Individual cognitive stimulation therapy for dementia: a clinical effectiveness and cost-effectiveness pragmatic, multicentre, randomised controlled trial

Article history

The research reported in this issue of the journal was funded by the HTA programme as project number 08/116/06. The contractual start date was in July 2010. The draft report began editorial review in October 2014 and was accepted for publication in April 2015. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.

Declared competing interests of authors

Dr Aimee Spector reports personal fees from NHS trusts, outside the submitted work. Professor Alistair Burns reports personal fees from the International Journal of Geriatric Psychiatry, personal fees from NHS England, non-financial support from King’s College London and non-financial support from the Driver and Vehicle Licensing Agency, outside the submitted work. Professor Robert Woods reports royalties for group cognitive stimulation therapy manuals paid to Dementia Services Development Centre Wales, Bangor University (Hawker Publication and Freiberg Press, USA) outside the submitted work. Professor Ian Russell reports grants from University College London, both for the submitted work and outside the submitted work. Lauren Yates, Professor Martin Orrell, Phuong Leung, Dr Aimee Spector, Professor Robert Woods and Dr Vasiliki Orgeta have a patent on the individual cognitive stimulation therapy manual.

Copyright statement

© Queen’s Printer and Controller of HMSO 2015. This work was produced by Orgeta 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.

Background

Aims and objectives

This report presents data on the development and evaluation of a home-based individual cognitive stimulation therapy (iCST) programme for people with dementia and their family carers. The intervention was evaluated using a pragmatic, single-blind, RCT design comparing the effectiveness of iCST to treatment as usual (TAU). The objectives of the study were the following:

• to develop an individual, home-based programme of CST for people with dementia and their family carers

• to assess the effectiveness of iCST in improving cognition and quality of life for people with dementia, mental and physical health in carers, and other outcomes in conjunction with TAU

• to assess the cost-effectiveness of iCST in comparison with TAU.

Development of individual cognitive stimulation therapy: overview and framework of development studies

The development of the iCST programme involved three separate components that informed the key characteristics of the intervention and its delivery in the main trial. We followed guidelines of the Medical Research Council15 for the development and evaluation of complex interventions characterised by multiple interacting components. 16 Following these guidelines, we used the best available evidence on group CST,2,6 appropriate theories5,17 and a series of development studies in order to develop the individual CST programme. The key objectives of the development phase were: (1) to ensure that the therapeutic materials were easy to use, clear and appropriately tailored to the needs of people with dementia and their carers; (2) to collect professional expertise data on the development of iCST; and (3) to gather data in relation to feasibility, appropriateness of materials and factors influencing fidelity. 18

Development study 1: service users’ views about the intervention

This component of the development phase involved assessing the appropriateness and acceptability of the intervention, by consulting people with dementia and their family carers using individual interviews and focus groups. During initial consultations of manual development, two family carers and two health and social care professionals were consulted. Carers’ and professionals’ feedback was sought in relation to the adaptation of group CST approaches6,19 and the key characteristics of previous individual cognitive-based interventions involving carers. 10,12 These consultations concluded that a carer-led manual should adapt similar layouts to those used in previous literature (i.e. group CST) but overall length should be reduced, academic terms should be simplified and simple instructions should be incorporated. At this stage, carers and professionals also identified the need to emphasise the dyadic nature of the intervention and to ensure that the manual is engaging. Data gathered from these first consultations resulted in the first draft of the iCST manual (and associated workbook). People with dementia and family carers taking part in the individual interviews and focus groups were recruited from local NHS and voluntary organisations in the North East London Foundation Trust. First drafts of the iCST manual and activity workbook were presented to service users for appraisal in a series of 10 individual interviews and six focus groups. Demographic characteristics of the sample taking part in Development study 1 can be seen in Appendix 1.

Ten caregiving dyads were recruited to participate in the individual interviews. People with dementia and their carers were interviewed separately, using a discussion guide that was applied to direct the content of the interviews, with each interview typically lasting 30–45 minutes. The interview with the person with dementia started with an appreciation of the concept of mental stimulation and involved completing a sample of iCST activities and collecting feedback about participants’ enjoyment and the level of difficulty. A general discussion about perceptions of, and needs for, a home-based programme of mentally stimulating activities followed. The aims of the carer interviews were similar, focusing primarily on collecting data about the quality and appropriateness of iCST, and identifying any practical issues that might affect the delivery of the programme and areas of support for carers.

Six focus groups were conducted with people with dementia and family carers. Thirty-two people participated in the groups, which aimed to identify key characteristics of mentally stimulating activities, to assess the feasibility of a home-based activity programme and to obtain feedback about the quality of materials presented. Two groups were held with carers, three groups were held with people with dementia and one group was held with both carers and people with dementia. Group discussions were conducted in a semistructured style guided by a series of pre-determined focus points. Details of the discussion points of the individual interviews and focus groups are presented in Appendix 1.

All individual interviews and focus groups were transcribed. Inductive thematic analysis techniques were employed in the coding and analysis of data,20 with meaningful excerpts of text extracted and used for categories emerging (i.e. ‘perceived barriers’). Two researchers independently reviewed all excerpts and additionally examined whether or not any could be coded to more than one category, reaching consensus over their category placement. Data from all focus groups were collated, then examined further by source (carers and people with dementia) to identify any variations in views. Individual interview data were also grouped by source and compared with data gathered from the focus groups.

The response to the first draft of the iCST manual and activity workbook was positive overall, with carers commenting that materials were clearly laid out and written in a way that was easy for people with dementia and carers to understand. Recommended changes to the manual included editorial changes to improve the clarity of instructions provided and alterations to the size of text and images. ‘Monitoring progress’ forms of overall enjoyment of activities underwent significant adjustments at this stage in response to feedback from carers that appraisal sessions should be informal in order to avoid the person with dementia feeling that their performance on the activities is being scrutinised. Appendix 1 provides a summary of the qualitative results of both the individual interview and focus group data.

