OBJECTIVE: To examine the predictive validity of the Modified Checklist for Autism in Toddlers (M-CHAT) administered at age 24 months for autism spectrum disorder (ASD) diagnosed at 10 years of age in a US cohort of 827 extremely low gestational age newborns (ELGANs) followed from birth.

STUDY DESIGN: We examined the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the M-CHAT in predicting an ASD diagnosis at age 10 years based on gold standard diagnostic instruments. We then assessed how these predictive parameters were affected by sensorimotor and cognitive impairments, socioeconomic status (SES), and emotional/behavioral dysregulation at age 2 years.

RESULTS: Using standard criteria, the M-CHAT had a sensitivity of 52%, a specificity of 84%, a PPV of 20%, and an NPV of 96%. False-positive and false-negative rates were high among children with hearing and vision impairments. High false-positive rates also were associated with lower SES, motor and cognitive impairments, and emotional/behavioral dysregulation at age 2 years.

CONCLUSIONS: Among extremely preterm children with ASD, almost one-half were not correctly screened by the M-CHAT at age 2 years. Sensorimotor and cognitive impairments, SES, and emotional/behavioral dysregulation contributed significantly to M-CHAT misclassifications. Clinicians are advised to consider these factors when screening very preterm toddlers for ASD.