24 shows a summary of physiotherapist views within NPT.

FIGURE 24.

Summary of physiotherapist views within NPT.

Sense-making

Stakeholders (physiotherapists and patients) distinguished the evaluation from other, mainly pharmaceutical, research (differentiation). Physiotherapists understood correctly and collectively agreed on the feasibility purpose of the research (communal specification); some thought that many patients saw the study as a way of getting AT for 6 months. This view was borne out by interviewed parents who professed a lack of equipoise in favour of AT and worried that participation would exclude their son from a drug trial, a declared reason for non-participation by parents who declined involvement and by some in the trial:

That was one of the worries that by partaking in this would it stop him being eligible for another trial because, as great as this is, as a parent, you’re always online seeing what NICE [National Institute for Health and Care Excellence] are going to approve.

Parent R02/001

Physiotherapists understood what the research required of them (individual specification) and constructed potential value for the research (internalisation). Specific value was expressed in terms of the study being a necessary precursor to a definitive evaluation and the general value of being involved in research. Physiotherapists believed that parental guilt (see Chapter 1, Significance in terms of ill health) or a sense that they had to do everything they could for their sons drove participation, and this was confirmed by interviews with parents.

Relational work

Site investigators drove the research forward (initiation) and physiotherapists agreed that the research should be part of their work (enrolment). They confirmed that participant enrolment was difficult because of competition with more attractive industry trials, and challenged the reasoning behind the Research Ethics Committee’s prohibition on co-enrolment (see Chapter 3, Participant recruitment and the prohibition on co-enrolment). Participant enrolment was particularly challenging at one site where access to AT was good. Two physiotherapists questioned the restrictiveness of the eligibility criteria, proposing that younger and more disabled children should be eligible. Physiotherapists bought into the research (legitimisation), but some questioned whether or not long follow-up (several years) might be needed to disaggregate the treatment effects of physical therapy from those of other interventions. They continued to support the research (activation) despite finding research procedures burdensome. They valued support from one individual in the trials unit, felt that they worked well as site teams and continued to support the trial (relational integration). However, they felt that participants’ continued engagement was contingent on their allocation to AT, something borne out in quantitative findings and parent interviews. Allocation to the control had been difficult for those with friends or brothers in the research arm.

Operational work

Physiotherapists performed the tasks required by the research (interactional workability), although, as elsewhere,214 clinicians selected out eligible patients thought to be capricious. They reported that families were struggling to complete LBT documentation or were dropping out because of it. Physiotherapists found documentation version control, data capture and data query resolution overly burdensome, but appreciated the rationale for them (relational integration). In particular, one interviewee found the AT logs confusing and restrictive compared with SOAP note taking, and this may account for certain data quality issues. Although some complained of insufficient administrative support, physiotherapists said that the research was adequately supported by host organisations (contextual integration). However, they said that backfilling hours was difficult with the resources available, and, other than at two organisations where dedicated research professionals were used for data collection and entry, physiotherapists conducted research procedures on top of their clinical workload (see Operational work):

Just the fact that we only got the one patient [randomised to AT in the pilot RCT] made it feasible for us. But if we’d have got a bigger uptake then we probably would have struggled.

Physiotherapist S05/002

The physiotherapists felt that, although research tasks were not always part of their normal job role, they were nonetheless appropriate for them (skillset workability). Most were resistant to involving generic research nurses, believing that they would not understand the clinical environment.

Appraisal work

Physiotherapists have access information about the trial and intervention feasibility (systematisation) and dissemination to participant families is planned. Communal and individual appraisal was positive. Physiotherapists made proposals on how the study design and procedures could be modified in response to their appraisal (reconfiguration): streamlining of documentation, smartphone/tablet access to the study database for easier data collection and extending routine clinical sessions by 1 hour to allow for completion of research-specific patient assessments. One physiotherapist wanted more mechanistic outcome assessments about fatigue, joint range and muscle power. More than one requested a longer, observational, design. The importance of measuring fatigue and pain pre and post session was stressed.