Development study 2: expert feedback

The main purpose of Development study 2 was to gather ‘expert data’ on the suitability of the iCST manual and associated workbook. We used consensus methods guidelines to collect ‘expert data’ from dementia care professionals. 21 Additional objectives were to address and identify key components of the intervention in order to inform its final development. This study comprised an online survey evaluating the draft of the iCST manual and associated workbook, followed by a consensus conference. Health-care professionals, academics, service users, and private and voluntary sector professionals were invited to participate in an online survey and were asked to provide their opinions on the suitability of the iCST manual and workbook. We also sought input from European experts in dementia care.

Experts evaluated the iCST manual and activity workbook on the following domains: overall quality and layout; language used; font size; amount of information presented; clarity and variety of activities; and level of engagement. Statements were evaluated on a 5-point scale as follows: ‘strongly disagree’ (1); ‘disagree’ (2); ‘neutral’ (3); ‘agree’ (4); and ‘strongly agree’ (5). Very high agreement was defined as a median of 5, an interquartile range of 0 and ≥ 80% of participants scoring 4 or 5. High agreement was defined by a median of 5, an interquartile range of ≤ 1 and ≥ 80% scoring a 4 or 5. Moderate agreement was defined by a median value of 4–5, an interquartile range of ≤ 2 and ≥ 60% of participants scoring a 4 or 5. 22 For overall quality a 4-point scale was used: ‘poor’ (1); ‘fair’ (2); ‘good’ (3); ‘excellent’ (4).

A total of 25 dementia experts took part in the online consensus survey, of which two were family carers (8%), 11 (44%) were working in the NHS or social services, three (12%) were working in the private sector, seven (28%) were academics in dementia care and two (8%) were professionals working in the voluntary sector. Of these experts, 16 (64%) attended the consensus conference and additional workshops. Results of the online survey for the iCST manual and associated workbook appear in Appendix 2.

Additional qualitative comments from the online survey data were subjected to a thematic analysis. Analyses of these data emerged in the following key domains:

• Person-centred focus: the activities and key principles of iCST should be more person-centred; there should be an emphasis on positive emotions and pleasurable experiences for both the person with dementia and family carer, and the manual should emphasise the dyadic nature of the intervention.

• iCST activities: for each activity the level of difficulty of the session should be clearly separated and additional activities for people with mobility issues or compromised hearing should be accommodated. It was emphasised that activities should be accessible to all demographics and that all iCST sessions should be ‘collaborative’, highlighting that people with dementia and carers ‘work together’.

• Layout and clarity of intervention: the manual should provide key information about the intervention only; it should incorporate a smaller and more manageable number of key principles and should emphasise that discussion is one of the key purposes of iCST by including open-ended questions.

Development study 3: field testing for final refinement prior to the main trial

The main aim of the third development study was to assess further key elements and components of adaptation of the intervention through field testing. Twenty-six people with dementia and their carers took part in this study. The majority of carers were family members of the person with dementia and were recruited either from the voluntary sector or from memory services in the North East London Foundation Trust. A small proportion of carers taking part were paid carers (n = 6), who were recruited from a private home care agency. People with dementia were screened for eligibility using the inclusion criteria of the main trial. Family carers were usually approached about the research study first by dementia care professionals (consultant old age psychiatrist) and then by the research team. A senior member of staff at the home care agency contacted potential carers working with people with mild to moderate dementia. If the dyad consented to participate, a set-up visit was arranged by local researchers. Written consent was provided by both the carer and the person with dementia at the beginning of the set-up visit. Demographic characteristics of the sample can be seen in Appendix 3.

For the purposes of the field testing, the 75-session programme was divided into six draft manuals and accompanying workbooks. Manuals 1–5 comprised a total of 60 sessions and manual 6 contained the remaining 15 sessions. Carers were asked to deliver up to 3 sessions per week. Participants were asked to complete a total of 24 sessions on average.

Contents of individual cognitive stimulation therapy

Dyads were provided with the iCST manual, the iCST activity workbook, two carer diaries and the iCST toolkit. The iCST manual provides guidance on how to run the iCST sessions, the key principles of iCST (Box 2) and guidance on activities. This manual was disseminated at the ninth UK Dementia Congress and has been published. 24 The iCST activity workbook contains paper-based resources for activities suggested in the manual, such as word puzzles and images to stimulate discussion.

Carer training

Carers were trained in their home by an unblinded researcher. A standardised training package was developed with interactive features, including a role-play exercise and the opportunity to see clips of group CST activities. The first part of the training session introduces the dyad to the iCST materials (manual, activity workbook, toolkit and carer diaries) and explains the session structure and key principles. Carers were encouraged to take part in a role-play exercise with the researcher, developed to demonstrate ‘good’ and ‘bad’ practice in iCST. In the final part of iCST training, family carers were invited to deliver their first iCST session with support from the unblinded researcher, who provided feedback afterwards. Where multiple family carers were involved in delivering the programme, the researcher invited them to be trained with the main carer.

Individual cognitive stimulation therapy support for carers

An unblinded researcher provided dyads with telephone support throughout their participation, providing weekly, fortnightly or monthly telephone support depending on carer needs and preference. Additional monitoring visits took place at 12 weeks and 25 weeks, which were aimed at collecting the iCST carer diaries, providing further support if necessary and completing measures of compliance. There were a total of 21 unblinded researchers supporting carers, of whom 81% were qualified professionals working in the local NHS trusts. Among qualified professionals, the majority were nurses (n = 13) or clinical psychologists (n = 3), with one member of staff being a qualified occupational therapist. The remaining staff were clinical studies officers (n = 2) or research assistants (n = 2). All unblinded researchers supporting carers received training in iCST.

