Spatial accessibility and outpatient utilization among children aged 1-5 years in South Korea: a nationwide...

South Korea is experiencing the fastest fertility decline among Organisation for Economic Co-operation and Development (OECD) countries, with the total fertility rate reaching 0.75 in 2024, resulting in demographic changes and challenges in the distribution of the pediatric healthcare workforce. Although national policies have attempted to strengthen pediatric care through financial incentives and the expansion of Moonlight Children's Hospitals (MCHs), no nationwide patient-level study has examined how realized travel burden is associated with pediatric outpatient utilization.

This study aimed to assess nationwide spatial accessibility to pediatric outpatient services and to examine its association with outpatient utilization among children aged 1-5 years in South Korea.

This nationwide cross-sectional study analyzed 2023 National Health Insurance claims data for 1,116,152 children, encompassing 17,731,015 outpatient visits. Geographic accessibility was measured using network-based travel distance and travel time from township-level population centroids to healthcare providers, including clinics, hospitals, and general hospitals. Negative binomial regression and multiple linear regression models were employed to examine the associations between travel distance, travel time, outpatient visit frequency, and total medical expenditures, adjusting for age, sex, insurance type, residential region, after-hours care visits, and visits for mild diseases. Total outpatient expenditures were log-transformed prior to regression analysis.

The mean travel distance and travel time were 7.7 km and 10.5 min, respectively. Most outpatient visits occurred within 20 min of travel, with 64% occurring within 10 min. Each 1-km increase in average travel distance was associated with a 0.9% decrease in outpatient visit counts, and each 1-minute increase in travel time was associated with a 0.9% decrease in visit counts (P < 0.001). Longer travel distance and time were also associated with lower total annual outpatient expenditures. Children residing in rural counties experienced longer travel distances and times and lower outpatient utilization than those living in urban areas. Larger healthcare facilities were associated with longer travel distances and times.

Geographic accessibility was significantly associated with pediatric outpatient care utilization in South Korea. Despite universal health coverage, disparities persist between rural and urban areas, underscoring the need for targeted policy interventions. These findings may inform geographically targeted pediatric workforce and facility planning aimed at improving equity in realized access to outpatient care.