The predictive validity of health-related quality of life measures: mortality in a longitudinal population-based study

Abstract

Objective: This study examined the association between health-related quality of life (HRQL) and mortality risk, and compared the predictive ability of Health Utilities Index Mark 3 (HUI3) with self-rated health (SRH).

Methods: Data were from the 1994/95 Canadian National Population Health Survey, consisting of 12,375 women and men aged 18 and older. Cox proportional hazards regression models were performed to estimate mortality risk over eight years.

Results: Mortality risks for people reporting good, fair, and poor health at baseline were, respectively, 1.44 (95% confidence interval [CI] 1.04, 2.00), 1.97 (1.35, 2.88), and 3.21 (2.08, 4.95) times greater than those who reported excellent health. In a model excluding SRH, the effect of HUI3 on mortality was strong and significant (HR = 0.47; 95%, 0.33, 0.67) when adjusted for possible confounders. When HUI3 and SRH were considered simultaneously, the effect of the HUI3 on mortality was somewhat attenuated, but still significant (HR = 0.61, 0.42, 0.89) after adjusting for potential confounders.

Conclusions: Although SRH is a modestly stronger predictor of mortality than HUI3, HUI3 adds to the mortality prediction ability of SRH.