Comparison of Available Tools to Screen for Autism at 12 and 15 Months.

Objective: To determine the performance of autism screeners at 12 and 15 months of age.

Methods: Children were screened either at 12- (n = 1473) or 15-month (n = 1227) primary care visits. Children were screened with both the Infant/Toddler Checklist (ITC) and the First Year Inventory-Lite (FYI-L) at 12 months and FYI-L and the Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F) at 15 months. After a positive screen and/or clinical concern, families were offered a no-cost diagnostic evaluation.

Results: Of the 1473 toddlers screened at 12 months, 223 screened positive and 107 attended a diagnostic evaluation. Of the 1227 children screened at 15 months, 252 screened positive and 94 attended the evaluation. Overall, specificity for autism was high (>0.94) for all screeners at 12 and 15 months. At 12-month screening, sensitivity for autism was low on the ITC (0.26) and moderate on the FYI-L (0.67). Positive predictive value (PPV) was low for both screeners (0.24 for ITC and FYI-L). At 15 months, both the FYI-L and the M-CHAT-R/F demonstrated moderate sensitivity (0.61 for FYI-L and 0.60 for the M-CHAT-R/F) and low PPV (0.16 for FYI-L and 0.31 for M-CHAT-R/F).

Conclusion: Although data do not support universal screening at younger ages, the study identifies tools that can be used at 12 and 15 months. Importantly, screening at these ages does not identify all cases of autism, and repeat screening at 18 months and beyond is essential to support autism detection as early as possible.