Individual cognitive stimulation therapy fidelity

To ensure that psychosocial interventions can be replicated, and to ensure that the treatment delivered was indeed the treatment intended (known as ‘treatment integrity’),25 iCST components were described in detail in a treatment protocol. This protocol formed the basis of training of all unblinded researchers supporting and training family carers in delivering iCST. iCST diaries provided a method of tracking compliance to the programme, whereby in each theme, carers were required to record whether or not the session had been completed, the date of completion and their relative’s interest, enjoyment and communication. Space was provided for dyads to provide any additional comments related to the sessions. The progress of dyads and compliance to the programme was also measured during support activities via treatment questionnaires during both the telephone support and visits. A telephone support questionnaire was used to gather data on the average number of sessions completed per week, average duration of sessions, average time spent preparing and any difficulties encountered. Carers completed a self-report measure of confidence and knowledge in the delivery of iCST, level of engagement of the person with dementia, use of iCST principles and satisfaction with the support provided in treatment visits.

Design

A multicentre, pragmatic, single-blind, two-treatment arm (iCST vs. TAU), randomised, controlled, clinical trial was conducted over 26 weeks. Participants were randomised to the two groups using a dynamic adaptive randomisation stratified for site and whether or not the person with dementia was taking acetylcholinesterase inhibitors at baseline. Data collection was at baseline, 13 weeks and 26 weeks after completion of the intervention. The primary outcomes were assessed at both time points, with the primary hypothesis examining outcomes at 26 weeks.

Ethics approval

A protocol was submitted for ethical review to the East London 3 Research Ethics Committee (REC) (reference number 10/H0701/71) in January 2010, with provisional approval being granted in July 2010. The following information was identified by the Committee as needing further clarification and amendment:

• Participant Information Sheet to be modified to cover video-recordings and information about the control/usual care group and minor editing changes (i.e. language use)

• consideration of a cross-over or add-on scheme and whether or not participants will be given a copy of a DVD and manual

• provision of additional information about the interviews in both consent and participant forms and further clarification over whether or not recruitment posters and leaflets would be used.

Final approval was granted in September 2010. Participating centres obtained approval from the appropriate local REC and relevant NHS research and development departments.

Intervention and control conditions

Participants randomised to the intervention group received iCST at their own home. The control condition was TAU, with participants in this group receiving no additional intervention. The services and interventions available to people with dementia and family carers randomised to receive TAU varied between and within the iCST centres and may have changed over time. We recorded the use of drugs and services across the two groups and any changes that occurred. In general, services offered to the TAU group were also available to those in the active treatment group condition.

It is very unlikely that any comparable (or even any other) individual cognitive stimulation intervention for the person with dementia would have been available, as these types of therapies are generally unavailable in the UK. We followed standard best-practice methods around pragmatic trials involving an intervention group compared with usual care. Outside the iCST intervention, both groups, in general, would have access to the same kinds of mentally stimulating activities. It is possible that some participants in the TAU group may have engaged in some form of mentally stimulating activities in day-centres; however, this is unlikely to have been as structured as iCST. We asked sites to note instances in which the person with dementia may have been engaged in cognitive stimulation groups by their local services. Those participants who have engaged in such activities during the 3 months prior to recruitment were considered to be ineligible.

Study population

Eight centres in England and Wales were involved in the study: London, Bangor, Hull, Manchester, Norfolk and Suffolk, Dorset, Lincolnshire and Devon (covering Devon North and Devon South), which comprised 12 recruitment sites in total. Researchers in three centres (London, Bangor and Manchester) were based in universities, whereas those in Hull, Norfolk and Suffolk, Dorset, Lincolnshire and Devon were based in NHS mental health services (Table 2). Recruitment commenced in April 2012 and was completed in July 2013.

Eligibility criteria

Sample size

The main analysis was based on intention to treat for the primary outcome of cognition [Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-Cog)]. Our group CST study6 had an effect size of 0.32. Our Cochrane review of RO26 found a standardised mean difference (SMD) of 0.58, whereas the individual RO/CST study12 found a SMD of 0.41. Taking a conservative approach, we estimated the SMD relative to TAU to be 0.35. A sample size of 260 will have to yield 80% power to detect a SMD of 0.35 using a two-group t-test with a 0.05 (two-sided) significance level comparing the iCST and the TAU groups. Assuming 15% attrition, we originally proposed to recruit 306 people with dementia. During the course of the trial the observed attrition rate was nearer to 25% than the 15% accounted for in the sample size calculation and, therefore, the target recruitment was revised to account for this. The final recruited sample size was 356.

Recruitment procedures

In each iCST centre, people with dementia and their family carers were recruited through mental health services for older people, such as Memory Clinics and Community Mental Health Teams, through dementia care professionals, including psychiatrists, and through local voluntary sector organisations, such as the Alzheimer’s Society (see www.alzheimers.org.uk). The centres in London, Bangor and Manchester were supported by clinical studies officers accessed through the National Institute for Social Care and Health Research Clinical Research Centre in Wales and the Dementias and Neurodegenerative Disease Research Network (DeNDRoN) in England. In Hull and the East Riding of Yorkshire, all patients and carers referred with dementia (and their general practitioners who currently have additional DeNDRoN support to assist with recruitment to dementia trials) were automatically provided with ‘opt-in information’ on current NHS portfolio studies in dementia care, via a centralised clinical academic unit, The Hull Memory Clinical Resource Centre.

The aim of the project was briefly described to potential participants by members of the research and clinical team, and permission for them to be contacted by local researchers was obtained prior to further contact. Research assistants discussed the project and provided full details to participants, answered any questions related to the project and, if participants agreed, undertook informed consent.

Informed consent

Participants enrolled to the study only after providing informed consent in line with guidelines set by the Mental Capacity Act 2005. 27 Participants were in the mild to moderate stages of dementia and were therefore expected to be competent to give informed consent for participation, provided that appropriate care was taken in explaining the research and sufficient time was allowed for them to reach a decision. It was helpful for a family member to be involved, and we aimed to ensure that this was done wherever possible. Both people with dementia and family carers were informed that no disadvantage would accrue if they chose not to participate, and all participants were provided with at least 24 hours to review information about the study prior to making a decision. In seeking consent, we followed current guidance from the British Psychological Society28 on the evaluation of capacity. In this context, consent is regarded as a continual process rather than a one-off decision, and willingness to continue participating was continually checked through discussion with participants during the assessments. If, at any point, the person with dementia or family carer became uncomfortable with the assessments, these were discontinued.

