Determining INR Awareness of the Patients who Use Warfarin and Rates of Achieving the Target Dosage

OBJECTIVES: Warfarin is the most frequently used therapy as an oral anticoagulant medication for reducing the risk of thromboembolic complications. However, poor adherence to therapy may cause ineffective INR levels with increased complication risk. In our study, we aimed to show the rates of INR awareness of patients with atrial fibrillation (AF) using warfarin and whether they achieved the targeted INR values. METHODS: In this study, 300 male (60%, n=180) and female (40%, n=120) patients over 18 years of age who applied to warfarin polyclinic and were receiving warfarin treatment due to AF were included. The levels of INR between 2-3 were estimated as effective. Same questionnaire was applied to all patients. RESULTS: Our study showed that 57% of the patients who used warfarin were not in the therapeutic range. We also determined that INR awareness was extremely low in the majority of the patients. In this study, 72.2% of the patients who used warfarin did not know the definition of INR, 68% of the patients did not know the side effects of the medicine, 75.7% of the patients did not know the precautions needed to be taken in daily life and 83.7% of the patients did not know the foods rich in vitamin K. Patients who knew the meaning of INR were more likely have INR levels in the effective range, but these rates were not statistically significant. There was no statistically significant relationship between the educational level, marital status, and INR control frequency of the patients with the achievement of targeted INR levels. CONCLUSION: At the beginning of the warfarin treatment, advantages and disadvantages should be balanced by the doctor. The patient and patient’s relatives should be informed directly and comprehensibly about the effects and side effects of the medicine, as well as the interactions, pursuance and precautions need to be taken in daily life. Various modern methods should be enabled for surveillance and the patients who are not in the therapeutic range should be followed closer.