Prevalence of Autism Spectrum Disorder in China: A Nationwide Multi-Centre Population-Based Study Among Children Aged 6 to 12 Years

Background: Autism has emerged as a major public health issue in children that imposes a significant socioeconomic burden in the United State and other developed countries. China has the world's largest population and has witnessed the same growing concern over the last decade. However, a reliable national prevalence estimate for autism spectrum disorder (ASD) is lacking. This study aimed to obtain the first national prevalence estimate for ASD in Chinese children. Methods: We targeted the population of 6 to 12-year-old Chinese children in eight selected representative cities for this prevalence study (Shanghai, Guangzhou, Changsha, Harbin, Beijing, Chongqing, Chengdu, and Wenzhou). The study sample was selected by multistage convenient cluster sampling of eligible children residing within the targeted areas. The parent and teacher Modified Chinese Autism Spectrum Rating Scale (MC-ASRS) was employed for the screening process. DSM-5 was used primarily for the case determination and followed by evaluation with the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R) in a subset of cases. Findings: Of the target population of 142,086 6 to 12-year-old children in eight sites, 88.5% (N=125,806; 53.0% male and 47.0% female) subjects with a mean age of 9.0±2.0 years, participated in this study. A total of 363 children (male to female ratio of 4.3 to 1) were confirmed as having ASD using either DSM-5 alone or together with ADOS or ADI-R. The estimated overall prevalence was 0.7% (95% CI: 0.64%-0.74%), with a prevalence of 0.95% (95% CI: 0.87%-1.02%) in boys and 0.30% (95% CI: 0.26%-0.34%) in girls. Of the 363 confirmed ASD cases, 43.3% were newly diagnosed, and most of those (90.4%) were attending regular schools. The newly diagnosed ASD cases were milder and had significantly higher IQ than previously diagnosed ASD cases. Interpretation: This first population-based and largest study reports a reliable estimate of 0.7% (1 in 143) ASD prevalence among 6 to 12-year-old children in cities in China. Importantly, almost half of the ASD cases were new and attending regular schools. Our findings provide information critical for the development of early screening, early intervention, and better care for children affected by ASD in China. Clinical Trial Number: Clinical Trials (NCT02200679). Funding Statement: This project was supported by the National Health Commission of the People’s Republic of China (201302002), and the Shanghai International Cooperation Ministry of Science Projects (14430712200). Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: The study was approved by the institute ethics committee at the Children’s Hospital of Fudan University. Written informed consent was obtained from parents of participants.