Objective: The Checklist for Autism in Toddlers (CHAT) has been demonstrated to be sensitive to the presence of autism in otherwise normally developing 18-month-old children. However, its ability to differentiate autism from other significant developmental delays is unknown. This study examined this question.
Method: The CHAT was applied to a group of 44 children aged 2 and 3 years, rigorously diagnosed with autism or with other developmental problems.
Results: By the original CHAT authors' criteria, the sensitivity and specificity of the CHAT were 65% and 100%, respectively. Slightly altering the criteria resulted in a sensitivity of 85% in the current group of children with developmental disabilities while maintaining specificity of 100%.
Conclusions: The current study is the first to demonstrate that the CHAT successfully discriminates 2-year-old children with autism from those with other developmental disorders. In addition, the increased sensitivity of the Denver Criteria in children with developmental disabilities may improve its usefulness as a screening tool for community-based early-diagnostic teams and general practitioners.