Although signed assent forms were available for all participants, interviewed children often could not remember being approached about entry into the study. Those who could remember the approach described feeling ‘good’, ‘excited’ or ‘nervous’. Parents were pleased to be approached about entry to the study, although expressed anxiety about forgoing the opportunity to be in future drug trials. Only one child recalled the randomisation process and reported not liking it. Only two parents (both in the AT arm) described a positive response to the randomisation process. Three families reported the number of items on the questionnaire battery as being too many. Only two families made more specific remarks, in each case in relation to well-documented problems with responding to vague questions on health-related quality-of-life instruments. 215

Results

Using NHS tariff costs, AT cost £113.88 for a first session and £76.61 for subsequent sessions. Over a 6-month course of AT this would result in a cost of £4021 over 52 sessions. Allowing for alternative attendance rates, costs of AT would range between £1970 (49% attendance rate) and £2734 (68% attendance rate) (Table 25).

Over a 6-month course of AT, staff costs would be £3504.28 and range between £1717 (49% attendance rate) and £2383 (68% attendance rate). Assuming annual maintenance costs of £12,424 for an AT pool used by a range of services and offered for 39 weeks per year during core hours would work out at £8.49 per hour.

Land-based therapy provided in its usual setting would cost the NHS between £80 and £320 over a 6-month period, assuming that physiotherapists saw boys once every 6 weeks to once every 6 months. The remainder of the costs of LBT would be borne by the carers and the education system (teaching assistants).

Development and implementation of the intervention

We have fully described not only what the intervention is and how it was developed, often poorly reported,221 but also how implementation and context affected its feasibility and acceptability. 131,222 There is no standard way to develop complex interventions. 223 We did not use formal consensus methods that, in any case, may not be important until finalising an intervention’s specifications. 223 Our development group contained too few parents of boys with DMD to reflect a broad range of concerns or to exercise an effective voice, and no community physiotherapists. Future development of AT programmes should fully and effectively involve these and other stakeholder groups, such as charities. Time prohibited iterative testing and adjustment before the pilot224,225 may have improved the intervention. The study team made it insufficiently clear to physiotherapists that they should generate a focused and achievable prescription to guide intervention sessions, leading to suboptimal prescriptions in five boys. Although all participating physiotherapists had been on a Chartered Society of Physiotherapy AT foundation course and received a training video, we are not clear how many watched it and not all took up face-to-face training.

The pilot trial

Pilot trials are not designed or powered to provide estimates of clinical effect that are adequate for decision-making. 70,71 We measured key process variables,70 describing fidelity, dose and reach;132 the study was not powered to test quantitatively for mechanisms of impact or the presence of contextual moderators. 131 As a result of the shortfall in recruitment, data are also inadequate for sample size estimation. 226 Although the consent/assent process was procedurally correct, participant recall of it was poor (see Chapter 5, Appraisal work), indicating that improvements are necessary in any further related research (see Chapter 9).

The decision to deliver AT outside its usual context of delivery by community physiotherapists in community pools to delivery by specialists in specialist centres was taken for the best of reasons. The national reorganisation of services in 2013 (see Chapter 3, Problems with the delivery of land-based therapy) left us lacking in confidence that we would be able to approach and engage the right people to set up the study. Although we have fully described the context of access and delivery, the evaluation we have delivered is of a decontextualised intervention. Many of the barriers that we encountered in the delivery of AT may not be encountered to the same extent if the intervention were to be delivered more locally to the service user and in community settings.

The clinical assessments focused on physiological function and paid insufficient attention to participation outcomes, the importance of which emerged during qualitative research and in consultation with PPI representatives. Agreed approaches to the conceptualisation and measurement of participation have been lacking,97,98,100 but two reviews and a conceptual framework100,227 now provide sound guidance for future research.

