Assessment of risk compensation following use of the dapivirine vaginal ring in southwestern Uganda

Objectives Participation in HIV prevention trials could trigger risk compensation among participants. We evaluated potential risk compensation following use of a vaginal ring microbicide by women in a phase III trial in southwestern Uganda. Methods We used markers of sexual risk behaviour documented on standardised questionnaires, tested for STIs at baseline and quarterly for 2 years. Risk compensation was defined as a significant increase (trend p<0.05) in the proportion of women reporting risky sexual behaviour or a diagnosed STI between baseline and end of follow-up. Results Between September 2013 and December 2016, 197 women (active arm: n=132 and placebo: n=65) were enrolled at the Masaka site. There were decreases in all markers of sexual risk behaviour with statistically significant decreases in only the proportion of women reporting ≥2 sexual partners, p=0.026 and those diagnosed withTrichomonas vaginalisp<0.001 and orNeisseria gonorrhoeaep<0.001 Conclusions No evidence of risk compensation was observed in this trial. Trial registration number NCT01539226 .