Research on the SILCS Diaphragm
The SILCS Diaphragm was developed over a nearly 20-year period of public-sector-supported research, including design and development, user acceptability studies, clinical studies of safety and effectiveness, and introduction research. These data ensure we have a strong foundation of safety and acceptability as we prepare to bring this product to market to expand women’s options for nonhormonal barrier contraception.
The design and development of SILCS began by PATH identifying the health need. Research on user perspectives on contraceptive acceptability identified that women wanted access to more methods that are under their control, that can be used only when needed, that have few side effects, and that could potentially protect from sexually transmitted infections. The diaphragm seemed to fit many of these criteria but was not being widely used or promoted.
The final design of SILCS has been tested in nine clinical studies that have been implemented in five countries. Studies in South Africa, Thailand, the Dominican Republic, the United States, and Zimbabwe confirmed the single-size device fits a broad range of women across different geographic regions, including women with different body mass indices and reproductive history. The study in Zimbabwe confirmed that cervical barriers are acceptable among at-risk youth in that country and that SILCS was preferred to other barrier methods. Likewise in the comparative evaluations in the Dominican Republic and the United States, SILCS was preferred overall by women and their partners.
Diaphragms have a long history of safe use, and the clinical studies with SILCS confirm that it too is as safe as the traditional diaphragm. The recently completed contraceptive effectiveness study implemented by CONRAD confirmed that SILCS used with contraceptive gel has efficacy similar to the multisize traditional diaphragm used with contraceptive gel. See press release announcing the study results on CONRAD’s website >>
Other studies implemented at the University of Pennsylvania and the California Family Health Council are building evidence about the feasibility and acceptability of SILCS as a microbicide delivery system and continue to confirm the single-size device fits most women and is safe and easy to use.
Based on the results of these studies, CONRAD is planning two clinical studies to evaluate the safety and barrier effectiveness of SILCS when used to deliver tenofovir gel—a microbicide gel shown effective at reducing the risk of HIV and herpes infections. If clinical evidence shows that this is a safe and effective way to deliver tenofovir, this would support future use of SILCS as a reusable delivery system for microbicide gel once a microbicide gel is approved and made available for distribution and sale.
Now that the design validation and clinical validation are complete, PATH is engaging in introduction research to inform strategies for future SILCS introduction in low-resource settings and identify local partners who will be instrumental in bringing this product to market. A country readiness assessment was conducted in Uganda in 2010 and findings were presented at the international family planning conference in Dakar, Senegal, in 2011. Two additional assessments are under way in 2012–2013 in South Africa and India.