Ethical arrangements

The study was approved through the appropriate REC. All researchers received training in Good Clinical Practice guidelines. 29 There appear to be no documented harmful side effects from participating in CST interventions or other types of cognitive-based interventions. Regular monitoring by, and support from, the key local unblinded researchers in each centre was undertaken during the intervention to ensure that people with dementia participating in the iCST sessions did not feel deskilled or undervalued.

Prospective participants were fully informed of the potential risks and benefits of the project. A reporting procedure was put in place to ensure that serious adverse events (SAEs) were reported to the Chief Investigator (see Appendix 8). On becoming aware of an adverse event involving people with dementia or their carers, a member of the research team assessed whether or not it was ‘serious’. A SAE was defined as any untoward occurrence experienced by either a person with dementia or carer that:

• resulted in death

• was life-threatening

• required hospitalisation or prolongation of existing hospitalisation

• resulted in persistent or significant disability or incapacity

• was otherwise considered medically significant by the investigator

• came within the scope of the Protection of Vulnerable Adults protocol,30 which was in place to ensure that suspected cases of abuse or neglect were followed up in an appropriate manner.

A reporting form was submitted to the Chief Investigator who assessed whether or not the SAE reported was:

• related to the conduct of the trial

• unexpected.

Serious adverse events that were judged to be related and unexpected were to be reported to the REC and the trial Data Monitoring and Ethics Committee (DMEC) within 15 days of occurrence.

Randomisation

Remote randomisation of participant allocation treatment was undertaken via a web-based randomisation service managed by the North Wales Organisation for Randomised Trials in Health (NWORTH) clinical trials unit, after baseline assessment and informed consent. Randomisation was completed using a dynamic adapative allocation method,31 with an overall allocation ratio of 1 : 1. Random allocation was stratified by site and receipt of acetylcholinesterase inhibitors (AChEIs). For each participant randomised, the likelihood of their allocation to each treatment group is recalculated based on the participants already recruited and allocated. This recalculation is done at the overall allocation level, within stratification variables and within stratum level (the relevant combination of stratification levels). By undertaking this recalculation, the algorithm ensures that balance is maintained within acceptable limits of the assigned allocation ratio while maintaining unpredictability.

Allocation concealment

The randomisation database was held at NWORTH, and the analysts involved in the trial did not have access to the database. The dynamic adaptive algorithm is tuned using weighting parameters. These parameters are chosen by simulation modelling to ensure that the balance is maintained at an acceptable level, while ensuring that the sequence of allocations does not become predictable. Strong parameters would make the randomisation algorithm behave in a deterministic way, thus making allocation concealment difficult. Unblinded researchers were the only staff who were informed at each of the iCST centres of participants’ allocation.

Implementation

A web-based randomisation system was set up at NWORTH. Unblinded researchers could log into the system, enter participants’ details and receive randomisation results on screen and by confirmation e-mail. The system ensured that each entry had a unique trial identification number.

Blinding

As with all psychosocial interventions, participants cannot be blind to the allocation they receive. Within each iCST centre, there were nominated blinded and unblinded researchers; both were able to conduct baseline assessments and request randomisation. However, once participants were randomised, follow-up data were collected by the team of blinded researchers only, whereas the training and carer support in delivering iCST was run by unblinded researchers. Given that participants may occasionally and inadvertently inform researchers of the treatment they are receiving, we aimed to reduce this bias by use of self-report measures wherever feasible and brief reminders to participants. We asked all blinded researchers to record their impression of the group to which each participant was allocated and their confidence in that prediction. Statisticians remained blind to allocation for the main analysis, whereas compliance analysis incorporating compliance to the intervention was conducted after the main analyses only.

Data collection

Primary and secondary measures were completed at baseline, 13 weeks after baseline (week 13) and 26 weeks after baseline (week 26). Researchers were instructed to conduct all week-13 assessments within the 13-week period, but no later than 2 months from the scheduled first follow-up appointment (starting at date of baseline assessment), and to conduct all week-26 assessments by 26 weeks, but no later than 2 months from the scheduled second follow-up (starting at date of baseline assessment).

Most interviews were conducted in dyads’ homes. All questionnaire instruments were arranged in the form of booklets, with additional show cards of responses supporting the person with dementia during the assessment. If, at any point, the person with dementia felt uncomfortable with the assessment this was discontinued and was only rescheduled to take place during a second visit where appropriate.

Measures

Data checking

A full data-management plan was written, encompassing data storage and processing, data filing, data sharing, data freezing and data archiving. Data were collected in questionnaire packs and entered into a data-management system (MACRO version 4.1.2.3750, InferMed, London), which was audited for data entry accuracy, before being exported to Statistical Package for the Social Sciences (SPSS) files. SPSS Predicative Analytics SoftWare version 20 (IBM Corporation, Armonk, NY, USA) was used for all further data manipulations and analysis. In all SPSS files, cleaning processes were undertaken, including checks for consistency and out-of-range data. If applicable, questionnaire data were cross-checked with the SPSS data to explore any issues of inconsistency. CSRI data were cleaned and analysed in Stata 13 (StataCorp LP, College Station, TX, USA), again checking for consistency. Adherence data were entered by unblinded researchers into the MACRO system and used in both outcomes and economic analyses.

Data analysis

Economic analyses

The economic evaluation was a cost-effectiveness analysis, conducted first from a health and social care perspective and, second, from a societal perspective. The primary outcome measures for the person with dementia were the incremental cost of achieving:

1. one SMD (taken to be 2.4 points on the scale) in the ADAS-Cog

2. one SMD (taken to be 1.7 points on the scale) in the QoL-AD.

