Am Fam Physician. 2009;80(3):232-233
Author disclosure: Nothing to disclose.
Clinical Scenario
A 30-year-old patient conceived a child while taking combined oral contraceptives (COCs) inconsistently. She now wants something less likely to lead to an unintended pregnancy.
Clinical Question
Is the use of contraceptive patches or vaginal rings more effective or safer than COCs?
Evidence-Based Answer
Based on moderate quality evidence, contraceptive effectiveness of the vaginal ring or patch is similar to COC.1 Compliance is better with the patch, but its use is discontinued more often than COCs or the ring because of adverse effects. Vaginal ring and COC users have similar rates of pregnancy, compliance, and adverse effects. However, vaginal ring users are more satisfied with their method of contraception than COC users.
Practice Pointers
An estimated one half of all pregnancies in the United States are unplanned, and contraception was used in up to one half of these pregnancies.2 As with COCs, the patch and the vaginal ring deliver combination hormones for three weeks, followed by a hormone-free week.
The method of hormone delivery can be selected based on patient preference and side effect profile. Hormonal contraceptives are equally effective in preventing pregnancy. Perfect use results in a failure rate during the first year of 0.3 percent, and typical use results in a failure rate of 8 percent.1 Patch users are more likely to experience breast pain, dysmenorrhea, and nausea or vomiting. Adverse effects are more likely to cause women to discontinue the patch. However, if they continue the patch, they are more likely to report being adherent. Vaginal ring users had higher rates of vaginal discharge and irritation, but were no more likely to discontinue than COC users and were more satisfied. High quality studies directly comparing the ring and the patch were not available.
One potential concern with the patch is that women are exposed to higher doses of estrogen that could lead to higher rates of venous thromboembolism (VTE).3 However, there were few serious adverse effects. In 11 trials, 6,470 women were followed for at least three cycles (3,622 women in studies comparing the patch with COC and 2,848 women in studies comparing the vaginal ring with COC).1 One woman in the patch group had pulmonary embolism, and no cases of VTE were reported in COC users. There were two cases of deep venous thrombosis among ring users, but one of the women had an additional risk factor. This yields an estimated risk of deep venous thrombosis for ring users of 149 per 100,000 women per year (95% confidence interval, 18 to 538).1 This compares to an overall incidence of 27 to 84 per 100,000 women per year for all women 15 to 19 and 40 to 44 years of age, respectively.4
The numbers of VTE events in the women included in this review were too low to reach a definite conclusion about safety. Other reviews of this topic, which included nonrandomized trials, concluded that the safety of the patch, ring, and COCs appears to be equivalent.5
Cochrane Abstract
Background: The delivery of combination contraceptive steroids from a skin patch or vaginal ring offers potential advantages over the traditional oral route. The skin patch and vaginal ring could require a lower dose because of increased bioavailability and improved user compliance.
Objectives: To compare the contraceptive effectiveness, cycle control, compliance, and safety of the skin patch or the vaginal ring versus combination oral contraceptives (COCs).
Search Strategy: The authors searched Medline, POPLINE, CENTRAL, EMBASE, and LILACS for trials of the contraceptive patch or the vaginal ring, and contacted manufacturers and researchers to identify other trials.
Selection Criteria: All randomized controlled trials comparing the skin patch or vaginal ring with a COC.
Data Collection and Analysis: Data were abstracted by two authors and entered into RevMan. For dichotomous variables, the Peto odds ratio (OR) with a 95% confidence interval (CI) was calculated. For continuous variables, the weighted mean difference was computed.
Main Results: Three trials of the skin patch and eight of the vaginal ring were found. Contraceptive effectiveness was similar for the patch or ring and the comparison COC. Patch users reported more compliant cycles than COC users; ORs were 2.05 (95% CI, 1.83 to 2.29) and 2.76 (95% CI, 2.35 to 3.24) in two trials. One crossover ring trial had more noncompliance for the ring users. Satisfaction with method was higher for ring users than COC users in two studies.
More patch users than COC users discontinued early in two trials (OR = 1.58; 95% CI, 1.25 to 1.99; and OR = 1.45; 95% CI, 1.11 to 1.90). Patch users also had more discontinuation because of adverse events. The ring trials generally showed similar discontinuation for ring and COC users. Compared with COC users, patch users were more likely to report breast discomfort, dysmenorrhea, nausea, and vomiting. Ring users reported less nausea, irritability, and depression than COC users in single trials. However, ring users had more vaginitis and leukorrhea. Bleeding problems were generally similar or less common for the ring versus COC.
Authors' Conclusions: Effectiveness rates were similar for the methods compared. The patch group had better compliance than the COC group. Compared with COC users, patch users had more effects. Ring users generally had fewer adverse events than COC users, but more vaginal irritation and discharge. The patch could lead to more discontinuation, whereas the vaginal ring showed little difference. High losses to follow-up can affect the validity of the results.
These summaries have been derived from Cochrane reviews published in the Cochrane Database of Systematic Reviews in the Cochrane Library. Their content has, as far as possible, been checked with the authors of the original reviews, but the summaries should not be regarded as an official product of the Cochrane Collaboration; minor editing changes have been made to the text (http://www.cochrane.org).