The global prevalence of autism spectrum disorder in children: a systematic review and meta-analysis

Objectives: The objective of this review was to analyze quantitative data on autism spectrum disorder (ASD) and to increase the accuracy of estimates of the prevalence of ASD. Methods: This review, which was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, included studies conducted from January 2008 to June 2024 on children aged 3 to 18 years that used standardized measurement tools and reported cut-off scores for ASD. The prevalence of ASD was the primary outcome analyzed in this review. The PubMed, Clinical Key, Scopus, Embase, CINAHL, and Web of Science databases were reviewed for relevant studies. The review protocol was registered with PROSPERO and followed the Cochrane collaboration guidelines. Results: A total of 66 studies reported on the prevalence of ASD, screening 21,313,061 children worldwide. Among these, 25 studies were conducted in Europe, 22 in Asia, and 13 in America. Additionally, 3 studies each were reported from Africa and Australia. According to a metaanalysis, 0.77% of children globally are diagnosed with ASD, with boys comprising 1.14% of this group. Notably, Australia showed the highest prevalence rate, with an effect size of 2.18, highlighting it as a critical area for public health focus. Conclusion: ASD represents a significant global health burden. Early detection, increased awareness among parents, and prompt intervention are crucial for mitigating developmental problems in children later in life. It is essential for health policymakers to acknowledge the prevalence and growing trends of ASD in order to implement effective interventions.