Sensitivity and Specificity of Developmental Surveillance and Autism Screening in an Australian Multicultural Cohort: The Watch Me Grow Study.

To examine accuracy of two-tiered surveillance to detect developmental disability and autism in a multicultural birth cohort; a subset of the Watch Me Grow Study. Surveillance tools were used at or soon after 18 months of age, including the Parents' Evaluation of Developmental Status (PEDS), the Ages and Stages Questionnaire (ASQ-3), and the revised Modified Checklist for Autism in Toddlers (M-CHAT-R/F). Children with and without identified concerns were assessed between 18 and 23 months using the Mullen Scales of Early Learning (MSEL) and the Autism Diagnostic Observation Schedule-2 (ADOS-2). Sensitivity and specificity of the surveillance tools used in isolation and in combination in this cohort ranged from 51 to 87% (n = 165). Some children (n = 21) who were not identified with high likelihood of difficulties were later assessed as having probable developmental disability. Adding the M-CHAT-R/F did not significantly improve autism likelihood identification in comparison with tiered developmental surveillance. There was highly variable sensitivity and specificity of combined tools for tiered developmental surveillance in this cohort. There remains a need in Australia to improve methods of, and engagement in, developmental screening and surveillance that includes detection of concerns in community and primary healthcare settings.