This is the meta-subject of a new paper in PLoS ONE by myself and my buddy/co-author Brendan Maughan Brown. Here is the abstract, which mostly explains everything:
Objectives
We examined whether knowledge of the HIV-protective benefits of male circumcision (MC) led to risk compensating behavior in a traditionally circumcising population in South Africa. We extend the current literature by examining risk compensation among women, which has hitherto been unexplored.
Methods
We used data on Xhosa men and women from the 2009 Cape Area Panel Study. Respondents were asked if they had heard that MC reduces a man’s risk of contracting HIV, about their perceived risk of contracting HIV, and condom use. For each gender group we assessed whether risk perception and condom use differed by knowledge of the protective benefits of MC using bivariate and then multivariate models controlling for demographic characteristics, HIV knowledge/beliefs, and previous sexual behaviors. In a further check for confounding, we used data from the 2005 wave to assess whether individuals who would eventually become informed about the protective benefits of circumcision were already different in terms of HIV risk perception and condom use.
Results
34% of men (n = 453) and 27% of women (n = 690) had heard that circumcision reduces a man’s risk of HIV infection. Informed men perceived slightly higher risk of contracting HIV and were more likely to use condoms at last sex (p<0.10). Informed women perceived lower HIV risk (p<0.05), were less likely to use condoms both at last sex (p<0.10) and more generally (p<0.01), and more likely to forego condoms with partners of positive or unknown serostatus (p<0.01). The results were robust to covariate adjustment, excluding people living with HIV, and accounting for risk perceptions and condom use in 2005.
Basically, our results show that women react to information on circumcision's protective benefits in a manner consistent with risk compensation, which is a phenomenon where individuals undertake risky behaviors if they feel that they are protected from its consequences somehow. Why do women respond differently from men? We aren't sure, but we theorize that it could be related to (some combination of):
-Misinformation among women about the protective benefits of circumcision as far as male-to-female HIV transmission (circumcision has only been shown to impact female-to-male transmission).
-Lack of opportunities for women to discuss circumcision, sex, and HIV in public places.
-Higher prior probabilities of contract HIV in women (which means risk information will be more likely to shift beliefs about HIV on the margin - good ole' Bayes's Theorem)
-A sense of reduced need among women to have to negotiate condoms, which could be tricky in a world where there is imbalance in power across genders.
Some new research by other groups (more on this in a later post) provides evidence that the first of these could be at play. Watch this space for more, as we attempt to find some explanations!