Introduction: Autism Spectrum Disorder (ASD) is a neurodevelopmental condition marked by heterogeneity in presentation. In recent decades, ASD prevalence has risen globally, yet data from non-Western and middle-income countries, including Russia, remain scarce. Thus, Russian official statistics report a prevalence of 0.41 per 1,000 (0.041%), far below global estimates of 32.2 per 1,000 (3.2%), indicating underdiagnosis. This study provides the first population-based estimate of ASD prevalence among Russian elementary school children and examines barriers to diagnosis and treatment. Methods: The study followed a two-phase epidemiological approach and utilized well-known instruments (SCQ, ADOS-2, ADI-R) for ASD identification. The target population included all students in grades 1-3 (n = 34,847), stratified into mainstream, special education, and resource classes. The diagnostic phase had a 25.6% participation rate. ASD prevalence was estimated using Bayesian regression correcting for screening misclassification. Results: The estimated ASD prevalence was 22.2 per 1,000 children (95% CIs: 18.6-36.0), substantially exceeding what is reported based on the RF administrative data. ASD was more frequently identified in students from special education and resource classes than in general education settings. A Bayesian sensitivity analysis confirmed the robustness of prevalence estimates across plausible values for sensitivity and specificity. Discussion: These findings suggest that ASD prevalence in Russia is considerably underestimated via administrative data. Systemic barriers-including limited access to diagnostic services and stigma surrounding psychiatric labels-may hinder ASD identification. Addressing these challenges is essential for improving early detection and service provision in Russia and similar contexts.
Talantseva et al. (Fri,) studied this question.