Brief report: independent validation of autism spectrum disorder case status in the Utah Autism and Developmental Disabilities Monitoring (ADDM) Network Site.

An independent validation was conducted of the Utah Autism and Developmental Disabilities Monitoring Network's (UT-ADDM) classification of children with autism spectrum disorder (ASD). UT-ADDM final case status (n = 90) was compared with final case status as determined by independent external expert reviewers (EERs). Inter-rater reliability (ICC = 0.84), specificity [0.83 (95 % CI 0.74-0.90)], and sensitivity [0.99 (95 % CI 0.96-1.00)] were high for ASD case versus non-case classification between UT-ADDM and EER. At least one EER disagreed with UT-ADDM on ASD final case status on nine out of 30 records; however, all three EERs disagreed with UT-ADDM for only one record. Findings based on limited data suggest that children with ASD as identified by UT-ADDM are consistently classified as ASD cases by independent autism experts.