Abstract
IMPORTANCE: Identifying factors that explain differences in physical performance measures by race and region in the US and whether they are associated with changes over time could inform preventive strategies. OBJECTIVE: To examine 10-year changes in physical performance across race and race-region among Black and White older adults and whether differences are explained by demographic, cardiovascular, socioeconomic, and cognitive factors. DESIGN, SETTING, AND PARTICIPANTS: The prospective Atherosclerosis Risk in Communities (ARIC) cohort study recruited participants between 1987 and 1989. This study included participants from 4 US communities in North Carolina, Mississippi, Maryland, and Minnesota who underwent physical performance evaluations initiated in 2011 to 2013 (visit 5 examinations) and in 3 subsequent in-person examinations conducted over a 10-year period through 2022. Data were analyzed from January through May 2025. EXPOSURE: Self-identified race and region. MAIN OUTCOMES AND MEASURES: Physical performance was assessed using the Short Physical Performance Battery (SPPB; score range, 0-12, with higher scores indicating better performance). Multivariable generalized estimating equations estimated cross-sectional differences as well as differences in 10-year changes by race and by race and region, adjusting for demographic, cardiovascular, socioeconomic, and cognitive factors. RESULTS: Among 5666 participants (mean [SD] age, 75.4 [5.1] years; 3258 [58%] women), 1233 (22%) self-identified their race as Black and 4433 (78%) self-identified their race as White. Adjusting for demographic, cardiovascular, socioeconomic, and cognitive factors explained observed cross-sectional differences in physical performance between Black participants and White participants. However, 10-year SPPB longitudinal declines were steeper for Black participants compared with White participants (absolute difference, -0.80 points; 95% CI, -1.19 to -0.41 points), even after adjusting for all factors that accounted for cross-sectional differences; this finding met the 0.50-point threshold for a clinically meaningful difference. Between-region declines within races also showed notable differences; for example, SPPB declines were steeper for White Maryland participants compared with White North Carolina participants (absolute difference, -1.14 points; 95% CI, -1.45 to -0.83 points), and declines were steeper for Black Mississippi participants compared with Black North Carolina participants (absolute difference, -1.72 points; 95% CI, -2.65 to -0.78 points). CONCLUSIONS AND RELEVANCE: In this cohort study of older adults, meaningful racial differences in physical performance declines were not explained by commonly suggested drivers of performance differences. Other unmeasured regional features may explain racial differences in decline in physical performance and warrant investigation.