The value of dementia care towards the end of life- A contingent valuation study.

OBJECTIVES
A Dementia Nurse Specialist (DNS) is expected to improve the quality of care and support to people with dementia nearing, and at, the end of life (EoL) by facilitating some key features of care. The aim of this study was to estimate willingness-to-pay (WTP) values from the general public perspective, for the different levels of support that the DNS can provide.


METHODS
Contingent valuation methods (CVM) were used to elicit the maximum WTP for scenarios describing different types of support provided by the DNS for end of life care in dementia. In a general population online survey, 1002 participants aged 18 years or more sampled from the United Kingdom provided valuations. Five scenarios were valued with mean WTP value calculated for each scenario along with the relationship between mean WTP and participant characteristics.


RESULTS
The mean WTP varied across scenarios with higher values for the scenarios offering more features. Participants with some experience of dementia were willing to pay more compared with those with no experience. WTP values were higher for high income groups compared with the lowest income level (p<0.05). There was no evidence to suggest that respondent characteristics such as age, gender, family size, health utility or education status influenced the WTP values.


CONCLUSION
The general population values the anticipated improvement in dementia care provided by a DNS. This study will help inform judgements on interventions to improve the quality of end of life care. This article is protected by copyright. All rights reserved.


| BACKGROUND
In 2017, there were approximately 50 million people worldwide living with dementia and by 2050, this is set to increase to over 130 million. 1 In the United Kingdom, it is predicted that there will be over 1 million people with dementia by 2025 if the current age specific prevalence remains stable. 2 In 2015, the cost of dementia care globally was estimated at $818 billion and is expected to increase to $2 trillion by 2030. 1 The current estimated annual societal cost of dementia in the United Kingdom is £26.3 billion (at 2012/2013 prices). 2 With such increases the need to provide good quality care and support for people with dementia whilst demand rises is well recognised both in the United Kingdom and internationally. 3,4 Dementia is a life limiting illness 5 and those with dementia nearing the end of life (EoL) have palliative care needs similar to those of cancer patients. 6 Therefore, the approach to 'end of life care' is an important component in the provision of appropriate care to dementia patients. 3,[7][8][9] In the United Kingdom, policy has significantly influenced both the quality of EoL care, via an End of Life Care Strategy 10 (applicable to all illnesses) and dementia care via a National Dementia Strategy 4 and Prime Minister's Challenge on Dementia 2020 11 published in 2015 by David Cameron (the then Prime Minister). However, care provided at the EoL to people with dementia remains inconsistent in quality and mostly consensus based. [12][13][14] To address this, the Supporting Excellence in End of life care in Dementia (SEED) Programme in the United Kingdom was undertaken. Following the MRC framework for complex interventions, 15 and using a mixed methods approach, the SEED programme developed, via co-design approaches with key stakeholders, a primary care-led, intervention to enable community-based professionals to deliver co-ordinated and proactive care to people with dementia and their families towards, and at, EoL (https://research.ncl.ac.uk/seed/). The intervention comprised a dementia nurse specialist (DNS), working with primary, secondary and community care teams, providing EoL care focused on seven key areas (see Table 1). 16,17 These features are key to the design of the DNS, and so understanding the value that is placed on these features should be measured when evaluating the DNS.
As, in the United Kingdom, the health care service is funded from taxation and available to everyone, the views of the public should be reflected in the decisions that are made. There is a need for decisions to be made in the management of dementia due to the increasing prevalence of the disease. This includes those with dementia themselves, carers and the general public as a whole. There has previously been work eliciting the views and perspectives of clinicians and carers 18,19 but there has been a paucity of evidence regarding the preferences of the general public. This study elicited the values of a representative sample of the general public using the contingent valuation method (CVM) to use in an economic evaluation of the DNS role.
Contingent valuation is a commonly used method in the valuation of non-market goods (such as environmental interventions) 20 and is being increasingly used in health care. The CVM involves setting up hypothetical scenarios which describe the proposed intervention and the expected health and non-health outcomes. Specifically, this takes the form of asking the participant their willingness to pay (WTP) for the intervention through a proposed payment vehicle appropriate in the particular context. This can include out of pocket payments, increases on bills and levies and increases in tax. 21 In this particular context (a publically funded health care system), a taxation vehicle was used, as this is way of funding health care that a UK population would be familiar with. Participants were asked whether they would be willing to pay an amount to make a DNS available to anyone who may need it. The value that participants may choose to give represents what is known as an opportunity cost, which is the benefit forgone from using a resource for one purpose as opposed to its best alternative use. 22 This amount volunteered demonstrates the willingness to forgo other personal benefits to gain access to the service thus demonstrating their value for it. In our study, we used this technique to measure the value a representative sample of the general public would place on a DNS, and measure the strength of their preference for such an intervention and the range of features provided.

| Study design
The CVM was used to measure the monetary valuation in terms of the WTP 21,23,24 for the expected improvement in dementia care. In T A B L E 1 Summary of the seven factors influencing good EoL care for people with dementia 16 Undertaking timely planning discussions to ensure plans are discussed when the person with dementia has capacity and that they are documented and disseminated as appropriate.
Recognising end of life and providing supportive care to ensure effective management of key symptoms (eg, pain, anxiety and nausea), and minimise distress by providing comfort in a familiar environment.
Co-ordination and continuity of care includes liaison between day and night staff in services and having established links with local services (eg, hospices), particularly for support out of hours.
Working effectively with primary care can be facilitated by having a named liaison person in the practice. For care homes, liaison can be improved by regular routine visits and limiting the number of general practices with which residents are registered.
Managing hospitalisation includes avoiding unnecessary admissions by appropriate out-of-hours support and documentation of wishes and preferences. It also involves managing admission and discharge effectively where hospitalisation is necessary.
Continuing care after death to enable family members to be supported by known members of staff who cared for the person with dementia at the end of life. This continuity of care is valued by family members.
Valuing staff and on-going learning facilitates staff retention and results in a more skilled and knowledgeable workforce. Stable staff teams are more able to detect emotional vulnerability in their colleagues and ensure timely and appropriate support.

