PURA-ECHO: Analysis of the evolution of Ultrasound utilization in austere health care settings in Costa Rica’s Geographic Empanelment Model

Geographic empanelment, a model in which patients are assigned to healthcare facilities based on defined catchment areas, has been adopted by Costa Rica’s national health system (Caja Costarricense de Seguro Social, CCSS) to promote equitable distribution of healthcare resources. Point-of-Care Ultrasound (POCUS) and radiology-based consultative ultrasound have become an increasingly important diagnostic tool in emergency and primary care, particularly in resource-limited settings. However, little is known about how geographic and system-level factors influence ultrasound adoption across diverse care environments. This study evaluates temporal and geographic patterns of ultrasound utilization, including both POCUS and radiology-based (consultative) ultrasound, within the CCSS following the implementation of geographic empanelment. The POCUS Utilization in Resource Austerity – Echocardiography (PURA-ECHO) study is a retrospective review of CCSS administrative data comparing ultrasound utilization across rural and urban Emergency Departments and urgent care clinics from 2006 to 2022. The primary outcome was the change in the number of POCUS and consultative ultrasound exams performed over time by geographic classification. Geospatial mapping was used to visualize topographical trends in ultrasound use, and linear regression models assessed the association between distance from urban referral centers and ultrasound adoption in rural facilities. Rural ultrasound utilization demonstrated a highly significant increasing trend from 2006 to 2022 (Mann-Kendall τ = 0.927, p < 0.001), with mean exams per site increasing from 485 [SD 341] to 1,101 [SD 953]. Urban centers showed no significant change over the same period (τ = -0.162, p = 0.393), with mean exams per site remaining stable at 2,575 [SD 1,826] in 2006 and 2,652 [SD 1,356] in 2022. The expansion in ultrasound utilization was driven primarily by rural centers, which increased total exam volume 3.2-fold while urban capacity remained stable. Geographic distance from the tertiary training center did not significantly predict ultrasound adoption rates (R² = 0.09, p = 0.39), indicating equitable technology diffusion across rural regions regardless of proximity to urban centers. Ultrasound utilization expanded markedly across Costa Rica’s national health system following geographic empanelment, with rural centers demonstrating the most rapid growth. The lack of association between distance from urban centers and adoption rates suggests that the EBAIS infrastructure successfully facilitated equitable ultrasound diffusion across all rural regions. These findings suggest that geographic empanelment models can effectively strengthen both POCUS and radiology-based ultrasound capacity in geographically isolated regions, enhancing diagnostic equity and access within resource-limited healthcare systems.