Evaluating a falls prevention intervention in older home care recipients: a comparison of SF-6D and EQ-5D.

Purpose: Health-related quality of life (HRQOL) is an important outcome in economic evaluations of health care interventions for older adults. The aim of this study was to compare two commonly used preference-based utility measures, SF-6D and EQ-5D, to provide knowledge on their applicability when evaluating falls prevention interventions in primary health care.

Methods: The study is a secondary analysis of longitudinal data from a randomised controlled trial, which included 155 older home care recipients participating in a falls prevention intervention in Norway. HRQOL was measured by SF-6D and EQ-5D. Physical function was measured by Berg Balance Scale, 4-m walk test, 30-s sit-to-stand and Falls Efficacy Scale International. Assessments were performed at baseline, 3 months and 6 months. The agreement between SF-6D and EQ-5D was examined using Bland-Altman plots and Spearman correlations. Elasticities from regression analysis were employed to compare the instruments' responsiveness.

Results: SF-6D and EQ-5D were strongly correlated (0.71), but there were differences in the instruments' agreement and domains of HRQOL covered. Participants with a higher mean HRQOL and/or better physical function scored generally higher on EQ-5D. Participants with a lower mean HRQOL and/or poorer physical function achieved a relatively higher score on SF-6D. EQ-5D was more responsive to changes in physical function compared to SF-6D.

Conclusions: SF-6D and EQ-5D have both similarities and differences regarding sensitivity, domains covered and responsiveness to changes when evaluating a falls prevention intervention. Selecting the appropriate instrument depends on the characteristics of the participants and the intervention being evaluated.