Comparison of contraceptive ring and patch for the treatment of symptomatic endometriosis

OBJECTIVE: To evaluate the efficacy and tolerability of a contraceptive vaginal ring and transdermal patch in the treatment of endometriosis-associated pain. DESIGN: Patient preference cohort study. SETTING: Academic center. PATIENT(S): Two-hundred and seven women with recurrent moderate or severe pelvic pain after conservative surgery for symptomatic endometriosis. INTERVENTION(S): Continuous, 12-month treatment with a vaginal ring supplying 15 mcg of ethinyl E and 120 mcg of etonogestrel per day or a transdermal system delivering 20 mcg of ethinyl E and 150 mcg norelgestromin per day. MAIN OUTCOME MEASURE(S): Satisfaction with treatment. RESULT(S): One-hundred and twenty-three women preferred the ring, and 84 preferred the patch. Forty-four ring users (36%) and 51 patch users (61%) withdrew. Thirty-six of 79 subjects (46%) in the ring group and 14 of 33 (42%) in the patch group shifted from continuous to cyclic use because of irregular bleeding. Pain symptoms were reduced by both treatments, with the ring being more effective than the patch in patients with rectovaginal lesions. According to an intention-to-treat analysis, 88 of 123 ring users (72%) and 40 of 84 patch users (48%) were satisfied with the treatment received. CONCLUSION(S): Patients who preferred the ring were significantly more likely to be satisfied and to comply with treatment than those who chose the patch. Both systems were associated with poor bleeding control when used continuously.