Diaphragm and lubricant gel for prevention of HIV acquisition in southern African women: a randomised controlled trial

Abstract

Background: Female-controlled methods of HIV prevention are urgently needed. We assessed the effect of provision of latex diaphragm, lubricant gel, and condoms (intervention), compared with condoms alone (control) on HIV seroincidence in women in South Africa and Zimbabwe.

Methods: We did an open-label, randomised controlled trial in HIV-negative, sexually active women recruited from clinics and community-based organisations, who were followed up quarterly for 12-24 months (median 21 months). All participants received an HIV prevention package consisting of pre-test and post-test counselling about HIV and sexually transmitted infections, testing, treatment of curable sexually transmitted infections, and intensive risk-reduction counselling. The primary outcome was incident HIV infection. This study is registered with ClinicalTrials.gov, number NCT00121459.

Findings: Overall HIV incidence was 4.0% per 100 woman-years: 4.1% in the intervention group (n=2472) and 3.9% in the control group (n=2476), corresponding to a relative hazard of 1.05 (95% CI 0.84-1.32, intention-to-treat analysis). The proportion of women using condoms was significantly lower in the intervention than in the control group (54%vs 85% of visits, p<0.0001). The proportions of participants who reported adverse events (60% [1523] vs 61% [1529]) and serious adverse events (5% [130] vs 4% [101]) were similar between the two groups.

Interpretation: We observed no added protective benefit against HIV infection when the diaphragm and lubricant gel were provided in addition to condoms and a comprehensive HIV prevention package. Our observation that lower condom use in women provided with diaphragms did not result in increased infection merits further research. Although the intervention seemed safe, our findings do not support addition of the diaphragm to current HIV prevention strategies.

Figure 1. Trial profile

Lost to follow up includes participants who might have had interim follow-up data but did not complete a closing visit. Withdrawals include participants who discontinued because of death (23) or who came back to study clinic and withdrew or were withdrawn early because of relocation (22), partner-related reasons (16), personal reasons (13), no time to participate (11), or other reasons (12). *Baseline sample. †M=month, data are number who attended/number expected; women who discontinued (withdrew early or completed the study on time) were removed from subsequent denominator. ‡Includes women confirmed to be HIV-negative at enrolment who had at least one subsequent HIV test result.

Figure 2. Cumulative HIV probability of infection (Kaplan-Meier estimates) by group

Figure 3. Proportions of women reporting (A) ever using condoms since last visit and (B) condom use at last sex, by visit