POWER is a theory-based, on-line HIV prevention intervention developed specifically for Black men who have sex with men and women (BMSMW), an understudied group significantly impacted by HIV. To test its efficacy, we recruited 224 BMSMW using chain referral methods and randomly assigned 108 to POWER and 103 to a health information comparison condition. Three months after the intervention, participants assigned to POWER had lower odds of reporting any condomless vaginal or condomless anal intercourse (CVAI) compared to those in the comparison group (aOR = 0.49; 95 % CI 0.25-0.98; p = 0.044). The intervention was associated with significantly lower odds of condomless anal intercourse with male partners (aOR = 0.55; 95 % CI 0.34-0.91; p = 0.020) but not with female partners and serodiscordant sex with male partners but not with female partners. Future studies are needed to replicate these findings in larger and more diverse samples of BMSMW and to understand the underlying mechanisms through which intervention efficacy was achieved.
Keywords: BMSMW; HIV prevention; Interventions; Sexual behavior.