Disparities in Spatial Access to Emergency Surgical Services in the US

This cross-sectional study estimates differences in access to hospitals with emergency surgical capability across the US using advanced geospatial metrics that capture distance, hospital capacity, and population demand. Importance Hospitals with emergency surgical services provide essential care for a wide range of time-sensitive diseases. Commonly used measures of spatial access, such as distance or travel time, have been shown to underestimate disparities compared with more comprehensive metrics. Objective To examine population-level differences in spatial access to hospitals with emergency surgical capability across the US using enhanced 2-step floating catchment (E2SFCA) methods. Design, Setting, and Participants A cross-sectional study using the 2015 American Community Survey data. National census block group (CBG) data on community characteristics were paired with geographic coordinates of hospitals with emergency departments and inpatient surgical services, and hospitals with advanced clinical resources were identified. Spatial access was measured using the spatial access ratio (SPAR), an E2SFCA method that captures distance to hospital, population demand, and hospital capacity. Small area analyses were conducted to assess both the population with low access to care and community characteristics associated with low spatial access. Data analysis occurred from February 2021 to July 2022. Main Outcomes and Measures Low spatial access was defined by SPAR greater than 1.0 SD below the national mean (SPAR <0.3). Results In the 217 663 CBGs (median [IQR] age for CBGs, 39.7 [33.7-46.3] years), there were 3853 hospitals with emergency surgical capabilities and 1066 (27.7%) with advanced clinical resources. Of 320 million residents, 30.8 million (9.6%) experienced low access to any hospital with emergency surgical services, and 82.6 million (25.8%) to advanced-resource centers. Insurance status was associated with low access to care across all settings (public insurance: adjusted rate ratio [aRR], 1.21; 95% CI, 1.12-1.25; uninsured aRR, 1.58; 95% CI, 1.52-1.64). In micropolitan and rural areas, high-share (>75th percentile) Hispanic and other (Asian; American Indian, Alaska Native, or Pacific Islander; and 2 or more racial and ethnic minority groups) communities were also associated with low access. Similar patterns were seen in access to advanced-resource hospitals, but with more pronounced racial and ethnic disparities. Conclusions and Relevance In this cross-sectional study of access to surgical care, nearly 1 in 10 US residents experienced low spatial access to any hospital with emergency surgical services, and 1 in 4 had low access to hospitals with advanced clinical resources. Communities with high rates of uninsured or publicly insured residents and racial and ethnic minority communities in micropolitan and rural areas experienced the greatest risk of limited access to emergency surgical care. These findings support the use of E2SFCA models in identifying areas with low spatial access to surgical care and in guiding health system development. Question How does spatial access to emergency surgical services vary across the US, and what community characteristics are associated with low access to care? Findings In this cross-sectional study using advanced geospatial metrics that capture distance, hospital capacity, and population demand for all 320 million US residents in 2015, an estimated 1 in 10 residents experienced low access to any hospital with emergency surgical capabilities, and 1 in 4 experienced low access to hospitals with advanced clinical resources. Communities with high proportions of uninsured, publicly insured, and racial and ethnic minority groups in micropolitan and rural regions were at the greatest risk of being in low-access areas. Meaning Substantial disparities exist in spatial access to emergency surgical care across the US; comprehensive metrics of spatial access, such as enhanced 2-step floating catchment models, should be adopted to identify targets for surgical health system development.