How Does Unpaid Caregiving Affect Health-Related Quality of Life? Longitudinal Analysis of SF-6D for Carers in the UK

OBJECTIVES: Cross-sectional evidence suggests that unpaid carers have worse health-related quality of life (HRQoL) than non-carers. However, this may be due to selection bias (people with worse HRQoL may be more likely to become carers). We wanted to understand how people’s HRQoL changes when they became, continued, or stopped providing unpaid care by analysing longitudinal data.

METHODS: We analysed 13 waves of data from Understanding Society (the UK Household Longitudinal Survey). We created dyads for carers and the person they looked after in their household (the “cared-for”). We used fixed effects models to analyse within-person effects. Our outcome variable was the carer’s SF-6D index score, calculated from the Short-Form 12. Our model included weekly volume of care (hours), number of consecutive years providing care, and the SF-6D of the cared-for. We hypothesized that people providing care at a higher volume or for longer would have worse HRQoL, and that carers’ HRQoL would worsen when the HRQoL of the person they cared for worsened.

RESULTS: Carers’ HRQoL worsened as the duration of caring increased, by 0.045 annually. Carer’s HRQoL worsened as the cared-for’s HRQoL worsened, with a coefficient of 0.123. These findings were robust to scenario analysis. The relationship between volume of care and HRQoL was less clear and was not consistently significant or of the same size across scenarios.

CONCLUSIONS: Carer utilities/disutilities can be predicted from information on patients’ utility and the duration of unpaid care. Delaying the onset of unpaid care and improving (or reducing decline in) patient’s HRQoL would improve carers’ HRQoL.