The effect of pack supply on oral contraceptive pill continuation: a randomized controlled trial.

Objective: The often small number of oral contraceptive pill (OCP) cycles provided may contribute to high rates of discontinuation. We examined the effect of an increased OCP supply on 6-month continuation rates.

Methods: This was a randomized trial of women initiating OCP use at an urban family-planning clinic (n=700). All participants were randomized to receive three or seven cycles of OCPs. Participants younger than age 18 years or uninsured received their entire supply as packs; those older than age 18 years with insurance were additionally randomized to receive either packs or a prescription for refills. We contacted participants by telephone 6 months after enrollment to assess OCP continuation and adverse events.

Results: We obtained follow-up information from 76% of participants (260 of 342 in the three-pack group, 244 of 319 in the seven-pack group). Participants who received seven packs had higher 6-month continuation than participants who received three packs (51% compared with 35%, P<.001). The treatment effect was greater among participants younger than 18 years of age (49% compared with 12%, P<.001) than among those aged 18 years and older (52% compared with 40%, P=.018). Participants who received a prescription were less likely to continue OCP use than those who received packs (42% compared with 21%, P=.027). Adverse events in the study were rare and not associated with receiving more OCP packs.

Conclusion: A greater OCP supply at the time of initiation can improve continuation rates, especially among women younger than 18 years of age.

Clinical Trial Registration: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00677742.

Level Of Evidence: I.