Use of M-CHAT for autism screening in well-baby clinics of a primary health care center in Dhahran, Saudi Arabia: a retrospective cross-sectional study

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition in which early identification and intervention significantly improve developmental outcomes. The Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F), is commonly used in primary care settings for early screening; however, real-world data on its performance in Saudi primary care, particularly within military healthcare systems, remain limited. The purpose of this study is to evaluate the outcomes of ASD screening using M-CHAT-R/F among toddlers attending the Well-Baby Clinics (WBCs) at the Armed Forces Hospital in Dhahran, including the positive screening rate, reported ASD diagnoses, associated demographic factors, and monthly trends in screening yield. A retrospective cross-sectional study was conducted at the Family Medicine Department WBCs of the Armed Forces Hospital in Dhahran. All toddlers aged 16–30 months who underwent ASD screening between January 2024 and July 2025 were included. Demographic data and M-CHAT-R/F results were extracted from electronic medical records. Screening followed the standardized two-stage M-CHAT-R/F protocol, including the structured Follow-Up Interview for medium-risk initial scores. Screen-positive children were referred to pediatric specialists, and ASD diagnosis status was determined based on medical record documentation or caregiver report. Data were analyzed using SPSS version 22.0. Chi-square and independent t-tests were used to assess associations, with significance set at p < 0.05. A total of 742 toddlers were screened (51.9% females, 48.1% males), with a mean age of 19.3 ± 2.2 months. Forty-nine children screened positive on M-CHAT-R/F, yielding a screen-positive rate of 6.6%. Of these, 12 were identified as having received an ASD diagnosis following specialist evaluation, resulting in an ASD diagnosis rate of 1.6% and a positive predictive value (PPV) of 24.5%. No significant associations were found between screening outcomes and sex (p = 0.145), age group (p = 0.551), or parental age (p > 0.05). Monthly screening positivity ranged from 0% to 14.6%, while ASD diagnosis rates following specialist evaluation ranged from 0% to 3.4%, with no consistent temporal trend. ASD screening using M-CHAT-R/F in primary care WBCs demonstrated a low rate of ASD diagnosis following specialist evaluation with low-to-moderate PPV. Screening outcomes showed variability over time and were not significantly influenced by demographic factors. These findings highlight the importance of continued evaluation of referral pathways and follow-up processes to support early ASD detection in primary care settings.