The qualitative research

The use of qualitative methods successfully captured breakdowns in implementation and views on the intervention131 and enabled us to recommend changes to the intervention. The use of a logic model, published empirical evaluations and social science theory ensured that key uncertainties and important questions were addressed. 131 Iterative data collection enabled the exploration of emergent themes. We did not use serial interviews to capture changes in the intervention or related experiences over time,131,228 or to adequately explore the relationship between families, community physiotherapists and schools.

Optimisation

As physiotherapy is a process that is poorly understood by analytical reasoning and requires extensive knowledge-based processing, it is not generally helpful to standardise it. 136 The decision to evaluate optimisation rather than fidelity of delivery was appropriate and ensures congruence with the intervention theory. 139,229,230 The use of an experienced independent physiotherapist with content expertise was appropriate, but might have been improved by a second rater working blind to the assessment of the first. Only two of the therapists took up the opportunity to respond to the independent assessment of their work; protocolisation and better scheduling of this opportunity might help to bring out important nuances in future optimisation exercises. We are unclear how adherent most participants were to their LBT exercises; it is plausible that we have good-quality data only on those who were able to comply both with their LBT prescription and with study procedures.

Health economics

This study has shown that the potential investment costs for families could be greater than those to the NHS. However, patients and carers were happy to commit to AT. Owing to the small numbers in this study, these findings have focused on the cost of delivery of the intervention and the impact on families; we have not been able to take into account variability in any assumptions, although we have reported ranges when applicable. In addition, we have not been able to use information on the CHU-9D and additional resource use owing to the small numbers and the lack of any meaningful interpretation. Although we have not used the information the study showed, it was feasible to collect it in this population.

Triangulation protocol

We selected a different method appropriate to the commissioning brief,131 but did not implement methods independently. 231 A formal mixed-methods approach allowed the robust use of qualitative data used to explain quantitative findings.

The need for new models of aquatic therapy access

Patient and public involvement coauthors, James Parkin and Victoria Whitworth, provide the following challenge for future research.

The ideal is open-ended, weekly, therapist-led AT, but the current service is sporadic 4- to 6-week blocks. James Parkin found that he had to rebuild all his confidence when coming back to therapist-led AT after breaks in service. Sustaining water confidence and self-esteem is very important to self-management. If you have a big break, each time you go back, the likelihood is that you have physically deteriorated – so the break just highlights the physical deterioration. It is easier, psychologically, to experience gradually increasing difficulties over time, rather than perceive step changes in the decline of physical function. The problem then is, how do we do approach the ideal?

Open-ended weekly AT, a priority for families, will be problematic to commission from NHS providers, even in the context of future research studies. More feasible models of care that extend access to AT are needed. The PPI coauthors suggest the following elements that are intended to augment the ‘blocks of sessions’ model (see Chapter 1, Current aquatic therapy provision in the UK). Suggestions a–c are feasible, based on their personal experience.

1. The number of sessions in a NHS AT block might be extended if the numbers of children with neuromuscular conditions in the pool could be increased to capacity, and the incremental cost to the NHS could be minimised by parents being in the pool. The same amount of face-to-face physiotherapy contact could be spread over a greater number of sessions, by leaving parents to practise exercises and allowing more NHS pool time, while a physiotherapist rotates between clients. This model was practised by James Parkin’s provider for many years, allowing increased access (6-week blocks between 12-week intervals) and enabling NHS AT access three times, rather than twice per year.

2. During routine NHS AT session blocks, parents are enabled to safely and effectively deliver AT, through in-pool training and diagram sheets. It is then their responsibility to access warm water pools between NHS session blocks. This merely extends the existing parental role of LBT delivery between physiotherapy consultations.

3. If parents of children with neuromuscular conditions were able to link with each other, then they could share the high costs of warm-water pool hire documented by MDUK (see Chapter 1, Current aquatic therapy provision in the UK), in order to do aquatic physiotherapy and other exercises reguarly. 64 James Parkin’s family was able to link with others in this way through a national charity, to access AT at the most convenient time, Sunday afternoons, with their families.

