Survey of autism spectrum disorder in Chandigarh, India.

Background & objectives: Prevalence of autism spectrum disorder (ASD) has been reportedly on the rise in western literature. However, accurate data from India are not available. The present study was planned to assess the community-based prevalence of ASD in Chandigarh, India. Methods: This study was a two-stage survey of representative child population of Chandigarh using stratified random sampling technique, covering 8820 children between the ages 1.5 and 10 yr. Proportionate population from urban (82.3%), rural (4.3%) and slum area (13.4%) were included in the study and screened using Chandigarh autism screening instrument (CASI). Thirty two children scored above cut-off, of whom two had shifted to other places before they could be assessed and 30 were assessed in detail. Detailed assessment was done using Autism Diagnostic Interview-Revised and Childhood Autism Rating Scale-2; diagnosis was made according to the Diagnostic and Statistical Manual-5. Nineteen were diagnosed with ASD. Results: Of the 8451 children screened between the age group of one and a half to 10 yr, 19 (10 boys and 9 girls) were diagnosed as ASD, thus the prevalence of ASD was found to be 2.25 per 1000 (0.69-5.19, 95% confidence interval) children in Chandigarh. No child below the cut-off on the screening instrument was diagnosed as ASD. Interpretation & conclusions: The results suggest that the prevalence of ASD in Chandigarh was in tandem with other reports from across India and was lower than western countries.