Evaluation of contraceptive efficacy and cycle control of a transdermal contraceptive patch vs an oral contraceptive: a randomized controlled trial
Audet, M.C.; Moreau, M.; Koltun, W.D.; Waldbaum, A.S.; Shangold, G.; Fisher, A.C.; Creasy, G.W.
JAMA 285(18): 2347-2354
2001
ISSN/ISBN: 0098-7484 PMID: 11343482 Document Number: 235040
Context: Oral contraceptive (OC) pills are effective, but poor compliance increases rates of pregnancy during treatment. Objective: To compare the contraceptive efficacy, cycle control, compliance, and safety of a transdermal contraceptive patch and an OC. Design: Randomized, open-label, parallel-group trial conducted October 1997 to June 1999. Setting: Forty-five clinics in the United States and Canada. Participants: A total of 1417 healthy adult women of child-bearing potential. Interventions: Participants were randomly assigned to receive a transdermal contraceptive patch (n=812) vs an OC (n=605) for 6 or 13 cycles. Patch treatment consisted of application of 3 consecutive 7-day patches followed by 1 patch-free week. Main Outcome Measures: Overall and method-failure Pearl Indexes (number of pregnancies/100 person-years of use) and life-table estimates of the probability of pregnancy were calculated. Cycle control, compliance, patch adhesion, and adverse events were also assessed. Results: Overall and method-failure Pearl Indexes were numerically lower with the patch (1.24 and 0.99, respectively) vs the OC (2.18 and 1.25, respectively); this difference was not statistically significant (P=.57 and .80, respectively). The incidence of breakthrough bleeding and/or spotting was significantly higher only in the first 2 cycles in the patch group, but the incidence of breakthrough bleeding alone was comparable between treatments in all cycles. The mean proportion of participants' cycles with perfect compliance was 88.2% (811 total participants, 5141 total cycles) with the patch and 77.7% (605 total participants, 4134 total cycles) with the OC (P <.001). Only 1.8% (300/16673) of patches completely detached. Both treatments were similarly well tolerated; however, application site reactions, breast discomfort, and dysmenorrhea were significantly more common in the patch group. Conclusion: The contraceptive patch is comparable to a combination OC in contraceptive efficacy and cycle control. Compliance was better with the weekly contraceptive patch than with the OC.