Mortality trends and geographic disparities in motor neuron disease among US adults aged 25 years and older, 1999–2024: a serial cross-sectional study using CDC WONDER

To examine long-term trends in mortality from motor neuron disease (MND) among adults aged 25 years and older in the United States from 1999 to 2024 using the CDC WONDER database, and to assess differences by demographic characteristics, geographic region, and urbanization level. This serial cross-sectional time-trend study used publicly available Underlying Cause of Death data from CDC WONDER. The analysis included deaths among adults aged 25 years and older for which ICD-10 code G12.2 was listed as the underlying cause of death. Outcomes included death counts, age-adjusted mortality rates (AAMRs) generated directly by CDC WONDER for the age-restricted population, crude mortality rates, and 95% confidence intervals. Joinpoint regression was used to estimate annual percentage changes (APCs) and average annual percentage changes (AAPCs). AAMRs were used for overall analyses and analyses stratified by sex, race/ethnicity, census region, state, and urbanization level, whereas age-specific crude mortality rates were used for age-group analyses. Urbanization analyses were restricted to 1999–2020. From 1999 to 2024, 170,570 MND deaths were recorded among US adults aged 25 years and older. Annual deaths increased from 5,121 to 7,551, representing a 47.45% increase, whereas the AAMR decreased from 2.87 to 2.58 per 100,000 population. The overall AAPC was − 0.50% (95% CI, -1.24 to 0.24), indicating no clear long-term increase in AAMR. Mortality burden was concentrated among adults aged 65 years and older, men, and non-Hispanic White individuals. The South had the largest number of deaths, whereas the Midwest had the highest AAMR. From 1999 to 2020, AAMRs were higher in nonmetropolitan than in metropolitan areas. From 1999 to 2024, MND deaths increased among US adults aged 25 years and older, but AAMRs did not increase correspondingly. The registered MND mortality burden varied by age, sex, race/ethnicity, geographic region, and urbanization level. These findings suggest that MND-related medical care, respiratory support, rehabilitation management, and public health service needs may continue to increase in the context of population aging; however, stratified and state-level findings should be interpreted as descriptive and exploratory.