4. If parent-led weekend AT ‘clubs’ were feasible, then it is possible that community physiotherapists could be attracted to that setting to monitor that treatment is being delivered optimally. This model could reduce the administrative burden on the physiotherapist as the (non-NHS) pool management would be responsible for safety, and the requirement for burdensome SOAP note taking during such sessions (see Chapter 5, Appraisal work) could be reduced.

An obvious limitation of this model is that greater parental time in the pool is predicated on an adult-to-child ratio that can assure safety; some of the parents we interviewed are on their own with more than one DMD boy during pool visits while their partner, if they have one, is working. Such barriers need not be insurmountable; in Leeds, children engage in 20-minute one-to-one tailored AT sessions with qualified physiotherapists supported by volunteer student physiotherapists from Leeds Beckett University. 232 The costs to the family are £7 per session with the remainder of the £40 direct costs made up through charitable donations. The Leeds service is based at the Penny Field School; coauthor and aquatic therapy specialist Heather Epps believes that, for some geographical pockets, training staff at special schools using the manual and course that we have developed may be more efficient and sustainable than delivery through the NHS. In Heather Epps’s catchment area, there are high numbers of boys with DMD at specialist schools. At state-funded Valence School in Westerham, Kent, staff deliver an AT programme, with oversight by NHS physiotherapists. The independent Treloar College in Holybourne, Hampshire, employs its own physiotherapists to deliver AT. Special schools that employ technical instructors and physical therapy assistants can deliver AT more cheaply than the NHS, but still work at a high level. Economies of scale could be achieved if they were to serve neighbouring special schools with no pool of their own.

In the rest of this section, we provide general recommendations for the development of collaborative services, based on the six principles for the future of health and social care services recently outlined by NHS England. 233

Person centred: personalised, co-ordinated and empowering

In theory, community physiotherapists are already delivering personalised care in the sense of working with boys and their parents to develop and implement action plans, and to monitor progress,33 although in practice this is often not the continuous process it should be (see Chapter 5, Environmental factors). Fully personalised care involves shared decision-making to agree goals and to identify support needs. 233,234 Physiotherapists may require training to deliver services that are flexible and responsive to help young people achieve individually defined goals. 235,236 Personalised care should also be minimally disruptive,16 given that it is unreasonable for schools to expect poor outcomes in students with a disability,237 efforts should be made to schedule AT so as to minimise impact on school participation. The integrated model of AT (see Figure 4)121 and models of developmentally appropriate health care238 highlight the rewards gained when delivery focuses not only on narrow physiological outcomes but also on social and psychological gains. Proper co-ordination is required (see Carers are identified, supported and involved), with 6-monthly identification of key problems, safety issues, ideas for exercises and how to make them fun by specialists in consultation with community physiotherapists, parents and teaching assistants.

Services that are created in partnership with citizens and communities

NHS England proposes that communities and local services can work together at all stages of the planning cycle, from the identification of needs through to implementation and evaluation. 233 Critically, if service managers cannot deliver the ongoing physiotherapy service that parents desire, then they may be able to support something else to happen. 239,240 Use of national involvement standards for public involvement241 and sound evaluation principles242 will increase the chances that new service models will meet the needs of service users and their families. At a minimum, stakeholders for the codesign or coproduction of future services should include DMD family members, specialist and community physiotherapists, representatives of schools and/or teaching assistants, community AT pool providers and third-sector organisations.

Focus is on equality and narrowing health inequalities

Participation is rarely equitable and more normally determined by location and income. 64,96 Clear principles are required to guide the coproduction of new services241 and these might be provided by the United Nations Convention on the Rights of Persons with Disabilities, which urges state providers to promote ‘full inclusion and participation in the community’ (Article 19), provide ‘services designed to minimize and prevent further disabilities, including among children . . . as close as possible to people’s own communities’ (Article 25), and to promote recreation, leisure and sport (Article 30). 243 At a national level, since the Children and Families Act 2014244 and associated guidance,245 families can sometimes access AT via Sections F (special educational provision required) and G (health provision reasonably required by learning difficulties or disabilities) of an education, health and care plan.

