Determining the optimal model for role substitution in NHS dental services in the UK: a mixed-methods study

Article history

The research reported in this issue of the journal was funded by the HS&DR programme or one of its preceding programmes as project number 11/1025/04. The contractual start date was in February 2013. The final report began editorial review in August 2015 and was accepted for publication in January 2016. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HS&DR editors and production house have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the final report document. However, they do not accept liability for damages or losses arising from material published in this report.

Declared competing interests of authors

none

Copyright statement

© Queen’s Printer and Controller of HMSO 2016. This work was produced by Brocklehurst et al. under the terms of a commissioning contract issued by the Secretary of State for Health. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK.

Outline of the report

This report is composed of seven chapters. Chapter 1 provides an introduction to the project and sets the scene.

Introduction

Maximising health gain for a given level and mix of resources is an ethical imperative for health-service planners. 1 An independent review of NHS dentistry in 20092 concluded that there was an overwhelming need to make best use of the whole dental workforce. Across England, approximately 55% of patients who attend for a regular dental check-up do not require any further treatment. 3 This costs the NHS over £1B per annum and represents around one-quarter of the total NHS expenditure on dental care. 3 By contrast, half of the population does not attend a general dental practitioner (GDP) on a regular basis, and this group tends to be the most disadvantaged and experiences the majority of dental disease. 4,5 As a result, patients with the least need are being seen and treated by the most expensive resource, the GDP, whereas patients with high levels of need can have problems accessing NHS dental services. 5

Role substitution occurs when appropriately qualified non-dentist team members undertake the clinical activity previously provided by GDPs. 6 In primary dental care, role substitution is provided principally by dental hygienists (DHs), dental hygiene therapists (DHTs) and dental therapists (DTs). For the remainder of this report, non-dentist team members capable of role substitution are referred to as dental care professionals (DCPs). This is in contrast to dental nurses, who augment the activity of the GDP in the form of role supplementation. Unlike role supplementation, role substitution has the potential to improve efficiency and the capacity to care and to lower costs. In addition, it has the potential to reduce inequalities in service delivery as resources can be diverted to the population with the greatest need. DCPs cover many different categories of dental professions. The scope of this programme of research was to examine DCP roles that could be used in role substitution, specifically DT, DHT and DH. For concision, this subcategory of roles (where role substitution may be expected to take place) is referred to as DCPs in the remainder of this report.

Technical efficiency is defined as the production of the maximum amount of output from a given amount of input so that a service operates at the production frontier. 7 Academic research into technical efficiency is being used increasingly in health-care evaluation,8 although no studies have investigated the efficiency of NHS dentistry or examined the impact of role substitution in dental practices. By contrast, NHS dental service provision has developed historically, with levels of future service provision being determined by past levels of provision, at a time when disease levels are actually reducing. 9–11

General dental practitioners are acutely sensitive to financial incentives within the dental contract,12–14 although intrinsic motivation and professional standards can also be important moderators. 15 Retrospective fee-for-service (FFS) remuneration systems can lead to overtreatment in order to maximise profit. 13,16,17 Prospective per capita remuneration systems reduce the financial risk for the third-party payer, at the potential cost of patient selection (skimping and dumping) and undertreatment. 18–20

Empirical research in medical settings suggests that appropriately trained nurses can deliver high-quality care that matches doctors’ performance in preventative health care, routine follow-up of patients with long-term conditions and as the first contact for people with minor illness. 21,22 However, efficiency gains are possible only if the doctor stops carrying out the tasks delegated to nurses. 23 In addition, role substitution may challenge the professional identity of both professional groups, leading to opposition as clinicians struggle to maintain traditional boundaries. 24,25

Given the hitherto ad hoc approach to service design, it is important to determine the most technically efficient model for role substitution a priori. As outlined above, in dentistry this has the potential to increase efficiency and effectiveness in service provision. 26 It also has the potential to release resources and increase the capacity to care. 27–30 Harris and Sun31,32 found that role substitution may be effective in improving efficiency, but this may be limited to particular situations when conditions are conducive. Therefore, not only is it critical to determine the most technically efficient role-substitutive models, but it is equally important to explore the values of policy-makers and clinicians to determine the factors affecting the implementation of such innovative designs and how patients would view such a change in service design.

This programme of research sought to address three research questions (RQs):

1. What is the technical efficiency of NHS dental teams that make use of GDPs and DCPs, that is, what is the relationship between clinical inputs and outputs across different role-substitutive models used in the UK?

2. What are the barriers to, and facilitators of, role substitution in NHS dental practices?

3. How do incentives in the remuneration systems in the UK influence the organisation of these inputs and production of outputs in the NHS?

Aims and objectives

The aim of this programme of research was to undertake a mixed-methods study to determine the technical efficiency of role substitution between GDPs and DCPs in NHS dental practices and ascertain if this is influenced by the incentives within the NHS remuneration system. Role substitution is defined as DCPs undertaking the clinical tasks previously provided by GDPs. Barriers of, and enablers to, the greater use of role substitution in a NHS dental practice were also examined, from the perspective of policy-makers, GDPs, DCPs and patients.

The objectives of the programme of research were to:

• conduct a cross-sectional study to determine the current working patterns of DCPs in NHS dental practices

• collect input data (NHS hours worked) and output data (clinical activity) from participating practices

• identify the most technically efficient provider mix among the different provider configurations observed in the study practices

• assess the external validity of the methods used for efficiency analysis

• explore barriers/enablers to the greater use of role substitution; and develop an understanding of the configuration of the dental team, collect the input data (NHS hours worked) and gain consent to collect the output data

• examine how the technical efficiency of the different provider models varies across different retrospective and prospective payment systems for adults in the UK

• explore how financial incentives in remuneration systems influence the organisation of inputs and the production of outputs in NHS dentistry.

Research design and project overview

A multimethod approach was adopted, integrating both qualitative and quantitative methodologies.

Data envelopment analysis (DEA) and stochastic frontier modelling (SFM) were used to determine the technical efficiency of different role substitution models. 33 Technical efficiency is the effectiveness with which a given set of inputs is used to produce an output. A dental practice is said to be technically efficient if it is producing the maximum output from the minimum quantity of inputs, such as labour, capital and technology. 33

Data envelopment analysis accommodates multiple inputs and multiple outputs in a single measure of technical efficiency and has become the dominant approach to efficiency measurement in health care and other sectors of the economy. 34 The most efficient practices/sites form a frontier of productive efficiency and those that lie below this frontier are allocated proportionally smaller efficiency values, which correspond to their distance from the frontier. Optimal service design is then relative to service design observed in other dental practices, after differences between practices in workplace and environmental characteristics are controlled for.

Stochastic frontier modelling is a regression approach to estimating the frontier of productive efficiency. The level of variation in health-care output that is not explained by variation in the level of inputs (i.e. the regression residuals) forms a measure of relative efficiency compared with average practices. The method divides the regression residuals into a ‘noise’ or ‘measurement error’ component and an efficiency component. The last component is used to make an assessment of how far each role substitutive model differs from the most efficient use of role substitution.

Estimates of differences between practices in efficiency of production were analysed and interpreted using DEA and validated using SFM. Factors that influenced the efficiency of different models of role substitution were explored and sensitivity analyses were also undertaken to determine the extent to which efficiency was affected by changes in other variables. Both DEA and SFM investigate units of production and do not account for the quality of dental health care delivered by practices.

Efficiency is understood in terms of the level of inputs used to achieve the outputs produced (‘technical efficiency’). Technical efficiency, the effectiveness with which a given set of inputs is used to produce an output, was determined using two principal measures of activity: total clinical activity and patient throughput. In England, the former is constrained as a result of the capped nature of the NHS dental contract. Dental practices face penalties if the contract value falls below 4% of its Annual Contract Value (ACV) or exceeds its ACV by 2% or more. This means that outputs are constrained in the DEA computation for dental practices from England.

The qualitative component of the programme was undertaken in parallel with the quantitative element. Interviews were undertaken with policy-makers, GDPs who made use of role substitution, GDPs who did not, DCPs and patients. The final number of interviews was determined by saturation (i.e. no new themes were emerging). The semistructured interviews were recorded and transcribed verbatim. Field notes were also undertaken as appropriate. The transcripts then underwent thematic analysis using the constant comparative method. 35 Initial coding focused primarily on the barriers to, and facilitators of, to role substitution in line with our RQ. In addition, inductive coding of data alongside the field notes was undertaken to produce a ‘thick description’ of the social processes involved. 36

Structure of the report

This report is arranged as follows.

