A Prospective Analysis of the Interrelationship between Physical Intimate Partner Violence and Alcohol Use: A Post-Hoc Analysis of Young Women Involved in the Stepping Stones and Creating Futures Trial in South Africa.

Prospective studies assessing women's experience of intimate partner violence (IPV) and alcohol use have shown mixed results and all are from high-income countries. Using longitudinal data from young women in South Africa we assess whether changes in physical IPV impact alcohol use, and whether changes in alcohol use impact physical IPV experience. Post-hoc analysis of women aged 18-30 living in informal settlements in eThekwini Municipality, South Africa, involved in the Stepping Stones and Creating Futures trial, between September 2015 and October 2019, with data collected at baseline ( = 677) and endline at 24 months ( = 545, 80.5% retention). At both timepoints, women were asked about their past year physical IPV experience and alcohol use. We estimated changes in physical IPV over time and whether this was associated with harmful alcohol use at endline. We then estimated changes in alcohol use over time, and whether this was associated with experience of past year physical IPV at endline. Women who experienced an increase in physical IPV over the study period were more likely to report harmful drinking at 24 months (aOR2.45, 95% CI 1.21-4.97). Similarly, women reporting increased alcohol use over time were more likely to report past year physical IPV at 24 months (aOR2.04, 95% CI 1.21-3.46). Among young women living in urban poverty those who experienced increasing physical violence from intimate partners were more likely to report increased and problematic alcohol use. Similarly, women reporting increasing alcohol use over 24 months were more likely to report physical IPV. However, there was no evidence that decreased alcohol use led to reductions in IPV, or that reduced IPV experience led to decreased alcohol use. Future research and interventions need to consider the reciprocal risks of physical IPV and alcohol use, with a focus on joint underlying drivers.