Racial Inequities, Multiple Sclerosis, and Implementation of a Novel Treatment Algorithm at the Health System Level.

Objective: Advances in multiple sclerosis (MS) have not translated into equitable improvements in MS treatment or outcomes among minoritized people. Our objective was to determine whether a health system intervention designed to increase use of highly efficacious treatments (HETs) was implemented equitably and led to similar improvements in MS outcomes across racial and ethnic groups.

Methods: We designed and implemented an MS treatment algorithm that aligns a person's risk of disability with appropriately efficacious disease-modifying therapies (DMTs) and incorporates social determinants of health and patient preferences that can adversely affect adherence but does not include race or ethnicity. We used Kaiser Permanente Southern California's electronic health record to conduct a trend study of DMT utilization and annual relapse rates (ARRs) stratified by race and ethnicity before (2009-2011) and during (2012-2023) implementation of the treatment algorithm.

Results: We identified 6,119 (978 Black, 1741 Hispanic, 3,400 White) DMT-treated patients with MS (mean age = 50.1 years, 75.4% female) during the study period. Before implementation, Hispanic DMT-treated patients had significantly higher ARRs per 1,000 person-years (PY) (245.1, 95%CI 205.5-284.8) compared with White DMT-treated patients (156.3, 95%CI 137.8-174.7). Black people had higher ARRs compared with White people before and during early implementation, but this difference was significant only in 2015. Over the 12 years of implementation, the increase in HET use (primarily rituximab) among DMT-treated patients with MS was highest among Hispanic people, followed by Black and White people (89.3%, 87.4%, and 82.9% in 2023, respectively). The corresponding decline in age-adjusted and sex-adjusted ARR (linear spline regression) was greatest among Hispanic (90%, 95% CI 89%-91%), followed by White (86%, 95% CI 85%-87%) and Black (82%, 95% CI 80%-84%) DMT-treated patients between 2011 and 2023. By 2023, no clinically significant difference in ARR between groups remained (35.5, 19.0, and 18.1 per 1,000 PY for Hispanic, Black, and White people, respectively).

Conclusions: Implementation of our novel health system intervention led to marked and equitable improvements in HET use and relapse rate reduction among Hispanic, Black, and White DMT-treated patients with MS. This indicates that implementing an algorithmic approach to increase HET use, particularly an affordable one, rituximab, can reduce racial and ethnic disparities in MS outcomes.