Normative Estimates and Agreement Between 2 Measures of Health-Related Quality of Life in Older People With Frailty: Findings From the Community Ageing Research 75+ Cohort

Abstract

Background Previous studies have summarised evidence on health-related quality of life (HRQOL) for older people, identifying a range of measures that have been validated, but have not sought to present results by degree of frailty. Furthermore, previous studies did not typically use quality of life measures that generate an overall health utility score. Health utility scores are a necessary component of Quality Adjusted Life Year calculations used to estimate costeffectiveness of interventions. Methods We calculated normative estimates in terms of mean and standard deviation for EQ-5D-5L, SF-36 and SF-6D for a range of established frailty models. We compared response distributions across dimensions of the measures and investigated agreement using BlandAltman and Interclass Correlation techniques. Results EQ-5D-5L, SF-36 and SF-6D scores decrease and their variability increases with advancing frailty. There is strong agreement between EQ-5D-5L and SF-6D across the spectrum of frailty. Agreement is lower for people who are most frail, indicating that different components of the two instruments may have greater relevance for people with advancing frailty in later life. There is a greater risk of ceiling effects using EQ-5D-5L rather than SF6D. Conclusions. We recommend SF-36/SF-6D as an appropriate measure of HRQOL for clinical trials if fit older people are the planned target. In trials of interventions involving older people with increasing frailty we recommend that both EQ-5D-5L and SF36/SF6D are included, and are used in sensitivity analyses as part of cost-effectiveness evaluation.