Racial Disparities In MS Disease-Modifying Therapies

By Jim Kling

A new analysis of the North American Registry for Care and Research in Multiple Sclerosis (NARCRMS), a physician-based longitudinal registry, underscores discrepancies in care between Whites and Blacks and Hispanics. The research also found that Blacks and Hispanics with multiple sclerosis (MS) experience more severe disease and are less likely than Whites to initiate disease-modifying therapies (DMTs).

A key question was whether the finding of differences in DMT use was caused by discrepancy in the availability of DMTs, or if they are less efficacious in some populations. “It’s very complex. I think it’s a combination of factors, because there’s no question that socioeconomic and cultural factors play a very important role in access to therapies in these particular groups,” said Victor Rivera, MD, during a Q&A session. Dr. Rivera, a distinguished professor emeritus at Baylor College of Medicine, Houston, presented the study at the 2021 annual meeting of the American Academy of Neurology.

A lack of granularity in racial data

Dr. Rivera noted that another presentation at AAN 2021 found that that Blacks may not respond as well to B-cell depletion agents, with B-cell counts repopulating more quickly. “That diminishes tremendously the efficacy of the therapy. I think it’s a combination of factors, not just the [socioeconomic and cultural] ones we discussed, but also biological, said Dr. Rivera.

“Their study reinforces current data from other studies, that there is a greater burden of disability in non-White groups,” said Daniel José Correa, MD, deputy chief of neurology at Montefiore and assistant professor of neurology at Albert Einstein College of Medicine, both in New York. who comoderated the session along with Payal Patel, MD, a pediatric neurologist from the University of Washington, Seattle. He noted similar limitations to other studies, namely that patients get lumped into categories of White, Black/African American, and Hispanic or non-Hispanic. Sometimes a Black Hispanic group can be analyzed, but there frequently isn’t enough data to include it. And there are many other populations that don’t get individual recognition, such as Caribbean Black; Native Americans from Central and South America; Persians; the Desi people of India, Pakistan, and Bangladesh; and subgroups of Whites.

Dr. Victor Rivera

Dr. Daniel José Correa

That lack of granularity can complicate efforts to understand disparities to specific groups. Dr. Correa suggests that more such data should be collected during practice as well as in research. “I would advocate that the research community consider the idea of having communities participating in research or individuals themselves self-describe the other race or ethnicity groups that they identify with. Over time, that may end up impacting our understanding within subgroups and improve what categories we actually use,” said Dr. Correa.

In the meantime, he suggested that the data from Dr. Rivera and other studies on DMTs emphasizes the need for immediate attention from physicians. It’s unclear from the study whether less uptake of DMTs is caused by mistrust, health literacy, social determinants of health, or access to care. “We can pursue some of that discussion. What are their concerns with various medications? Where are they getting their information, and can we provide them with better health information, or direct them to better quality sources?” said Dr. Correa.

He thinks that greater engagement can not only improve outcomes in day-to-day care, but it might even improve participation of underrepresented groups in clinical studies. “If we make addressing people’s unmet social needs and screening social determinants of health [a part of] standard of care, we’ll establish a much better relationship and get to see much better health outcomes in our population than if we’re just focusing on a single therapeutic,” said Dr. Correa.

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Image credit: Jose Luis Pelaez/The Image Bank/Getty Images
Overall, 57% of subjects were treated with DMTs, including 64% of White non-Hispanic patients, 45% of White Hispanic, 39% of Black/African American non-Hispanic, and 26% of Black/African American Hispanic patients.

NARCRMS survey data

The group led by Dr. Rivera included data from 695 patients aged 18-50 years across the United States, Puerto Rico, and Canada. The mean age was 40.1 years, and 71% of patients were female. 84% were White, 11% were Black/African American, and 5% were listed as other or unknown. 73% were non-Hispanic, 24% were Hispanic. 79% of Hispanic subjects were White, 11% were Black/African American, and 10% were other or unknown.

About 8% of Black/African American subjects were unemployed, compared with 3% of Whites. The racial groups had generally comparable education levels, but the composition of professional/skilled workers was 72% White, 18% White Hispanic, 9% Black/African American non-Hispanic, and 2% Black/African American Hispanic. 16% of Black/African American subjects earned less than $15,000 annually, compared with 6% of Whites. About 11% of Black/African Americans earned more than $100,000 versus 39% of Whites.

73% of the overall group had mild MS, but 21% of Black/African Americans had substantial MS-related disability (EDSS score ≥4), versus 10% of Whites. About 14% of Hispanics had substantial MS-related disability, compared with 10% of non-Hispanics.

Overall, 57% of subjects were treated with DMTs, including 64% of White non-Hispanic patients, 45% of White Hispanic, 39% of Black/African American non-Hispanic, and 26% of Black/African American Hispanic patients.

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Dr. Rivera has received honoraria from Biogen, EMD Serono, and Roche. Dr. Correa has no relevant financial disclosures.