Behavioural changes may prevent the spread of HIV in developing countries (Hearst et al. 1995) , but a continuing challenge is to accurately measure and influence behavioural change. Few national data are available that measure how behavioural changes reduce the risk of HIV infection (Parkhurst 2008) . Furthermore, process data such as the number of clients served or the number of condoms distributed are not very helpful measures (Davis et al. 2000) . Better predictors of HIV prevention are consistent condom use versus ''ever using a condom'' and the number of concurrent partners an individual has versus their number of lifetime partners (Parkhurst 2008) .