Post-discharge venous thromboembolism and bleeding in a large cohort of patients undergoing total hip or total knee arthroplasty

• Objective: To examine the incidence of and risk factors for venous thromboembolism (VTE) and bleeding in a US population of total hip or total knee arthroplasty (THA/TKA) patients. • Design: Retrospective database study. • Setting: Health care claims records (2004-2009) from a large insurance plan linked to an inpatient database. • Participants: THA/TKA patients with no evidence of prior orthopaedic surgeries or prior VTE and no postdischarge orthopaedic surgeries. • Measurements: ICD-9-CM and CPT/HCPC codes were used to identify symptomatic VTE and bleeding events up to 90 days post-surgery. • Results: Of 9167 linked patients (3109 THA; 6058 TKA; median age 60 years; mean Charlson-Quan comorbidity score 0.5), 98% received thromboprophylaxis in hospital and 26% received it post-discharge. Mean overall duration of antithrombotic drug exposure was 10.7 days. 226 (2.5%) patients experienced VTE, and 324 (3.5%) had bleeding. Consistent covariates of post-discharge VTE and bleeding were inpatient VTE or bleeding events, respectively, and all-cause rehospitalization. Post-discharge thromboprophylaxis did not achieve statistical significance as a bleeding risk factor. • Conclusion: Patients who experience VTE or bleeding events during index hospitalization and those rehospitalized within 90 days have higher odds of postdischarge thromboembolic and bleeding outcomes, respectively. Post-discharge thromboprophylaxis for THA/TKA does not significantly increase the risk of post-discharge bleeding.