Risk behaviour

There has been concern that the availability of PEP for sexual and IDU exposures might paradoxically increase risk behaviour. However most studies have in fact shown that people take fewer sexual risks after having taken PEP, probably because the experience made them re-evaluate their behaviour. Nonetheless there are fears that if PEP becomes a standard and repeated prevention resource, a subset of high-risk people may become complacent about risk if repeated PEP is seen as a routine solution to exposure cases.

A study from Guy’s and St Thomas’ hospitals in London presented at the 2010 BHIVA/BASHH conference¹ looked at behaviour change in 83 gay men given PEP. At six months, the proportion of gay men reporting risky sex in the previous three months declined significantly from 51% at baseline to 8.7%. The proportion reporting new sexually transmitted infections in the previous three months dropped, from 16.7% at three months to 8.7% at six months. Twelve-month results will be published later.

One San Francisco programme addressed these concerns by giving 457 PEP patients five sessions of risk reduction counselling.² The study found that two sessions of counselling achieved a statistically significant reduction in risk exposures among ‘lower-risk’ patients (those having had risky sex no more than four times before the request for PEP), but that it took five sessions to achieve a reduction in risk among patients who had had more exposures.

In the study, only 10% of people seeking PEP reported an increase in risk behaviour following a PEP consultation whereas 74% reported a decrease in risk behaviour and 16% reported no change.