Flowers and colleagues drew tight criteria for inclusion in
their meta-analysis. They only included studies in which at least 60% of
participants were HIV-negative men who have sex with men; they only included
studies published since 2000, as they wanted to exclude studies conducted in
the days before effective antiretroviral therapy (ART) became available; and
they only included studies of brief interventions, which meant five sessions or
fewer. The latter was because the commissioning call from NIHR required the
evidence for brief interventions.

They found eleven studies in all, which varied greatly in
their methodology. Some were online and/or used novel intervention strategies:
a graphic novel, a telephone intervention, or an informational video added to
counselling sessions. Others were face-to-face. Six out of the eleven studies
used a version of Personalised
Cognitive Counselling (PCC)
, an adaptation of CBT for single or brief
interventions, designed to be used at the time of or close to HIV testing. In
addition to the six PCC-based interventions, there were two peer-delivered
interventions where the basis of the intervention is not stated. Four were
delivered at an HIV testing appointment (three after the negative result was
given, one while waiting for the result); two were given during or after
testing to both HIV-positive and negative test recipients; and four, primarily
the online interventions, were given to people who recorded themselves as being
HIV-negative and not at a testing appointment. The follow-up period over which
the effect of the intervention was measured varied from two to ten months, with
six studies using six months.

As we said above, the eleven studies produced an overall
reduction in condomless sex (measured in various ways) of 25% (95% confidence
interval, 9% to 38%). Six out of the eleven produced statistically significant

This agrees well with the second-largest
meta-analysis of behavioural interventions
, which included 102 studies and
was published in 2013: this found a 27-30% reduction in condomless sex among
its study recipients, which included HIV-positive and HIV-negative gay and
heterosexual men. The
largest meta-analysis, the 354-study one mentioned above
, found a 38%
reduction in condomless sex among recipients of ‘active’ prevention methods,
i.e. ones with a counselling component, and 19% in ones without a counselling
component such as videos and information sessions.

Flowers’ findings were therefore broadly in line with these.
The problem is, however, that the behaviours that interventions may wish to
change are now different. The crucial question then, is whether the skills and
rethinks taught by the studies involve the kind of learning that might also
encourage people to seek and adhere to PrEP, test for HIV regularly, and so on.

As clues to devising an intervention that could reinforce
these behaviours as well as condom use, Flowers’ team did some sub-analyses of
factors associated with significant reductions in condomless sex.

They found that two methods were associated with significant
reductions. The first was using goal-setting and action-planning as part of the
method, to get recipients to set behavioural targets. The second was using
methods that drew attention to contradictions and justifications in
participants’ thinking and thus helped them to feel more understanding,
positive and capable about their ability to change. Taken together, these
methods were 34% effective. Other methods such as information-giving, social
support and an emphasis on threat or danger were not associated with effectiveness.

Interventions delivered via telephone or online were not
effective. In contrast interventions delivered face-to-face were 34% effective.
If the intervention was delivered immediately after receiving a test result,
the average effectiveness was 36%; delivered longer after the result,
interventions were not effective.

Although these factors were not quantified, the study found
also that interventions were effective if they were delivered by professionals,
but ones with clear and contemporary knowledge of the gay scene and MSM sex.