Chapter 2 describes the historical context of NHS dentistry, the use of role substitution in NHS dentistry and the role of financial incentives in how services are organised.

Chapter 3 presents a descriptive study that was undertaken across the UK to understand the current levels of DCP utilisation.

Chapter 4 describes an economic analysis of the technical efficiency of DCP utilisation in England, using DEA and SFM. Supplementary analyses were performed for Northern Ireland, Scotland and the community dental services. These were based on much smaller samples of practices and could not be combined with the English analysis because of differences in the way these services are managed and funded. The results of these supplementary analyses are provided in Appendix 1.

Chapter 5 examines role substitution using the qualitative paradigm, exploring the barriers to, and facilitators of, role substitution in NHS dental practices (thereby addressing RQ2).

Chapter 6 then uses data from a large, 3-year project in Northern Ireland to look at how incentives in the remuneration systems in the UK influence the organisation of inputs and production of outputs in the NHS.

Finally, Chapter 7 integrates the findings from the empirical work and provides an overview and assessment of the contribution of role substitution and financial incentives to the technical efficiency of practices in NHS dentistry.

Introduction

This chapter provides the context for the programme of research undertaken. It describes the organisation of NHS dentistry in primary care in England, Northern Ireland and Scotland. It then goes on to describe role substitution in NHS dentistry in primary care and describes the role of financial incentives in NHS dentistry.

Organisation of NHS dentistry in primary care in England and Wales

NHS dentistry began in 1948. The National Health Service Act (1946)37 had three key principles: (1) no one would ever have to fear not getting care they needed because they could not afford it; (2) care would be free at the point of delivery; and (3) care would be based on clinical need. As a result, NHS dental services were provided free of charge for the entire population. GDPs were considered to be independent contractors under the NHS [General Dental Services (GDS) contracts] regulations and so could establish their practice anywhere in the UK. GDPs’ GDS remuneration was based on a FFS basis (i.e. the volume and type of work undertaken) and, although they were self-employed, dentists were eligible for a NHS pension. By 1950, the government became concerned about the affordability of the new service, given the volume of work being undertaken by NHS GDPs (mostly extractions and fillings). This resulted in the introduction of the Patient Charge Regulations (1952),38 which required patients to contribute to the bulk of the cost of treatment according to a Statement of Dental Remuneration (a list of available treatments under the NHS).

Other than minor changes to the Statement of Dental Remuneration, the shape of GDS provision remained relatively static until the introduction of a new contract in 1990. 39 For the first time, the NHS dental contract contained an element of prospective payment. The remuneration arrangements for adults and children were split, with adults still treated under FFS arrangements (plus additional continuing care payments) but children treated on a wholly capitation basis. As a result, approximately 20% of the income for NHS GDPs was based on the number of dental patients registered (on a per capita basis), rather than simply being based on the volume of activity on a FFS basis. The policy intention of the 1990 contract was to encourage registration and promote prevention and continuity of care, moving service provision away from treating disease to maintaining oral health. 39 However, higher-than-expected expenditure in the following year led to the government making substantive cuts to NHS fees in 1991. Those in the dental profession felt that they were unfairly penalised by this ‘claw-back’ and many GDPs felt unhappy with the new NHS system of payment. This triggered a progressive shift towards the provision of privately funded dentistry within the profession, with a reduction in the availability of NHS services. By the mid-1990s, access to dental services for NHS patients was becoming a political issue and it was increasingly recognised that reform of the NHS contract was necessary. As highlighted by the Bloomfield report40 the ‘system of remuneration for dentists seems to have an inherent leaning towards instability which threatens to undermine the commitment of dental practitioners to the NHS’.

The NHS (Primary Care) Act 199741 enabled the voluntary establishment of personal dental services (PDSs) pilot schemes to explore alternative ways of delivering NHS dental services. A key feature of these new contracts was how they were tied to local issues around need and access to care through contracting arrangements with primary care trusts (PCTs). For NHS GDPs, the new PDS contracts offered greater flexibility for the provision of services, with less emphasis on the volume of activity provided. Instead, NHS GDPs were paid on a per capita basis and rewarded for improving access to care and maintaining oral health for those patients who were already registered. The net effect of paying the PDS schemes was a dramatic reduction in NHS service activity, a fall in the provision of complex treatments and loss of Patient Charge Revenue. 42 The last was particularly worrying for the government as patient charges had become an important component of funding for NHS dentistry. However, many viewed the PDS pilots as a success, given the focus on local needs. 42,43

In 2000, Modernising NHS Dentistry – Implementing the NHS Plan44 was introduced in England. Again, improving access was considered to be the most important policy objective for the government and the new proposals gave PCTs powerful new commissioning tools to improve access to NHS dentistry, the provision of preventative services and to monitor the performance of GDPs. This was further emphasised in Options for Change in 2002. 43 However, a question that remained for the government was how to concomitantly improve access to care and the provision of prevention, while maintaining Patient Charge Revenue (i.e. the income generated from patient charges, which accounts for approximately 25% of the payment to the NHS GDP).

In 2006, a new NHS dental contract was introduced in England,45 organised around a local commissioning model. NHS GDPs were paid according to activity categorised in one of three bands of treatment, rather than the 400 individual treatment items in the Statement of Dental Remuneration. Band 1 attracted one Unit of Dental Activity (UDA) and included an examination, radiographs as appropriate, and a simple scale and polish. Band 2 attracted three UDAs and included restorations, extractions and root canal treatments, while more complex crowns, bridges and dentures attracted 12 UDAs as a band 3 treatment. Patient Charge Revenues were also simplified so that there were only three levels of payment tied to each band. To reflect individual variation among NHS GDPs, the value of the UDA was based on individual earnings in a reference period, although for most, this meant that a UDA was worth between £20 and £25. One feature of the new NHS contract was that NHS GDPs would receive three UDAs for one band 2 treatment (i.e. they would be paid the same amount), whether they did one restoration in a single visit or multiple restorations over a number of visits. In a similar manner, NHS GDPs were also allocated 12 UDAs for one band 3 treatment irrespective of whether they provided one crown or multiple crowns within one course of treatment.

A key feature of the 2006 contract was cost containment, that is, GDPs’ NHS activity and revenue was capped at an agreed number of UDAs per year, known as an ACV. NHS GDPs were then paid one-twelfth of their ACV on a monthly basis, less than the anticipated Patient Charge Revenue. As a result, NHS GDPs’ outputs under the new contract in England were constrained and they were penalised if they underperformed (< 96% of their ACV) or overperformed (> 102% of their ACV). Patient registration in the 2006 contract also ceased to exist, along with the contractual responsibility for NHS GDPs to provide emergency care for their patients. Instead, this responsibility was devolved to PCTs along with the planning and securing of NHS dental services for their locality.

The effect of this NHS contract change in England in 2006 was investigated by an earlier National Institute for Health Research (NIHR) Service Delivery and Organisation programme funded study (reference number 08/1618/158). 13,14 Large and abrupt changes in the provision of a number of treatments coincided with the introduction of the 2006 contract. 13 The number of complex treatments provided (root canal treatments, crowns and bridges) fell dramatically, whereas the number of extractions rose. This appeared to reflect an increase in those activities that were easier and less costly to perform at the expense of those treatments that were more time intensive or that incurred laboratory costs for crowns and bridges. The authors concluded that ‘the change in treatment patterns suggests that significant numbers of dentists [were] attempting to hit their UDA contract targets in the most efficient way possible, i.e. shifting towards treatments where rewards are high relative to costs, as opposed to selecting on the basis of clinical factors’. 13 In addition, McDonald et al. 14 remarked ‘it is the interests of dentists, as opposed to patients, which [were] being prioritised’.

Given this change to activity following the 2006 contract and mounting dissatisfaction among NHS GDPs and patients, the House of Commons Health Select Committee undertook a review in 2008. 46 The review identified key problems with the NHS contract, including failure to improve patient access, higher patient charges, problems caused by removing the patient registration process, lack of incentives to promote prevention, incentives to provide treatment which may not best align with a patient’s needs (e.g. extraction over a root canal treatment) and a highly unpopular UDA payment system. This was followed by an independent review of NHS service provision in England by Steele in 2009. 2 Again, this found that the incentives for NHS GDPs were not aligned with the goal of securing oral health. The independent review highlighted a number of substantive inefficiencies in the system and recommended that a new NHS contract that had clearer incentives for improving health, access and quality be developed in England. 2

In 2011, 70 NHS dental pilots were established in England to explore how NHS dentistry could shift its focus from primarily treatment and repair to prevention and oral health. 47 This process was built around a new oral health assessment that aimed to assess the risk of the patient, enabling them to be assigned to new clinical care pathways to create a healthy oral environment based on their level of need. This was supported by three different types of remuneration models to test different ways of remunerating NHS GDPs. All three models were based on a prospective payment system (per capita), in which dental practices would be remunerated based on the number of patients they cared for and their quality of care (not FFS).

