Military Service and Survival Among Persons With ALS in the U.S. National ALS Registry, 2011-2023.

INTRODUCTION/AIMS: Military service has been associated with increased risk of amyotrophic lateral sclerosis (ALS) but less is known about survival after diagnosis. We evaluated the association between military service and survival after ALS diagnosis among U.S. National ALS Registry participants. METHODS: Participants who completed the Registry's Military History Survey between 2011 and 2023 and had valid ALS diagnosis and mortality follow-up information were eligible. Military service was classified as veteran or nonveteran. Mortality was ascertained through National Death Index linkage. Kaplan-Meier methods evaluated survival distributions, and Cox proportional hazards models estimated adjusted mortality associations. RESULTS: Among 8643 participants, 1735 (20.1%) were veterans and 6908 (79.9%) were nonveterans. Veterans were older at diagnosis and reported greater smoking and alcohol use. The median observed time from ALS diagnosis to death or censoring was 3.77 years among veterans and 4.79 years among nonveterans, an approximate 1-year difference; Kaplan-Meier estimated 5-year survival was 47.1% and 57.4%, respectively. Veterans experienced significantly poorer survival than nonveterans (log-rank χ2 = 113.45, p < 0.0001). In the primary adjusted Cox model, military service remained associated with increased mortality (HR 1.25, 95% CI 1.15-1.35; p < 0.0001). Findings were consistent across sensitivity analyses accounting for disease severity, symptom onset site, and delayed Registry entry. DISCUSSION: Military service was associated with poorer survival after ALS diagnosis. Veterans had lower 5-year survival and higher mortality hazards than nonveterans, suggesting military history may be an important prognostic factor in ALS.