O3327: Spatial Distribution of Interstate Pediatric Transfers at a Single Tertiary Center

Background: Specialized or critical pediatric care often necessitates interfacility transfers, frequently crossing state lines. These interstate transfers can encounter delays influenced by diverse state regulations that affect transport logistics. This study leverages a geographic information system to explore the spatial dynamics of pediatric transports from a single center in Maryland, aiming to inform policy where public data is scarce.

Methods: This analysis focused on the Johns Hopkins Children's Center (JHCC) Pediatric Transport service, reviewing demographic and transport specifics of all pediatric interstate transfers recorded between July 1, 2022, and June 30, 2023. Data included were supplemented by U.S. Census Bureau cartographic shapefiles for counties and states. Patient locales were anonymized to zip codes and along with hospital locations, were geocoded for spatial analysis in ArcGIS Pro 2.9.5. Techniques such as buffer analysis within a 150-mile radius, proximity evaluation relative to MD and JHCC, and Global and Local Moran's I to assess spatial autocorrelation, were employed to find mean and median patient home zip code centers.

Results: Out of 118 analyzed transports, 101 (85.6%) were categorized as urgent/emergent and 17 (14.4%) as elective (initiated more than 24 hours post-request). Nearly all (99.2%) occurred within a 150-mile radius of JHCC. Of the patients, 88 (74.6%) resided out-of-state, whereas 30 (25.4%) were Maryland inhabitants. The transport modes included 100 (84.7%) by ground and 18 (15.3%) by air, originating from 33 facilities across DC, DE, PA, VA, and WV. The transport distances ranged from 32 miles (Washington, DC) to 185 miles (Pittsburgh, PA). The mean and standard deviation of distances to MD and JHCC were 20 (20.7) and 70 (34.9) miles, respectively. Spatial analysis indicated no significant clustering of origins (p=0.449 to 0.973), implying a random distribution. The geographic centers of patient zip codes were predominantly southwest of JHCC.

Conclusion: The majority of JHCC's pediatric interstate transfers are conducted within a 150-mile radius, with a notable portion of patients traveling for care within their own state.. Current data limitations preclude targeted policy interventions. Establishing a national pediatric transport data repository or conducting a multi-center study could support future research, potentially guiding policy adjustments to reduce regulatory transport delays across states.