Leung Vivian W Y, Soon Judith A, Lynd Larry D, Marra Carlo A, Levine Marc
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada.
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada; Centre for Health Evaluation and Outcomes Sciences, Providence Health Research Institute, Vancouver, BC, Canada.
Int J Gynaecol Obstet. 2016 Jun;133(3):342-6. doi: 10.1016/j.ijgo.2015.10.017. Epub 2016 Feb 24.
To estimate and compare the effectiveness of the levonorgestrel and Yuzpe regimens for hormonal emergency contraception in routine clinical practice.
A retrospective population-based study included women who accessed emergency contraceptives for immediate use prescribed by community pharmacists in British Columbia, Canada, between December 2000 and December 2002. Linked administrative healthcare data were used to discern the timings of menses, unprotected intercourse, and any pregnancy-related health services. A panel of experts evaluated the compatibility of observed pregnancies with the timing of events. The two regimens were compared with statistical adjustments for potential confounding.
Among 7493 women in the cohort, 4470 (59.7%) received levonorgestrel and 3023 (40.3%) the Yuzpe regimen. There were 99 (2.2%) compatible pregnancies in the levonorgestrel group and 94 (3.1%) in the Yuzpe group (P=0.017). The estimated odds ratio for levonorgestrel compared with the Yuzpe regimen after adjusting for potential confounders was 0.64 (95% confidence interval 0.47-0.87). Against an expected pregnancy rate of approximately 5%, the relative and absolute risk reductions were 56.0% and 2.8%, respectively, for levonorgestrel and 36.7% and 1.8% for the Yuzpe regimen.
The levonorgestrel regimen is more effective than the Yuzpe regimen in routine use. The data suggest that both regimens are less effective than has been observed in randomized trials.
评估并比较左炔诺孕酮和尤兹佩方案在常规临床实践中用于激素紧急避孕的有效性。
一项基于人群的回顾性研究纳入了2000年12月至2002年12月期间在加拿大不列颠哥伦比亚省从社区药剂师处获取紧急避孕药立即使用的女性。利用关联的行政医疗保健数据来确定月经时间、无保护性交时间以及任何与妊娠相关的医疗服务。一个专家小组评估观察到的妊娠与事件发生时间的相容性。对这两种方案进行比较，并对潜在混杂因素进行统计调整。
队列中的7493名女性中，4470名（59.7%）接受了左炔诺孕酮，3023名（40.3%）接受了尤兹佩方案。左炔诺孕酮组有99例（2.2%）符合条件的妊娠，尤兹佩组有94例（3.1%）（P = 0.017）。在调整潜在混杂因素后，左炔诺孕酮与尤兹佩方案相比的估计比值比为0.64（95%置信区间0.47 - 0.87）。相对于约5%的预期妊娠率，左炔诺孕酮的相对和绝对风险降低率分别为56.0%和2.8%，尤兹佩方案为36.7%和1.8%。
在常规使用中，左炔诺孕酮方案比尤兹佩方案更有效。数据表明，这两种方案的有效性均低于随机试验中的观察结果。
