Effect of Knowledge on Medication Adherence and International Normalized Ratio (INR) Control Among Patients on Oral Anticoagulants: A Randomized Controlled Trial

Abstract

Background: Anticoagulants must be provided with careful monitoring and adjusted individual dose due to their narrow therapeutic index due to significant risk of medication-drug interactions, drug-food interactions, and adverse drug reactions. Regular monitoring of INR, adequate knowledge and adherence to oral anticoagulant therapy plays a vital role in achieving better therapeutic outcomes. Thus, our study aims to assess level of adherence and knowledge of the patients.Materials and Methods: A prospective interventional study, enrolled 66 patients (control 33) and intervention (33) of both IPD (Inpatient Department) or OPD (Outpatient Department) patients with thromboembolic disorders between the age of 18-65 years and who were on oral anti-coagulant therapy. Utilization of Morisky medication adherence scale (MMAS-8) and Oral Anticoagulant Knowledge (OAK) questionnaire to assess adherence and knowledge on oral anti coagulation therapy.Results: Out of 66 patients, 56.1% male patients predominate over the 43.9% female patients, most of them were of age between 41-50 years. Majority of the patients of the intervention group were highly adhered (27.3%), moderately adhered (51.5%) and have adequate knowledge (90.9%) at follow ups after providing pharmaceutical care. Therapeutic INR has been improved among 36.4% patients. Most common cause for non-adherence is forgetfulness.Conclusion: Collaboration with clinical pharmacists can increase anticoagulant adherence and provide necessary information. Anticoagulant clinics run by pharmacists have shown to be helpful in managing anticoagulation treatment for both hospitalized and outpatient patients.

Keywords: Adherence; International Normalized Ratio; Knowledge; Oral anticoagulants