The Incidence and Economic Burden of In-Hospital Venous Thromboembolism in the United States.

BACKGROUND: Venous thromboembolism (VTE) is a potentially preventable and costly complication after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The in-hospital incidence and economic burden of VTE following total joint arthroplasty (TJA) in the United States is unknown. The aim of this study was to examine this issue.
METHODS: The Nationwide Inpatient Sample was used to estimate the total number of THA, TKA, and VTE events using International Classification of Diseases, Ninth Revision procedure codes from years 2002 to 2011. The rate of in-hospital deep vein thrombosis (DVT) and pulmonary embolism (PE), associated length of hospitalization, and current and projected in-hospital charges were obtained.
RESULTS: Revision arthroplasties had higher rates of in-hospital VTE compared to primary TJAs (2.5% vs 1.6%, P < .0001). Among primary TJAs, the median rate of in-hospital VTE was 0.59% (0.55%-0.63%) for primary THA and 1.01% (0.94%-1.08%) for primary TKA. Revision THAs developed more VTE events compared to revision TKAs (1.35% [1.25%-1.46%] vs 1.16% [1.07%-1.26%]). Patients with a VTE have longer hospitalizations (median primary TKA: 7 vs 3; median primary THA: 6 vs 3, P < .0001). The overall rate of VTE decreased over the last decade; however, the PE rates have remained relatively constant. Moreover, the associated costs with VTE events have increased significantly over the last decade.
CONCLUSION: Based on the analysis of the Nationwide Inpatient Sample database, the rate of in-hospital DVT following TJA appears to have declined over the last decade while the incidence of PE has remained constant. This may indicate that the current recommendations by the American Academy of Orthopaedic Surgeons for VTE prophylaxis are adequate for preventing DVT without increasing the rate of PE or that institutional screening and reporting of DVT has been reduced because DVTs became a "never" event.