PITTSBURGH, Feb. 4 - In the first study to directly compare a contraceptive vaginal ring and skin patch, more women indicated overall satisfaction with the vaginal ring, researchers report in the current issue of Obstetrics and Gynecology, a publication of the American College of Obstetricians and Gynecologists. Using the same combination of hormones included in prescription birth control pills, these products became available in 2002 as an alternative to taking a pill every day. Ring and patch are left in place for three weeks at a time.
The study evaluated the experiences of 500 women who were randomly assigned to use the ring or patch for four consecutive menstrual cycles in 2005 and 2006. Of these, 249 used the ring and 251 used the patch. In addition to regular study visits for physical evaluation, participants completed a questionnaire and talked to investigators by phone following the study period.
"What we found is that more women are happier with the ring than the patch," said Mitchell Creinin, M.D., professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine and the study's first author. "On the whole, they report fewer complications, and a significant majority preferred the ring to their pill." The University of Pittsburgh served as sponsoring institution for the trial, which was conducted at 10 centers nationwide.
In November 2005, the U.S. Food and Drug Administration issued a warning regarding estrogen levels in the contraceptive patch and related risk of blood clots, changing the package labeling to reflect the warning. Participants enrolled in the study, regardless of study product assignment, were given standard, written information about the warning. Five women who used the contraceptive patch said they were influenced by the FDA labeling change, opting to discontinue use at the conclusion of the study.
"Overall, however, patch users were twice as likely to discontinue using the product by the end of the third cycle, and seven times more likely to say they had no wish to continue once the study was over," said Dr. Creinin, who also is director of family planning at Pitt and a senior investigator at the Pitt-affiliated Magee-Womens Research Institute. The most commonly cited reasons for discontinuation were adverse effects, including longer periods, cramps, nausea, mood swings, skin irritation or problems with the patch falling off. The most common reasons for discontinuation among women who used the ring were discomfort and more frequent vaginal discharge.
"Although oral contraceptives are the most commonly used reversible form of contraception in the United States, continuation rates are only 40 percent at six months of use," the authors write. In addition, prior studies have shown that in the third month of use, about half of women miss three or more pills each cycle, likely decreasing contraceptive effectiveness.
"The two alternative delivery systems for combined hormonal contraceptives had not been evaluated in a single randomized trial, making it difficult for clinicians to compare and contrast these options for their patients," Dr. Creinin said. "But now we can provide more accurate counseling to patients who might be interested in a nondaily birth control method."
Additional participating centers for the study are Boston University, Columbia University, Eastern Virginia Medical School, Johns Hopkins University, Oregon Health and Science University, University of California, Los Angeles, University of Chicago and the University of Wisconsin.
Other authors are Leslie A. Meyn, M.S., University of Pittsburgh; Lynn Borgatta, M.D., Boston University School of Medicine; Kurt Barnhart, M.D., University of Pennsylvania; Jeff Jensen, M.D., Oregon Health and Science University; Anne E. Burke, M.D., Johns Hopkins University; Carolyn Westhoff, M.D., Columbia University; Melissa Gilliam, M.D., University of Chicago; Caryn Dutton, M.D., University of Wisconsin; and Susan A. Ballagh, M.D., Eastern Virginia Medical School.
Financial disclosure: Although this study was funded in part by Organon U.S.A. Inc., manufacturer of the Nuvaring vaginal contraceptive, the money was provided as part of an investigator-initiated, nonrestricted grant from the company. Organon had no role in study design, data acquisition, analysis, manuscript preparation or study supervision. Dr. Creinin reports additional research funding from Bayer Healthcare Pharmaceuticals and Galen Holdings Plc.