Stroke survivors’ long-term QALY-weights in relation to their spouses’ QALY-weights and informal support: a cross-sectional study

Abstract

Background: Healthcare interventions that have positive effects on the stroke survivors’ health-related quality of Life (HRQoL) and quality-adjusted life-years (QALYs) might also have positive effects for their spouses in terms of improved HRQoL and/or reduced spousal informal support. However, knowle dge about stroke survivors ’ HRQoL and QALY and the consequences for their spouses’ HRQoL and QALY is limited. Therefore, the aim of this study was to describe the HRQoL and QALY-weights in dyads of stroke survivors in comparison with dyads of healthy controls, and to study the relationship between the stroke survivors’ QALY-weights and consequences for spouses in terms of QALY-weight and annual cost of informal support, using a long-term perspective. Methods: Data on stroke survivors, controls, and spouses were collected from the seven-year follow-up of the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). HRQoL was assessed by the SF-36, and the preference-based health state values were assessed with the SF-6D. The magnitude of the support was assessed with a study specific time-diary. An ordinary least squares (OLS) regression was used to estimate the association between stroke survivors’ and spouses’ QALY-weights. A two-part econometri c model was used to estimate the association between stroke survivors’ QALY-weights and the time spent and cost of spouses’ informal support. Results: Cohabitant dyads of 248 stroke survivors’ aged <70 at stroke onset and 245 controls were included in the study. Stroke survivors had lower HRQoL in the SF-36 domains physical functioning, physical role, general health, vitality (P <0.001), and social functioning (P = 0.005) in comparison with their cohabitant spouses. There was no significant difference in HRQoL for the dyads of controls. The results from the regression analyses showed that lo wer QALY-weights of the stroke survivors were associated with lower QALY-weights of their spouses and increased annual cost of spousal informal support. Conclusion: Our results show that the QALY-weight s for stroke surv ivors had consequences for their spouses in terms of annual cost of spousal informal support and QALY-weights. Hence, economic evalu ation of interventions that improve the HRQoL of the stroke survivors but ignore the consequences for their spouses may underestimate the value of the intervention.