Background: This study examines the relationship between race and mobility over 5 years in initially well-functioning older adults and evaluates how a broad set of socioeconomic status indicators affect this relationship.
Methods: Data were from 2,969 black and white participants aged 70-79 from the Health, Aging, and Body Composition study. Mobility parameters included self-reported capacity to walk a quarter mile and climb 10 steps and usual gait speed. Incident mobility limitation was defined as reported difficulty walking a quarter mile or climbing 10 steps at two consecutive semiannual assessments. Gait speed decline was defined as a 4% reduction in speed per year.
Results: At baseline, even though all participants were free of mobility limitation, blacks had slower walking speed than their white counterparts, which was not explained by poverty, education, reading level, or income adequacy. After 5 years, accounting for age, site, and baseline mobility, blacks were more likely to develop mobility limitation than whites. Adjusting for prevalent conditions at baseline eliminated this difference in women; controlling for education eliminated this difference in men. No differences in gait speed decline were identified.
Conclusions: Higher rates of mobility loss observed in older blacks relative to older whites appear to be a function of both poorer initial mobility status and existing health conditions particularly for women. Education may also play a role especially for men.