Associations between health-related quality of life and mortality in older adults

Abstract

This study measures the use and relative importance of different measures of health-related quality of life (HRQOL) as predictors of mortality in a large sample of older US adults. We used Cox proportional hazards models to analyze the association between general self-reported health and three "healthy days" (HDs) measures of HRQOL and mortality at short-term (90-day) and long-term (2.5 years) follow-up. The data were from Cohorts 6 through 8 of the Medicare Health Outcomes Survey, a national sample of older adults who completed baseline surveys in 2003-2005. At the long term, reduced HRQOL in general health and all categories of the HDs were separately and significantly associated with greater mortality (P < 0.001). In multivariate analysis of long-term mortality, at least one HD category remained significant for each measure, but the associations between mental health and mortality were inconsistent. For short-term mortality, the physical health measures had larger hazard ratios, but fewer categories were significant. Hazard ratios decreased over time for all measures of HRQOL except mental health. In conclusion, HRQOL measures were shown to be significant predictors of short- and long-term mortality, further supporting their value in health surveillance and as markers of risk for targeted prevention efforts. Although all four measures of HRQOL significantly predicted mortality, general self-rated health and age were more important predictors than the HDs.