Frequency, Types and Predictors of Concurrent Sexual Partnerships Among a Sample of Heterosexual Men and Women at Risk for HIV infection

The leading category of HIV transmission among women and the second leading category among men is heterosexual contact. Concurrent sexual partnerships accelerate the transmission of HIV and other STIs and different types of concurrent partnerships may have different implications for the efficiency of STI transmission. In this study, we examined types of concurrency (transitional, experimental, contained) over time among a sample of high-risk young adults and used multilevel mixed-effects logistic regression to identify demographic and behavioral characteristics associated with engaging in concurrency. Men (N=261) and women (N=277) ages 18-30 at increased risk of HIV were recruited in Los Angeles and completed four in-person interviews at four-month intervals over a one-year period. Concurrency type was determined using dates of first and last sex, that were reported for each sexual relationship in the previous four months. Among this sample, 39% had concurrent sexual partnerships within the one-year study period. Of the total, 18% reported transitional concurrency (in which a second partnership begins before an earlier one ends); 22% reported experimental concurrency (a second partnership of less than a month that begins and ends during an ongoing partnership); 24% reported contained concurrency (a second partnership of at least one month is reported during an ongoing partnership); and 36% had multiple concurrent partnerships within at least one of the four-month intervals (of the same or various types). Male gender and the number of lifetime sex partners were strongly associated with concurrency. Additional results from multivariate analysis and implications for prevention programs will be discussed.