Objective: To study relapse into unsafe sex among homosexual men using a novel method.
Design: Time from safer to unsafe sexual behaviour was analysed using Kaplan-Meier procedures. Cox proportional hazard analysis was performed to quantify the relation between duration of safer sex and several covariates.
Subjects: Subjects were homosexual men enrolled in a longitudinal cohort study in Amsterdam and included in the present assessment if they had ever reported an episode of safer sexual behaviour of at least 12 months.
Results: Of the 402 participants who met the inclusion criterion, 289 (72%) reported at least one episode of unprotected anogenital intercourse during follow-up. The median time from safer to unsafe sexual behaviour was 30 months. After 88 months of follow-up, the cumulative incidence of unsafe sexual behaviour reached 88%. Younger age, HIV seropositivity and use of amyl nitrites (poppers), were related to a shorter time to unsafe sexual behaviour.
Conclusions: Based on these findings it is possible to target relapse prevention at specific groups of homosexual men, thereby increasing programme effectiveness and efficiency.