Trends in Spatial Access to Colonoscopy in South Carolina, 2000-2014

Abstract Background Colonoscopy use has increased since Medicare began covering screening for average-risk persons. Our objective was to describe changes in spatial access to colonoscopy in South Carolina (SC) between 2000 and 2014. Methods Using data from the SC Ambulatory Surgery Database, we created annual ZIP Code Tabulation Area (ZCTA) spatial accessibility scores. We assessed changes in accessibility, colonoscopy supply, and potential demand, overall and by metropolitan designation. Spatial clustering was also explored. Results Spatial accessibility decreased across both small rural and metropolitan ZCTAs but was significantly higher in metropolitan areas during the first part of the study period . The proportion of persons with no access to colonoscopy within 30 minutes increased over time but was consistently higher in small rural areas. Clusters of low accessibility grew over time. Conclusions The supply of colonoscopy facilities decreased relative to the potential demand, and clusters of low access increased, indicating a contraction of services.