Ibis Reproductive Health, Cambridge, MA 02138, USA.
Contraception. 2011 Jun;83(6):556-63. doi: 10.1016/j.contraception.2010.10.018. Epub 2011 Jan 26.
There is little data on contraceptive effectiveness or use patterns from sub-Saharan Africa.
We analyzed data from women at risk of pregnancy (n=4905) in the Methods for Improving Reproductive Health in Africa trial of the diaphragm for HIV prevention. We described reported contraceptive method use and calculated rates of pregnancy by contraceptive method. We compared time to first pregnancy by study arm (condoms or condoms plus diaphragm), and estimated a Cox proportional hazards model to identify predictors of pregnancy.
Condoms (25.8%), injectables (25.4%) and OC (21.6%) were the most commonly used methods; long-acting method use was rare. During the trial, 51.6% of women used the same method, 27.4% switched to a more effective method and 20.9% switched to a less effective method; 21.4% of women became pregnant. Pregnancy rates by contraceptive group mirrored published estimates; frequency of study product use was not associated with pregnancy.
Long-acting methods of contraception should be made available in HIV prevention trials and to women in Southern Africa.
撒哈拉以南非洲地区关于避孕有效性或使用模式的数据很少。
我们分析了在预防艾滋病毒的隔膜方法改善非洲生殖健康试验中处于妊娠风险的妇女（n=4905）的数据。我们描述了报告的避孕方法使用情况，并按避孕方法计算了妊娠率。我们比较了研究组（避孕套或避孕套加隔膜）的首次妊娠时间，并估计了 Cox 比例风险模型以确定妊娠的预测因素。
避孕套（25.8%）、注射剂（25.4%）和口服避孕药（21.6%）是最常用的方法；长效方法的使用很少。在试验期间，51.6%的女性使用相同的方法，27.4%的女性改用更有效的方法，20.9%的女性改用效果较差的方法；21.4%的女性怀孕。避孕组的妊娠率反映了已发表的估计值；研究产品的使用频率与妊娠无关。
长效避孕方法应在艾滋病毒预防试验中以及在南部非洲的妇女中提供。