The primary outcome measure for the carer was the incremental cost per quality-adjusted life-year (QALY) (derived using the EQ-5D-3L with societal weights).

In the analysis plan, the secondary economic measures for the person with dementia were set out as: QALYs derived from the DEMQOL-U and DEMQOL-Proxy-U, the MMSE, BADLS, GDS-15 and QCPR. Secondary economic measures for the carer were the HADS, MCS-12, PCS-12 and QCPR.

Summary of changes to the protocol

Approval was obtained from the REC for one substantial amendment to the protocol during the trial. This was related to the inclusion of additional questionnaires for both the person with dementia and their family carer. There was one non-substantial amendment notified to the study’s sponsor (University College London) representative, which was related to minor changes to the study protocol and inclusion of new sites and investigators. There was one protocol violation (this is described in detail in Appendix 9).

Randomised allocation

The 356 dyads gave informed consent to the study and were randomised after completion of the baseline assessment between April 2012 and July 2013. A total of 180 dyads were randomised to iCST and 176 to TAU. Table 7 provides rates of randomisation for each of the iCST centres.

Follow-up retention rates

Ratings of perception of allocation of dyads by blinded researchers

A total of 264 perception ratings were completed during week 13. These perception ratings asked the blinded researcher to assess, after a follow-up visit, which treatment the dyad had been allocated to using a 5-point Likert-type scale (‘definitely in iCST group’, ‘more likely to be in iCST group’, ‘equally likely to be in iCST or TAU’, ‘more likely to be in TAU group’, ‘definitely in TAU group’). Table 9 provides the results of these perception ratings in terms of the proportion that were correct, neutral and incorrect for treatment allocation at week 13. A total of 60% of blinded researchers rated dyads as being equally likely to receive iCST or TAU, with 23% making a correct judgement, of which 7% of these ratings were a definite judgement, and 17% making an incorrect judgement, of which only 5% were definite.

A total of 255 perception ratings were completed during week 26. Table 10 provides the results of these perception ratings in terms of the proportion that were correct, neutral and incorrect for treatment allocation at week 26. In a similar manner to the judgements for week 13, 57% of researchers rated treatment allocation equally to iCST and TAU, with a total of 23% making a correct judgement, of which 10% were definite judgements. A similar percentage to week 13 (20%) also made an incorrect judgement about dyad allocation.

Analysis

Economic evaluation

Data on service use and unpaid care were collected using the CSRI at each assessment point. The rates of completion of the CSRI were high at each point. At baseline, one iCST participant/carer dyad did not complete the CSRI. At week 13, of 142 iCST dyads completing outcome assessments, 141 completed a CSRI; of 146 TAU dyads completing outcome assessments, 145 completed a CSRI. At week 26, of 134 iCST dyads completing outcome assessments, 133 completed a CSRI; of 139 TAU dyads completing outcome assessments, 138 completed a CSRI. Thirteen dyads in the TAU group and 16 dyads in the iCST group completed only one follow-up CSRI. Information was available at all three time points for 129 iCST dyads and for 135 TAU dyads. There was a difference of nine dyads in the complete case information available for the costs analyses relative to the 26-week outcomes analyses (264 vs. 273). Owing to a protocol violation (see Appendix 9), one participant who should have been assigned to the control group received the intervention. For the cost-effectiveness analyses, costs of all participants have been retained and the analysis carried out according to the intended allocation.

Background

Despite the increasing number of RCTs evaluating cognitive-based interventions for people with dementia, little is known about the experiences of people with dementia taking part. This is the first RCT to conduct an embedded qualitative study exploring experiences of people with dementia taking part in a cognitive stimulation intervention alongside their family carers. In this study we used qualitative methods to explore the views of people with dementia taking part in the iCST programme. Given that qualitative data from the development phase of the trial indicated that interpersonal aspects of the caregiving relationship may be particularly relevant within the context of a home-based, carer-led individual cognitive stimulation approach, we additionally explored whether or not taking part in iCST was associated with any changes in interpersonal aspects of quality of life such as the relationship between the person with dementia and their family carer.

Aims

To explore the experiences of people with dementia and family carers taking part in the iCST programme.

Methods

Discussion

The study aimed to explore experiences of people with dementia and their carers taking part in the iCST programme through semistructured qualitative interviews. Major themes emerging from the qualitative data were opportunities for stimulation, changes in everyday life, interpersonal issues, such as the caregiving relationship, and understanding dementia in everyday life. The study findings suggested that taking part in the iCST programme provided opportunities for both general and intellectual stimulation, helping people with dementia to ‘think better’ and increase their alertness and awareness. 72 Some participants perceived the design and structure of the iCST programme as a tool which helped them to open up conversations and provided a frame for communication. A large number of participants and carers found that iCST offered opportunities to be involved in enjoyable and pleasant activities, revisiting or focusing on new interests and hobbies. In line with previous qualitative findings, although a few people with dementia expressed that they could not remember all of the activities they have completed during the intervention, they were able to reflect on moments of enjoyment and their feelings. 73

Interestingly, reports were consistent with the observation that iCST provided opportunities for people with dementia and their carers to ‘come closer’ and further strengthen their relationship. This is in line with results of the secondary analyses of more positive perceptions of relationship quality by people with dementia. As most people with dementia are cared for at home by family carers, it will be important for future research to understand better the factors that are likely to influence the caregiving relationship within the context of a carer-led, cognitive-based intervention. A considerable number of carers emphasised that iCST provided a framework for gaining a better understanding of the needs of the person with dementia, possibly by making carers more aware of the nature of the difficulties encountered by people with dementia and the experience of dementia in everyday life from the perspective of the person with dementia.

