Diaphragm, Lubricant Gel May Not Prevent HIV in Women

June 17, 2007 — In sexually active HIV-negative women, use of a diaphragm and lubricant gel in addition to male condom use has no protective benefit against HIV infection compared with male condom use only, according to the results of an open-label randomized trial published in the July 13 Early Online Publication issue of The Lancet. The authors conclude that the diaphragm and lubricant gel are not effective preventive HIV interventions.
"Female-controlled methods of HIV prevention are urgently needed," write Nancy S. Padian, PhD, from the University of California in San Francisco, and colleagues from the Methods for Improving Reproductive Health in Africa (MIRA) Team. "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.... Because of sociocultural constraints and power differentials in gender roles, these women are often unable to negotiate the use of male condoms, a key component of HIV prevention strategies."
Women who were HIV negative and sexually active were recruited from clinics and community-based organizations, and they were all given an HIV prevention package consisting of pretest and posttest counseling about HIV and sexually transmitted infections (STIs), testing, treatment of curable STIs, and intensive risk-reduction counseling. Participants were randomized to an intervention group (diaphragm, lubricant gel, and male condoms; n = 2472) or control group (male condoms only; n = 2476) and were followed up quarterly for 12 to 24 months (median, 21 months). The main endpoint was incident HIV infection, and analysis was with intent-to-treat.
Overall HIV incidence was 4.0% per 100 woman-years (4.1% in the intervention group and 3.9% in the control group), yielding a relative hazard ratio of 1.05 (95% confidence interval [CI], 0.84 - 1.32). Compared with the control group, the intervention group had a significantly lower proportion of women using condoms (54% vs 85% of visits; P < .0001). Both groups had similar proportions of participants who reported adverse events (60% [1523] vs 61% [1529]) and serious adverse events (5% [130] vs 4% [101]).
"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," the authors write. "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."
Study limitations include study population mainly consisting of women in primary partnerships, lack of generalizability to other groups exposed to different risks and in other cultures, possible inaccuracy of self-report, uncertainty about self-reported condom use, and limited statistical power.
"Women who cannot convince their male partners to use condoms are still in urgent need of a female-controlled method of protection," the authors conclude. "In addition to research on methods that are inherently more efficacious, we must develop the instruments to allow assessment of even modest amounts of protection."
The Bill and Melinda Gates Foundation funded the MIRA trial. The authors have disclosed no relevant financial relationships.
In an accompanying editorial, Ronald H. Gray, MBBS, and Maria J. Wawer, PFRH, from Johns Hopkins University in Baltimore, Maryland, note that randomized trials of HIV prevention are difficult to perform and that nearly all such trials have failed to show protection from HIV infection.
"Ongoing trials of herpes virus [HSV-2] suppression, PREP [pre-exposure prophylaxis], or of antiretroviral microbicides offer hope for female-controlled prevention, but these methods are user-dependent and the studies are thus vulnerable to the less than ideal compliance that has bedevilled other prevention trials," Drs. Gray and Wawer write. "Padian and colleagues did an innovative trial of an available technology, and the disappointing results must not discourage the testing of other novel approaches."
Drs. Gray and Wawer have disclosed no relevant financial relationships.
Lancet. Published online July 13, 2007.