Original Article Patterns and Predictors of Use of Anticoagulants for the Treatment of Venous Thromboembolism Following Approval of Rivaroxaban Roxanne Dault, MSc 1 , Alain Vanasse, MD, PhD 1,2 , Lucie Blais, PhD 2,3,4 , Sylvie Perreault, BPharm, PhD 3 , Paul Farand, MD, MSc 2,5 , Genevie `ve Le Templier, MD 6 , and Marie-France Beauchesne, PharmD 1,2,3,7 Abstract Background: Few studies have identified patterns and predictors of use of direct oral anticoagulants for venous thromboem- bolism (VTE). Objective: To describe the use of anticoagulants and assess predictors associated with the prescription of riv- aroxaban over vitamin K antagonist (VKA) for the subsequent treatment of VTE. Methods: This cross-sectional study was built with all consecutive patients newly diagnosed with acute VTE admitted between February 18, 2013, and September 18, 2013, in an academic tertiary care center in Quebec, Canada. Patient characteristics and VTE treatments were described. Univariate analyses and a multiple forward stepwise logistic regression were performed to assess predictors of rivaroxaban use over VKA for the subsequent treatment of VTE. Results: The study included 256 patients, 36.7% with a diagnosis of deep vein thrombosis (DVT) and 63.3% with pulmonary embolism (PE). Mean age was 63.1 years, and 28.1% of patients had cancer-associated VTE. Overall, rivaroxaban was prescribed in 1.6% of patients for the initial treatment and in nearly 20% of patients for the subsequent treatment of VTE. Low-molecular-weight heparin and VKA were mostly prescribed. Independent predictors associated with the pre- scription of rivaroxaban over VKA were as follows: age < 65 years (OR: 2.86, 95% CI 1.29-6.37), a diagnosis of DVT versus PE (OR 2.54, 95% CI 1.20-5.40), and an emergency department visit rather than a hospitalization (OR 2.24, 95% CI 1.06-4.71). Conclusion: Several months following its availability, rivaroxaban was rarely prescribed for acute VTE disease. It also appears to be prescribed in different patient populations than VKA. Keywords anticoagulant drugs, choice behavior, rivaroxaban, venous thromboembolism, warfarin Introduction In the general population, the annual incidence of venous throm- boembolism (VTE) is between 1 and 2 events per 1000 adults. 1 Anticoagulants are essential and effective in treating VTE symptoms, preventing pulmonary embolism (PE) in patients with deep vein thrombosis (DVT), and decreasing the risks of recurrent VTE and death. 2 However, they are associated with bleeding risks, and nearly 2% of patients will experience a major hemorrhage during a long-term treatment with an oral anticoa- gulant (vitamin K antagonist [VKA]), which may be fatal. 3 Standard treatment of VTE includes initial therapy with a par- enteral anticoagulant such as unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), or fondaparinux, fol- lowed by an oral VKA for at least 3 months. 4 Because the onset of anticoagulant activity with VKA is delayed for several days, an initial period of overlap with parenteral anticoagulant is used. 5 Vitamin K antagonists also require frequent monitoring 1 Faculty of Medicine and Health Sciences, Universite ´ de Sherbrooke, Sher- brooke, Quebec, Canada 2 Research Center, Centre hospitalier universitaire de Sherbrooke, Sher- brooke, Quebec, Canada 3 Faculty of Pharmacy, Universite ´ de Montre ´al, Montreal, Quebec, Canada 4 Research Center, Ho ˆpital du Sacre ´-Cœur de Montre ´al, Montreal, Quebec, Canada 5 Department of Cardiology, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Quebec, Canada 6 Department of Internal Medicine, Centre hospitalier universitaire de Sher- brooke, Quebec, Canada 7 Department of Pharmacy, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Quebec, Canada Corresponding Author: Marie-France Beauchesne, Department of Pharmacy, Centre hospitalier uni- versitaire de Sherbrooke, 580 Bowen Sud Street, Sherbrooke, Quebec, Canada J1G 2E8. Email: marie-france.beauchesne@umontreal.ca Clinical and Applied Thrombosis/Hemostasis 2016, Vol. 22(8) 765-771 ª The Author(s) 2015 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1076029615611249 cat.sagepub.com