Evaluating Patients' Understanding of Printed Warfarin Medication Information.

Objective: Warfarin is a high-risk medication whose safe use may be greatly improved by patient education. This study evaluate evaluated patients' understanding of warfarin instructions, medication management, the Food and Drug Administration's (FDA) warfarin medication guide content, and patient information recommendations.

Methods: Interviews conducted at 2 hospital-based outpatient primary care sites with patients initiated on warfarin therapy within the last year.

Results: Interviews were conducted with 49 patients. Seventy percent were between 36 and 64 years old and reported taking between 1 and 18 different medications daily. Many (76%) received information about warfarin when first prescribed to them, 65% written and 60% verbal (answers reflect more than one response). Patients found content in the medication guide difficult to understand; 18% were unable to identify information about diet and 21% were unable to locate information about when to call their provider. Analysis showed that 19% had trouble with numeracy issues related to warfarin. Patients' suggestions of ways to convey warfarin information included more graphics, in-person counseling, and multilingual translations.

Conclusion: This study demonstrates gaps in patients' understanding of warfarin therapy. Relying solely on the information in the FDA medication guide is insufficient to guarantee adequate understanding. Utilizing the suggestions from patients' feedback on other ways to deliver information should help future patients with different learning abilities and styles.