Limiting Options: Sex Ratios, Incarceration Rates, and Sexual Risk Behavior Among People on Probation and Parole

Background: To investigate how incarceration may affect risk of acquiring HIV and other sexually transmitted infections, we tested associations of ex-offenders' sexual risk behavior with the male-female sex ratio and the male incarceration rate. Methods: Longitudinal data from 1287 drug-involved persons on probation and parole as part of the Criminal Justice Drug Abuse Treatment Studies were matched by county of residence with population factors, and stratified by race/ethnicity and gender. Generalized estimating equations assessed associations of having unprotected sex with a partner who had HIV risk factors, and having >1 sex partner in the past month. Results: Among non-Hispanic black men and women, low sex ratios were associated with greater risk of having unprotected sex with a risky partner (adjusted relative risk [ARR] = 1.76, 95% confidence interval [CI] = 1.29, 2.42; ARR = 2.48, 95% CI = 1.31, 4.73, respectively). Among non-Hispanic black and non-Hispanic white (NHW) women, low sex ratios were associated with having >1 sex partner (ARR = 2.00, 95% CI = 1.02, 3.94; ARR = 1.71, 95% CI = 1.06, 2.75, respectively). High incarceration rates were associated with greater risk of having a risky partner for all men (non-Hispanic black: ARR = 2.14, 95% CI = 1.39, 3.30; NHW: ARR = 1.39, 95% CI: 1.05, 1.85; Hispanic: ARR = 3.99, 95% CI = 1.55, 10.26) and having >1 partner among NHW men (ARR = 1.92, 95% CI = 1.40, 2.64). Conclusions: Low sex ratios and high incarceration rates may influence the number and risk characteristics of sex partners of ex-offenders. HIV-prevention policies and programs for ex-offenders could be improved by addressing structural barriers to safer sexual behavior.