Contraception. 2017 Dec 18. pii: S0010-7824(17)30537-1. doi: 10.1016/j.contraception.2017.12.011.
Factors associated with non-adherence to instructions for using the Nestorone®/ethinyl estradiol contraceptive vaginal ring
Stifani BM, Plagianos M, Vieira CS and Merkatz RB
Abstract
Objective: We sought to identify factors associated with non-adherence to instructions for using a novel contraceptive providing 1-year of protection.
Study design: Data from a multi-country Phase 3 trial of the Nestorone® (segesterone acetate)/ethinyl estradiol (NES/EE) CVR were analyzed. Participants were instructed to use the CVR over 13 cycles and follow a 21/7 regimen. Their reports of CVR removals >2h outside scheduled removal periods served as a proxy for non-adherence. We used multivariate logistic regression to determine factors associated with such use.
Results: Of 905 participants, 120 (13%) reported CVR removals >2h. Removals for washing (OR 3.96, 95%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 >2h. Lower educational attainment also predicted ring removal >2h (OR 3.23, 95%CI 1.55-6.75). Women residing in Europe or Australia were less likely to remove the ring for >2h compared with women in the US (OR 0.44, 95%CI 0.24-0.83 and OR 0.13, 95%CI 0.02-0.98, respectively). Participants who reported removals >2h 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 before intercourse are factors associated with non-adherence to ring use. These are important topics for counseling women who are considering or using vaginal rings, including the NES/EE CVR.
Implications: Findings from this study may be useful in guiding counseling for current and prospective vaginal ring users. Anticipatory guidance should focus on how the ring feels in the vagina and during sex. Asking about ring removals may help identify women who are at increased risk for having an unplanned pregnancy.
Comment:There are several contraceptive vaginal rings available, with good efficacy, if used correctly and consistently. This study shows which specific factors play a role in non-adherence, and therefore lower efficacy. An important article for those who counsel women on the correct use. (HMV)
