Table 1.

Comparison of UDS-based approach for defining FQHC service areas vs. Primary Care Service Area and County (2015)

	UDS-based service areas	Primary Care Service Areasb	Countyc
Mean [IQR] # ZIP codes per FQHC included in service area	8.9 [6-11]	8.0 [3-11]	24.3 [8-31]
Mean [IQR] proportion of FQHC patients included	86% [80–94]	49% [30–68]	71% [54–92]
Total # of ZIP codes included in FQHC service areas	8,713	8,568	10,105
Total population included in FQHC service areas (millions)	167.1	107.7	215.7
% of FQHC service area population with income < 200% FPL that visited an FQHCa	29%	22%	22%
% of delivery site ZIP codes included in FQHC service areas	100%	53%	74%

^aEstimated by calculating total number of patients from FQHC’s defined service area divided by population of service area under 200% FPL

^bDefined by identifying ZIP codes with largest proportion of patients per FQHC, linking ZIP code to associated PCSA, and then including all ZIP codes linked that PCSA in the service area

^cDefined by identifying ZIP codes with largest proportion of patients per FQHC, linking ZIP code to the associated county, and then including all ZIP codes linked that PCSA in the service area