Does switching contraceptive from oral to a patch or vaginal ring change the likelihood of timely prescription refill?

ABSTRACT

OBJECTIVE: This study evaluated contraceptive refill patterns of women insured commercially in the US who switched from oral contraceptives (OCs) to the patch or vaginal ring and assessed if switching contraceptive methods changes refill patterns. STUDY DESIGN: Women aged 15-44 with ≥2 patch or ring prescriptions and ≥2 OC prescriptions before the first patch/ring prescription were identified from the MarketScan® Commercial database (1/1/2002-6/30/2011). Refill patterns 1-year pre- and postindex date (first patch/ring prescription) were evaluated, and women were categorized as timely or delayed refillers on OCs and patch/ring. Regression modeling was used to investigate the association between refill patterns and contraceptive methods and switching effects on refill patterns. RESULTS: Of 17,814 women identified, 7901 switched to the patch, and 9913 switched to the ring. Among timely OC refillers, the percentage of timely refills decreased (patch 95.6% to 79.4%, p<.001; ring 96.5% to 74.3%, p<.001). However, among delayed OC refillers, the percentage of timely refills improved (patch 47.9% to 72.2%, p<.001; ring 50.4% to 64.0%, p<.001) during patch/ring use. Nonetheless, compared to timely OC refillers, women who were delayed OC refillers had 1.68-fold [95% confidence interval (CI) 1.52-1.84, p<.001] and 1.85-fold greater odds (CI 1.69-2.02, p<.001) of being a delayed refiller while on the patch and ring, respectively. CONCLUSION: Switching to the patch or ring may improve refill behavior for women who have problems refilling OCs timely; however, the magnitude of the improvement may fail to improve ultimate contraceptive efficacy by simply switching to the patch or ring. IMPLICATIONS The impact on timely refills of switching from OCs to either the patch or ring is complex and varies depending on the pattern of timely refills on OCs.