Person-Centered Social Determinants and Neighborhood-Level Deprivation Associated With Disability in Hispanic People With Multiple Sclerosis.

BACKGROUND AND OBJECTIVES Multiple sclerosis (MS)-related disability in Hispanic people with MS is associated with inequities in social determinants of health (SDOH) as measured by composite indices of areal-level census data. Studies of individual-level measures of SDOH are lacking. This study examined the separate and joint effects of person-centered SDOH indicators and an area-level composite on MS disability measures. METHODS Hispanic people diagnosed with MS (≤5 years) who had SDOH and Social Deprivation Index (SDI) based on 2015-2019 American Community Survey estimates were included. At study entry, data on MS disability outcomes were collected: Expanded Disability Status Scale (EDSS) score, Symbol Digit Modality Test (SDMT) score, Hauser Ambulation Index (HA index), and 25-Foot Walk Time (25FWT). Principal component analysis was used to identify person-centered SDOH factors, mapped across a socioecological model. Multivariable regression modeling measured separate and joint effects of SDOH principal components (PCs) and SDI on outcome measures. RESULTS Of the 170 participants with MS, most were women (71.9%) and had a mean age at first symptom of 34.01 (SD ±11.24) years and at diagnosis of 36.27 (SD ±10.68) years. The top 2 PCs were identified to represent person-centered SDOH related to assimilation and socioeconomic disadvantage in multivariable models. In both separate and joint effect models, both PC1 and PC2 were significantly associated with longer 25FWT (β 0.43, 95% CI 0.04-0.82, and β 0.66, 95% CI 0.28-1.05), higher HA index (β 0.22, 95% CI 0.04-0.41, and β 0.31, 95% CI 0.12-0.51), and higher EDSS score (β 0.39, 95% CI 0.16-0.62, and β 0.36, 95% CI 0.13-0.60). PC1 was also significantly associated with a lower SDMT score (β -4.15, 95% CI -5.60 to -2.69). SDI was significantly associated with lower SDMT score and higher HA index in separate effect models but was not associated with any outcome measure in joint effect models with PCs. DISCUSSION Our findings suggest that census-based indicators may underestimate the effect of SDOH on MS outcomes and the person-centered level measures are better markers of disease severity in Hispanic people with MS. Future research and policy change can focus on the amelioration of assimilation barriers and socioeconomic disadvantage because these were strongly associated with MS-related ambulatory and cognitive disability.