Early Screening for Autism Spectrum Disorder in Toddlers Aged 16-30 Months Using M-CHAT-R/F: A Cross-Sectional Study

Abstract

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder listed under the umbrella of developmental disorders or intellectual disabilities that affect social communication and behavior. Early identification is critical for initiating timely interventions, which improve developmental outcomes. The Modified Checklist for Autism in Toddlers, Revised with Follow-Up (MCHAT-RF) is an evidenced-based screening tool for identifying children at risk for ASD between 16 and 30 months and with a follow-up for toddlers who are scored medium risk in 1st stage between 24 and 30 months. The purpose of this study was to assess the magnitude of ASD and to assess the performance of M-CHAT-R/F as a screening tool in toddlers.  A cross-sectional study was conducted on 2,400 toddlers aged 16-30 months attending the Pediatric OPD of a tertiary care center in urban Maharashtra. Screening was performed using M-CHAT-R/F, a 2-stage tool involving an initial questionnaire and structured follow-up interviews for at-risk responses. Screen-positive cases underwent further diagnostic evaluation by a child psychiatrist. Of the 2,400 toddlers screened, 2040 (85%) were classified as low risk (LR), 349 (14.5%) as moderate risk (MR), and 11 (0.5%) as high risk (HR). Follow-up screening identified 35 screen-positive cases among moderate-risk toddlers, leading to 8 new ASD diagnoses and 18 cases of developmental delay. The overall prevalence of ASD in our study was 0.75%. Our study demonstrates the feasibility and reliability of M-CHAT-R/F for ASD screening in resource-limited settings