Archer David F, Cullins Vanessa, Creasy George W, Fisher Alan C
Contraceptive Research and Development Program, Clinical Research Center, Eastern Virginia Medical School, Norfolk, VA, USA.
Contraception. 2004 Mar;69(3):189-95. doi: 10.1016/j.contraception.2003.10.006.
The contraceptive efficacy of perfect dosing cycles and imperfect dosing cycles has not been described previously. Method compliance determines the proportion of perfect and imperfect dosing cycles, and together can form the basis for evaluating differences in efficacy based on differences in compliance.
The transdermal contraceptive delivery system (Ortho Evra) has been studied in a North American randomized trial vs. an oral contraceptive (OC) and in total has been evaluated in 3319 women in contraceptive clinical trials. This article explores the impact of perfect vs. imperfect compliance with the contraceptive method on contraceptive efficacy. Previously published data for a transdermal system (Patch, n = 812) and OC (Triphasil, n = 605) users from the North American comparative study were reanalyzed to determine the effect of imperfect use on the contraceptive efficacy of the different methods.
Contraceptive efficacy was significantly better (p = 0.007) in cycles with perfect dosing (Pearl Index = 0.83) compared to those with imperfect dosing (Pearl Index = 6.32) for both methods. This difference is homogeneous (p = 0.62) across the Patch and OC groups. Pooled data for all Patch users confirm that perfect dosing cycles are associated with significantly better efficacy than imperfect dosing cycles (p = 0.047). In addition, compliance did not vary by age in the pooled Patch data, which are in agreement with the previously published Patch data from the comparative study. In the comparative study, the percentage of cycles with perfect dosing was significantly higher with the Patch than with the OC (88.7% vs. 79.2%, p < 0.001), and was consistently high in all age groups (range, 89.6-91.8%). By contrast, among OC users, the percentage of cycles with perfect dosing increased with increasing age (p < 0.001) from 67.7% in users aged 18-20 years to more than 80% in those aged 30 years and older.
In conclusion, deviations from perfect use (whether corrected or not) of a transdermal contraceptive system and of an OC increase contraceptive failures by approximately 5-10-fold when compared to perfect use. The weekly change schedule of the transdermal contraceptive delivery system is associated with a significantly greater proportion of cycles in which there is perfect dosing compared to an OC.
此前尚未描述过完美给药周期和不完美给药周期的避孕效果。方法依从性决定了完美和不完美给药周期的比例，二者共同构成了基于依从性差异评估避孕效果差异的基础。
在一项北美随机试验中，对经皮避孕递送系统（Ortho Evra）与口服避孕药（OC）进行了研究，在避孕临床试验中总共对3319名女性进行了评估。本文探讨了完美和不完美依从避孕方法对避孕效果的影响。对北美比较研究中经皮系统（贴片，n = 812）和OC（三相片，n = 605）使用者先前发表的数据进行重新分析，以确定不完美使用对不同方法避孕效果的影响。
两种方法中，完美给药周期（Pearl指数 = 0.83）的避孕效果显著优于不完美给药周期（Pearl指数 = 6.32）（p = 0.007）。贴片组和OC组之间的这种差异具有同质性（p = 0.62）。所有贴片使用者的汇总数据证实，完美给药周期的避孕效果显著优于不完美给药周期（p = 0.047）。此外，在贴片汇总数据中，依从性不因年龄而异，这与比较研究中先前发表的贴片数据一致。在比较研究中，贴片完美给药周期的百分比显著高于OC（88.7% 对79.2%，p < 0.001），且在所有年龄组中一直很高（范围为89.6 - 91.8%）。相比之下，在OC使用者中，完美给药周期的百分比随年龄增长而增加（p < 0.001），从18 - 20岁使用者的67.7% 增至30岁及以上使用者的80% 以上。
总之，与完美使用相比，经皮避孕系统和OC不完美使用（无论是否纠正）会使避孕失败率增加约5至10倍。与OC相比，经皮避孕递送系统的每周更换时间表与完美给药周期所占比例显著更高相关。
