An ongoing long-term study of men who have sex with men (MSM) in Chicago has found that their condom-use patterns evolve over time and that such patterns differ between age cohorts, aidsmap reports.

Publishing their findings in The Archives of Sexual Behavior, researchers in the RADAR study are following three cohorts of MSM in Chicago who are at risk for HIV and were recruited when they were 16 to 20 years old. A total of 117 were recruited in 2007, 450 were recruited in 2010 and 589 were recruited in 2015. The investigators collect data on the young men every six to 18 months. The oldest participants are currently 26 years old.

The average age of participants upon entry into the study was 19 years old. Thirty-eight percent of the participants were African American, 26% were Latino, 25% were white and 11% were Asian or Pacific Islander, Native American or a different race. Sixty-nine percent identified as gay, 23% identified as bisexual and 8% identified as an “other” sexual orientation.

When they were 17 years old, the young men reported an average of 10.2 anal sex acts during the previous year, 57% (5.8 acts) of which were condomless. At 26 years old, they reported an average of 19.5 anal sex acts in a year, 30% (5.9 acts) of which were condomless.

The 2010 cohort reported an average of 5.8 condomless sex acts during the previous year at 17 years old, 6.4 condomless sex acts at 23 years old and 5.86 condomless sex acts at 26 years old. The 2015 cohort reported an average of 3.24 condomless sex acts at 17 years old and 8.71 condomless sex acts at 23 years old.


“The present study suggests that [young] MSM recruited in 2015 have very different trajectories of [condomless anal sex] compared to previous cohorts, including lower risk in late adolescence, but with the potential for higher risk after the transition into adulthood.”

To read the aidsmap article, click here.

To read the study abstract, click here