Four years on, the information generated from these pilots remains unclear. Although the dental pilots presented an ideal opportunity to address the issues raised by the Steele review,2 the findings reported were mainly descriptive in nature. The evaluation of the oral health assessment (and associated risk algorithms) was also limited to professional and social acceptability and its predictive validity remains untested.

In 2015, new dental ‘prototypes’ were introduced, which appeared to build on the limited information generated from the pilots. 48 The principles of the ‘prototypes’ were again based on an initial assessment and a care pathway approach to prevention and care. In aligning to the Building the NHS of the Five Year Forward View,49 emphasis was placed on prevention, empowering patients to take control of their own oral health and making the most efficient use of NHS resources. Although they still included capitation payments and remuneration for quality, an important difference with the 2011 pilots was an emphasis on activity, through a blend of both capitation and FFS. 48

In terms of the dental workforce, the latest information from the Health and Social Care Information Centre reveals that 23,723 NHS GDPs were undertaking activity within the NHS during the period April 2013 to April 2014. 3 This is an increase of 17.7% (n = 3563) compared with 2006, when the existing contract in England started. Approximately half of the workforce was female (46.1%). A total of 29.9 million patients were seen in the 24-month period ending June 2014 (55.9% of the total population). In 2014, 54.5% of all NHS activity was related to band 1 payments, 29.7% related to band 2 and 5.6% related to band 3. The remaining UDAs (10.2%) were allocated to emergency and other payments.

Organisation of NHS dentistry in primary care in Northern Ireland and Scotland

The provision of NHS dentistry in Northern Ireland and Scotland followed a similar trajectory to NHS dentistry in England up until the 2006 contract. Instead of moving towards a banded system of retrospective payment (the UDA system), both Northern Ireland and Scotland remained with the existing Statement of Dental Remuneration and FFS payment system. As such, although a few minor changes were made at a national level, the shape of the NHS contract in both countries is very similar to the 1990 contract in England and is primarily based on FFS for adults and capitation for children.

In Northern Ireland, approximately 1100 NHS GDPs work in 380 dental practices. Unlike England’s current NHS contract (the UDA system), there is no local commissioning model and so outputs remain unconstrained. This means that there is no limit on the amount of FFS NHS activity that can be produced. This has led to costs for NHS dentistry doubling in the last 5 years. In 2013–14, the total cost was estimated to be £124M, of which £20M came from Patient Charge Revenue. There are also no limitations on where new NHS practices can be established or the number of new NHS GDPs that can enter the market. As highlighted above, this is in contrast to England, where, under the local commissioning model, new NHS GDPs have to obtain agreement before setting up any new service. The number of NHS GDPs in Northern Ireland in 2014 was twice the level recorded in 1989.

As a result of this dramatic rise in activity, costs and the number of NHS GDPs, Northern Ireland began piloting a new dental contract in 2015. This is based on per capita payments and is the subject of a new NIHR Health Services and Delivery Research programme study by the authors (reference number 14/19/12). The technical efficiency of NHS GDPs working under a capitation arrangement in an earlier 3-year pilot aimed at improving access to care in 2010 is reported in Chapter 6.

In Scotland, the number of NHS GDPs rose from 2848 in 2011 to 3035 in 2014. 50 Over 4.6 million people were registered with a NHS GDP in 2014 (87% of the population) and over 74% had seen their NHS GDP in the previous 2 years. 3 The proportion of both children and adults registered with a NHS GDP continued to increase during the last 2 years, with more than 91% of children and 83% of adults registered at the end of March 2014. 3

Role substitution in NHS dentistry in primary care

Designing the most appropriate dental workforce for NHS dentistry is critical to ensure ‘the right number of people with the right skills are in the right place at the right time to provide the right services to the right people’. 50,51 At its inception in 1948, the only type of clinician working within NHS dentistry was the GDP. In 1921, the Dentists Act 192152 created the UK Dental Board, whose role was to be the professional body for dentistry and oversee its practice, regulating who could practise as a GDP. In 1946, the Teviot Report53 argued that the dental profession had become sufficiently mature to self-govern and, by 1956, the new Dentists Act 195654 had enshrined this principle in law. To discharge this Act, the functions of the board were taken over by the General Dental Council (GDC).

The Dentists Act 195654 also allowed the training of ‘dental auxiliaries’ for the first time and, in 1960, the first ‘auxiliary’ school was opened at New Cross Hospital in London, UK. The newly formed GDC subsequently developed the regulated titles of ‘DH’ and ‘DT’, but restricted the types of clinical activities that they could legally undertake. The duties of the former role related to the provision of prevention and periodontal treatment, while the latter role was permitted to provide a range of direct restorative procedures and extract deciduous teeth. DHs were allowed to practice in the NHS, but it was not until 2002 that a new Dentists Act 200255 allowed DTs to work in NHS dental practices (their role before this had been limited to the provision of care in NHS community dental services settings only). Since 1983, UK dental schools also offered ‘dual’ integrated training over a period of 2 years. The new ‘DHT’ was able to offer the full range of clinical activities that both DHs and DTs could legally undertake. 56

Common to all these roles, however, was the inability of patients to directly access their services. All patients had to be seen by a GDP first and then referred on to a DH, DT or DHT. A further factor in the provision of care within the NHS that had kept GDPs as the ‘gate-keeper’ was the inability of DCPs to directly contract with the NHS. Under both the current GDS and PDS agreements of 2005, only GDPs can legally establish a NHS contract and be entered onto a Performers List to provide NHS care. In 2013, a contested landmark decision by the GDC57 allowed patients for the first time to access the care of DHs, DTs and DHTs without a referral from a GDP. This was known as ‘direct access’ and led to the expansion of DCPs’ scope of practice. 58 However, DHs, DTs and DHTs remain unable to contract directly with the NHS and so the majority are employed by NHS GDPs on a sessional, salary or activity basis.

The Nuffield inquiry on the education and training of personnel auxiliary to dentistry was published in the UK in 1993. 59 It focused on a redefinition of the dental team through which dental care would be delivered and also examined if, and how far, the role of auxiliaries could be expanded. Since the publication of the Nuffield report,59 much has been written in the dental literature about the need to adopt a model of care in the NHS that makes greater use of ‘skill mix’. 6 Skill mix is a term that is used to describe a model of care in which the whole of the clinical team is utilised in delivering service activity. 60 The use of skill mix in medicine is relatively developed, but dentistry has always appeared to lag behind. 6 Skill mix can be further subdivided into role substitution and role supplementation. The former is when DCPs undertake clinical tasks instead of a GDP, whereas the latter is when other team members augment the activity of a GDP (e.g. dental nurses or dental technicians). It is argued that both should play a substantive role in shifting dentistry from a ‘cure’ to a ‘care’ culture in the future. 61

Population health needs are changing. From the most recent epidemiological survey undertaken in the UK, 90% of young adults are expected to have more than 20 teeth in 10 years’ time and the levels of dental caries and periodontal disease have fallen dramatically. 2,9,11 However, social inequalities have remained relatively static, disease in young children remains intransigent (although geographical variations are evident) and there is a burgeoning group of older people who are now keeping their teeth for longer. 10,62–64 In addition, approximately 45% of the adult population in England do not use NHS dental services routinely and much of the activity that is undertaken by NHS GDPs relates to band 1 (primarily check-ups without treatment) activity. 3

As population needs continue to change, there are increasing calls for the development of a NHS dental workforce that can best meet the emerging needs of these strata: maintaining the health of routine attenders, while freeing up resources to increase the capacity to care and reduce social inequalities in oral health. 65 These calls reflect a growing international debate on the subject. 27,28,60 In a review of the international literature, Nash et al. 66 conclude that ‘access to basic dental care will not be available without the utilisation of dental therapists in the workforce’, while Johnson67 argues for a paradigm shift using DCPs to shift the culture ‘from treatment to prevention, wellness and self-care’.

