RESUMEN
AIM: To examine the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F), with follow-up screening and diagnostic outcomes for children born preterm. A secondary aim was to examine diagnostic evaluation attendance after screening to inform clinical practice. METHOD: Using a cross-sectional design, 9725 toddlers (4951 males; 4774 females) whose gestational age was reported were screened at 15-month, 18-month, or 24-month well-child visits; screen-positive children were invited for an autism evaluation. Screening measure performance and diagnostic outcomes were evaluated according to preterm classification (Screening: nExtPreterm = 111; nVeryPreterm = 186; nModPreterm = 1122; nFullTerm = 8306; Evaluation: nExtPreterm = 27; nVeryPreterm = 21; nModPreterm = 86; nFullTerm = 301). RESULTS: Screen-positive rates were highest for children born extremely preterm (51.35%) and lowest for children born at term (6.95%). Evaluation attendance for screen-positive cases did not differ according to preterm classification. Rates of autism diagnoses differed depending on preterm birth status: for children born extremely preterm, it was 16.05%; for children born very preterm, it was 2.00%; for children born moderately preterm, it was 2.89%; and for children born at term, it was 1.49%. M-CHAT-R/F sensitivity decreased with increasing gestational age, whereas specificity improved with increasing gestational age. Positive predictive value was highest for children born extremely preterm and children born at term. Negative predictive value was consistently strong across all groups. The likelihood ratio for positive screening increased with gestational age. INTERPRETATION: The sensitivity and specificity of the M-CHAT-R/F are acceptable in toddlers born preterm. Autism screening-positive rates and prevalence increased with earlier preterm birth. Those born extremely preterm showed the greatest likelihood of an autism diagnosis; screening should not be delayed based on adjusted age.
RESUMEN
OBJECTIVE: To evaluate timing and accuracy of early and repeated screening for autism spectrum disorder (ASD) during well-child visits. STUDY DESIGN: Using a longitudinal study design, toddlers (n = 5784) were initially screened at 12 (n = 1504), 15 (n = 1228), or 18 (n = 3052) months during well-child visits, and rescreened at 18, 24, and 36 months. Of those screened, 368 toddlers attended an ASD evaluation after a positive screen and/or a provider concern for ASD at any visit. RESULTS: Screens initiated at 12 months yielded an ASD diagnosis significantly earlier than at 15 months (P = .003, d = 0.99) and 18 months (P < .001, d = 0.97). Cross-group overall sensitivity of the initial screen was .715 and specificity was .959. Repeat screening improves sensitivity (82.1%), without notably decreasing specificity (all >93.5%). Screening at 18 months resulted in significantly higher positive predictive value than at 12 months (X2 (1, n = 221) = 9.87, P = .002, OR = 2.60) and 15 months (X2 (1, n = 208) = 14.57, P < .001, OR = 3.67). With repeat screening, positive predictive value increased for all screen groups, but the increase was not significant. CONCLUSIONS: Screening as early as 12 months effectively identifies many children at risk for ASD. Children screened at 12 months receive a diagnosis of ASD significantly earlier than peers who are first screened at later ages, facilitating earlier intervention. However, as the sensitivity is lower for a single screen, screening needs to be repeated.