Access to health services and sexually transmitted infections in a cohort of relocating African American public housing residents: an association between travel time and infection.

BACKGROUND: High incidence and prevalence of sexually transmitted infection (STI) in blacks have been attributed to multiple factors. However, few articles have discussed spatial access to healthcare as a driver of disparities. The objective of this analysis was to evaluate the relationship between travel time to a healthcare provider and the likelihood of testing positive for 1 of 3 STIs in a sample of adults living in public housing.
METHODS: One hundred and eight black adults in Atlanta, GA from November 2008 to June 2009, completed a survey that queried sexual behavior and healthcare use and had urine tested for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis by molecular methods. Travel time was a continuous variable capturing the number of minutes it took to reach the place where participants received most of their care. Multivariate analyses tested the hypothesis that individuals reporting longer travel times would be more likely to test positive for an STI. Travel time was squared to linearize its relationship to the outcome.
RESULTS: Thirty-six residents (37.5%) tested positive for ≥1 STI. A curvilinear relationship existed between travel time and STI status. When travel time was <48 minutes, a positive relationship existed between travel time and the odds of testing positive for an STI. An inverse relationship existed when travel time was ≥48 minutes.
CONCLUSION: Residents of impoverished communities experience a curvilinear relationship between travel time and STI status. We discuss possible factors that might have created this curvilinear relationship, including voluntary social isolation.