Title : Trends and disparities in respiratory disease related mortality in multiple sclerosis in US (1999-2020)
Abstract:
Background: Respiratory diseases are a leading cause of morbidity and mortality in patients with multiple sclerosis (MS), particularly as disease progression can lead to neuromuscular respiratory complications. Despite advances in MS care, respiratory-related deaths remain a significant concern.
Objectives: This study aimed to analyze national trends and disparities in respiratory disease related mortality among adults with multiple sclerosis in the United States from 1999 to 2020. Mortality patterns were evaluated by sex, age group, race (NH Black vs. Non-Hispanic White), and U.S. Census geographic regions to inform future targeted public health strategies.
Methods:Mortality data were obtained from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) database for the period 1999–2020. Adults aged ≥25 years with MS (G35) and respiratory diseases (J00–J98) listed as contributing causes of death were included. Age-adjusted mortality rates (AAMRs) per 100,000 population were calculated using the 2000 U.S. standard population. Jointpoint regression analysis was used to assess temporal trends and estimate annual percentage changes (APC) and average annual percentage changes (AAPC), stratified by sex, age group, race (Non-Hispanic Black vs. NH White), and geographic region (Northeast, Midwest, South, West).
Result: Between 1999 and 2020, 39,080 deaths occurred among adults aged ≥25 years with respiratory diseases and multiple sclerosis as contributing causes. The overall age-adjusted mortality rate (AAMR) declined over the study period. Females exhibited higher AAMR than males (AAMR: 1.03 vs 0.69), although both showed significant declining trends (AAPC females: -0.89%; 95% CI: -1.37 to -0.43; AAPC males: -1.34%; 95% CI: -2.09 to -0.56). By race, Non-Hispanic (NH) White adults had a higher AAMR (0.86) compared to NH Black or African American adults (0.68). However, while Black individuals initially experienced a decline, they showed a marked increase in mortality after 2015 (APC: 8.37%; 95% CI: 2.37 to 23.26). In contrast, Whites had a more stable declining trend (AAPC: -0.50%; 95% CI: -1.29 to -0.10). Deaths stratified by age group showed the highest crude mortality rate (CMR) observed among adults aged 75–84 years (CMR: 2.15). The most pronounced decline in AAMR was seen in the 35–44 age group (AAPC: -4.41%; 95% CI: -5.40 to -3.56). Geographically, the Midwest had the highest AAMR (1.01), followed by the Northeast (0.93). All regions showed decreasing trends, with the most notable declines in the Northeast (AAPC: -1.33%) and Midwest (AAPC: -0.98%).
Conclusion: Respiratory disease-related mortality in adults with multiple sclerosis declined overall from 1999 to 2020, but significant disparities persist. Higher AAMRs were observed among females, Non-Hispanic Whites, and those in the Midwest, highlighting the need for targeted interventions to reduce inequities.
