Source
Emory University School of Medicine, Atlanta, Georgia, USA.
Abstract
OBJECTIVE:
To present efficacy and cycle control data pooled from three pivotal studies of the contraceptive patch (Ortho Evra/Evra).
DESIGN:
Three multicenter, open-label, contraceptive studies that included up to 13 treatment cycles.Setting: 183 centers.
PATIENT(S):
3,319 women.Intervention(s): Three consecutive 7-day patches (21 days) with 1 patch-free week per cycle.
MAIN OUTCOME MEASURE(S):
Contraceptive efficacy and cycle control.
RESULT(S):
Overall and method failure life-table estimates of contraceptive failure through 13 cycles were 0.8% (95% CI, 0.3%-1.3%) and 0.6% (95% CI, 0.2%-0.9%), respectively. Corresponding Pearl indices were 0.88 (95% CI, 0.44-1.33) and 0.7 (95% CI, 0.31-1.10). Contraceptive failure among women with a body weight < 90 kg (<198 lb) was low and uniformly distributed across the weight range. A subgroup of women with body weight > or = 90 kg (> or = 198 lb) may have increased risk of pregnancy. The incidence of breakthrough bleeding was low and decreased over time.
CONCLUSION(S):
In contraceptive patch users, the overall annual probability of pregnancy was 0.8% and the method failure probability was 0.6%. The efficacy of the patch was high and similar across age and racial groups. Among women < 90 kg (<198 lb), contraceptive failure was low and uniformly distributed across the range of body weights. In women > or = 90 kg (> or = 198 lb), contraceptive failures may be increased. Efficacy and cycle control have been shown to be comparable to an established oral contraceptive.