Factors associated with nonadherence to instructions for using the Nestorone®/ethinyl estradiol contraceptive vaginal ring

Objectives: We sought to identify factors associated with nonadherence to instructions for using a novel contraceptive providing 1 year of protection. Study design: Data from a multicountry Phase 3 trial of the Nestorone (R) (segesterone acetate)/ethinyl estradiol (NES/EE) contraceptive vaginal ring (CVR) were analyzed. Participants were instructed to use the CVR over 13 cycles and follow a 21/7 regimen. Their reports of CVR removals >2 h outside scheduled removal periods served as a proxy for nonadherence. We used multivariate logistic regression to determine factors associated with such use. Results: Of 905 participants, 120 (13%) reported CVR removals >2 h. Removals for washing [odds ratio (OR) 3.96, 95% confidence interval (CI) 2.50-6.27] or sexual intercourse (OR 3.19, 95% CI 2.03-4.99), and finding CVR insertion difficult (OR 2.80, 95% CI 1.36-5.80) were factors associated with removals >2 h. Lower educational attainment also predicted ring removal >2 h (OR 3.23, 95% CI 1.55-6.75). Women residing in Europe or Australia were less likely to remove the ring for >2 h compared with women in the United States (OR 0.44, 95% CI 0.24-0.83 and OR 0.13, 95% CI 0.02-0.98, respectively). Participants who reported removals >2 h were more likely to discontinue CVR use (OR 1.93, 95% CI 1.24-2.95), report dissatisfaction (OR 2.20, 95% CI 1.32-3.69) and become pregnant during the study (OR 4.07, 95% CI 1.58-10.50). Conclusions: Removing the CVR for washing and removing it before intercourse are factors associated with nonadherence to ring use. These are important topics for counseling women who are considering or using vaginal rings, including the NES/EE CVR. (C) 2017 Elsevier Inc. All rights reserved.