Small-area variation in hypertension prevalence among black and white medicaid enrollees

Abstract

Objectives: To examine within-state geographic heterogeneity in hypertension prevalence and evaluate associations between hypertension prevalence and smallarea contextual characteristics for Black and White South Carolina Medicaid enrollees in urban vs rural areas. Design: Ecological Setting: South Carolina, United States. Main Outcome Measure: Hypertension prevalence Methods: Data representing adult South Carolina Medicaid recipients enrolled in fiscal year 2013 (N=409,907) and ZIP Code Tabulation Area (ZCTA)-level contextual measures (racial segregation, rurality, poverty, educational attainment, unemployment and primary care physician adequacy) were linked in a spatially referenced database. Optimized Getis-Ord hotspot mapping was used to visualize geographic clustering of hypertension prevalence. Spatial regression was performed to examine the association between hypertension prevalence and small-area contextual indicators. Results: Significant (alpha=.05) hotspot spatial clustering patterns were similar for Blacks and Whites. Black isolation was significantly associated with hypertension among Blacks and Whites in both urban (Black, b=1.34, P