Poverty, Gender Inequality, AND STIs in Baltimore City Neighborhoods, 2002-2005

Background: Recent investigations of racial disparities for sexually transmitted infections (STIs) have focused on neighborhood context. Although the sex ratio is a contextual feature hypothesized to influence STIs, empirical evidence has been unsupportive. Gender-based power may be a more relevant factor for STIs, because partners with the most power in relationships often influence behaviors. At the neighborhood-level, gender-based power represents an aspect of the normative environment that prescribes the acceptable and unacceptable behaviors, attitudes and beliefs with regard to male-female interactions. As such, power may influence the probability that individual-level STI risk behaviors occur. This analysis examined 1) gender-based power as a mediator of the association between poverty and 2002-2005 gonorrhea incidence (GC) in Baltimore City (BC) neighborhoods and 2) whether gender-based power better mediated the poverty-GC relationship than the sex ratio.

Methods: Gonorrhea case information was obtained from the BC Health Department. Cases were geocoded to census block groups using ArcGIS. Our gender-based power measure was theoretically-based and developed in a previous analysis. Neighborhood poverty and sex ratio were calculated using Census 2000 data. Mediation was examined using longitudinal binomial regression.

Results: The results were supportive of mediation. The effect of poverty on GC was reduced by 30% after accounting for power (IRR=1.52 vs IRR=1.23), and there was a dose-response relationship between power and GC. The sex ratio did not reduce the effect of poverty (IRR=1.52 vs IRR=1.50), although it was independently associated with GC.

Conclusions: It is important to identify contextual influences on STIs for more effective interventions.