Abortion Safety and Use with Normally Prescribed Mifepristone in Canada
Abortion Safety and Use with Normally Prescribed Mifepristone in Canada
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DOI：
10.1056/nejmsa2109779
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发表时间：
2021-12-08
影响因子：
158.5
通讯作者：
Norman, Wendy V.
中科院分区：
文献类型：
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作者：
Schummers, Laura;Darling, Elizabeth K.;Norman, Wendy V.
无限制米非司酮的流产结果使用安大略省基于人口的行政数据，调查人员发现，与未获得米非司酮时期相比，米非司酮以普通处方获得后，流产率保持相对稳定，药物流产的比例迅速增加，不良事件和并发症保持稳定。缓解策略 (REMS) 限制，尽管没有证据支持此类限制。自 2017 年 11 月起，米非司酮已在加拿大以普通处方上市。方法使用加拿大安大略省基于人群的行政数据，通过间断时间序列分析检查堕胎的使用、安全性和有效性，比较米非司酮上市前（2012 年 1 月至 2016 年 12 月）的发病率趋势与不受限制地上市后（2017 年 11 月 7 日至 2020 年 3 月 15 日）的发病率趋势。结果 在米非司酮上市之前，总共进行了 195,183 例流产，而在米非司酮上市后，总共进行了 84,032 例流产。在按常规处方提供米非司酮后，流产率继续下降，尽管比米非司酮问世前趋势的预期要慢（时间序列分析中调整后的风险差异，每 1000 名 15 至 49 岁女性居民中有 1.2 例；95% 置信区间 [CI]，1.1 至 1.4），而通过医疗程序提供的流产百分比则从 2.2% 增加至 31.4%（调整后风险差异，28.8 个百分点；95% CI，28.0 至 29.7）。米非司酮上市前与非限制期之间，严重不良事件发生率（0.03% vs. 0.04%；调整后风险差异，0.01 个百分点；95% CI，-0.06 至 0.03）、并发症（0.74% vs. 0.69%；调整后风险差异，0.06 个百分点；95% CI，-0.07 至 0.03）没有实质性变化。 0.18），或流产后检测到异位妊娠（0.15% vs. 0.22%；调整后的风险差异，-0.03 个百分点；95% CI，-0.19 至 0.09）。持续宫内妊娠持续分娩的人数略有增加（调整后风险差异，0.08%；95% CI，0.04 至 0.10）。结论 米非司酮成为常规处方后，与未使用米非司酮时期相比，流产率保持相对稳定，药物流产比例迅速上升，不良事件和并发症保持稳定。 （由加拿大健康研究所和妇女健康研究所资助。）
Abortion Outcomes with Unrestricted Mifepristone Using population-based administrative data from Ontario, investigators found that after mifepristone became available with a normal prescription, the abortion rate remained relatively stable, the proportion of abortions provided by medication increased rapidly, and adverse events and complications remained stable, as compared with the period when mifepristone was unavailable.Background In the United States, mifepristone is available for medical abortion (for use with misoprostol) only with Risk Evaluation and Mitigation Strategy (REMS) restrictions, despite an absence of evidence to support such restrictions. Mifepristone has been available in Canada with a normal prescription since November 2017. Methods Using population-based administrative data from Ontario, Canada, we examined abortion use, safety, and effectiveness using an interrupted time-series analysis comparing trends in incidence before mifepristone was available (January 2012 through December 2016) with trends after its availability without restrictions (November 7, 2017, through March 15, 2020). Results A total of 195,183 abortions were performed before mifepristone was available and 84,032 after its availability without restrictions. After the availability of mifepristone with a normal prescription, the abortion rate continued to decline, although more slowly than was expected on the basis of trends before mifepristone had been available (adjusted risk difference in time-series analysis, 1.2 per 1000 female residents between 15 and 49 years of age; 95% confidence interval [CI], 1.1 to 1.4), whereas the percentage of abortions provided as medical procedures increased from 2.2% to 31.4% (adjusted risk difference, 28.8 percentage points; 95% CI, 28.0 to 29.7). There were no material changes between the period before mifepristone was available and the nonrestricted period in the incidence of severe adverse events (0.03% vs. 0.04%; adjusted risk difference, 0.01 percentage points; 95% CI, -0.06 to 0.03), complications (0.74% vs. 0.69%; adjusted risk difference, 0.06 percentage points; 95% CI, -0.07 to 0.18), or ectopic pregnancy detected after abortion (0.15% vs. 0.22%; adjusted risk difference, -0.03 percentage points; 95% CI, -0.19 to 0.09). There was a small increase in ongoing intrauterine pregnancy continuing to delivery (adjusted risk difference, 0.08%; 95% CI, 0.04 to 0.10). Conclusions After mifepristone became available as a normal prescription, the abortion rate remained relatively stable, the proportion of abortions provided by medication increased rapidly, and adverse events and complications remained stable, as compared with the period when mifepristone was unavailable. (Funded by the Canadian Institutes of Health Research and the Women's Health Research Institute.)