Sexual partner concurrency: is it a useful concept for HIV prevention? A systematic review of the evidence for intervention effectiveness in low- and middle-income countries.

If sexual partner concurrency drives HIV transmission dynamics, shouldn't HIV prevention efforts be addressing this behavior? We systematically reviewed studies evaluating interventions to reduce sexual partner concurrency in low- and middle-income countries using pre/post or multi-arm designs. Only two studies met our inclusion criteria; neither found significant differences by intervention exposure on self-reported concurrency. Overall, very few interventions have specifically targeted concurrency, and those that did have not been rigorously evaluated. In practice, concurrency may be difficult to separate from multiple partnerships more generally.