Key Points
• The need for quality care and support to dementia patients is well recognised both in the United Kingdom and internationally.
• A potential way of improving care and support to dementia patients nearing the end of life is by having a dementia nurse specialist (DNS).
• The general population value the improvement in dementia care resulting from different levels of support that a DNS can provide.
• People with experience of dementia express higher willingness to pay (WTP) and WTP varies depending on the degree of support offered.
this study, a community perspective was taken, with respondents asked to give their WTP for the SEED intervention to be available through the NHS even though they would not (necessarily) benefit from it themselves. Given this perspective, respondents were asked their WTP in the form of an additional tax per month (as the NHS is funded through taxation) that they would pay for the next 10 years.
The 10-year duration was chosen as a meaningful timescale for respondents and representative of how long a policy intervention might exist before it was redesigned.
Five scenarios were developed each representing an alternative package of care that could be provided by via the DNS. One scenario had all seven key features of care, the others had a varying number of factors; this was done to assess whether participants valued different features of care differently. The content of the scenarios was based on the seven key components to support good EoL care identified in the SEED intervention (Table 1). 16 The main scenario is presented in presented with three different scenarios (everyone was presented with the 'main' scenario first and then two randomly selected alternatives from the four remaining scenarios). Respondents were presented with a scenario and first asked if they would be willing to pay anything for the intervention as described to be provided. If they answered 'yes', then they were presented with a series of payment cards at random on the screen and were asked to state their WTP for the proposed scenario with a question 'Would you be willing to pay £X for scenario described?' with 'X' representing the randomly picked up amount from the payment cards. Then the respondents were asked to sort out the payment cards by dragging and dropping (using the com-

| Pre-test and piloting
Pre

| Study participants
Whilst earlier CV studies in dementia generally estimated the value placed by sample of carers of people with dementia or service providers, it would be most appropriate to generate the values of people with dementia for whom the interventions are intended. 27 Therefore, the participants in this study were sampled from the online panel members of the market research company, ResearchNow. The sample was selected to be representative of the UK general public by age (18 years or above) and gender.
There is no formal framework for calculating a sample size for a contingent valuation study. This sample size has been selected as it is judged to be both feasible in terms of time for recruitment as well as a large enough sample for meaningful statistical analysis including appropriate sub-group analysis. In this study, a sample of 1000 respondents was targeted with quotas on age, gender and geographical regions to be representative of the UK general population.

| Survey administration
The survey was delivered online using randomly selected existing

| Data analysis
The data were analysed in statistical programming language R. 28 We report the mean and median WTP for each of the five scenarios con-

| RESULTS
A total of 1002 individuals completed the online survey. Table 2 presents the number of responses per scenario.  Table 2).
The characteristics of respondents after removing the protest responses are presented in Table S1 and of those remaining after excluding the top 1% WTP values 30 are presented in Table S2.  The results of the regression analysis of WTP values on selected respondent characteristics for each of the scenarios are presented in Table 5. There was no evidence to suggest that patient characteristics
In the case of the main scenario individuals with a household income of £60 000 to £69 999 were more likely (P < .05) to have a higher WTP compared with those with an income under £10 000. The WTP for the main scenario was also higher for the individuals with a household income of £90 000 to £99 999 (P < .05), £100 000 to £149 999 (P < .01) and £500 000 or more (P < .001) compared with those with income less than £10 000.
The WTP value for alternative 1 was higher only in those with a household income of £500 000 or more (P < .05) compared with those with an income below £10 000. The WTP value for alternative 2 was higher in individuals with a household income of £50 000 to £59 999 (P < .05), £60 000 to £69 999 (P < .05), £70 000 to £79 999 (P < .01), £80 000 to £89 999 (P < .05), £100 000 to £149 000 (P < .001) and £200 000 to £499 999 (P < .001) compared with those with an income less than £10 000. Whilst, the WTP value for alternative 3 was significantly higher in individuals with an income £100 000 to £149 000 (P < .001), £200 000 to £499 999 (P < .05) and £500 000 or more (P < .001), the WTP for alternative 4 was higher only in individuals with an income £200 000 to £499 999 (P < .01) compared with those with an income of less than £10 000. In terms of implications of our findings for practice, the pilot study of the SEED intervention showed that the DNS intervention, with key features including proactive care planning, care co-ordination and educating and supporting family and professional carers, was feasible and acceptable and integrated easily into existing structures. The DNS model was also highly valued by all 'users', that is, professionals, patients and family carers. Given this, the next stage is to conduct a wider evaluation of the potential benefit of the inclusion of a DNS in the health care service. The WTP values estimated in the study reported here could be used to carry out cost-benefit analysis (CBA) comparing multiple dementia improvement initiatives in terms of net monetary benefits. While the CBA approach is not as typically used in the evaluation of new health care interventions, it is the recommended and most used approach across the rest of UK public sector and provides a clear decision rule to guide and inform NHS decision making. 34 The next stage is important as recent UK research has revealed that symptom management in people with advanced dementia is still suboptimal with high levels of observed pain and agitation. 35 Also despite national policy recommending that older people be cared for in their homes, or usual place of care, for as long as possible including up to death, currently nearly 40% of people with dementia in England die in acute hospitals. 36 In addition to the public placing high value on the newly developed SEED model, evidence shows there is still an urgent need for interventions which improve quality of care in this complex and challenging area of practice.