The purpose of this study was to identify the functional domains and etiological risk factors of children with developmental delay (DD). During a 41-month period, a retrospective chart review was carried out on all 1192 patients who visited pediatric clinics for evaluation of developmental delay or behavioral problems. Etiological risk factors or associated disorders were identified after the completion of clinical evaluation and a series of laboratory investigations. Clinical psychologists examined the functional domains of those patients who underwent developmental and psychological assessments. Those children who met the criteria of DD were subdivided into six functional subtypes, including cognitive, motor, language, social adaptation, global and non-specific developmental delay. A total of 1192 children were diagnosed as DD, 86.7% had cognitive DD, 58.4% had language DD and 47.9% had motor DD. Of 1192 children, 831 were male, and the ratio male to female was 2.3 to 1. Only 20.5% (244) of children had identifiable etiological risk factors and 35.6% (424) had associated disorders. Results showed DD was more prevalent in males, and cognitive delay was the most common subtype. Identifying the etiological risk factors of DD remains difficult because of its heterogeneity.
