Kaunitz Andrew M, Portman David J, Hait Howard, Reape Kathleen Z
Department of Obstetrics and Gynecology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL 32209, USA.
Contraception. 2009 May;79(5):350-5. doi: 10.1016/j.contraception.2008.11.011. Epub 2009 Jan 17.
A cross-study analysis of contraceptive clinical trials for two different 91-day oral contraceptive (OC) regimens was performed to examine the impact on bleeding patterns when supplementing the 7-day hormone-free interval with 10 mcg ethinyl estradiol (EE) daily.
Two separate 1-year Phase 3 clinical programs were conducted using similar study designs. The percentages of subjects reporting bleeding and spotting using electronic diaries for each 91-day cycle were compared.
Scheduled bleeding with the EE regimen was less than that reported with the regimen utilizing placebo during Days 85-91, with significant differences noted for all four 91-day cycles. Unscheduled bleeding decreased more quickly with the 91-day regimen containing low-dose EE in place of placebo, with significant differences noted during the third cycle.
This cross-study comparison suggests that the administration of low-dose estrogen in place of placebo in a 91-day extended regimen OC improves the bleeding profile.
对两种不同的91天口服避孕药（OC）方案进行了避孕临床试验的交叉研究分析，以探讨在7天无激素间隔期每天补充10微克炔雌醇（EE）对出血模式的影响。
使用相似的研究设计进行了两个独立的为期1年的3期临床项目。比较了每个91天周期中使用电子日记报告出血和点滴出血情况的受试者百分比。
在第85 - 91天，EE方案的计划性出血少于使用安慰剂方案的出血情况，在所有四个91天周期中均观察到显著差异。与含安慰剂的91天方案相比，含低剂量EE的91天方案非计划性出血减少得更快，在第三个周期观察到显著差异。
这项交叉研究比较表明，在91天延长方案的OC中用低剂量雌激素替代安慰剂可改善出血情况。