Role substitution by DHs, DTs and DHTs is long established in a number of countries and there are varying models of independent practice. 66,68 Sweden and the Netherlands were among the first countries to allow DHs to practise independently, and this was legalised in 1964 and 1978, respectively. 69 Finland, Denmark and Norway have allowed independent practice since 1994, 1996 and 2001, respectively. Similar practices are found in Switzerland, which started in 1997, and in Italy, where DHs have been able to work as independent practitioners since 1999. 69 In the USA and Canada, DHs are part of a growing profession; they can practise with varying degrees of independence in a number of US states, such as California, Colorado, Montana, Nebraska, New Mexico, Oregon and Washington, and Canadian provinces such as British Columbia, Alberta, Saskatchewan and Manitoba, although some restrictions remain in terms of settings. 70 Tasmania has a liberal regulatory model where DHs and DTs practise independently and can own private practices. 69 DTs are also considered to be independent in New Zealand, although they are not able to treat adults. In Samoa and Singapore, DTs must work under the supervision of a GDP. Fiji has allowed DTs to assume independent responsibility for managing clinics since 1985 and DTs have been allowed to practise independently in South Africa since 1994. 69

The research evidence for the greater use of DHs, DTs and DHTs is emerging. In Galloway et al. ’s71 systematic review, DCPs were found to be better than GDPs at oral health promotion, and in the most recent Cochrane systematic review72 survival rates of resin fissure sealants were similar over various time periods. Previous studies have found that DCPs are able to screen for oral diseases. 73–79 Treatment outcomes for atraumatic restorative techniques were also similar across a number of criteria for single-surface (small) and multisurface (large) restorations for DCPs and GDPs. 72 In a review of the literature on direct access,80 DCPs were again found to perform to a similar standard as GDPs, although the evidence base found by Dyer et al. 72 and Brocklehurst et al. 80 was mainly descriptive with only a few experimental studies.

Although DHs appear to be well-accepted members of the dental team in the UK,81,82 financial considerations appear to play a significant part in the decision to use a DT in the NHS. 56,83–90 Of the few studies that have examined DTs’ profitability, patient charges generated did not cover the cost associated with their use. 91 As a result, many DTs have been employed by the NHS as DHs in England, limiting their ability to use the full range of their skills. 92 Although the social acceptability of DTs appears to be positive,93–95 public awareness of DTs as a professional group is not widespread. 93 Despite this, it does appear that adults are willing to receive treatment from DCPs under the NHS and there is evidence of increased patient satisfaction. 95 However, some patients expect to pay less for treatment provided by a DCP and are reticent about care provided by a DCP for young children or when anxious. 93

The NHS GDPs run their practices as businesses to offset the cost of the capital risk of the premises and the equipment that they own, while ensuring liquidity to cover their overheads. 46 This means that the use of role substitution must be profitable and is sensitive to the remuneration system. 96 In medicine, transaction costs can be offset by economies of scale, which enable a broader range of services to be made available. 97 However, historically the size of dental practices has been limited to a small number of surgeries, with approximately one-third run single-handedly. 98 It also requires all GDPs in the dental team to refer patients to DCPs and there is evidence that not all do this because of the GDP effectively losing income to the DCP. 31

One study that examined the efficiency of using DTs in the NHS found that this was described by NHS GDPs as the optimum use of surgery time to manage patient flow, provide patient satisfaction and maintain activity levels. 32 However, some efficiency gains were noted in the nine practices examined. Harris and Sun99 concluded that role substitution ‘may be limited to particular situations where conditions are conducive’. For example, the type of patient care was found to be relevant to whether or not referrals to DTs were deemed efficient. Patients with high levels of disease (many restorations) were thought less suitable for referral because GDPs would undertake care in fewer visits and there was a risk of complications necessitating referral back to a GDP.

Management of change is also a potential problem with role substitution, as professionals seek to protect their clinical roles and maintain traditional boundaries. 70 Managing a transition to role substitution takes time and good human resource skills. 100 As highlighted by Watt et al. ,101 the most important factors influencing change in dentistry include concerns about financial risk, progressive practice environment, supportive organisational structure, supportive professional networks and opportunity for training. McDonald et al. 102 found that the key factors that determined the acceptability of changes to role boundaries included the clarity around roles and responsibilities as well as personal relationships with colleagues, which raise issues of mutual trust and respect. The importance of financial incentives has also been identified. 14,102,103

Financial incentives in NHS dentistry in primary care

As highlighted above (see Organisation of NHS Dentistry in primary care in England and Wales), NHS GDPs are part of an altruistic profession, yet much of their activity in primary care is driven by the ‘profit principle’ to maintain the viability of their practices. NHS GDPs are acutely sensitive to incentives within the remuneration system. 13,15,16,104 Retrospective payment systems like FFS commonly lead to overtreatment,17,18,104 whereas prospective systems or ‘per capita’ payments often lead to undertreatment. 18 When incentives promote preventative activity, NHS GDPs tend to actively engage and shape their dental team accordingly, greatly increasing the use of role supplementation and substitution. 105 Little is known about how the efficiency of NHS dental services is affected by role substitution. The only study in the UK (at the time of writing) used only nine practices. 99

Oral health follows a social gradient, with the poorest experiencing the majority of the disease. 106 However, prevention and treatment of oral diseases are determined by an individual’s ability to pay for services. 107 As a result, access to services tends to be greatest in those groups with the fewest needs. 108,109 Public funding of health and social care provides a means of overcoming the divergence between the ability to pay for care and need for care. It offers the opportunity for improving both efficiency (increasing health gains produced from available health-care resources) and equity (removing barriers to access to services associated with individuals’ income or wealth). In an evaluation of the previous contract reform in England, Whittaker and Birch110 found that the dental reforms impacted on access. Copayments via Patient Charge Revenue have also been a fundamental component of the NHS dental contract since the 1950s. In the USA, Manning et al. 111 found that dental service use increased as copayments decreased in a randomised trial of alternative insurance plans, whereas Parkin and Yule112 found a negative relationship between price and dental care use in Scotland. Little is known about the impact of remuneration systems on the efficiency of NHS practices and how they might influence outputs such as access.

Concluding remarks

The preceding sections have highlighted a range of issues relating to the NHS dental contract in England, Northern Ireland and Wales. It has also highlighted the factors that can impact on the use of role substitution in NHS dentistry and how in turn, this may impact on key areas of quality, including access, efficiency, efficacy, inequalities and social acceptability. Chapter 3 explores the distribution of DCPs across the UK, if role substitution is associated with efficiency in NHS dentistry in England, the types of barriers to and enablers of the greater use of role substitution in NHS practices across the UK and the role that financial incentives have on the organisation and efficiency of NHS dental teams.

Introduction

The publication of the Nuffield Report led many in the dental profession to articulate the importance and potential of using skill mix in NHS dentistry. 59 Although the GDC provided oversight on the range of clinical duties that DCPs could perform, it was not until 2008 that it required DHS, DTs and DHTs to be registered with the dental regulator. Prior to this point, the ‘stock and flow’ of DCPs in the dental marketplace could be estimated only from the number of training places available in the UK dental schools. By 2008 there were over 5000 DHs and DHTs registered with the GDC and approximately 250 dually qualified DHTs were being trained each year across 10 dental schools. 113

Despite the potential for using DCPs as part of the NHS dental team, there is evidence that some DCPs are not being fully utilised in the NHS. 92,114–118 The oldest studies found that one-fifth of DH students who graduated from Liverpool in 1989 and one-tenth in 2000 did not stay in the dental profession. 117,118 In 2002, a survey undertaken in the south of England found that only one-fifth of DHs worked within the NHS, spending their remaining time undertaking private activity. 116 In the north of England, this proportion was slightly higher, at one-third, and in Scotland just over half (54%) of all DH activity was undertaken on NHS patients (in those NHS practices that utilised DCPs). 115 The most recent survey across the UK found again that just over one-fifth of practising DHs undertook activity on NHS patients. 114 The proportion of DCPs who work with NHS and private patients was not examined in these surveys, although they are capable of treating both.

There is also evidence from Godson et al. 92 that many DTs are not working to their full scope of practice (i.e. the range of clinical tasks that they are trained to perform) in the NHS in England. 92 Many DTs surveyed, who went on to record their views via free-text box (46.6%), stated that they practised exclusively or nearly exclusively as a DH. Approximately one-third (36%) worked wholly under NHS regulations, whereas a further 32% spent the majority of their time (50–99%) on NHS work.

