Factors Associated with Delays in the Diagnosis of Autism Spectrum Disorders: A Cross-Sectional Study Based on Data from the Hamadan Province Registry System

Background and Objectives: The present study aimed to identify these factors and propose practical strategies for the early diagnosis and timely provision of supportive and interventional services for children with autism and their families. Materials and Methods: This study was conducted on 198 children diagnosed with Autism Spectrum Disorder (ASD) who were registered in the Hamadan University of Medical Sciences system by the end of December 2024 in Hamadan Province. Autism diagnosis was made by a psychiatrist based on DSM-V and ADI-R criteria. Demographic information of children and parents, pregnancy- and delivery-related factors, as well as potential risk factors for ASD, were extracted from the system, and their associations with the timing of autism diagnosis were examined. The Log-rank test was used to compare the median age at diagnosis across different variable categories. Results: In the present study, children residing in rural areas had a significantly longer median age at diagnosis (48 months) compared to children living in urban areas (36 months) (P=0.03). The median age at diagnosis was significantly higher among children whose fathers had primary education (45 months) than those whose fathers had secondary school education (36 months) or academic education (35.5 months) (P=0.03). Furthermore, exclusive breastfeeding during the first six months of life was associated with the timing of autism diagnosis (P=0.005). In addition, children with mild autism exhibited a significantly longer median age at diagnosis (P=0.04). Conclusion: The present study demonstrated that children residing in rural areas, those with fathers having primary education, and those with milder forms of autism were diagnosed with ASD at a later stage.