Alexandra M Minnis, Irene A Doherty, Tracy L Kline, William A Zule, Bronwyn Myers, Tara Carney, Wendee M Wechsberg

Inequitable gender-based power in relationships and intimate partner violence contribute to persistently high rates of HIV infection among South African women. We examined the effects of two group-based HIV prevention interventions that engaged men and their female partners together in a couples intervention (Couples Health CoOp [CHC]) and a gender-separate intervention (Men's Health CoOp/Women's Health CoOp [MHC/WHC]) on women's reports of power, communication, and conflict in relationships. The cluster-randomized field experiment included heterosexual couples from a high-density South African township in which neighborhoods were randomized to one of the intervention arms or a control arm that received the WHC only. Participants completed in-person study visits at baseline and 6-month follow-up. We examined group differences using one-way analysis of variance and multivariable regression models. Of the 290 couples enrolled, 255 women remained in the same partnership over 6 months. Following the intervention, women in the CHC arm compared with those in the WHC arm were more likely to report an increase in relationship control (β=0.92, 95% confidence interval [CI]: 0.02, 1.83, P=0.045) and gender norms supporting female autonomy in relationships (β=0.99, 95% CI: 0.07, 1.91, P=0.035). Women in the MHC/WHC arm were more likely to report increases in relationship equity, relative to those in the CHC arm, and had a higher odds of reporting no victimization during the previous 3 months (MHC/WHC vs WHC: odds ratio =3.05, 95% CI: 1.55, 6.0, P=0.001; CHC vs MHC/WHC: odds ratio =0.38, 95% CI: 0.20, 0.74, P=0.004). Male partner engagement in either the gender-separate or couples-based interventions led to modest improvements in gender power, adoption of more egalitarian gender norms, and reductions in relationship conflict for females. The aspects of relationship power that improved, however, varied between the couples and gender-separate conditions, highlighting the need for further attention to development of both gender-separate and couples interventions.