Objective: Warfarin is a medication commonly prescribed to prevent strokes associated with certain medical conditions such as atrial fibrillation; however, little is known about how people taking warfarin perceive the goal of therapy and how they describe strokes. We assessed the stroke-related health literacy of anticoagulated patients to inform ways in which to improve health communication among people taking warfarin.
Methods: We conducted a mixed-methods study of an ethnically and linguistically diverse sample of people taking warfarin to prevent stroke (N=183) and measured literacy using the short-form Test of Functional Health Literacy in Adults. We asked participants to (1) describe their indication for warfarin, and (2) describe a stroke. Transcribed answers were coded as concordant or discordant with established indications for warfarin and definitions of stroke.
Results: Forty-three percent of participants provided a discordant response when describing their indication for warfarin. Only 9.3% reported that the purpose of taking warfarin was to prevent stroke. Not speaking English [OR=2.4 (1.1-5.6)] and less than a college education [OR=3.3 (1.4-7.3)] were independently associated with discordant answers about warfarin. Nearly 40% of subjects had inaccurate perceptions of stroke, and only one-third of subjects described a symptom or sign of stroke. Among English and Spanish-speaking participants, inadequate literacy was strongly associated with discordant responses about stroke [OR=5.8 (2.1-15.6)].
Conclusion: Among high-risk people taking warfarin to prevent stroke, significant gaps in stroke-related health literacy exist. These gaps likely represent mismatches in the ways clinicians teach and patients learn.
Practice implications: Since stroke risk awareness and early recognition of the signs and symptoms of stroke are critical aspects of stroke prevention and treatment, clinicians should more strongly link warfarin therapy to stroke prevention and ensure that patients know the presenting symptoms and signs of stroke. Public health communication strategies regarding stroke prevention need to target individuals with limited literacy and limited English proficiency.