Given this range of utilisation, the objective for this part of the research programme was to conduct a cross-sectional study to determine the current working patterns of DCPs in NHS dental practices across the UK. This was then used as part of the sampling strategy for the studies reported in Chapters 4 and 5.

Methods

Following NHS ethical approval (12/WA/0403), the membership of the British Society of Dental Hygiene and Therapy (BSDHT) was contacted and asked to complete a questionnaire in 2013. Questionnaires were distributed to all of the 3100 members of the BSDHT (saturation sampling) using a letter of invitation that was cowritten by the research team and the president of the BSDHT. The questionnaires were mailed out using the BSDHT database that was used to distribute their newsletter. The BSDHT is the predominant professional organisation for DHs, DTs and DHTs.

The questionnaire recorded the type of DCP and the address of the practice where they worked. It also asked participants to record the time in their current NHS post, the number of clinically active hours worked per week on NHS patients, the proportion of time working with children and adult NHS patients and the number and type of DCPs that they worked alongside.

The distribution process was managed by the BSDHT. Reminder letters and repeat questionnaires were mailed out twice, so that each of the 3100 members of the BSDHT was approached a maximum of three times.

The results of these questionnaires were then compiled and the addresses were used to geographically locate the practices where they worked, using ArcGIS (Esri, Redlands, CA, USA). Maps were created to record the distribution of NHS provision (see Figure 1).

Results

A total of 1859 responses were returned (60.0%), of which 287 (15.4%) were from DHs, DTs and DHTs working in 432 NHS practices. The remaining responses either related to DCPs working in private practice or had been left blank or were unusable.

Based on the responses, the most common DCP type working in the NHS was the DH (64.1%) (Table 1) followed by DHTs (33.8%) and DTs (1.0%).

The mean age of the DCPs was 42.1 years and the mean number of years qualified was 16.5. Almost all of the DCPs were female and the mean time in post was 8.4 years. More than half of the DCPs worked in one practice, but a substantial majority worked in more than one practice. The mean number of additional DCPs that the respondents worked with was 1.7.

The geographical spread of DCPs that work in the NHS is provided in Figure 1 and Table 2 highlights the distribution of the 10 most common models in use in the NHS across the UK.

FIGURE 1.

Distribution of DHs, DTs and DHTs in NHS practices across the UK.

Discussion

The most common type of DCP seeing NHS patients in the group investigated was the DH (64.1%), suggesting that role substitution for periodontal treatment was more common than for DCPs who undertake direct restorations (DHTs and DTs). These results are consistent with Godson et al. ,92 who found that, even where DHTs are employed, they are commonly used to undertake periodontal treatment. This may reflect a difference in the availability of work within the NHS or it may equally reflect a reluctance in GDPs to allow DHs, DTs and DHTs to encroach over traditional role boundaries. The role of DT in NHS practices was permitted only in 2002 and there appears to be evidence that both GDPs and dental students are either not aware of the expanded scope of practice for DTs and DHTs, or that they choose not to support this expansion of their role. 113

Over half of the NHS practices employed DCPs, with the most common additional DCP type being the DH. The mean number of additional DCPs employed at a practice was 1.7 (see Table 1). This suggests that the practice culture and ethos is an important determining factor, that is, if skill mix is perceived to be important for the practice, it is common for multiple DCP roles to be employed.

The mean number of hours worked per week by NHS DHs, DTs and DHTs was 12.6, which means that most only worked for three or four sessions at any one practice. This is consistent with the finding that over one-third of these DCP roles worked in more than one practice. Eaton et al. 114 found that the mean number of clinical hours worked per week was 24.6 hours. This propensity for part-time working among DCPs is consistent with findings from other studies. 92,119,120 Eaton et al. 114 reported that 62.7% of DCPs worked in more than one practice. However, they did not distinguish between NHS activity and private activity, so this may explain some of the differences with this study.

Concluding remarks

The objective of this component of the research programme was to provide a snapshot of DCP utilisation in the NHS and contribute towards the development of a sampling frame for the studies highlighted in Chapters 4 and 5. It is clear from the results that not all NHS high-street dental practices use DHs, DTs and DHTs and those that do are not employing them full time. Instead, it appears that it is common for DCPs to work across multiple practices.

Introduction

The independent review of NHS dentistry in 20092 concluded that there was an overwhelming need to make best use of the whole dental workforce. The greater use of DCPs and role substitution provides a potential strategy for increasing the efficiency of NHS dentistry. Technical efficiency is defined as the production of the maximum amount of output from a given amount of input so that a service operates at the production frontier. 7 In NHS dentistry, this could be achieved by either increasing the amount of NHS activity produced (including the capacity to care) with the same level of input or producing the same level of activity (output) with a reduced input.

Role substitution is already established in medicine. 21,22 However, practice efficiency is improved only when (1) physician time is released from the tasks delegated to nurses (i.e. nurse time replaces physician time in these activities, as opposed to supplementing it) and (2) that released physician time is used for tasks that only physicians can perform. 23

Harris and Sun32 found that role substitution may improve efficiency in NHS dental service provision, but that this may be limited to particular situations or contexts. Therefore, it is important to determine (1) whether or not the way role substitution is used is associated with higher levels of technical efficiency and (2) whether or not the potential efficiency gains of role substitution are constrained by structural constraints. There is little evidence on the economic consequences of role substitution in NHS dental practices,2 even though such evidence is important for commissioning NHS services across the UK.

In the UK, GDPs who work in the NHS are either practice principals (PPs) or associate GDPs. PPs own the NHS dental practice and are responsible for paying estate, staff and consumables associated with the delivery of a NHS dental contract. Associate GDPs are self-employed NHS GDPs who have their own subcontract with the NHS and who rent facilities and support staff time from the PP.

As highlighted in Chapter 2, PPs and associate GDPs in England do not receive any additional remuneration for NHS care delivered in excess of 102% of their ACV and are penalised through a pro rata ‘claw-back’ of remuneration if their activity falls below 96% of their ACV. As such, practices in England are output constrained and PPs organise their practices to operate within these constraints.

Dental care professionals are a heterogeneous group including DHs, DTs or DHTs. DCPs also include dental nurses and dental technicians, but these roles are predominantly supplementary in nature and so the term DCPs in this report collectively describes those non-GDP clinicians able to perform a range of clinical tasks as defined by their legislated scope of practice (regulated by the GDC). 58 One method of making efficiency improvements in NHS GDP practices is to substitute lower cost time of these DCPs for higher cost GDP time, as any output is constrained by the ACV threshold. However, as DHs, DTs and DHTs cannot contract with the NHS, the predominant model in NHS dentistry in England is to add the number of UDAs that these DCPs produce to the PP’s NHS contract. As a result, there is an incentive for PPs to encourage role substitution and a disincentive for associate GDPs to support role substitution.

Methods

Results

Discussion

Concluding remarks

The technical efficiency of practices was found to be associated with many factors, including the practice’s staffing capacity and ownership structure. We found no evidence of positive efficiency gains from the use of DCPs. However, this might reflect limitations in the way DCPs are currently being used in the NHS, as well as constraints imposed by the use of historically based UDA targets as the basis for contracted activity and a lack of incentive for associate GDPs to utilise DCP skills.

Introduction

Role substitution in dentistry has traditionally lagged behind its use in medicine. 6 This may reflect struggles between NHS GDPs and DCPs regarding role boundaries and jurisdictions. 70 McDonald et al. 102 found that the acceptability of role substitution in the medical workforce relies on a number of factors, including distribution of rewards in relation to effort across the team, clarity around roles and responsibilities and personal relationships with colleagues, which raise issues of trust and respect. As highlighted in previous chapters in this report, many DCPs are not being used to their full scope of practice within NHS dentistry. It may also reflect the concerns of NHS dental teams about patients’ attitudes to role substitution, although the evidence in the literature is mixed. 93–95 Taken together, there is a need to explore the views of patients and the different members of the dental team on role substitution to examine the formal and informal aspects of organisational life.

The objectives for this part of the research programme were:

• to undertake semistructured interviews with GDPs, DCPs and patients to explore barriers/enablers to the greater use of role substitution

• to undertake semistructured interviews with key policy-makers to determine their perspective on the greater use of role substitution in NHS dentistry.

Methods

Qualitative methods were used to explore these issues, as we needed to obtain an understanding of relationships and activities within practices and the ways in which these relate to skill mix patterns.