There are several limitations in this qualitative study, especially in relation to the fact that this was a convenience subsample. Most participants interviewed have done well with the intervention and reported higher than average compliance, which may have biased findings towards reporting positive changes related to the intervention. We did not interview dyads that did not complete any sessions or reported poor compliance (i.e. 10 sessions or fewer). In addition, data could have been affected by social desirability bias and participants thinking that the intervention has worked. Most people with dementia and their carers found the iCST programme to be interesting, useful and of value; however, a few reported that the programme was too easy and did not help them in terms of stimulating their thinking, judging the programme overall as not suitable for them. Future research should investigate issues of suitability of cognitive-based interventions and the importance of matching activities to personal preferences and ‘level of stimulation’.

This study reflected the experiences of people with dementia and their carers taking part in iCST and provided further insight into the perspectives of people with dementia and their feelings relating to engaging in a home-based cognitive stimulation programme. Some participants did not remember details of the activities but they were able to reflect on feelings of enjoyment and expressed the importance and value of taking part, its impact on their everyday life and their relationship with their family carer. The results indicate that many carers and people with dementia found iCST to be of great value in promoting mental stimulation and communication, and enhancing their relationship. These findings indicate that it will be important for future studies to include qualitative data in the design and evaluation of cognitive-based interventions for people with dementia and their carers.

Main findings

The iCST trial was a pragmatic, multicentre, RCT of a complex, individual, carer-led cognitive stimulation intervention. The trial was designed to evaluate the effects of iCST on cognition and quality of life for people with dementia and their family carers. We recruited a total of 356 caregiving dyads, making this study the largest in the current literature on CST-based approaches.

Primary outcomes

For people with dementia, the primary outcomes did not indicate any specific benefit for those allocated to receive iCST, given that there was no clinically significant improvement in cognition or quality of life compared with people with dementia receiving usual care. Carers’ physical and mental health was not significantly different between the intervention and control groups.

Secondary outcomes

We found no evidence that iCST reduced behavioural and psychological symptoms or depressive symptoms for people with dementia. There was also no evidence of change in activities of daily living. Although no effects were observed on most of the secondary outcomes, analyses indicated that people with dementia allocated to receive the intervention reported improvements in relationship quality with their family carer. iCST did not improve secondary outcomes such as carers’ mood, resilience or relationship quality with the person with dementia. Despite no differences in most secondary outcomes, health-related quality of life ratings for family carers allocated to the intervention group improved at the primary end point. This, however, was in contrast to no evidence of improvement on carers’ SF-12 component scores. This discrepancy in findings between the two generic instruments (SF-12 and EQ-5D-3L) may reflect intrinsic differences between these two instruments or differences in terms of each instrument’s sensitivity to change.

This is the first economic analysis of an iCST intervention for people with dementia and their family carers. Although costs from either the health and social care or the societal perspective did not differ substantially between the groups at either follow-up time point, there was a consistent pattern of lower costs in the iCST group over the 26-week period. In terms of the primary outcomes for people with dementia, it appears that iCST is not more cost-effective than TAU from either cost perspective, when we take sampling uncertainty into account. There are no established societal WTP thresholds for improvements in ADAS-Cog, QoL-AD or QCPR. In terms of QALY gain for carers, iCST was more effective than TAU. Taking carers’ costs into account, costs in the iCST group were lower, but not significantly lower, than in the TAU group. Taking sampling uncertainty into account, and assuming no further change in utility or costs in either group for the following 6 months, the probability that iCST is cost-effective was 93% at a societal WTP per QALY of £30,000. Under the same assumptions, we can be confident that iCST is cost-effective at a societal WTP of approximately £47,300 to gain a QALY, and, excluding costs to carers from this calculation, we can be confident that iCST is cost-effective at approximately £84,200 per QALY. The intervention can be considered to be cost-effective in improving unpaid carers’ health-related quality of life only at a societal WTP well above the NICE threshold of £20,000–30,000. However, societal decision-makers may be willing to accept somewhat lower levels of certainty to achieve this outcome. Given the results of the sensitivity analysis, this conclusion is dependent on a relatively low valuation of carer time.

When considering the number of sessions received, as opposed to allocation, some improvements were observed. People with dementia completing more sessions were more likely to experience gains in terms of the caregiving relationship at 26 weeks. Reports of improvements in the caregiving relationship by people with dementia are consistent with previous studies indicating that meaningful activities conducted alongside family carers can preserve and enhance the caregiving relationship. 74 Improvements were observed for carers completing more sessions with their relative, expressed by a reduction in depressive symptoms. These findings are consistent with previous research, in which a home-based cognitive stimulation programme was associated with lower depressive affects in carers. 11

Overall, however, findings are in contrast to previous studies demonstrating that group short-term CST benefits cognition and quality of life for people with dementia,6 and maintains quality of life improvements when provided long term. 19 These results also contrast with previous RCTs reporting benefits in cognition for people with dementia associated with home-based individual RO/cognitive stimulation. 12 In relation to effects on cognition, not replicating results of group CST approaches may be attributable to the lack of a group setting when CST sessions are provided. In addition, although we tried to use similar activities to those provided in group CST, it is unlikely that the activities were the same, indicating that differences may relate to differences on group versus individual CST approaches. In relation to effects of quality of life, this is the first study to include a measure of quality of life for a home-based approach for people with dementia. Our results therefore indicate that the benefits in quality of life are more likely to be associated with interventions that combine or use CST approaches within a social setting. Our findings may be of importance in relation to updating the Cochrane review. This may indicate the need for separate analyses of group and individual approaches to cognitive stimulation.

Treatment implementation is an important parameter when evaluating psychosocial interventions. In order to ensure that iCST was ‘delivered as intended’, we used a treatment protocol that specified all components of the intervention in detail, in order to ensure that the intervention was delivered as planned. Each unblinded researcher received training in iCST, and there were frequent opportunities for researchers supporting carers in the delivery of iCST to receive supervision and feedback. Furthermore, there were a number of challenges associated with implementing iCST, particularly with regard to carers fitting iCST into a busy timetable, the lack of ‘stimulation’ for some participants and difficulties reported by carers in engaging in the intervention with their relative. Compliance will be, therefore, an important component to consider in order to optimise similar psychosocial interventions for people with dementia and their carers. At this stage, it is not clear if there are any specific characteristics that would identify the very low compliance group who completed no sessions at all, but we plan to look at further analyses on this topic in due course.

