The Female Condom and STDs

Abstract

OBJECTIVES: The main purpose of this study is to compare sexually transmitted disease (STD) prevalence in cohorts of women with and without access to female condoms.

METHODS: Six matched pairs of communities were identified from Kenya tea, coffee and flower plantations. One community within each pair was randomly selected to receive the female condom intervention. Approximately 160 eligible women were enrolled at each site. Female condom communities underwent an education program on use of female and male condoms and STDs, comprising group meetings, puppetry and other folk media, and training of clinic service providers and community outreach workers. Control communities received similar information on use of male condoms (freely available at all sites). At baseline, participants were tested for cervical gonorrhea and chlamydia and vaginal trichomoniasis, to be repeated at 6 and 12 months. The study has 80% power to detect a 10% prevalence difference, assuming an aggregate STD prevalence of 20% with 25% loss to follow-up and intracluster correlation of 0.03.

RESULTS: Among 1929 women at baseline, the mean age was 33.1 years; 78% had never used a male condom. The prevalences of gonorrhea, chlamydia and trichomoniasis were 2.6%, 3.2% and 20.4%, respectively (23.9% overall). The intracluster correlation based on these data was near zero.

CONCLUSIONS: Comparable pairs of study sites have been selected. STD prevalence is sufficiently high, and the variation between sites is acceptably low. The study is feasible as designed.

Introduction

Public health interest in barrier methods of contraception, including male and female condoms, has been invigorated because they are the only contraceptives that can reduce the risk of contracting or transmitting sexually transmitted diseases (STDs). But barrier prevalence and consistency of use, and impact, remain low in most populations, even among groups at high risk of contracting STD.

The female condom (Reality® in the U.S.) is as effective a contraceptive as other barrier products 1, 2. It is made of polyurethane, a stronger material than the latex used for male condoms. Other advantages include: its loose fit in the vagina, allowing the penis to move freely inside it; it covers the vulva during coitus; it can be used with oil-based or water-based lubricants; and it is female-inserted and so (at least partly) female-controlled. Disadvantages include the device's relatively high price (about U.S. $3, with a public-sector price of about U.S. $0.60) and its unsightly extrusion from the vaginal canal. Laboratory studies have found that the female condom is impermeable to various STD organisms, including HIV (3). In one human use study, women with recurrent vaginal trichomoniasis were assigned to a group using the female condom or a control group of non-users. Following a 45-day period of their usual sexual activity, re-infection with trichomonas occurred in 14% of controls, 14.7% of non-perfect users, and in none of the 20 perfect users of the female condom (4). A second study found that a group of sex workers receiving female condoms and male condoms had a one-third lower incidence of STDs than a comparable group of women relying on male condoms alone (5).

Women's health advocates enthuse about a device that empowers women at risk of STD to protect themselves (6). Acceptability studies in the developing world have been encouraging (7), including two studies in Kenya (8, unpublished FHI report). A female prophylactic may have a greater impact on infection among women than male devices—the man's accession to his partner's female condom use may be easier to achieve than his active decision to wear a male condom (6). Offering the female condom as one choice among barrier methods has resulted in less unprotected intercourse in at least three settings: a U.S. STD clinic (9); a Zambian STD clinic (10); and a cohort of Zimbabwean sex workers [unpublished report cited in (7)].

Yet to be demonstrated is whether distribution of a female barrier method can reduce STD rates on a large scale. Interventions have generally described process information and self-reported behavior change without STD data (11). Until recently, weak designs were common, leading to calls for randomized studies of HIV/STD interventions 11, 12.

We designed a randomized community intervention trial in Kenya to determine the effect of introducing female condoms in communities with a high prevalence of STDs. This article describes the design and analysis of the trial, and presents results from its baseline phase. The primary objective of the trial is to measure and compare STD prevalence in cohorts of Kenyan women with and without access to female condoms as part of a replicable intervention. Secondary objectives are to: compare the incidence of STD syndromes (vaginal discharge; genital ulcer; lower abdominal pain) in cohorts with and without female condoms; measure the impact of female condom introduction on the consistency of male condom use; collect acceptability information among female and male users of female condoms; and compile cost data on female condom provision.