Results

Discussion

The PPs interviewed in this study appeared to be in agreement that, within the current NHS contract, the greater use of DCPs did not result in financial gain. These views support the findings from Chapter 4. The current system appears to disincentivise the use of role substitution. Although those PPs who did not use DCPs fully did talk about financial ‘disincentives’, this was not the primary reason for their lack of use. 31,56,83–90 Instead, the attitudes and beliefs of PPs appeared to be highly influential in terms of explaining the organisation of the practice; that is the type and organisation of the practice culture that cascaded down from the practice owner (PP) was key. This concurs with the findings of Watt et al. 101 and McDonald et al. 102

Practices with low role substitution utilisation appeared to be led by PPs who were concerned about the abilities of DCPs, in particular how much longer it might take a DCP to carry out a treatment than a GDP. 32 However, it is worth noting that PPs who used DCPs tended to have confidence in the ability of their own DCPs, but were less confident in the ability of DCPs in general. This suggests that experience of working with DCPs may be a factor that influences GDPs’ attitudes and beliefs about DCPs. 56,113

The professional domain of DCPs was also limited by many PPs to the provision of periodontal treatment. This concurs with the work of Godson et al. ,92 who found that many DHTs and DTs in England were employed in the NHS as DHs, rather than being utilised across their full range of skills. Those PPs who supported the greater use of DCPs for more interventional treatment (e.g. preparing teeth for restorations) limited their activity to children and anxious patients, on the basis that these types of patients took up more surgery time. As a result, DCPs appeared to be used by many PPs to improve their own efficiency, at the cost of the efficiency of their own DCPs. This may help explain why there was no net effect across the practice. Periodontal treatments are limited to band 1 payments (and some band 2 payments for complex activity), so the number of UDAs produced by DCPs would be reduced.

Overall, financial incentives remained important for PPs, but so were the beliefs and attitudes of PPs to role substitution and DCPs generally. 31,83–86,88–90 It may be the case that these attitudes could change over time if there was greater alignment in the system between financial incentives and the greater use of DCPs. This has been shown to increase utilisation in medicine. 14,102,103

Among DCPs themselves, a number of day-to-day barriers were found to reduce the efficiency of working in the practice environment. These included not being able to prescribe fluoride varnish and the inability to prescribe local analgesia when they were asked to carry out more interventional treatments. Some practices had developed organisational systems to work around these barriers, such as setting up a ‘patient group directive’ (an agreement overseen by a pharmacist that allows DCPs to prescribe medicines using their own assessment of patient need). However, many practices did not have such agreements in place and this meant that every time a DCP wished to issue fluoride supplements or provide local analgesia prior to treatment, they had to get approval from the GDP.

Another important related restriction is the inability for DCPs to examine patients or to provide a treatment plan under the NHS dental contract regulations. Although the dental regulator recently changed the scope of practice for DCPs,58 within the NHS, the GDP still needs to see the patient first. This creates an extra step in the referral pathway and substantial transactional cost, as patients that are seen by GDPs first have to be then ‘booked back in’ with a DCP if they require treatment. In contrast, GDPs have the freedom to conduct the treatment in the same visit, immediately after the examination, if they have time. Both care pathways generate three UDAs, so the efficiency of the latter is far greater than the former and may contribute to the results found in Chapter 4. Furthermore, some of the DCPs interviewed reported that they were not referred enough work to keep them busy all day, a factor that would again reduce their efficiency. This was particularly marked for those DCPs that worked in corporate practices, where they were paid on a FFS basis rather than by an hourly rate.

This reliance on referrals from GDPs appeared to reduce the DCP workload in the practice and a substantial proportion of those interviewed worked across a number of practices (between two and eight). This is consistent with the research that has been conducted in England92,114 and highlights the precarious nature of professional work for many DCPs.

In general, the majority of patients had a low level of awareness of the roles of different members of the dental team. Most patients interviewed were familiar with GDPs and DHs, but they were not usually aware of DTs. Patients tended to compartmentalise their views on who did what in dental practices; fillings, crowns and bridges were activities undertaken by the GDP, while periodontal treatment (‘hygiene work’) fell within the expertise of DHs. All patients were happy to have hygiene work carried out by a DH. Although most were open to a DT carrying out simple restorative work, some were adamant that they would only be happy with a GDP carrying out this treatment. These views concur with earlier research. 93–95 However, all patients who had had an experience of being treated by a DT were happy. This may indicate that patients’ prior experience of treatment is key. If their only experience was treatment by a GDP, then treatment by a DT may appear daunting. Once they realise that there is no real difference in their management, they appear happy to accept being treated by a DT.

The majority of patients interviewed were simply not interested in the debate about who treated them. Instead, they reported that they just wanted to know that any treatment being carried out was undertaken with a suitably qualified clinician. They all appeared to place a great deal of trust in the NHS, the regulatory system and in the opinion of their GDP. Patients were happy to comply with what was recommended to them. In similarity to the findings by Northcott et al. ,133 if the GDP was happy to refer them, they were happy too. 133 Essentially, they felt that the system/regulator/practice/GDP would look after their best interests.

Concluding remarks

In relation to RQ2, the barriers to, and facilitators of, role substitution in NHS dental practices were varied. Financial implications were important, but the organisational culture at the practice was also critical. PPs views of role substitution were varied and key. As PPs own their practices, their views heavily influenced the culture at a practice. DCPs highlighted the inability to prescribe fluoride, local analgesia and radiographs as important barriers to efficient working practice in the NHS. Patients appeared to have an inherent trust in the ‘system’ and prior experience of role substitution was influential on its acceptability.

Introduction

Chapters 4 and 5 highlight the variation in efficiency in NHS dental practices and the range of factors that can influence it, including role substitution. This chapter details how the research team used a natural experiment to explore the impact of a change in the remuneration system on the delivery of dental services in a large group of NHS dental practices in Northern Ireland.

In May 2009, the Northern Ireland Health Minister, Michael McGimpsey, announced a plan to improve access across the province to enable ‘people to get the health service dental treatment they need’. Rather than paying NHS dental practices via FFS, new contracts were to be based on capitation. Oasis Dental Care was among a number of groups that responded to the tender and, in April 2010, it was successfully awarded funding to provide 38 GDPs working in 14 new practices located in regions where patient access to oral health care was limited. Oasis Dental Care was chosen for their ‘extensive expertise and experience in providing dental services to health Trusts across the United Kingdom’.

Contracts were awarded for a period of 3 years and they were to be paid in a block contract payment to register and provide services up to 57,000 patients by 1 August 2012. 131 No additional NHS payments were to be made to Oasis for patient registrations that exceeded this target. Practices were opened at different time points in the first year of this contractual period and each practice was given a target number of registrations to reach within the first year. The Health and Social Care Board in Northern Ireland monitored monthly registrations closely and held regular monitoring meetings with Oasis Dental Care. 131 They considered Oasis to have made ‘reasonable efforts’ to achieve the target if they operated within a 5% level of the target. Penalties were to be applied if they fell outside this range.

The aim of this study is to examine how specific health-care service indicators differ between the Oasis practices and control practices paid by traditional FFS payments after controlling for other patient and practice characteristics. We addressed the following RQs:

1. Patient selection: do Oasis practices serve a different population of patients from control practices?

   1. Is the proportion of registered patients who are ≥ 60 years of age greater in Oasis practices than in control practices?

   2. Is the proportion of registered patients who are ≤ 18 years of age greater in Oasis practices than in control practices?

   3. Is the proportion of registered exempt patients ≤ 18–60 years of age greater in Oasis practices than in control practices?

2. Receipt of care among registrants: do patients registered to Oasis practices:

   1. See the GDP less frequently than patients in control practices?

   2. Have fewer treatment courses than patients in control practices?

   3. Receive less costly treatment than patients in control practices?

3. Type and mix of treatment received: are patients seen in Oasis practices:

   1. More likely to receive an examination than patients in control practices?

   2. More likely to receive an extraction than patients in control practices?

   3. More likely to receive a filling than in control practices?

   4. More likely to receive a scale and polish than in control practices?

   5. More likely to receive prevention/topical fluoride than in control practices?

4. Financial viability:

   1. Is the payment charge revenue generated per registered patient less among Oasis practices than in control practices?

   2. Is the payment charge revenue generated per treatment course less among Oasis practices than in control practices?

Methods

Results

Discussion

In similarity to earlier findings, financial incentives in the remuneration system did impact on the clinical activity undertaken in the NHS. 13,14,135 A major consideration in comparing different practice models was whether the different models attract and/or serve populations with different needs. Our analysis indicated that the proportion of registered patients aged ≤ 18 years was significantly less in Oasis practices, but no differences were found in the proportions of registered patients aged ≥ 60 years, or eligible for exemption from NHS payment charges for reasons associated with higher probability of need. This suggests that there is no evidence of patient selection (or ‘cherry picking’) associated with need for care among Oasis practices.