In line with our projections in relation to sample size, a total of 81% of the sample completed the 13-week assessments and 71% completed the 26-week assessments. The most common reason for not being available to complete follow-up appointments was reporting problems with engaging in iCST, indicating that, although the intervention may have a high uptake, it still may be difficult or not suitable for some carers and people with dementia. Although most carers were able to engage in iCST with their relative, there were frequent reports by carers of struggling to engage with their relative in the sessions and, often, this was a common reason of loss to follow-up. A total of 22% of dyads allocated to receive iCST did not complete any sessions and 13% completed fewer than 10. A threshold of completing over 38 sessions was set on the basis of number of sessions completed by the whole of the sample, as indicative of compliance to the intervention. We did not find any evidence of differential attrition, and analyses exploring differences between completers versus non-completers did not suggest any differences between the two groups in terms of baseline characteristics.

In terms of cognition and quality of life, our findings do not provide support for the use of home-based cognitive stimulation programmes for people with dementia, which is contrary to previous work on home-based memory rehabilitation10 and RO for people with dementia. 12 It is unclear which factors could account for the differential efficacy. It is likely that in some studies participants are highly selected, resulting in different patient groups recruited and, therefore, different levels of dementia severity and cognitive function. For example, in our study most of the sample had mild dementia in comparison to previous studies. Other factors could reflect differences between studies in terms of power or chance variation, given that previous studies are of varying quality with small samples overall. 2 Importantly, although treatment compliance is not reported in detail across studies, the ‘dose’ received in each of the studies may be an important determinant of efficacy.

Despite generally negative findings, people with dementia reported better relationship quality with their carer, indicating that individual cognitive stimulation interventions have the potential to improve inter-relationship outcomes for people with dementia. Relationship quality, rated by the person with dementia, has been shown to be an important contributor to quality of life for people with dementia and is the cornerstone of relationship-centred care. 75 We also found that health-related quality of life for family carers significantly increased, indicating that carer involvement in cognitive-based interventions may increase carer well-being. This may be related to the fact that, although iCST was developed largely as a home-based, carer-led, individual cognitive stimulation approach, the intervention incorporated additional psychoeducational elements such as communication, opportunities to increase pleasant events for both carers and people with dementia, which are components less likely to be incorporated in group CST-based approaches. This is consistent with the findings of the qualitative study where carers reported that iCST provided opportunities to understand dementia, its impact on communication and confidence for the person with dementia, and to increase pleasant activities both for themselves and their relative. Interventions that therefore target communication between people with dementia and their carers may reduce the strain on the caregiving relationship and may potentially improve general well-being outcomes for both.

A further variable of interest is unblinded researchers’ level of expertise and experience, which is an important factor to consider in the development of psychosocial interventions. Consultation groups with unblinded researchers indicated that they were generally well received by carers and people with dementia, although dyads differed widely in their level of engagement with the intervention. The level of expertise was judged as sufficient, and training and background in dementia care was considered to be important in supporting carers in delivering the sessions.

Implications for health care

It was expected that iCST may be beneficial for people with dementia in terms of cognition; however, this was based on smaller studies using both cognitive stimulation and RO techniques and using less well-defined methods. However, it is notable that participants in this study had better cognition (mean baseline MMSE score of 21) than those in the original group CST study (mean baseline MMSE score of 14), which was also limited to people with dementia scoring between 10 and 24 on the MMSE. This suggests that in the current study there was less scope for improvement, and some participants may have had cognitive function that was too high to benefit from iCST.

Most of the evidence on effects on cognition for cognitive stimulation is based on group approaches, so future research will need to focus on understanding the mechanisms that are more likely to be associated with the reported effects and differential effects of outcomes between group versus individual approaches. There was evidence in this trial that some people with dementia and their family carers will not be able to engage successfully in iCST, as 34% of the sample allocated to receive the intervention completed 0 or fewer than 10 sessions. Our qualitative findings indicated that, although most people with dementia and carers enjoyed the sessions, there were also a few comments that the iCST sessions were not challenging enough, indicating that the type of carer-led, cognitive-based intervention may be key in terms of producing a therapeutic effect. Despite overall negative findings, improvements on the carer–patient relationship and carers’ health-related quality of life suggest that iCST may have a key role in improving communication for people with dementia and their carers.

Limitations

Participants dropping out will have introduced bias if they had a different response to the intervention or TAU conditions compared with those that completed the trial. However, there was no evidence from demographic variables or baseline outcome scores that those who did complete the study were different from those who did not.

Although significant efforts were made to obtain outcome data, the trial may have been underpowered to detect significant differences for the primary outcome measure owing to the attrition rate and low levels of compliance in the overall number of sessions completed. Nevertheless, this is the largest RCT of a cognitive stimulation intervention in which carers lead the sessions and which shows no effect on cognition and quality of life for people with dementia compared with usual care.

An important limitation is that the observed differences of improvement in the caregiving relationship for people with dementia and health-related quality of life for carers may be attributable to incidental findings, driven by the multiple comparisons tested, and may, therefore, be attributable to chance. Despite people with dementia and carers expressing interest in the intervention, compliance was low overall, indicating that cognitive stimulation interventions delivered by carers may not be the ideal mode of delivery for many, thereby limiting wider applicability and generalisability of this approach, and indicating that better methods of monitoring and support for adherence are needed. Identifying subgroups of caregiving dyads that are more likely to benefit from this intervention is likely to be an important aim for future research.

