Detecting autism spectrum disorder from early intervention charts: methodology and preliminary findings.

Federal laws mandating a "single point of entry" for early intervention (EI) create a potential database for surveillance of early childhood disabilities. This study evaluated EI records for estimating rates of autism spectrum disorder (ASD) using a chart abstraction protocol, with good interrater agreement (k = .86). Sampling 304 EI records yielded a point prevalence of (per 1,000) 8.5 (95% CI: 4.8-10.9) and a cumulative incidence of 7.4 (95% CI: 5.5-12.4). These rates are similar to recent published estimates. Additionally, the male-to-female ratio for autism, and rates of other developmental disorders were found to be consistent with current literature. These results suggest that local systems EI records may provide an excellent resource for ASD surveillance and research.