Association of multiple sclerosis with risk of mortality among a nationally representative sample of adults in the United States

BACKGROUND: Multiple sclerosis (MS) has been associated with increased mortality ratios, but few studies have investigated the independent association of MS with mortality. OBJECTIVE: To examine the prospective association of MS with risk of mortality in a nationally representative sample of U.S. adults. METHODS: This prospective study included 23,053 adults aged 45–79 years who participated in the National Health Interview Survey in 2002 and 2008. Physician-diagnosed MS was reported by participants during household interviews. These participants were linked to death records from survey date through December 31, 2015. RESULTS: Among the 23,053 participants included in this study, 120 reported a physician’s diagnosis of MS, with a higher prevalence in females (0.85%) than in males (0.31%). During on average 9.4 years (maximum 13.8 years) of observation, 4208 deaths occurred. After adjustment for age, sex, race/ethnicity, socioeconomic factors, lifestyle factors, and BMI, participants with MS had an 80% higher risk of mortality (HR 1.80; 95% CI, 1.11–2.92), compared with those without MS. The association remained significant (HR 1.75; 95% CI, 1.07–2.87) after further adjustment for baseline diabetes, cardiovascular disease, chronic lung disease, and cancer. CONCLUSION: In this nationally representative sample of U.S. adults, MS was associated with an increased risk of mortality.