Association between knowledge of anticoagulation, INR control, and warfarin-related adverse events: a cross sectional study.

OBJECTIVE: This cross-sectional observational study, conducted from 01/09/2023 to 01/11/2023, involved 200 warfarin-using patients outpatient clinics to assess the knowledge and understanding of warfarin among patients through face-to-face interviews.

RESULTS: Almost 70% of participants displayed insufficient knowledge about their warfarin therapy, potentially linked to inadequate counseling or patient comprehension. The participants had an average weekly warfarin dose of 32.9 ± 11.2, and more than half had used warfarin for at least 2 years. Only one third of patients most recent INR level was within the target range. Thirty-seven percent of patients experienced a thromboembolic event, and most of them required hospitalization. One hundred and eight patients (54.0%) experienced bleeding (minor, or major, or both). Eighty-two percent of participants correctly answered Question 8 of the OAK questionnaire regarding warfarin's indication for treating blood clots and 78% of the participants knew what the INR was. Moreover, the research revealed a positive correlation between higher education and adequate knowledge, with university-educated individuals exhibiting superior understanding. Conversely, a prolonged warfarin duration correlated with diminished knowledge, possibly indicating decreased patient vigilance. Furthermore, maintaining INR within the target range showed an association with sufficient knowledge.