Prescription Patterns of Non-Vitamin K Oral Anticoagulants Across Indications and Factors Associated with Their Increased Prescribing in Atrial Fibrillation Between 2012-2015: A Study from the Norwegian Prescription Database.

Abstract

We studied prescription patterns for non-vitamin K oral anticoagulants (NOACs) in Norway between 2012 and 2015, and compared NOAC and warfarin patient characteristics such as age, gender and cardiovascular (CV) co-medications across reimbursed indications. Factors associated with NOAC prescribing in atrial fibrillation (AF) were also analysed. All Norwegian patients (N=156,124) who received at least one dispensed NOAC or warfarin prescription within the indications of AF, deep vein thrombosis and pulmonary embolism (DVT_PE) or prevention of venous thromboembolic events after a hip or knee surgery (VTE_surg) between 2012 and 2015 were included in the study. Descriptive statistics was applied to compare patient characteristics between NOACs and warfarin across indications and a logistic regression model was used to identify factors associated with NOAC prescribing in AF. NOACs and warfarin were most commonly prescribed in AF (83,729 patients in 2015), followed by DVT_PE (16,077 patients) and lastly in VTE_surg (4060 patients). In 2015, NOACs achieved a dominant (>50%) patient share over warfarin in AF and DVT_PE, and were prescribed in>80% of new oral anticoagulation (OAC) patients. Apixaban, despite its delayed market entry, emerged as the preferred NOAC in VTE_surg (46% share), whereas rivaroxaban captured a 43% patient share in DVT_PE. Warfarin patients were on average older and received more CV co-medication than NOAC patients in AF and DVT_PE. Age, gender and certain CV co-medications emerged as significant predictors of NOAC prescribing in AF. AF patients <70years old had higher odds of NOAC prescribing (OR 1.19-1.29, depending on age category), in contrast to patients >74years old (OR 0.51-0.77). Women had 32% higher odds of receiving a NOAC in AF. NOACs achieved a dominant market share over warfarin within 3years from receiving reimbursement in Norway. There were significant differences in patient characteristics between drugs and indications.