After controlling for differences between the two groups in practice and patient characteristics, the number of unique patients seen per 100 patients registered at the practice per month and the average value per treatment course claim were lower in Oasis practices than the control group. This suggests that registered patients at Oasis practices were less likely to visit the GDP than patients in control group practices and received less treatment when they did attend. However, it is important to note that this might be the result of unobserved heterogeneity between practices. As a result, it cannot be concluded that these differences were caused by the different ways the providers were remunerated. For example, Oasis practices were set up where populations were unable to get access to a NHS dentist, hence one could hypothesise that the Oasis practice population might have already had their care needs met by an abundance of provision in the private sector.

It is unlikely that the findings related to the care received among registered patients reflect underlying differences in needs of the patient populations of the two groups of practices. This is because the models included explanatory variables that captured the age mix of the practice population, the prevalence of exemption from NHS payment charges for reasons of higher risks of oral health problems and the level of deprivation in the local community. The findings cannot be explained by Oasis practices having a lower capacity to care for their registered patients because the number of active GDPs in each practice is included as an explanatory variable in the regression model. Although causality is not established by the modelling approach, the findings were consistent with GDPs working under capitation-based remuneration systems seeing patients less frequently and ‘doing less’ to patients when they do see them.

In terms of the type and mix of services delivered, we found that Oasis practices had higher levels of tooth extractions but lower levels of examinations, scale and polishes and restorations (fillings) than control practices. A factor that is important to consider here is that extractions take less time than other treatment alternatives, that is, clinicians operating within a capitation system could prefer a management option that requires less time. 136 A ‘scale and polish’ is a preventative procedure aimed at removing calculus and plaque that can cause oral health problems (gum disease) in the future. Equally, it is a procedure that many patients like, because of its aesthetic value (removal of stained deposits). This suggests that Oasis practices were not any more prevention oriented than control practices. However, the application of fluoride varnish is potentially a better marker of prevention orientation and its use on the registered patient population was no different between Oasis practices and the control group. The lower prevalence of examinations and fillings among Oasis practices suggests that patients registered with these practices were not seen as often and had longer recall periods. Although this might reduce the prevalence of unnecessary interventions among patients, equally it may also lead to some oral health problems being missed and interventions being delayed.

Finally, no evidence was found that patient payment charge revenue differed between Oasis practices and those that operated on a FFS basis. Although Oasis practices received less patient payment charge revenue per course of treatment than control practices (explained by the lower value of treatment per course), the revenue per registered patient was not significantly different. However, Oasis practices had a smaller proportion of children who were exempt from NHS patient charges than control practices, which would offset the reduced revenue per patient income and account for the non-significant findings in overall patient payment charge income.

The main limitation of the study concerned the limited amount of information available on the practices and the populations served by the practices as well as the non-random nature of allocating the provider payment methods and allocation of patients. Receipt of oral health care is conditional on registration, therefore the models used in this study were conditional on registrations and hence subject to selection bias. One approach to correct for sample selection is the Heckman model. 137 This incorporates the probability of registration within the population, but as this study is confined to practice populations, such methods cannot be used. Instead, an OLS regression model with robust standard errors was used. As highlighted above, the study was designed to minimise the impact of patient and practice heterogeneity between Oasis and control practices. As a result, a ‘difference in difference’ design could not be used (there was no ‘before-intervention’ period for the Oasis practices). 138 Although we were able to identify statistically significant differences in some aspects of patient populations, receipt of care among registrants, service mix and patient payment charge revenue, data were not available on patient outcomes. As such, it is not possible to determine whether the lower prevalence of interventions in the Oasis practices was the result of inappropriate supplier-induced demand among control practices (unnecessary interventions) or the failure to intervene in a timely way among Oasis practices (supervised neglect).

Concluding remarks

The natural experiment described in this chapter explored the change of remuneration in Northern Ireland and enabled the research team to address the third RQ. Capitation influenced the organisation of inputs and outputs in NHS dentistry in Northern Ireland. Practices examined fewer patients and undertook fewer restorations. Capitation remuneration did not improve the level of prevention (fluoride varnish) offered, but did increase the number of extractions performed.

These results must be interpreted with caution. The success of the findings to indicate comparative differences depends on the populations being distinct from each other only in the type of remuneration system. Oasis practices were set up in areas of lowest dental health-care access in Northern Ireland, although, to account for the influence that may have had on interpreting the effect of remuneration incentives, a control variable for regional deprivation was included in the regression analysis and the comparison group chosen from nearby practices. Unfortunately, the circumstances of this natural experiment (there was not a group of Oasis practices remunerated in the same way as GDS practices) prevented an analysis of the remuneration incentives that was dissociated from the management systems and culture. Oasis practices were set up and administered by a corporate provider where the organisational environment (e.g. ways of recruiting, supervising and remunerating the work of staff) might not necessarily match that of the GDS practices.

Considerations for future policy

The growing demand for health care in the UK, recent rises in NHS expenditures and decreasing health-care budgets highlight the importance of paying attention to the organisation and performance of the dental health-care system and of providing policy-makers and practice owners with evidence-based information to better inform their decisions. On account of this background, efficiency analysis and benchmarking has an important role in enabling health policy-makers, practice managers and dental professionals to identify and assess different approaches to organising the delivery of dental health care, including the success of different dental team structures in terms of processes and outcomes. We found a comprehensive analysis of dental health-care efficiency in the UK a challenging task, primarily because data were more readily available on units of health-care output than service quality or patients’ oral health gains from treatment. We also found that dental practices were reluctant to provide cost information that could be used to estimate the profitability of their service. In these circumstances, in which data collection is limited, it is possible that findings have been influenced by unobserved determinants of practices’ choice of inputs that also determine output, for example past investment in equipment or the attitudes of dentists towards DCPs.

Strengths and limitations of the research

This was the first study of its kind to empirically examine the efficiency of dental teams in the NHS that make use of role substitution. It was also of methodological interest, given that both models for determining efficiency in health care were utilised and the results were found to be robust and independent of the method of analysis, that there was consistency across both the non-parametric and parametric methods that were utilised. The study was also the first to compare the efficiency of NHS dental teams across different remuneration systems, although the limited sample sizes in Northern Ireland and Scotland prevented a fully robust comparison.

We examined a range of environmental and organisational influences, both internal and external to the dental practice, to establish associations with more efficient production. Ideally we would have applied longitudinal data with frequent waves to account for changes in the dental practice team and changes in care patterns over time. Without longitudinal data it was not possible to identify the extent of change in the efficiency of dental services or determinants of improvements in service performance.

Efficiency studies in NHS dental service provision to date have not adopted a robust empirical design and have used a limited range of input and output measures. A strength of our findings is that they are presented with both activity-based measures (patients seen and treatment plans) and price-based measures (NHS remuneration income). These measures allowed us to explore technical inefficiency (inefficiency caused by the wasteful use of inputs) although limitations in the availability of price and cost data prevented us from exploring allocative inefficiency (inefficiency caused by selection of an inappropriate input mix).

A major limitation of the programme of study was that it was not possible to observe inputs or outputs produced independently by DCPs who were capable of role substitution. Given that the current contractual relationship is between the NHS and the GDP alone, it was not possible to determine the efficiency of DCPs independently. Study findings therefore require careful interpretation, as we only estimate the effect of role substitution on the output of the whole dental team rather than the individual DCPs’ output. In addition, we relied on practice-reported input measures recorded via a questionnaire. The pilot questionnaire was tested in depth and a balance had to be found between the inclusion of variables that were considered to be important in the production function and the likelihood of practices participating and returning the questionnaire. Any more detailed analysis would have required a prospective study. The research team also found that many dental practices were wary of sharing too much financial information and had to be reassured that the linkage between input data and the output data kept by the NHS would be anonymised at the source.

Another limitation is that random selection of practices did not take place. This would influence findings if there were factors unobserved to researchers that were related to the incidence of role substitution (e.g. dentists’ choice to work with DCPs or limited dentist awareness of DCPs full scope of practice), as this may influence both the choice to hire a DCP and the supervision they receive to produce output. However, a broad range of covariates was entered into the analysis and the results remained robust.

