Evaluation of patients’ knowledge on warfarin in outpatient pharmacy of a tertiary care cardiac center

Abstract

BackgroundWarfarin is widely used for the prevention and treatment of cardiac, thromboembolic and hypercoagulable diseases. Since warfarin is a narrow therapeutic index medicine, it requires close monitoring when used in the outpatient setting and on long term basis. Warfarin has been found to be associated with a number of complications especially bleeding. Patients’ knowledge on warfarin can improve anticoagulation control with decrease in adverse drug reaction and other associated complications. The objective was to assess knowledge level of warfarin therapy among its users and to provide adequate education and counseling to the patients.MethodsIn the present cross sectional study, 34 patients on warfarin were interviewed. Patients’ knowledge on warfarin was assessed using a validated Anticoagulation Knowledge Assessment (AKA) questionnaire comprising 29 questions. Each correct answer scored 3.45 points whereas an incorrect answer scored zero point. Patient who answered at least 21 questions correctly or scored (21 × 3.45 = 72.4 %) was considered to have adequate level of knowledge or have obtained a passing score. Association between independent variables and AKA score was assessed using Pearson Chi square test or Fisher’s exact test for categorical variables. Patients were counseled regarding proper warfarin use by the researcher pharmacists at the end of each data collection schedule.ResultsOf the 34 patients, only 5.8 % (n = 2) achieved a passing score whereas 94.1 % (n = 32) failed to achieve the passing score. 67.6 % of the patients (n = 23) achieved a score below 50 %. More than 50 % of the patients incorrectly answered 15 questions in the questionnaire. None of the patients scored 100 %. No significant association was found between age, gender of patients and total warfarin score. A significant association (p < 0.05) was found between duration of warfarin therapy and total warfarin score.ConclusionsWarfarin knowledge was poor among the patients. Hence, regular counseling with timely assessment of their understanding was felt necessary.

Patient Knowledge about Oral Anticoagulation Therapy Assessed during an Intermediate Medication Review in Swiss Community Pharmacies

“…Our findings of inadequate OAC knowledge in chronic patients during a medication review such as the PMC (Part A) is in agreement with results of other studies that investigated patient knowledge about OAC [6,28,29].…”

Assessment of patients&rsquo; warfarin knowledge and anticoagulation control at a joint physician- and pharmacist-managed clinic in China

“…The AKA questionnaire was selected to assess patients’ warfarin knowledge. 8 – 10 The AKA questionnaire comprises 29 multiple-choice questions related to different aspects of warfarin therapy. The English questionnaire was translated into a Chinese version according to the standard translation procedures.…”

“…It has been shown that patients’ knowledge of warfarin can improve anticoagulation control, with a decrease in adverse drug reaction and other associated complications. 8 To date, there have been no studies that have either assessed the knowledge level among warfarin users in mainland China or examined the relationship between patients’ warfarin knowledge and anticoagulant control. There is an urgent need to identify the factors related to patients’ INR variations through assessment of patients’ warfarin knowledge.…”

Are Patients on Oral Anticoagulation Therapy Aware of its Effects? A Cross-sectional Study from Karachi, Pakistan

“…Despite the prevalence of their use and risk of serious adverse effects, several studies have shown that most patients do not have adequate knowledge of the OAC they are using 5,6 . Other studies have found that long-term outcomes of OAC are better when patients possess greater knowledge regarding OAC medications 7,8 .…”