Recommendations for future research

The null effect reported in this study leaves unanswered the question of whether or not carer-led cognitive stimulation interventions are effective. Despite the appeal of home-based programmes led by carers, cognitive stimulation approaches may be better provided on a group basis unless further evidence becomes available.

1. If carer-led interventions are to be further pursued, future research should identify which factors are more likely to make the intervention most successful and adaptable to the needs of people with dementia. As feedback from people with dementia in the qualitative interviews indicated that some sessions were not stimulating enough, future studies should consider that people earlier in the disease trajectory may have different cognitive stimulation needs from those with moderate dementia.

2. Given that less than half of the iCST group completed at least two sessions per week this reduced the power of the study to identify potential differences with the control group and indicates limitations in relation to the applicability of the intervention. Future work is needed to investigate the characteristics of caregiving dyads that are most likely to adhere to and benefit from carer-led individual cognitive stimulation interventions and methods to improve adherence. The involvement of paid domiciliary care workers or volunteer befrienders in delivering sessions should be explored further, as this may increase adherence by placing less responsibility on family carers.

3. Given that carer-led, cognitive-based approaches are relatively new treatments, research designs that address their efficacy are more relevant than designs addressing mechanisms at this point. Therefore, comparisons of group versus individual approaches are likely to be premature at this stage.

4. It is important that future research and different research groups evaluate further the effects of individual cognitive stimulation interventions. This work will help to ensure the reliability and robustness of the effects reported in this trial, in relation to benefits of relationship quality for people with dementia and health-related quality of life for carers.

Conclusions

The evidence from this trial suggests that taking part in iCST sessions does not result in improvements on cognition or quality of life for people with dementia. There was no evidence of improvements for carers’ mental and physical health. There was no evidence that iCST improved secondary outcomes for people with dementia, such as activities of daily living, mood or behavioural and psychological symptoms. Analyses indicated that iCST did not confer any benefit for carers’ mood, resilience or relationship quality with the person with dementia. Although people with dementia receiving iCST reported better relationship quality with their carer (in itself, an important component of quality of life for people with dementia) and carers reported improved health-related quality of life, these findings need to be interpreted with caution given limitations owing to multiple testing. Despite efforts to minimise loss to follow-up, the study may have still been underpowered to detect significant differences for the primary outcome. Given that iCST did not achieve the expected change, it is unlikely to lead to clinical benefit in improving cognition and quality of life for people with dementia.

Contributions of authors

Vasiliki Orgeta (Senior Research Associate) supervised and planned the development of iCST, contributed to the development of iCST materials, planned and conducted one of the development studies, was responsible for the day-to-day operation and management of the study in all centres, contributed to the study design and drafted most of the final report.

Phuong Leung (PhD researcher) contributed to the development of iCST materials, trial management and data collection, planned and conducted the qualitative study, and wrote sections of this report.

Lauren Yates (PhD researcher) contributed to the development of iCST materials, recruitment and data collection, planned and conducted two of the development studies, and wrote sections of this report.

Sujin Kang (Research Officer, Statistics) was a trial statistician, undertook the statistical analyses and drafted sections of the report.

Zoe Hoare (Research Fellow, Statistics) was a trial statistician, developed the statistical analysis plan, undertook the statistical analyses and drafted sections of the report.

Catherine Henderson (Research Fellow, Health Economics) advised on the supervision of data collection of health economics, undertook the health economic analyses and drafted the health economic section of the report.

Chris Whitaker (Senior Statistician) was trial statistician, advised on the statistical analysis plan, the statistical analyses and statistical input in sections of the report.

Alistair Burns (Professor of Old Age Psychiatry, Honorary Consultant Old Age Psychiatrist) was principal investigator of the Manchester site.

Martin Knapp (Professor of Health Economics) oversaw the health economics of the study.

Iracema Leroi (Clinical Senior Lecturer and Honorary Consultant in Psychiatry) was principal investigator of the Manchester site.

Esme D Moniz-Cook (Professor of Clinical Psychology and Ageing) was principal investigator of the Hull site.

Stephen Pearson (Consultant Psychiatrist in Old Age) was principal investigator of the Devon sites.

Stephen Simpson (Consultant Psychiatrist in Old Age) was principal investigator of the Dorset site.

Aimee Spector (Senior Lecturer in Dementia) contributed to the planning and design of the study and provided expertise in CST.

Steven Roberts (Head of Dementia Services) was principal investigator of the Lincolnshire site.

Ian T Russell (Professor of Clinical Trials) contributed to the planning and design of the study and oversaw the methodological aspects of the trial.

Hugo de Waal (Honorary Senior Lecturer, Consultant Psychiatrist in Old Age) was principal investigator of the Norfolk and Suffolk site.

Robert T Woods (Professor of Clinical Psychology of Older People) contributed to the planning and design of the study, provided expertise in CST and was principal investigator of the Bangor site.

Martin Orrell (Professor of Ageing and Mental Health) was the chief investigator, conceived, designed and planned the study, and supervised its conduct. He was the principal investigator for the London sites and contributed to all sections of this report.

All study authors contributed to the preparation and review of this report.

Publications

Orrell M, Yates LA, Burns A, Russell I, Woods RT, Hoare Z, et al. Individual Cognitive Stimulation Therapy for dementia (iCST): study protocol for a randomised controlled trial. Trials 2012;13:172.

Yates LA, Orrell M, Spector A, Orgeta V. Service users’ involvement in the development of individual Cognitive Stimulation Therapy (iCST) for dementia: a qualitative study. BMC Geriatr 2015;15:4.

Orrell M, Woods B, Spector A. Should we use individual cognitive stimulation therapy to improve cognitive function in people with dementia? BMJ 2012;344:e633.

Yates LA, Leung P, Orgeta V, Spector A, Orrell M. The development of individual Cognitive Stimulation Therapy (iCST) for dementia. Clin Interv Ageing 2014;10:95–104.

Data sharing statement

All available data can be obtained by contacting 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 HTA 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 HTA programme or the Department of Health.