Recommendations for further research

Further research is needed to fill the gaps in some areas of our productive efficiency model, such as a greater range of capital resources. Use of a health-related quality-of-life measure would provide a measure of the effect that dental health care has on patients’ oral health. However, there are difficulties with this approach. Routine dental patients are largely non-symptomatic, so quality-of-life measures in this population would not identify subtle variations in effect and appropriately discriminate. 139,140

To better inform future planning decisions, it is recommended that future research integrate efficiency analysis with other relevant factors of overall performance in NHS dentistry such as equity, service coverage and access to care, responsiveness to changes in population needs and preferences for services, and accurate alignment at a national level of supply (e.g. the size of the workforce and health-care budget) with population needs for care (driven by, for example, population demographics and oral epidemiology). However, there are challenges to accessing the level of detail required for a full analysis of efficiency at a NHS practice. Prospective studies could offer potential, but do require the full co-operation of the NHS dental practice and our experience to date is that not all appreciate the extent of information required.

Concluding remarks

The use of DCPs capable of role substitution in NHS dental teams is not associated with higher levels of efficiency at the practice level. More attention needs to be paid to identifying the conditions under which DCP use improves practice efficiency and how NHS contracts could be developed in the future to support the efficient use of role substitution within NHS dentistry.

Contributions of authors

Professor Paul Brocklehurst (Director of NWORTH Clinical Trials Unit, Professor of Health Services Research and Honorary Consultant in Dental Public Health, Bangor University) led the research team and provided oversight on both main workstreams. He also oversaw the preparation and writing of the report.

Professor Stephen Birch (Professor in the Department of Clinical Epidemiology & Biostatistics, McMaster University and Professor of Health Economics, University of Manchester) led the development of the RQs and study objectives for workstream 1. He also oversaw the design of the workstream, the interpretation of the results and the preparation and writing of the report.

Professor Ruth McDonald (Professor of Health Services Research and Policy, University of Manchester) led the development of the RQs and study objectives for workstream 2. She also oversaw the design of the workstream, the interpretation of the results and the preparation and writing of the report.

Dr Harry Hill (Post-doctoral Research Associate, University of Manchester) undertook the research and analysis for workstream 1. He also wrote the section of the report on the use of technical efficiency (see Chapter 4).

Dr Lucy O’Malley (Lecturer in Oral Health Research, University of Manchester) undertook the research and analysis for workstream 2. She also wrote the section of the report that examined the experience of DCPs in the workplace (see Chapter 5).

Mr Richard Macey (Doctoral student, University of Manchester) also undertook the research and analysis for workstream 2. He also wrote the section of the report that examined the experience of DCPs in the workplace (see Chapter 5).

Professor Martin Tickle (Director of the Institute of Population Health, Professor and Honorary Consultant in Dental Public Health) helped to interpret the findings of both main workstreams and contributed to the writing of the report.

Contributions outside the study team

We would particularly like to thank all those from the NHS and associated organisations who gave so freely of their time during every phase of the project. Particularly, we would like to thank the following:

• Brenda Gannon from the Centre of Health Economics, University of Manchester

• Sandy Fitzpatrick from the Business Services Organisation

• Gillian McCrory from the Business Services Organisation

• Michael Donaldson from the Health and Social Care Board

• Donncha O’Carolan from the Health and Social Care Board

• Jan Clarkson from the Scottish Practice Based Research Network

• Linda Young from the Scottish Practice Based Research Network

• Lorna Barnsley from the Scottish Practice Based Research Network

• the Business Services Authority

• the National Information Centre

• the Privacy Advisory Committee.

Publications

Brocklehurst PR, Birch S, McDonald R, Tickle M. Determining the optimal model for role substitution in NHS dental services in the United Kingdom. BMC Oral Health 2013;13:46.

Data sharing statement

Data can be obtained from the corresponding author.

Disclaimers

This report presents independent research funded by the National Institute for Health Research (NIHR). The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, NETSCC, the HS&DR programme or the Department of Health. If there are verbatim quotations included in this publication the views and opinions expressed by the interviewees are those of the interviewees and do not necessarily reflect those of the authors, those of the NHS, the NIHR, NETSCC, the HS&DR programme or the Department of Health.

Topic guide: general dental practitioners

1. What do you see as the advantages and disadvantages of using DCPs at the practice?

2. What model of DCPs and dentists do you currently have in your practice?

   1. – Why is this?

   2. – How well do you think this model works?

3. What do you perceive to be the optimal combination of DCPs and dentists in your practice?

4. Could DCPs be utilised more in practice?

   1. – In what way?

   2. – What are the potential barriers?

5. Have your views on the use of DCPs in the practice team changed over time?

   1. – How?

   2. – Why do you think this is?

   3. – Have the views of your colleagues changed?

   4. – What about new associates?

6. What do you think about the duties that DCPs can carry out under their current scope of practice?

   1. – Should they be doing more/less?

   2. – Does it work well in practice?

7. What do you think about the recent expansion in the scope of practice of DCPs?

   1. – Has it changed the way you have chosen to utilise DCPs at this practice?

   2. – What are your dentist colleagues’ views about the change?

   3. – What are your DCPs’ views about the change?

   4. – What are your views about direct access?

8. How do patients respond when you refer them to DCPs?

   1. – For treatment and for hygiene/advice?

   2. – Are patients aware of the role of DCPs?

   3. – Which way is best to communicate this to patients?

   4. – What about for more complex treatments?

9. How does the way that dentists get paid in the NHS affect the dental team?

   1. – Does it affect the types of tasks that you refer to DCPs?

10. Has using DCPs freed up your time to concentrate on more complex cases?

    1. – Does this happen often at the practice?

    2. – If so, how often?

    3. – What kind of tasks?

    4. – Are you happy with seeing more complex cases rather than the routine care?

11. What would prompt you to use DCPs more at the practice?

12. How do you think that your use of DCPs over the last few years has affected the profitability of this practice?

13. Where do you think we will be in ten years’ time in respect to the DCPs’ role in delivering dental health care?

14. How do you think the changing oral health needs of the population will affect the way you organise your practice in the future?

Topic guide: dental care professionals

1. How are DCPs used in your practice at the moment?

   1. – Who completes which tasks?

   2. – How do you refer to the dentist?

   3. – How do they refer to you?

   4. – Associates? Do they refer to you?

2. What do you think about the recent expansion in the scope of practice of DCPs?

   1. – Has it changed your practice?

   2. – What are your colleague’s views about the change?

3. Could DCPs be utilised more in practice?

   1. – Could you do more?

   2. – Would you want to do more?

4. What are your views about direct access?

   1. – How successful has this been in your practice?

   2. – Do you think it has changed the way that care is delivered?

   3. – What are your colleagues’ views about the change?

   4. – Do you think this will change over time?

5. What response do you get from patients that come to see you?

   1. – Do they accept receiving care from the whole dental team, rather than just the dentist?

6. Do you think they are aware of the different types of roles that DCPs can undertake?

   1. – How does your practice communicate this to patients?

7. Would changes to the way that the NHS pays the dental team affect the types of tasks that you undertake?

8. How happy are you with the level of support you have in the surgery?

   1. – Dental nurse?

9. Does using DCPs help to free up time for dentists to concentrate on more complex cases?

   1. – Does this happen in practice?

10. How confident are you about performing dental procedures without oversight from a dentist?

    1. – Which tasks?

11. What would prompt dentists to use DCPs more at the practice?

12. Where do you think we will be in ten years’ time in terms of the role of DCPs?

Topic guide: patients

To open: how long have you been coming to this practice?

1. When you last saw or were treated by a DHT what treatment did you receive?

   1. – How did you feel about receiving this treatment from your DHT rather than from your dentist?

   2. – Was it different seeing a DHT rather than a dentist?

   3. – Were you happy with the service you received?

2. How much do you know about the roles and duties of a DHT?

   1. – Are there any tasks that only a dentist can do?

3. If, in the future, your dentist referred you to a DHT for a filling how would you feel?

4. How do you think other patients at this practice would feel about seeing DHTs instead of dentists?

5. What things could your practice do to help patients manage the change from seeing the dentist regularly to seeing the DHT?

6. How much information do you think patients would want or need about the role of DHTs?

7. What do you think is the best way to communicate this type of information to patients?