Adherence Among a Cohort Taking Progestin-Only Pills Prescribed by a Healthcare Provider: Results of the BENCHMARK Study

Bradford RD, Farnsworth SJ, Laurora I, Sober S, Guillard H, Glasier A, Shiffman S. Contraception 112 (2022) 48–53. https://doi.org/10.1016/j.contraception.2022.04.006

Objectives: To measure adherence over six months of progestin-only pill (POP) use.

Study Design: Prospective observational cohort study measuring adherence to daily dosing and timing of dose in patients prescribed a POP, with up to six months of follow-up, conducted from January to October 2020. A pharmacy benefit manager identified potential participants with a newly prescribed POP and extended an invitation to participate. We enrolled qualified respondents by telephone, trained them to use an electronic diary to report daily whether they had taken their POP and at what time. We followed participants for up to six months. We calculated adherence to daily pill taking as the proportion of evaluable days in which a participant took a POP, and the proportion of participants reporting ≥85% adherence. We calculated adherence to same time each day as the proportion of doses taken no later than three hours after the previous dose time of day.

Results: The user population comprised 199 participants, 154 (77.4%) of whom completed six months of follow-up. The majority (n = 170, 85.4%) were taking norethindrone. Norethindrone users reported POP intake on 22,327 (96.4%) of 23,156 evaluable days, with 155 (91.2%) participants reporting ≥85% adherence; less than half (n = 73, 42.9%) reported 100% adherence. Participants reported adherence to same time each day on 21,698 of 22,157 (97.9%) evaluable days.

Conclusions: Among participants taking a prescribed POP, participants demonstrated high adherence for daily pill taking and the same time of day, though the majority were not 100% adherent.

Implications: This study reports data specific to adherence among those taking a progestin-only pill (POP) in the prescription setting. Clinicians who counsel patients about POP use should be aware that majority of patients were not 100% adherent, although most report ≥85% adherence.