Does proximity to clinic affect immunization rates and blood pressure?

Primary care clinics are frequently placed in neighborhoods to improve access. Little is known whether or not this improves outcomes. We sought to determine if childhood immunization rates and adult blood pressure (BP) levels are related to proximity of home to clinic.

We conducted a retrospective chart review in a community family medicine clinic in a neighborhood grocery store (CC) and a hospital-based family medicine residency clinic (HC) in Milwaukee, Wisconsin. Randomly selected subjects included children aged 2-5 years (n = 151 CC; 241 HC) and adult continuity patients (n = 197 CC; 242 HC). ARC-GIS was used to geocode patient home addresses, and distances were analyzed using Kruskal-Wallis, Spearman's rank correlation, or Mann-Whitney test. Proportion of primary immunization by age 2 and age at completion, numerical BP, and proportion abnormal BP were each correlated to distance and driving distance to clinic.

Median driving distance of patient to clinic was significantly less for CC than HC (children = 1.47 versus 2.35 miles, p < 0.0001; adults = 1.53 versus 3.12, p < 0.001). For each clinic, and for all subjects combined, and for subsets by gender, ethnicity and insurance status, there was no significant correlation between proportion immunized by age 2 or age at completion and linear or categorical driving distance (or linear distance) to clinic (p = 0.12-0.99), or between BP values or proportion abnormal and distances to clinic (p = 0.44-0.97).

In this urban area, proximity of home to clinic did not correlate with primary immunization completion or blood pressure in either a hospital-based or a community clinic.