Non-Hispanic Women Have Highest MS Mortality Rates, But Blacks Die Earlier, USC Survey Finds

Non-Hispanic whites, especially females, are more likely to die from multiple sclerosis (MS) than any other racial group, though blacks tend to die earlier, concludes a study by researchers at the University of Southern California’s Keck School of Medicine.

Their survey, “Multiple Sclerosis Mortality by Race/ Ethnicity, Age, Sex, and Time Period in the United States, 1999-2015,” appeared in the journal Neuroepidemiology.

USC researchers used a large database, WONDER, created by the Centers for Disease Control and Prevention to analyze MS deaths over a 16-year period.

Researchers classified death records into five racial/ethnic groups: non-Hispanic white, non-Hispanic black, non-Hispanic Asian or Pacific Islander, non-Hispanic American Indian or Alaska Native, and Hispanic of any race. Then they calculated the age-adjusted and age-specific MS mortality rate (per 100,000 individuals) by race/ethnicity and sex over time.

Of the 59,462 patients analyzed, 66 percent were women and 34 percent were men. Death rates were highest among non-Hispanic whites, which accounted for 86 percent of all MS-caused deaths in the period analyzed.

Non-Hispanic females had an MS-related death rate of 1.5 per 100,000 inhabitants — the highest of all ethnic groups — compared to 0.9 per 100,000 for non-Hispanic females.  Likewise, the rate for non-Hispanic black women was 1.42, and for non-Hispanic black men, 0.75 per 100,000. By contrast, MS killed only 0.12 of every 100,000 females of Pacific island origin, and only 0.05 of every 100,000 males in that same ethnic group.

According to the survey, Hispanics, American Indians and Alaska Natives had similarly lower age-adjusted MS mortality rates when compared to non-Hispanic blacks and whites.

The analysis also revealed a rapidly rising trend of MS-specific mortality among non-Hispanics in general, and a strong age-specific mortality pattern in non-Hispanic blacks, with higher mortality rates among those younger than 55, and non-Hispanic whites, who had the highest mortality rate after that age point.

“This may suggest that the burden of disease weighs differently by race/ethnicity at least in the United States,” researchers wrote. “For these two groups, MS mortality increased with age in both sexes and peaked at ages 55-64 for NH blacks and 65-74 for NH whites before declining substantially.”

Among non-Hispanic Asian or Pacific Islanders, Hispanics and American Indian or Alaska Natives, the risk plateaued after 55 years old.

Overall, these results suggest that MS-specific mortality is affected by race/ethnicity and age, and that whites and females — the two groups most affected by the disease — are at higher risk of dying from MS.

“The findings of blacks dying at an earlier age and having more substantially increasing mortality trends than whites suggest that MS burden weighs unequally by race,” the USC researchers concluded. “Further investigation into these trends may provide additional evidence into risk or protective factors within each group.”