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.