Patient understanding of oral contraceptive pill instructions related to missed pills: a systematic review

Background: Instructions on what to do after pills are missed are critical to reducing unintended pregnancies resulting from patient non-adherence to oral contraceptive (OC) regimens. Missed pill instructions have previously been criticized for being too complex, lacking a definition of what is meant by "missed pills," and for being confusing to women who may not know the estrogen content of their formulation. To help inform the development of missed pill guidance to be included in the forthcoming US Selected Practice Recommendations, the objective of this systematic review was to evaluate the evidence on patient understanding of missed pill instructions. Study design: We searched the PubMed database for peer-reviewed articles that examined patient understanding of OC pill instructions that were published in any language from inception of the database through March 2012. We included studies that examined women's knowledge and understanding of missed pill instructions after exposure to some written material (e.g., patient package insert, brochure), as well as studies that compared different types of missed pill instructions on women's comprehension. We used standard abstract forms and grading systems to summarize and assess the quality of the evidence. Results: From 1620 articles, nine studies met our inclusion criteria. Evidence from one randomized controlled trial (RCT) and two descriptive studies found that more women knew what to do after missing 1 pill than after missing 2 or 3 pills (Level I, good, to Level II-3, poor), and two descriptive studies found that more women knew what to do after missing 2 pills than after missing 3 pills (Level II-3, fair). Data from two descriptive studies documented the difficulty women have understanding missed pill instructions contained in patient package inserts (Level II-3, poor), and evidence from two RCTs found that providing written brochures with information on missed pill instructions in addition to contraceptive counseling significantly improved knowledge of how to manage missed pills for up to three months compared to contraceptive counseling alone (Level I, fair). Evidence from one RCT found that graphic-based missed pill instructions were better than text-only instructions (Level I, good), and data from two RCTs found that less information resulted in improved comprehension (Level I, good to fair). Evidence from one descriptive study found that many women missing pills did not intend to follow recommended actions per missed pill instructions despite understanding the guidance (Level II-3, poor). Conclusions: There is wide variability in the percent of women having correct knowledge on what to do when pills are missed after exposure to written missed pills instructions, with more women knowing what to do after missing 1 pill than after missing 2 or 3 pills. Women have difficulty understanding missed pill instructions contained in patient package inserts. Providing written brochures with information on missed pill instructions in addition to contraceptive counseling may improve knowledge of how to manage missed pills. Graphic-based missed pill instructions and those containing less information may result in improved comprehension. Even with clear instructions, many women missing pills may choose not to follow the recommended actions. Published by Elsevier Inc.