Incidence of autism spectrum disorder in children in Kazakhstan and risk factors associated with all-cause hospitalizations.

We aimed to describe incidence and period prevalence of Autism Spectrum Disorder (ASD) and examined risk factors associated with all-cause hospitalizations in children registered in the Unified National Electronic Healthcare System (UNEHS) in 2014–2021 in Kazakhstan. Cohort comprised of patients less than 18 years old with ASD defined according to the International Classification of Diseases, 10th revision (ICD-10) as codes: F84.0-F84.1, F84.5, F84.8-F84.9, registered in the UNEHS from 2014 to 2021. The study included 9,993 children with ASD, of whom 5,912 (59.2%) experienced at least one hospitalization during follow-up. The incidence proportion of ASD increased from 12.8 to 26.6 per 100,000 children between 2014 and 2021, while period prevalence rose from 7.2 to 148.2 per 100,000 during the same period. ASD incidence was substantially higher among males than females. In adjusted Cox models, gastrointestinal disorders (HR 3.86, 95% CI 3.47–4.28), hydrocephalus (HR 1.50, 95% CI 1.29–1.74) and anemia (HR 1.37, 95% CI 1.23–1.51) were associated with increased hospitalization risk. Children aged 11–17 years had higher hospitalization risk compared with those aged 6–10 years (HR 1.35, 95% CI 1.22–1.50), whereas ADHD was associated with a lower risk of hospitalization (HR 0.64, 95% CI 0.49–0.85). Several comorbidities, particularly gastrointestinal and neurological disorders, were strongly associated with hospitalization risk. These findings highlight the importance of comprehensive clinical management and early detection of comorbidities among children with ASD.