Using growth mixture modeling to identify heterosexual men who reduce their frequency of unprotected sex following a behavioral intervention.

Using growth mixture modeling, two 12-month trajectories of unprotected sex were identified in 210 heterosexual men (76 % African American, M(age) = 33.2 years) attending a sexual risk reduction intervention. Risk Reducers (46 %) reported fewer acts of unprotected sex following intervention, whereas Risk Maintainers (54 %) reported continuously high levels of unprotected sex. These groups did not differ with respect to demographic characteristics or intervention type. However, Risk Maintainers were more likely than Risk Reducers to report lifetime sex work, forced sex in the past year, and alcohol use before sex at baseline. They had higher levels of peak alcohol use, poorer condom skills, and scored lower on stage of change for condom use at baseline. Risk Maintainers were also more likely to have steady partners at baseline and less likely to change partner status following intervention. Understanding factors distinguishing these groups can contribute to the development of targeted Risk Reduction interventions.