Evaluation of patients' knowledge on their vitamin K antagonist treatment.

INTRODUCTION: Vitamin K antagonists (VKA) are currently the most prescribed oral anticoagulant treatment in Tunisia. Despite the standardization of biological monitoring and the better definition of therapeutic objectives, their side effects are a frequent reason for hospitalization.

AIM: To evaluate patients' knowledge about their VKA treatment.

METHODS: We realized a cross-sectional descriptive study in the Cardiology Department of HabibThameur Hospital from September to October 2016. A questionnaire consisting of 14 items was used in a semi-directed interview in order to assess patients' knowledge on their VKA treatment.

RESULTS: Our study included one hundred patients. Mean age was 61 ± 12 years and sex ratio of 1.8. Forty-eight per cent were illiterate. The median duration of AVK intake was 5 years. Atrial fibrillation (AF) was the most frequent indication (57%). Eighty percent of patients had more than five correct answers on the eight items of knowledge: VKA's name (96%), tablet description (93%), dose (99%), time (94%), VKA's effect (70%), INR (56%), treatment's risk (49%) and the target INR (20%). Twenty-two percent had more than four correct answers on the 6 items of know-how: what to do in case of haemorrhage (70%), what to do in case of oblivion (45%), interactions precautions to be observed with food (13%), activities advised against (49%) and medical procedures advised against (27%). In multivariate analysis, only prior VKA information was significantly associated with a better knowledge of VKA (p = 0.027).

CONCLUSION: Our patients' knowledge on their VKA treatment was insufficient to ensure the safety and efficacy of treatment. The creation of a therapeutic education program on is therefore necessary to reduce the iatrogenic risk of this treatment.