The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE): Venous Thromboembolism Prophylaxis Practices in Acutely Ill Medical Patients.

Background Despite consensus group recommendations indicating that medical patients should receive appropriate venous thromboembolism (VTE) prophylaxis, prophylaxis practices remain poorly characterized. This analysis of IMPROVE, a prospective study of acutely ill medical patients, describes in-hospital prophylaxis practices prior to the publication of updated VTE prevention guidelines by the American College of Chest Physicians.

Methods Patient recruitment began in July 2002. Patients ≥18 years old, and hospitalized for ≥3 days with an acute medical illness are enrolled consecutively. Exclusion criteria are: therapeutic antithrombotics/thrombolytics at admission; major surgery or trauma during 3 months prior to admission; and VTE treatment begun within 24 hours of admission.

Results Data were from 4315 patients (32% from USA) enrolled up to 30 June 2004 in 37 hospitals in 11 countries (76% with 3-month follow-up data). Patients are 50% female, median (IQR) age 69 (50–80) years, median length of hospital stay 8 (5–14) days, median weight 68 (58–80) kg, and 40% were immobile for ≥3 days (median length of immobility 7 [4–14] days, including immobility immediately prior to admission). In-hospital VTE prophylaxis was received by 41% of patients (Table 1). Of patients with no risk factors (44%), one risk factor (40%), or ≥2 risk factors (16%), 25%, 49%, and 67% received prophylaxis, respectively. 12% of IMPROVE patients would have been eligible for inclusion in the MEDENOX study. Of these, only 52% received prophylaxis in hospital. Prophylaxis was provided to 6% of patients during the 3-month follow-up period, and continued in 11% of patients after discharge.

Conclusions Only 41% of IMPROVE patients received VTE prophylaxis, with considerable variation in types and regimens of prophylaxis used. While MEDENOX showed the benefits of VTE prophylaxis (enoxaparin 40 mg) in acutely ill medical patients, only half of MEDENOX-eligible patients received prophylaxis.

Table 1. Use of in-hospital VTE prophylaxis (N=4315)