Excess Mortality in Individuals with Autism Spectrum Disorder: A Population-Based Cohort Study

Autism spectrum disorder (ASD) may be associated with increased mortality, but relevant findings have been inconsistent. The modifying effects of gender and intellectual disability on excess mortality in individuals with ASD are underexplored. Using Taiwan's National Health Insurance Research Database and the National Death Registry, this population-based cohort study selected the data of 75,946 patients with ASD (ASD cohort) and 75,946 age group-, gender-, and income-matched (1:1) patients without ASD (non-ASD cohort). Cox proportional hazards models were used to compare mortality rates between the cohorts, and stratified analyses were used to evaluate the influence of gender and intellectual disability on mortality risk. The ASD cohort had higher mortality rates for all causes of death than did the non-ASD cohort (adjusted hazard ratio 1.64, 95% confidence interval 1.54-1.75). Comorbid intellectual disability was associated with an increased risk of mortality, and this association was stronger in female patients than in male patients. Moreover, when focusing on deaths from natural causes, we found a significantly higher odds ratio for mortality in the ASD population with ID compared to those without ID. ASD is associated with increased mortality, especially among female individuals and those with intellectual disability.