Health-related quality of life in middle-aged African Americans.

Abstract

In this article we explore the measurement properties of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) in 49- to 65-year-old African Americans, compare their health-related quality of life (HRQoL) with that of the nation, and evaluate the association of selected covariates with HRQoL. A probability sample of 998 African Americans in St. Louis received comprehensive in-home assessments. We used an item analysis, exploratory and confirmatory factor analysis, and internal consistency reliability to evaluate the measurement properties of the eight SF-36 scales and their interrelationships. We used a multiple linear regression analysis to characterize the effects of the demographic, socioeconomic status, psychosocial attributes, and biomedical markers. Assessments averaged 2.5 hr. Each SF-36 scale was unidimensional, all items had robust factor loadings, and all but one scale achieved excellent (alpha > or = .80) internal consistency reliability levels. The overall factor structure of the SF-36 scales was generally consistent with national norms. Substantial variance was explained by the covariates, mostly attributable to socioeconomic status and the biomedical markers. The SF-36 is a reliable and valid measure of HRQoL for use with African Americans. In this sample, the HRQoL was below national averages. Future social epidemiologic studies should include grip strength, vision, and hearing assessments, which had substantial and consistent associations with the SF-36 scale scores.