Background Partner concurrency, or overlapping sexual partnerships, is associated with the transmission of HIV and other STIs. In the United States, some urban populations report high rates of partner concurrency but relatively few U. S. studies have investigated correlates of partner concurrency empirically. The purpose of the present study was to investigate the prevalence and correlates of partner concurrency among urban patients attending a publicly-funded STI clinic.

Methods Participants were 502 patients attending an STI clinic (41% female; 69% African American). They completed a computerised survey assessing demographic characteristics, partner concurrency, substance use, concurrency norms, environmental factors affecting concurrency (i.e., shortage of men), attitudes towards concurrency, and self-efficacy for having one partner.

Results Nearly one-half of the sample (46%) reported concurrent sexual partnerships in the past 3 months. In univariate analyses, being male, drinking more, using marijuana more frequently, perceiving multiple partners as normative, perceiving that the shortage of men influenced sexual partnerships, more positive concurrency attitudes, and less self-efficacy for having one partner were associated with concurrency (all ps < 0.05). Other demographic characteristics (race, income, education, age) were not associated with concurrency. In multivariate analyses, greater marijuana use (OR = 1.17) and having more positive concurrency attitudes (OR = 1.95) were independently associated with partner concurrency (ps < 0.05).

Conclusion The prevalence of concurrency was high in this population of patients attending an STI clinic. Interventions to reduce concurrency should target marijuana use and attitudes towards concurrency.