Title: Econometric analysis of carer health-related quality of life for use in economic evaluation for healthcare decision-making
Funder: Department of Health and Social Care

Abstract: Background Interventions for patients can affect carer outcomes. Improving patients' health can reduce their informal care needs, and so improve the health-related quality of life (HRQL) of carers. The National Institute for Health and Care Excellence (NICE) specifies in their Methods Guide that benefits in economic evaluation should include health effects to patients and carers. However, the inclusion of carer HRQL in NICE economic evaluations featured in only 15 appraisals up until mid-2018. The rationale for excluding carer health effects in economic evaluation include paucity and poor quality or limited applicability of data. Furthermore, there is concern over the most appropriate methodology for including carer HRQL in economic models. Including carer health is essential to maximise population health rather than just patient health, and will change the decisions NICE makes about which interventions should be reimbursed. NICE cannot make equitable and efficient decisions if economic evaluations do not all use consistent methods and include the same costs and benefits. Therefore, there is a need to understand the carer health effects across a range of conditions and interventions. Aims This project aims to improve the methods and data available for considering the effect of interventions for patients on the health of carers. Plan of investigation Understanding Society is a large observational dataset that includes information collected over time about people living in the same household. This information includes diagnosis of health conditions, HRQL and the amount of informal care each person provides to other household members or people outside the household. I will link together health condition, HRQL and care provision data for household members, to analyse how a patient's health condition and HRQL predicts the HRQL of their carer. This will include cross-sectional analysis for comparison with published evidence, and longitudinal analysis to understand how changes in caring responsibility influences a person's HRQL. I will analyse how the number of hours a person spends caring for an individual outside their household affects their HRQL, using cross-sectional and longitudinal methods. Data exist linking patient HRQL to carer burden irrespective of disease, so linking carer burden to carer HRQL would allow carer HRQL to be estimated for people caring for an individual outside their household. A systematic literature review will provide evidence on how carer health changes over time, to inform the choice of econometric models and variables in my analysis. I will use my econometric models to incorporate carer HRQL in case studies of economic models, to demonstrate how these data can be used and how they affect results, and how uncertain the results are. I will use these data to estimate the displaced carer QALYs from currently funded interventions, as required for decision making. Summary of the potential benefits to patients and the NHS Decisions made by NICE impact the health of the UK population, including the UK's 6.5 million informal carers. Developing a consistent approach and using the same data source for carer HRQL for all diseases will facilitate efficient decision-making, and therefore improve population health.

Lay abstract: Background Health interventions (treatments or services) for patients may affect carers' health too. The National Institute for Health and Care Excellence (NICE) decides which interventions the National Health Service (NHS) should pay for in England. NICE does this by comparing the costs and health effects of the new and existing interventions. When considering a new intervention, NICE always includes the effects on the health of patients. Sometimes, NICE also includes the effects on people who care for the patient. It is unclear why NICE includes carer health effects only for some diseases, but it may reflect whether or not the right data on the carer's health has been collected. If an intervention does improve carer health but there is no data for this, then the health effects would be underestimated. Only including health effects for some diseases might bias which interventions the NHS funds. Aims of this research My research aims to improve the methods and data available for considering the effect of interventions for patients on the health of carers. 'Understanding Society the UK Household Longitudinal Study' (UKHLS) is a large survey collecting data over time for everyone aged 16 or over in the same household. UKHLS asks people about the care they provide for people they live with, and for people they do not live with. Analysing UKHLS will provide NICE with data they can use to include carer health effects in all diseases. Design and methods I will review published research papers to understand which factors lead to changes in carers' health. This will ensure I include the correct data in my analysis. UKHLS contains health data for all people living in one house, so it provides a unique opportunity to study how a carer's health changes as the health of the person they care for and live with changes over time. If someone cares for a person who they do not live with, UKHLS does not contain data on the health of the person they care for. So, in this case, I will explore how a carer's health changes as the amount of time they spend caring for someone they do not live with changes over time. I will consider what happens when a person becomes a carer, how long they have been a carer, when they increase or decrease the amount of time they spend caring, and when they stop being a carer. I will consider the different reasons a person stops, increases or decreases the amount of time they spend caring as this could impact how their health changes. I will use the data from UKHLS in examples where NICE has compared the costs and health effects of new and current interventions, to demonstrate how carer health would change in these examples. Patient and Public Involvement I have involved carers in the design of the research, and in writing the Plain English Summary. Carers will continue to advise on the research and help to design materials for reporting the findings. I will arrange workshops for carers to input into the study design, and help me explain the project findings. Reporting resultsI will publish the results in academic journals, and through online reports that include plain English summaries and graphics that can be shared through carer groups. This will increase awareness of carer health effects. This will prompt groups like NICE to rethink their methods, and allow people comparing costs and benefits to include carer health effects for all interventions. This will allow NICE to make better decisions about which interventions the NHS should fund and improve the health of patients and carers.

Research activity codes: 8.2 HEALTH AND WELFARE ECONOMICS
Health categories: GENERIC HEALTH RELEVANCE