Original research articleComparative acceptability of combined and progestin-only injectable contraceptives in Kenya
Introduction
Progestin-only injectable contraceptives are popular because of their relatively long duration of action (2 or 3 months), high efficacy, safety, convenience, privacy and reversibility and because they do not interfere with the spontaneity of intercourse. However, they also cause changes in menstrual bleeding patterns in most users, including amenorrhea and prolonged or irregular spotting/bleeding. Also, because progestin-only injectables are long acting, there may be a delay in the return of fertility. These factors can limit their acceptability, especially among young and low-parity women.
Injectable contraceptives containing both progestin and estrogen (combined injectables) were developed to provide better cycle control than progestin-only injectables. However, the greater frequency of injections required and the narrower window in which they must be scheduled (±3 days compared with ±2 or 4 weeks for progestin-only injectables) may be inconvenient for some users, and the monthly injections entail an increased workload for family planning providers.
In Kenya, the use of Depo-Provera, a progestin-only injectable, is well established and is one of the leading methods of contraception. As of 1998, it was used by 27% of married women of reproductive age who were using a modern family planning method [1]. In our previous study of Depo-Provera in Kenya, the 12-month continuation rate was 61%, and only 9% of discontinuations were due to menstrual changes [2]. The high acceptance of Depo-Provera in Kenya suggests that conditions are favorable for acceptance of combined injectables, which could provide an effective family planning option for Kenyan women concerned about menstrual changes or the time required to return to fertility.
The primary objective of this study was to compare 12-month continuation rates and menstrual bleeding patterns between users of Depo-Provera and users of Cyclofem, the combined injectable most widely used outside Kenya. A secondary objective was to compare menstrual bleeding patterns and other measures of acceptability for both methods.
Section snippets
Study design, dosing and population
The study was conducted at three sites: (1) a young adults' clinic in Nairobi; (2) a family planning clinic at Riruta (on the outskirts of Nairobi); and (3) a family planning clinic at Thika (in the Central Province). The young adults' clinic serves unmarried women aged between menarche and 25 years who have already carried a pregnancy to delivery or abortion; these young adults are not considered minors in Kenya. Eligible women were recruited from among clients seeking family planning services
Results
One hundred twenty participants from each site, for a total of 360 participants, were randomly assigned to receive either Cyclofem or Depo-Provera. All participants received the method randomly assigned at their first visit and therefore were included in the statistical analysis. Three participants, one in the Cyclofem group and two in the Depo-Provera group, who later were found not to meet one of the eligibility criteria after the study was ended were also included in the statistical analysis.
Discussion
In this 1-year comparative study, the continuation rates for Depo-Provera were significantly higher than those for Cyclofem at all time points measured. At the end of the year, the continuation rate for Depo-Provera was 75.4% compared with 56.5% for Cyclofem. The 12-month continuation rate for Depo-Provera in this study is comparable with that observed in a previous nonrandomized study also conducted in Kenya [2]. The 12-month continuation rate for Cyclofem is in the range reported in Cyclofem
Acknowledgments
Support for this study was provided by Family Health International (FHI) with funds from the Andrew W. Mellon Foundation, Department of Reproductive Health and Research of the WHO and the United States Agency for International Development (USAID) cooperative agreements CCP-A-00-95-00022-02, CCP-3079-A-00-5022-00, DPE-3041-A-00-0043-00 and DPE-0537-A-00-4047-00. The views expressed in this article do not necessarily reflect those of the Andrew W. Mellon Foundation, the WHO or the USAID. The FHI
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