Patient information about warfarin: an assessment of accuracy and readability.

O ral vitamin K antagonists, such as warfarin, are among the most commonly prescribed and potentially dangerous classes of medications. For many high-risk drugs, such as warfarin, there is a strong link between patient knowledge about the medication and their safe use. For warfarin, provision of high-quality education improves compliance, increases time in the therapeutic range, and leads to a reduction in complications. Patients are largely educated about warfarin through written information sheets provided by their pharmacies. Therefore, it is critical that these sheets are both accurate and understandable. The objectives of this study were to assess the content (accuracy and completeness) and reading level of patient education sheets (PES) about warfarin provided to patients by community pharmacies in Ontario, Canada, and by pharmaceutical producers of this high-risk drug.