Carers are identified, supported and involved

Models of coproduction239,240 and developmentally appropriate health care246,247 would suggest that service managers now need to recognise parents and teaching assistants as assets and allow specialist and community physiotherapists to build their capability for safe and effective delivery of LBT and AT outside the NHS. If the distribution of this work is to remain ‘joined up’ in how it works across roles (physiotherapists, parents and teaching assistants) and organisations (tertiary centres, community providers of physiotherapy, schools), then co-ordination is necessary.

New models of participation-based physiotherapy for disabled children see the therapist as a consultant, who shares information and educates to build capacity for the work of rehabilitation in the child, family, and community. 248 To be family centred, the family should identify needs, but also share responsibility, and health professionals should empower the family. 88,249,250 Support for shared management support might include effective training in, and printed information on, exercises that parents can perform safely and effectively with their children, as well as improved signposting to services. Key worker, partnership and skills training models of this kind reduce the stress experienced by parents of disabled children by helping them to understand the service environment, and to understand services to understand their needs. 198 Family-centred and shared-management approaches to physiotherapy for disabled children are emerging, with associated models for implementation and evaluation. 248,250,251 They stress that investment may be needed to train physiotherapists in practical coaching and facilitation skills. 251

This study identified that parents delivering physiotherapy to their children suffered injury as a result. Work-related musculoskeletal disorders, especially back pain, are common among physical therapists and parents of children with musculoskeletal disorders. 252,253 It is particularly important that parents and teaching assistants delivering LBT receive structured education and feedback on the safe delivery of exercises to their sons. We also identified that not all parents habitually prioritise the delivery of LBT. Although this can be seen as a function of burden of treatment, parents who are interested in habituating the evening delivery of LBT to their sons may benefit from interventions such as written exercise instructions or behavioural interventions with booster sessions and goal setting. 254

Careful work is required to ensure that involvement and mutual responsibility works for parents and is not received by them as part of the ‘growing demands’ for them ‘to organize and co-ordinate their own care’. 113 Carer engagement should not be used as a staging post for rationing by denial, selection, deterrence or dilution,255 not least because safety concerns (see Chapter 1, Physiotherapy) mean that carers need some level of education in pathology and oversight and treatment.

Voluntary sector as a key partner and enabler

In the past, the voluntary sector has contributed to the costs of group AT sessions and they are currently active in charting the location of warm water pools in the NHS, specialist schools, gyms, hospices and other areas. 64 They may also be persuaded to fund the training of community physiotherapists to deliver AT, and to act as more effective co-ordinators of the distributed work of care, at least in the context of further research. Perhaps the most important role for the voluntary sector is to build social capital for DMD families. Social capital is defined as a ‘public good consisting of ties, trust and norms’, which is based on social activities rather than private property. 210 The social capital of families is often weakened on receipt of a chronic disease diagnosis for their child. 256 In theory, building social capital increases participation and social inclusion for people with disabilities and their families257 through the removal of social and economic barriers to participation in services and leisure activities. 258 Charities can build social capital in two ways: (1) through changing norms, expectations and attitudes about access to services, and (2) by enabling DMD families to link into social networks of mutual support.

Social action as a key enabler

Social action is about ‘people coming together to help improve their lives and solve the problems that are important in their communities’. 259 If DMD families are able to link together, then other benefits should follow, other than sharing the cost of hiring private warm-water pools (see The need for new models of aquatic therapy access). Peer support groups are of practical importance for parents of disabled children in terms of information, advice and improving relationships with professionals; they also offer an opportunity to forge a community of shared experience. 260