“…The literature focusing on health care catchment areas is extremely limited, with significant gaps in accounts of the methodologies used to develop health care catchment definitions (Schuurman, Fiedler, Grzybowski, & Grund, 2006). Previous research has used zip codes, counties, and specified mileages or travel times to define health care markets (Basu & Cooper, 2000; Gresenz, Rogowski, & Escarce, 2004; Grzybowski, Stoll, & Kornelsen, 2011; Hall, Kaufman, & Ricketts, 2006; Lowe et al, 2009; Rudavsky & Mehrotra, 2010; Schuurman et al, 2006; Virnig, Ma, Hartman, Moscovice, & Carlin, 2006).…”