Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common post-operative complication. The necessity for anticoagulant therapy after orthopedic surgeries is widely understood, but treatment administration patterns in the prevention of venous thromboembolism (VTE) after orthopedic surgeries during the hospital stay have yet to be examined.

The main objective of this study is to perform a comparative effectiveness review examining the benefits and harms associated with venous thromboembolism prophylaxis in patients undergoing orthopedic surgeries.

It is around efficacy and safety evaluation of using anticoagulant for thromboprophylaxis in patients undergoing orthopedic surgeries taking into the account the reliable selection of patients most benefit.

The aims of this study is to analyze patient records in teaching hospitals database of our country (including: Hanoi Medical University, Bach Mai Hospital, Cho Ray Hospital, Viet Duc University Hospital) and compare the outcomes and costs between different types of anticoagulant medications that were prescribed for the prevention of VTE following orthopedic surgeries. This analysis will assess and quantify the outcomes, resource utilization, and cost of care for patients receiving rivaroxaban or enoxaparin. The outcomes of interest include the occurence of DVT and PE, rates of major bleeds, medical resource utilization, and total costs (medical plus pharmacy).

Inclusion Criteria:

• Undergo Orthopedic Surgery
• Thromboprophylaxis Decision Taken
• At least 18 years of age

Exclusion Criteria:

• Planned intermittent pneumatic compression
• A requirement for anticoagulant therapy that could not be stopped
• Severe hypersensitivity reaction (eg, anaphylaxis) to rivaroxaban or enoxaparin.
• Received another anticoagulant for more than 24 hours
• Active bleeding or a high risk of bleeding
• Thrombocytopenia associated with a positive test for antiplatelet antibody.
• Warfarin associated international normalized ratio (INR) more than 1.5 on the day of the surgery
• Conditions preventing bilateral venography
• Intensive care unit (ICU) stay after surgery
• Pregnant or breast-feeding
• Creatinine clearance less than 30 ml per minute or acute renal failure before the surgery or at any point during the study period.
• Moderate or Severe (Child Pugh B or C) hepatic Impairment or in patients with any hepatic disease associated with coagulopathy.
• Concomitant use of drugs that are both P--glycoprotein inhibitors and moderate to strong cyp3a4 (ketoconazole, itraconazole, lopinavir/ritonavir, ritonavir, indinavir/ritonavir & conivaptan)
• Creatinine clearance (CrCl) 15 to 80 mL/min and concurrent use of P-glycoprotein inhibitors or moderate CYP3A4 inhibitors (eg, abiraterone acetate, diltiazem, dronedarone, erythromycin, verapamil)

Patients aged 18 years or older who experienced a orthopedic surgeries during the hospitalization were the initial target population.