Standardized Thromboembolism Prophylaxis in Orthopedic Patients to Prevent Venous ThromboEmbolism Study: A Novel Prospectively Validated Electronic Risk Stratification Tool for Elective Hip and Knee Joint Replacement Patients.

Background: Venous thromboembolism (VTE) includes pulmonary embolism (PE), and deep vein thrombosis (DVT) and is a complication of total hip and knee (THR/TKR) joint replacement surgery. Guidelines historically recommended anticoagulation thromboprophylaxis for patients undergoing elective THR/TKR, and aspirin has emerged as an alternative for select patients. VTE risk stratification may identify patients who can safely receive aspirin. Limited evidence informs how to risk-stratify THR/TKR patients, then recommend risk-stratified thromboprophylaxis. Methods: We derived and implemented "Standardized Thromboembolism Prophylaxis in Orthopedic Patients to prevent Venous ThromboEmbolism (STOP-VTE)," an evidence-based electronic heath record embedded VTE risk assessment model in our 23-hospital-integrated health system. The model classified patients as at high or standard risk of VTE and recommended anticoagulation (mostly apixaban 2.5 mg twice daily for 28 days) or aspirin (81 mg twice daily) prophylaxis, respectively. The primary implementation outcome for this prospective management study was adherence to STOP-VTE guidance, and the primary clinical outcome was VTE. Among 38,207 consecutive patients, we recorded surgeon adherence to STOP-VTE guidance and outcome rates of 90-day VTE, PE, DVT, mortality, and rates of 30-day major bleeding, emergency department visits, and hospitalization. Outcomes were recorded for 2 years preceding implementation of STOP-VTE (baseline) and for 6.8 years after STOP-VTE implementation (intervention). Results: For the primary implementation outcome during the baseline period, 57.4% (1,467/2,554) received aspirin or anticoagulant prophylaxis consistent with risk classification, and during the intervention, this rate increased to 77.8% (27,744/35,653; p < 0.001). Clinical outcome rates at baseline vs. intervention were the following: for 90-day VTE, 0.9% vs. 0.65%; PE, 0.7% vs. 0.39%; DVT, 0.31% vs. 0.29%; and mortality, 0.16% vs. 016%. Thirty-day major bleeding was 0% vs. 0.04%; emergency department and rehospitalization rates were 6.97% vs. 5.31% and 2.45% vs. 1.71%, respectively. Pulmonary embolism, emergency department, and hospitalization visit rates significantly declined. Conclusion: STOP-VTE guidance was implemented and broadly adopted. Adherent chemoprophylaxis was associated with low rates of 90-day VTE, major bleeding, decrease in anticoagulant chemoprophylaxis, increase in aspirin chemoprophylaxis, and cost savings. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.