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

Background 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 (M-CHAT) 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 among toddlers attending the Well-Baby Clinics (WBCs) at the Armed Forces Hospital in Dhahran, including the prevalence of positive screening, confirmed ASD diagnoses, associated demographic factors, and monthly trends in screening yield. Methods 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 results were extracted from electronic medical records. Screen-positive children were followed to determine confirmed ASD diagnosis by specialists. 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. Results 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, yielding a screening prevalence of 6.6%. Of these, 12 were confirmed to have ASD, resulting in a confirmed prevalence of 1.6% and a positive predictive value 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 confirmed ASD prevalence ranged from 0% to 3.4%, with no consistent temporal trend. Conclusions ASD screening using M-CHAT in primary care Well-Baby Clinics (WBCs) demonstrated low confirmed ASD prevalence with moderate positive predictive value. Screening outcomes showed variability over time and were not significantly influenced by demographic factors. These findings highlight the importance of continuous evaluation of screening practices and strengthening referral and diagnostic pathways to optimize early ASD detection in Saudi primary care settings.