Thromb Haemost 2010; 104(05): 955-961
DOI: 10.1160/TH10-04-0236
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Does ambulation modify venous thromboembolism risk in acutely ill medical patients?

Alpesh N. Amin
1  University of California-Irvine, Orange, California, USA
Frederick Girard
2  sanofi-aventis, Bridgewater, New Jersey, USA
Meyer M. Samama
3  Hotel Dieu University Hospital, Paris, France
› Author Affiliations
Financial support: The authors received editorial/writing support in the preparation of this manuscript funded by sanofi-aventis U.S., Inc. The authors are fully responsible for all content and editorial decisions and received no financial support or other form of compensation related to the development of the manuscript.
Further Information

Publication History

Received: 16 April 2010

Accepted after major revision: 02 July 2010

Publication Date:
24 November 2017 (online)


In the US, ambulatory status is often a criterion for stopping prophylaxis for venous thromboembolism (VTE). In an analysis of the prophylaxis in MEDical patients with ENOXaparin (MEDENOX) trial, ambulatory status was assessed as outcome and patients grouped accordingly for further analysis. Rates of VTE and bleeding were evaluated. Using multivariate logistic regression, the relationships between thromboprophylaxis, VTE risk, and ambulatory status were assessed. Ambulatory status was reached in 607/1,084 patients, in a mean time of 4.4 days. Thromboprophylaxis was provided for 7.3 and 7.7 days in the ambulatory and non-ambulatory groups. Although VTE rates were lower in ambulatory patients, enoxaparin 40 mg once daily significantly reduced the risk of VTE vs. placebo in ambulatory (3.3% vs. 10.6%; relative risk [RR] = 0.31; 95% confidence interval [CI], 0.13ﺹ0.78; p=0.008) and non-ambulatory patients (9.0% vs. 19.7%; RR = 0.46; 95% CI, 0.23ﺹ0.91; p=0.02). Major bleeding was not significantly different between enoxaparin and placebo in either group. By multivariate regression analysis, VTE risk in ambulatory patients was lower with enoxaparin vs. placebo (odds ratio [OR] = 0.28; 95% CI, 0.11ﺹ0.74; p=0.01), but higher in patients with a history of VTE (OR = 3.74; 95% CI, 1.59ﺹ8.84; p=0.003) or cancer (OR = 2.12; 95% CI, 1.00ﺹ4.48; p=0.049). Despite timely mobilisation, patients who become ambulatory are at VTE risk and experience a significant risk reduction with enoxaparin 40 mg. Therefore, it is essential that ambulatory patients receive recommended thromboprophylaxis.