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 due to increased bioavailability and improved user compliance.
Objectives: To compare the contraceptive effectiveness, cycle control, adherence (compliance), and safety of the skin patch or the vaginal ring versus combination oral contraceptives (COCs).
Search strategy: For trials of the contraceptive patch or the vaginal ring, we searched MEDLINE, POPLINE, CENTRAL, EMBASE, LILACS, ClinicalTrials.gov, and ICTRP. We 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 95% confidence intervals (CI) was calculated. For continuous variables, the mean difference was computed.
Main results: We found 5 trials of the skin patch and 10 of the vaginal ring. Contraceptive effectiveness was similar for the patch or ring versus the comparison COC. More patch users discontinued early than COC users: ORs were 1.59 (95% CI 1.26 to 2.00), 1.56 (95% CI 1.18 to 2.06), and 2.57 (95% CI 0.99 to 6.64). Patch users also had more discontinuation due to adverse events. Compared to COC users, patch users reported more breast discomfort, dysmenorrhea, nausea, and vomiting. Patch users reported more compliant cycles than the COC users in two trials: ORs were 2.05 (95% CI 1.83 to 2.29) and 2.76 (95% CI 2.35 to 3.24). The ring trials generally showed similar discontinuation for ring and COC users. Ring users reported less nausea, acne, irritability, and depression than COC users. Ring users had more vaginitis and leukorrhea but less vaginal dryness. Ring users had similar adherence to COC users in two trials but less adherence in one. Cycle control was generally similar for the patch and COC, and was similar or better for the ring versus COC.
Authors' conclusions: Effectiveness was similar for the methods compared. The patch could lead to more discontinuation while the vaginal ring showed little difference. The patch group had better compliance than the COC group but more side effects. Ring users generally had fewer adverse events than COC users but more vaginal irritation and discharge. High losses to follow up can affect the validity of the results.