Analysis of venous thromboprophylaxis duration and outcomes in orthopedic patients.

BACKGROUND

Venous thromboembolism (VTE) following total hip replacement (THR) and total knee replacement (TKR) surgery imposes significant health and economic burden.

OBJECTIVE

To examine the impact of thromboprophylaxis duration on deep vein thrombosis (DVT), pulmonary embolism (PE), total VTE (DVT and PE), and bleeding events among THR/TKR patients.

METHODS

A retrospective study (April 1, 2004, to December 31, 2006) was conducted using a US health plan claims database linked to an inpatient database containing medication use. Outcomes were compared using χ2 tests; predictors of outcomes were analyzed using multivariate logistic regression.

RESULTS

Of 3497 patients, 3195 (91%) received thromboprophylaxis for =1 day postsurgery. Most patients (67%) received short-duration (1-14 days) rather than extended-duration (>14 days) thromboprophylaxis. The incidence of thromboembolic and bleeding events was higher in those who received short-duration thromboprophylaxis: DVT (2.84% vs 1.24%; P = .0038), PE (1.12% vs 0.19%; P = .0052), total VTE (3.96% vs 1.43%; P <.0001), and major bleeding (1.68% vs 0.38%; P = .0011). Multivariate logistic regressions (adjusted for observed demographic and clinical characteristics) revealed similar results. Baseline comorbidity score was significantly associated with major bleeding; most of the bleeding events in those who received short-duration thromboprophylaxis occurred within the first 14 days.

CONCLUSIONS

In this database analysis of patients who had undergone THR/TKR surgery, a large proportion of patients did not receive the minimum duration of thromboprophylaxis recommended by the guidelines. Extended-duration thromboprophylaxis was associated with a significantly lower risk of DVT, PE, and VTE compared with short-duration thromboprophylaxis.