Unpaid Caring and Health-Related Quality of Life: Longitudinal Analysis of Understanding Society (the UK Household Longitudinal Survey).

Decision models for economic evaluation are increasingly including health-related quality of life (HRQoL) for informal/unpaid carers, but these estimates often come from poor quality data and typically rely on cross-sectional analysis. We aimed to identify within-person effects using longitudinal analysis of 13 waves of Understanding Society (the UK Household Longitudinal Survey). We analyzed data for coresident carer and care-recipient dyads, where the carer reported "looking after or giving special help to" the care recipient in any of the 13 waves. We used fixed-effects models to study the effects of caring for the care recipient (the "caregiving" effect) using volume of care (hours per week) and continuous duration of caregiving (years) and caring about the care recipient (the "family" effect) using the care recipient's HRQoL on the carer's HRQoL. HRQoL was measured using the Short Form 6 Dimension, calculated from the Short Form 12. We found consistent evidence for the family effect: improving care recipient's HRQoL by 0.1 would improve carer's HRQoL by approximately 0.012. We also consistently found evidence of a small but statistically significant decrement to carer's HRQoL for each additional year of caring. These findings were robust to scenario analyses. Evidence for the relationship between volume of care and carer's HRQoL was less clear. We propose that our estimates can be used to populate economic models to predict changes in carers' HRQoL over time and allow disutilities to be estimated separately for the family and caregiving effect. • Much evidence for the relationship between informal/unpaid caring and health-related quality of life (HRQoL) relies on analysis of cross-sectional data, but we identify within-person effects using longitudinal data. • Carers' HRQoL declines as the duration of caring increases (the "caregiving" effect) and declines as care recipient's HRQoL declines (the "family" effect"). • Our findings can be used in economic evaluations to estimate carers' HRQoL changes from patient HRQoL changes and caring duration. [ABSTRACT FROM AUTHOR]