Walking and physical performance in black and white adults with multiple sclerosis controlling for social determinants of health

Background: There is evidence for reduced walking and physical performance in persons with multiple sclerosis (MS) compared with healthy controls (HCs). There is further evidence suggesting increased overall mobility disability in Black persons with MS compared with White counterparts, yet little is known about the interplay of social determinants of health (SDOH) when considering differences in walking and physical performance. Purpose: This cross-sectional, comparative study examined differences in walking and physical performance in Black and White persons with MS and HCs (MS Status), statistically controlling for SDOH. Methods: The study sample consisted of 208 persons with MS (141 White participants and 67 Black participants) and 95 HCs (59 White participants and 36 Black participants). Walking and physical function were measured using timed 25-foot walk (T25FW), six-minute walk (6MW), timed-up-and-go (TUG), and short physical performance battery (SPPB). We examined the differences in the walking and physical functions as a function of MS Status (MS vs. HCs) and Race (Black vs. White) using Multivariate Analysis of Covariance, controlling for age, sex, marital status and SDOH (i.e., education, employment, income). Results: There were no significant interactions between MS Status and Race on the outcomes, and the main effects of MS Status and Race remained statistically significant, controlling for SDOH and covariates. The main effects indicated significant lower T25FW (F = 34.6, p < .001, eta(2)(p) = 0.11), 6MW (F = 58.5, p < .001, eta(2)(p) = 0.18), TUG (F = 22.1, p < .001, eta(2)(p) = 0.08), and SPPB (F = 25.2, p < .001, eta(2)(p) = 0.09) performance for MS than HCs, and lower T25FW (F = 15.5, p < .001, eta(2)(p) = 0.05), 6MW (F = 11.6, p < .001, eta(2)(p) = 0.04), and TUG (F = 4.1, p < .05, eta(2)(p) = 0.02) performance in Black than White samples. Conclusions: We conclude that MS Status and Race independently influence walking and physical performance even after accounting for SDOH, and Black persons with MS have compromised walking and physical performance, perhaps necessitating focal rehabilitation.