Abstract
BACKGROUND: Age-disparate partnerships are hypothesized to increase HIV-risk for young women. However, the evidence base remains mixed. Most studies have focused only on unprotected sex among women in the partnership. Consequently, little is known about other risky behaviours, such as transactional sex, alcohol use, and concurrency, as well as the behaviours of the men who partner with young women. We therefore examined differences in various sexual behaviours of both young women and their male partners by partnership age difference. METHODS: We used nationally representative data from South Africa (2012) on partnerships reported by 16-24 year old black African women (n = 818) and by black African men in partnerships with 16-24 year old women (n = 985). We compared sexual behaviours in age-disparate partnerships and age-similar partnerships, using multiple logistic regression to control for potential confounders and to assess rural/urban differences. RESULTS: Young women in age-disparate partnerships were more likely to report unprotected sex than young women in similar-aged partnerships (aOR:1.51; p = 0.014; 95%CI:1.09-2.11). Men in partnerships with young women were more likely to report unprotected sex (aOR:1.92; p<0.01; 95%CI:1.31-2.81), transactional sex (aOR:2.73; p<0.01; 95%CI:1.64-4.56), drinking alcohol before sex (aOR:1.60; p = 0.062; 95%CI:0.98-2.61), and concurrency (aOR:1.39; p = 0.097; 95%CI:0.94-2.07) when their partners were five or more years younger. The association between age-disparate partnerships and transactional sex (aOR:4.14; p<0.01; 95%CI: 2.03-8.46) and alcohol use (aOR:2.24; p<0.013; 95%CI:1.20-4.19) was only found in urban areas. CONCLUSIONS: Results provide evidence that young women's age-disparate partnerships involve greater sexual risk, particularly through the risky behaviours of their male partners, with the risk amplified for young women in urban areas.