Trends in participation and abnormal screening results in the National Health Screening Program for Infants and Children in South Korea, 2010–2023

Background: The National Health Screening Program for Infants and Children (NHSPIC) provides nationwide early detection of developmental issues. However, evidence regarding long-term national trends and regional disparities remains limited. We examined 14-year variations in screening participation and abnormal screening results.Methods: We analyzed nationally aggregated NHSPIC data from the Korean Statistical Information Service for the period 2010‒2023. Outcomes included annual screening participation rates and the prevalence of any abnormal overall screening result. Abnormal results were defined as “Caution” or “Follow-up needed,” based on integrated assessments of growth and nutrition, developmental screening, sensory function, and oral health. Temporal trends were assessed using joinpoint regression to estimate annual percent changes and to identify statistically significant change points. Regional risk ratios and risk differences were calculated using national estimates for reference.Results: National screening participation increased from 50.0% in 2010 to 87.1% in 2021, followed by a decline to 76.7% in 2023. The prevalence of any abnormal overall screening result increased from 8.6% to 19.3%, largely driven by a nearly threefold increase in the “Follow-up needed” category, from 3.0% to 8.8%. Across 17 regions, participation rates ranged from 66.9% to 79.7%, and abnormal result prevalence ranged from 11.4% to 18.3%, indicating persistent geographic disparities.Conclusions: Over a 14-year period, NHSPIC coverage expanded substantially but declined in recent years, while regional disparities persisted in both participation and abnormal screening results. These patterns underscore the need for targeted regional strategies to improve access, strengthen follow-up systems, and support equity-oriented monitoring of early childhood screening outcomes.