Autism Prevalence in Chile: Unmet Special Education Needs using Data Linkage and Bayesian Analysis of Three Million School-Aged Children

Prevalence estimates of autism spectrum disorder (henceforth autism) in Latin America thus far have been limited by a lack of reliable population-level data. We analyzed autism school prevalence across 29 Chilean health service regions for students aged 6-18 years, standardized by age and sex. We validated these results using electronic health records from one of Chiles largest regional health service, the Servicio de Salud Araucania Sur (SSAS). We then projected Bayesian prevalences, reporting nationally, and by health service, ethnicity, immigration background, and rurality. We found a standardized national school autism prevalence of 0.46% (95% CI, 0.46%-0.47%), with boys having six times higher odds of autism than girls (OR 6.10 [95%CI: 5.82-6.41]). The sex - and age-adjusted clinical prevalence in the SSAS trust was 1.22% (95% CI: 1.16%-1.28%) and the projected Bayesian national autism prevalence was 1.31% (95% Credible Interval: 1.25%-1.38%). Our results indicate a higher autism prevalence than previously reported in the south of the Araucania region with observed disparities in prevalence across sex, ethnic groups, and health services.