Modelling carer health-related quality of life
Three stages and reports for modelling carer health-related quality of life.
Stage one
Modelling carer health-related quality of life in NICE technology appraisals and highly specialised technologies
NICE’s reference case for the Methods of Technology Appraisal (TA) states that "the perspective on outcomes should be all direct health effects, whether for patients or other people".
NICE does not currently specify how the health effects for people other than the patient should be incorporated, and so there is variation in how these are considered in TAs. There is variation in both the source of carer quality of life data, and in the way that this is incorporated in the modelling.
This project focuses on the health effects of interventions for patients on people beyond the patient, termed 'spillover' effects in the literature.
Stage two
Systematic review of cost-utility analyses that have included carer and family member health-related quality of life
Health interventions for patients can also affect the health of informal carers who provide unpaid care for patients, and other family members. These changes in carer or family member health are sometimes referred to as health spillovers. Health spillovers could be reflected in economic evaluation through the measurement and inclusion of their quality-adjusted life years (QALYs) in cost-utility analysis (CUA).
A systematic review identified 38 CUAs published between 1999 and 2019 and conducted in 15 different countries including 11 in the UK, across a range of conditions. The EQ-5D was the most common utility measure used for carer quality of life, applied in 23 studies.
There was considerable variation in the impact of including health spillovers on cost-effectiveness. QALY gains for carers were similar to or greater than QALY gains for patients in three studies. In 10 studies by including carer QALYs the incremental cost-effectiveness ratio (ICER) was reduced relative to patient QALYs alone. However, in 6 studies QALY gains for carers were very small compared to patients, or made little difference to the ICER.
Only four studies provided information on both the impact of including family member QALYs and how this changed the ICER. Greater uncertainty in the estimation of carer QALYs compared to patient QALYs was noted across a number of studies.
Several factors may have had an effect on the impact of including health spillovers in the analysis, including the number of carers, and whether informal care costs were simultaneously included, and the measures and methods used. Generally, including carer QALYs appeared to increase the difference in QALYs between the intervention and comparator.
Very few economic evaluations have included carer QALYs and the methods for doing so are not consistent and data sources are often limited.
Developers of future guidance for the reporting of economic evaluations may wish to consider specifying that justification for including or excluding carer QALYs should be provided, the methods for doing so should be described, and results should be reported separately for patients and carers.
Stage three
Critique of a systematic review of studies reporting health related quality of life effects for caregivers and family members
A recent systematic review sought to examine spillover effects, and to catalogue spillover-related utilities to facilitate their consideration in cost effectiveness analyses. The objective of the current paper was to summarise the findings and provide a critical appraisal of this recent review.
Alzheimer’s disease and other types of dementia were the most frequently studied conditions. The majority of the studies focused on caregivers/family members of ill adults, EQ-5D was the most common instrument used to measure caregiver/family member utility, and most of the studies were conducted in in Europe (66%), the US and Canada (25%).
The results of the critique demonstrated that, overall the quality of the review was acceptable. The remit of the systematic review was to document clearly and comprehensively the range of studies reporting preference-based family member utility values. The review did not seek to provide further analysis of these data, other than narrative synthesis, and tabulation of the studies, and did not intend to infer anything further from these results.
The authors concluded that in general, utilities indicated a loss in quality of life associated with being a caregiver or family member of an ill relative. Most studies reported caregiver/family member utility without any comparator, limiting the ability to infer spillover effects. They also highlight the spectrum of diseases and conditions for which caregiver and family members’ spillover effects have been measured, and the variation in measurement methods used.
With careful consideration of quality of the individual studies, there may be generalisations made in terms of the methods and measures used in future CUAs. This may have implications for NICE and HTA bodies, pharmaceutical companies and researches.
DSU reports
Modelling carer health-related quality of life in NICE Technology Appraisals and Highly Specialised Technologies (PDF, 1.2MB) (Stage one – April 2019)
This report describes our review of NICE Technology Appraisals and Highly Specialised Technologies to identify those which considered the impact of an intervention on carer or family members QALYs. We discuss the data sources and approach to modelling carers used, identify key issues and suggest areas for further research.
This report presents a systematic review. The review identified 38 cost utility analyses that included carer or family member QALYs. Generally, including carer QALYs appeared to increase the difference in QALYs between the intervention and comparator. Very few economic evaluations have included carer QALYs and the methods for doing so are not consistent and data sources are often limited.
This report presents a summary and critique of a recent systematic review that sought to examine spillover effects, and to catalogue spillover-related utilities to facilitate their consideration in cost effectiveness analyses. The results of the critique demonstrated that, overall the quality of the review was acceptable. The authors of the review concluded that in general, utilities indicated a loss in quality of life associated with being a caregiver or family member of an ill relative.
Publications
A. Scope, A. Bhadhuri and B. Pennington (2022) "Systematic Review of Cost-Utility Analyses That Have Included Carer and Family Member Health-Related Quality of Life". Value in Health. DOI: https://doi.org/10.1016/j.jval.2022.02.008