Comparative Outcomes of Teacher Coaching Versus Parent‐Implemented Intervention for Preschoolers at Risk of Developmental Delay in Thailand

Background: Early childhood developmental delays are a major concern in low- and middle-income countries (LMICs), where gaps often exist between developmental surveillance and follow-up support. In Thailand, the Developmental Surveillance and Promotion Manual (DSPM) provides a national framework for screening and promotion; however, practical models for integrating DSPM guidance into daily classroom and home routines in community daycare settings remain limited. Aim: To compare two brief nurse-facilitated implementation models-teacher coaching using practice-based coaching (PBC) and a parent-implemented intervention (PII)-and examine their effects on adult practices and short-term developmental outcomes in preschool children at risk of delay. Methods: A quasi-experimental, two-group pretest-posttest study was conducted in two community daycare centers. Forty-nine at-risk children and primary caregivers were enrolled (PBC: 26 dyads; PII: 23 dyads), along with 17 teachers (PBC: 8; PII: 9). Each center implemented one model over a 4-week intervention period with follow-up assessment approximately 4 weeks later. Outcomes included teacher developmental knowledge, teacher and caregiver developmental-promotion behaviors, and child pass/fail status across five DSPM domains. Continuous outcomes were analyzed using 2 × 2 mixed-design repeated-measures ANOVA; within-center domain changes used exact McNemar's tests. Results: Teacher knowledge improved over time, and the magnitude of improvement differed between models (group-by-time interaction), with larger gains in the PII center than the PBC center. Teacher and caregiver developmental-promotion behaviors improved significantly from pre to post (main effects of time), while group-by-time interactions were not significant, indicating comparable behavioral gains across pathways. Within-center DSPM analyses suggested short-term reductions in delayed status in selected domains in both centers. Conclusion: Thai Clinical Trials Registry (TCTR): TCTR20250106003.