Use and Adherence to Oral Anticoagulants in a Tertiary Care Hospital

Background: In patients at risk of thromboembolism, oral anticoagulants (OAC) are effective, but there are limited data from India on OAC use and adherence. This study in a tertiary care hospital aims to record the pattern of prescription of OAC and medication adherence over 6 months. Materials and Methods: Medications prescribed were recorded, and a follow-up at 3 and 6 months was done to record outcomes and adherence to medication. Modified Morisky medication adherence scale (MMAS-8) was used and compliance to monthly International Normalized Ratio (INR) monitoring was recorded. Results: Of the 140 patients included, mean age was 55.32 (±18.04 years), and 84 (60.0%) were males. Indications for OAC were deep vein thrombosis 64 (45.7%) and atrial fibrillation 42 (30.0%). After initial injectable anticoagulants, majority of patients were shifted to Vitamin K antagonists. Most common OAC was nicoumarol 73 (52.1%), followed by warfarin 43 (30.2%), dabigatran 12 (9.2%), and apixaban 12 (9.2%). Over 6 months, 12 patients were lost to follow-up and 16 (11.4%) deaths were recorded. Monthly INR was done by 23 patients till the 3 rd month but only by five patients between 3 rd and 6 th month. By the 3 rd month, 19 (86.3%) and between 3 rd and 6 th month 4 (13.7%) patients were nonadherent. At 6 th month, 78 (86.6%) had a MMAS-8 score of 8 (high adherence). The presence of a caretaker in 37 (41.2%) emerged as the most important factor contributing to adherence. Conclusion: Early identification of patient-specific barriers for INR monitoring and adherence to medications should be sought in patients with thromboembolism.