An analysis of more than 42,000 U.S. deaths linked to multiple sclerosis (MS) found that death rates varied by age, geography, and race and ethnicity, with Black patients dying younger than white patients and high blood pressure emerging as a growing contributor. The findings, just published in the journal Neurology, point to the need for timely diagnosis and better prevention strategies to help people with MS live longer.
MS is a chronic disease that damages the brain and spinal cord, leading to vision problems, muscle weakness, fatigue and other symptoms. Although people with MS have shorter life expectancies than the general population, the disease affects each person differently.
"There are lingering questions about how factors such as health care access, coexisting health conditions, and demographic characteristics affect a person's risk of mortality," said Lilyana Amezcua, MD , an associate professor of neurology and division chief for neuroimmunology and multiple sclerosis at the Keck School of Medicine of USC , who led the research.
Overall, the researchers found that death rates among people with MS increased over the 12 years analyzed, even when comparing people in the same age groups.
"We would expect that advances in treatments for MS might flatten these trends over time, but we continue to see increasing death rates," Amezcua said. "That tells us we still have work to do, particularly when it comes to managing other health conditions that affect people with MS."
Differences in mortality
To uncover details about MS mortality, Amezcua and her collaborators from the University of Kentucky and the University of Virginia analyzed 42,205 death certificates from the U.S. Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiological Research (WONDER) database. The study included deaths between 2012 and 2023 from the mainland U.S. where MS was listed as the underlying cause.
The researchers then examined how death rates varied by age, sex, and race and ethnicity. They found that Black individuals had the highest death rates linked to MS, followed by white individuals, with lower rates among other races. Black patients with MS tended to die younger, with death rates peaking between ages 65 and 74, whereas white patients were most likely to die between ages 75 and 84. In the Hispanic population, death rates increased among female patients between ages 45 and 84.
Next, the researchers collected data from each death certificate about co-occurring health conditions, finding that MS-related deaths involving high blood pressure increased between 2019 and 2023, particularly among white and Black individuals. MS-related deaths involving cardiac arrest also rose between 2019 and 2022, especially for Black patients.
The study also revealed geographic differences in MS death rates. The highest rates were concentrated in parts of the northern and midwestern United States (Wyoming, Oregon, Utah, Nebraska, Kansas, Minnesota, Michigan, New Hampshire and Maine). While MS is known to be more common in northern regions, the researchers say health care access, demographics and other factors may also help explain these patterns.
Because the study relied on death certificates, the researchers could not account for factors such as MS severity, treatments or health care access. They also note that the COVID-19 pandemic may have influenced mortality trends in the final years of the study.
Co-occurring health conditions
A key takeaway from the study is that co-occurring conditions, particularly cardiovascular problems, are linked to worse long-term outcomes for people with MS.
"Many of these conditions are preventable or treatable," Amezcua said. "Instead of focusing solely on MS, it's important to provide comprehensive care that takes a person's overall health into account."
Amezcua said co-occurring conditions may also contribute to delays in MS diagnosis. For example, damage caused by cardiovascular disease can resemble MS on brain scans, making it more difficult to distinguish between the two conditions. Advances in brain imaging may help doctors diagnose MS earlier and more accurately.
The team is now studying why some patients with MS are diagnosed later than others. Previous research found that patients from racial and ethnic minority groups may wait up to 10 years longer for an MS diagnosis than White patients, delaying timely treatment.
About this research
In addition to Amezcua, the study's other authors are Min-Woong Sohn and Chae Won Kim from the Department of Health Management and Policy, University of Kentucky; Jennifer M. Lobo from the Department of Public Health Sciences, University of Virginia; and Myla D. Goldman from the Department of Neurology, University of Virginia.
This work was supported in part by the Department of Defense [MSRP W81XWH2210955] and the Bristol Myer Squibb Foundation [013360- 00001].
Disclosure statement: Amezcua is a local principal investigator for commercial trials funded by Genentech and Sanofi/Genzyme and has received consulting fees from Biogen Idec, Novartis, Genentech and EMD Serono. Goldman is on the Independent Data Monitoring Committee for Immunic Therapeutics and has received consulting fees from Novartis, Genetec, Kiniksa and TG Therapeutics.
