A
longitudinal study using multiple cohorts of young men who have sex with men in
Chicago aimed to investigate changes in condom use over time, from late
adolescence to adulthood (aged 17-26), as well as historical patterns of change
for cohorts of men recruited in different years. This research was carried out
by Gregory Swann and colleagues at Northwestern University and is published in
the May issue of The Archives of Sexual
Behavior
.

Researchers
found that while men had more anal sex as they got older, there was a decrease
in the proportion of that sex that was condomless. In terms of historical
changes, of the three cohorts followed (recruited in 2007, 2010 and 2015), the
2015 cohort reported less condomless sex at age 17, but a higher growth in the proportion
of sex that was condomless as they got older. This study is the first of its
kind to indicate that cohorts recruited in more recent years may have different
risk trajectories over time when compared to cohorts recruited previously.

Young men
who have sex with men (MSM) have the highest HIV incidence in the US. Between
2001 and 2011, youth between the ages of 13-24 represented the fastest growing
age group for new infections. In 2015, rates of new diagnoses stabilised for
this age group but continued to increase among MSM aged 25-34, with a 23%
increase from 2010-2015.

“Given these
high rates and trends, understanding how HIV risk changes from adolescence to
young adulthood is especially important,” the authors say. “The goal of the
present study was to observe how engagement in condomless anal sex changes over
time from late adolescence to adulthood in young MSM. We also set out to assess
whether cohorts of young MSM
recruited in 2007, 2010, and 2015 differed in patterns of change in condomless
anal sex from late adolescence to adulthood.”

In terms of
historical changes, social factors, such as greater recognition of same-sex
relationships and marriage equality, and biomedical developments, such as
pre-exposure prophylaxis (PrEP) and treatment as prevention (TasP), may have had
an impact. However, PrEP is only FDA-approved for those over 18 years of age
and uptake has been low among young MSM, especially those of colour. Thus,
condom use is still an important HIV prevention tool for this at-risk group.

Turning to
changes as young men get older, previous longitudinal research on condom use
has had varied findings. One study found that MSM who were younger at baseline
were more likely to have higher increases of condomless sex over time; another found
no significant changes over time in terms of condomless sex acts; and one reported
that individuals were inconsistent over time in their
sexual risk behaviour. However, these studies tended to follow
men for less than two years and thus do not offer insight into change over
longer periods of time.