Cleland Kelly, Wagner Brandon, Smith Nicole K, Trussell James
Office of Population Research, Princeton University, Princeton, New Jersey, USA.
Texas Tech University, Lubbock, Texas, USA.
Women Health. 2020 Mar;60(3):241-248. doi: 10.1080/03630242.2019.1635560. Epub 2019 Jul 8.
Emergency contraceptive (EC) pills may be less effective for women with higher body mass index (BMI), but little is known about public response to the fact that EC may lose efficacy as weight increases. In November 2013, European authorities changed the label for a levonorgestrel EC product to warn of a reduction in effectiveness for women with higher BMI, garnering significant media coverage in the United States. Ulipristal acetate (UPA) EC may be more effective than levonorgestrel for women with BMI levels designated as obese. Among 8,019 women who received UPA from the online pharmacy KwikMed from 2011 to 2015 and self-reported their height, weight and reasons for seeking UPA online, we analyzed changes in the proportion of women in different BMI categories before and after the label change. For the 25 month-period after the label change, the proportion of women in the obese category rose by 26.7 percentage points relative to the 35 months before (B = 0.2665, < .01). Mean BMI (25.5 versus 29.4, < .001) and average weight (148.6 pounds versus 175.5 pounds, < .001) of users were higher after the label change. Some women appear to have acted on the information that EC efficacy may be associated with body weight.
紧急避孕药（EC）对体重指数（BMI）较高的女性可能效果较差，但公众对EC可能会随着体重增加而失去效力这一事实的反应却知之甚少。2013年11月，欧洲当局更改了左炔诺孕酮EC产品的标签，以警告BMI较高的女性其有效性会降低，这在美国引起了媒体的大量报道。对于BMI被认定为肥胖的女性，醋酸乌利司他（UPA）EC可能比左炔诺孕酮更有效。在2011年至2015年期间从在线药房KwikMed获得UPA并自行报告其身高、体重及在线寻求UPA原因的8019名女性中，我们分析了标签更改前后不同BMI类别女性比例的变化。在标签更改后的25个月期间，肥胖类别女性的比例相对于之前的35个月上升了26.7个百分点（B = 0.2665，P <.01）。标签更改后，使用者的平均BMI（25.5对29.4，P <.001）和平均体重（148.6磅对175.5磅，P <.001）更高。一些女性似乎已根据EC有效性可能与体重有关的信息采取了行动。
