Relationship Between Sexually Transmitted Infections and Social Determinants of Health in Durham County, North Carolina, United States.

Background: Sexually transmitted infections (STIs) are increasing in the United States, and certain populations are more at risk than others. One explanation for this is inequities in underlying social determinants of health (SDOH). Methods: We analyzed chlamydia, gonorrhea, and syphilis cases in Durham County, North Carolina, from 01/01/2020 to 12/31/2020 by select SDOH at the census tract level. We included 48 variables of interest, including variables related to income, education, transportation, and health insurance. For each variable, we modeled STI incidence at the census tract level using Poisson regression. Wald's chi-square was used to determine which variables were significantly associated with STI incidence. Results: Of 24 variables that were statistically associated with STI incidence at the census tract level, 9 were negatively associated and 15 positively associated with STI incidence. Having employer health insurance was most strongly associated with lower-than-expected STI incidence, and having Medicaid insurance, no health insurance, using public transportation, and income below the poverty level were most strongly associated with higher-than-expected STI incidence. Lastly, STI incidence was not associated with race or ethnicity overall across Durham County, except in historically marginalized areas, where we found higher-than-expected STI incidence. Conclusions: We found that lacking health insurance, having Medicaid insurance, using public transportation, and income below the poverty level were most strongly associated with higher-than-expected STI incidence. Strategies to combat increasing STIs may include improving access to health insurance, reducing barriers to cost-effective and timely transportation to medical appointments, and raising wages to bring individuals out of poverty.