Skin patch and vaginal ring versus combined oral contraceptives for contraception

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, compliance, and safety of the skin patch or the vaginal ring versus combination oral contraceptives (COCs). Search strategy We searched MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS for trials of the contraceptive patch or the vaginal ring. 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 weighted mean difference was computed. Main results We found three trials of the skin patch and eight of the vaginal ring. 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 discontinued early than COC users: OR 1.58 (95% Cl 1.25 to 1.99) and 1.45 (95% Cl 1.11 to 1.90) in two trials. Patch users also had more discontinuation due to adverse events (AEs). The ring trials generally showed similar discontinuation for ring and COC users. Compared to 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 to COC users, patch users had more side effects. Ring users generally had fewer adverse events than COC users but more vaginal irritation and discharge. The patch could lead to more discontinuation while the vaginal ring showed little difference. High losses to follow up can affect the validity of the results.