Prevalence of Autism Spectrum Conditions in Mainland China

The China SCORE study is a prevalence study of Autism Spectrum Conditions (ASC) in 14 regions in mainland China. It will include the following steps: 1. Large population-based screening This study will be conducted in urban areas but not rural areas across mainland China. One city of each region will participate, and in total there will be 14 cities for screening. Within each city, a number of 40 to 60 ordinary primary schools will be randomly selected from the defined region. All the students who are in 1st to 4th grade will asked to participate in order to form a sample of approximately 20,000 students. Screening questionnaires The screening pack includes the Chinese CAST, the AQ-Child, the AQ-Adult short version (10 items), and risk factors questionnaire. An information sheet and consent form will be included in the pack as well. 2. Further assessments We expect approximately 5% on the CAST will score positive in ordinary school population. Thus, for a 20,000 sample, we would expect 900 positives (90% response rate). All the screen-positives and a random selected 5% from borderline group will be invited for clinical assessment. The diagnosis of clinical assessment will be divided into three categories: definite ASC, suspected ASC, and non-ASC. Then all the children with clinical assessment results as definite ASC and suspected ASC and a randomly selected 10-20 non-ASC will be invited for research diagnostic assessment using the ADOS and ADI-R, as well as RPM as IQ test. After that, the consensus diagnosis between ADOS/ADI-R assessment and the clinical diagnosis will be the final diagnosis. 3. Case identification in special schools All the children in special schools or training institutes in study region will be asked to fill in the screening pack. The children who do not attend any ordinary or special schools will be identified according to their residential ID in the studied regions. All screen-positives in special education will be assessed using the ADOS