September 2007

Thromboprophylaxis Rates In US Medical Centers: Success or Failure?

Amin A, Stemkowski S, Lin J, et al.  Thromboprophylaxis rates in US medical centers:  success or failure?  J Thromb Haemostas 2007; 5: 1610-1616.

ABSTRACT: BACKGROUND: As hospitalized medical patients may be at risk of venous thromboembolism (VTE), evidence-based guidelines are available to help physicians assess patients' risk for VTE, and to recommend prophylaxis options. The rate of appropriate thromboprophylaxis use in at-risk medical inpatients was assessed in accordance with the 6th American College of Chest Physicians (ACCP) guidelines.  METHODS: Hospital discharge information from the Premier Perspective™ inpatient data base from January 2002 to September 2005 was used. Included patients were 40 years old or more, with a length of hospital stay of 6 days or more, and had no contraindications for anticoagulation. The appropriateness of VTE thromboprophylaxis was determined in seven groups with acute medical conditions by comparing the daily thromboprophylaxis usage, including type of thromboprophylaxis, dosage of anticoagulant and duration of thromboprophylaxis, with the ACCP recommendations. RESULTS: A total of 196 104 discharges from 227 hospitals met the inclusion criteria. The overall VTE thromboprophylaxis rate was 61.8%, although the appropriate thromboprophylaxis rate was only 33.9%. Of the 66.1% discharged patients who did not receive appropriate thromboprophylaxis, 38.4% received no prophylaxis, 4.7% received mechanical prophylaxis only, 6.3% received an inappropriate dosage, and 16.7% received an inappropriate prophylaxis duration based on ACCP recommendations. CONCLUSIONS: This study highlights the low rates of appropriate thromboprophylaxis in US acute-care hospitals, with two-thirds of discharged patients not receiving prophylaxis in accordance with the 6th ACCP guidelines. More effort is required to improve the use of appropriate thromboprophylaxis in accordance with the ACCP recommendations.

The Amin Report: Low Rates of VTE Prophylaxis Persist in the US Medical Centers

Review by Kim M. Hickman, BS and Samuel Z. Goldhaber, MD

Amin and colleagues (1) studied 200,000 high-risk hospitalized medical patients and showed that U.S. hospitals have failing grades for thromboprophylaxis against pulmonary embolism (PE) and deep vein thrombosis (DVT).  The absolute rate of prophylaxis was low.  And among those prophylaxed, the pharmacologic regimens were often inadequate with respect to proper drug, dose, and duration. 

The overall VTE thromboprophylaxis rate should have been 100% but was only 62%, of whom only half received appropriate prophylaxis.  The least frequently prophylaxed patients had cancer, severe lung disease, or acute spinal cord injury (without undergoing surgery).  Fortunately, there was a slight trend toward increasing use of appropriate prophylaxis when assessing the data year-by-year from 2002 through 2005.  Among Internal Medicine and Subspecialty Medicine physicians, cardiologists had the highest rate of appropriate VTE prophylaxis.  Ironically, hematologists and oncologists had one of the lowest rates of prophylaxis. 

In a separate survey of inpatients in Canada, the situation may be even bleaker.  Of 4,124 Canadian medical admissions, only 16% received appropriate prophylaxis (2). 

Evidence-based medicine justifies VTE prophylaxis.  There is an 8-fold greater death rate from autopsy proven PE among unprophylaxed surgical patients (3).  And three major pharmacological prophylaxis trials in hospitalized medical patients—MEDENOX (4), PREVENT (5), and ARTEMIS (6)—showed that VTE prophylaxis can cut the rate of VTE in half.  Meta-analyses confirm these findings (7, 8).  Furthermore, asymptomatic proximal DVT at 3 weeks after hospitalization is associated with a marked increase in death rates at 90 days (9). 

VTE is much easier and less expensive to prevent than to diagnose or treat (10).  And by preventing inpatient VTE, the rate of community-acquired outpatient VTE will decrease because most outpatient VTE can be traced back to a hospitalization or surgical procedure within the prior 90 days (11). 

As a community of investigators interested in VTE, we need to deliver a unified message that VTE prophylaxis is important.  Education and ongoing research such as our multicentered Human Alert Trial will prove crucial. 

References:

1. Amin A, Stemkowski S, Lin J, et al.  Thromboprophylaxis rates in US medical centers:  success or failure?  J Thromb Haemostas 2007; 5: 1610-1616.
2. Kahn SR, Panju A, Geerts W, et al.  Multicenter evaluation of the use of venous thromboembolism prophylaxis in acutely ill medical patients in Canada.  Thrombosis Research 2007; 119: 145-155.
3. International Multicentre Trial: Prevention of fatal postoperative pulmonary embolism by low doses of heparin. Lancet 1975 July 12;45-51.
4. Samama MM, Cohen AT, Darmon JY, et al: A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. Prophylaxis in Medical Patients with Enoxaparin Study Group. N Engl J Med 1999;341:793-800.
5. Leizorovicz A, Cohen AT, Turpie AG, et al: Randomized, placebo-controlled trial of dalteparin for the prevention of venous thromboembolism in acutely ill medical patients. Circulation 2004; 110:874-879.
6. Cohen AT, Davidson BL, Gallus AS, et al: Efficacy and safety of fondaparinux for the prevention of venous thromboembolism in older acute medical patients: randomised placebo controlled trial. BMJ 2006; 332:325-329. 
7. Dentali F, Douketis JD, Gianni M, Lim W, Crowther MA. Meta-analysis: Anticoagulant prophylaxis to prevent symptomatic venous thromboembolism in hospitalized medical patients.  Annals of Internal Medicine. 2007; 146: 278-288.
8. Wein L, Wein S, Haas SJ, Shaw J, Krum H. Pharmacological venous thromboembolism prophylaxis in hospitalized medical patients a meta-analysis of randomized controlled trials. Arch Intern Med. 2007; 167: 1476-1486.
9. Vaitkus PT, Leizorovicz A, Cohen AT, Turpie AG, Olsson CG, Goldhaber SZ.  Mortality rates and risk factors for asymptomatic deep vein thrombosis in medical patients.  Thromb Haemost. 2005; 93: 76-79.
10. Goldhaber SZ, Turpie AG. Prevention of venous thromboembolism among hospitalized medical patients. Circulation. 2005; 111: e1-3.
11. Spencer FA, Lessard D, Emery C, Reed G, Goldberg RJ. Venous thromboembolism in the outpatient setting.  Arch Intern Med. 2007; 167: 1471-1475.

About Kim M. Hickman, BS: Kim Hickman is Research Coordinator for the Venous Thromboembolism Research Group at Brigham and Women’s Hospital.  Kim has spent the past several years working with Dr. Goldhaber’s team on numerous research and education projects.  Her primary research interest is the Physician Alert Trial, a national multicenter trial set to enroll 2,500 patients.