Risk for Venous Thromboembolism High After Hospital Discharge

Laurie Barclay, MD
July 13, 2007 — A high proportion of patients are at risk for venous thromboembolism (VTE) after hospital discharge, according to the results of a study reported in the July issue of the American Journal of Hematology.
"Our findings suggest that each year, almost one-third of hospitalized patients are at risk of VTE," lead author Frederick Anderson, MD, from the University of Massachusetts Medical School, Worcester, says in a news release. "This highlights the magnitude of the US public health risk posed by this potentially preventable condition."
The objective of this study was to estimate the number of inpatients in US acute-care hospitals who were at risk for VTE, using criteria established by the Seventh American College of Chest Physicians (ACCP) Consensus Conference on Antithrombotic and Thrombolytic Therapy guidelines for VTE prevention.
Using the 2003 Nationwide Inpatient Sample from the Healthcare Cost and Utilization Project, the investigators identified patients undergoing major surgery who were over 18 years of age and had a length of hospital stay of 2 days or more, as well as medical patients 40 or more years of age with a length of hospital stay of 2 or more days. ACCP guidelines were used to estimate the number of surgical and medical patients who were at risk of developing VTE.
Of an estimated 38,220,659 discharges in 2003, 7,786,390 (20%) were surgical inpatients. Of these, 44% were at low risk, 15% were at moderate risk, 24% were at high risk, and 17% were at very high risk for VTE.
Of the remaining 15,161,586 medical patients, 7,742,419 (51%) met ACCP criteria for risk for VTE. Overall, more than 12 million patients (31% of US hospital discharges in 2003) were at risk for VTE.
"Given the existence of internationally-accepted evidence-based guidelines for prevention of VTE, research is required to establish if this patient population is receiving recommended VTE prophylaxis," the authors write.
Study limitations include inability to determine whether or not the at-risk patients did indeed receive VTE prophylaxis and whether antithrombotic therapies, when used, were given appropriately.
"This large number of inpatients at risk for VTE provides support for developing and monitoring compliance with hospital protocols and national guidelines for VTE prevention," the authors conclude. "Furthermore, based on the large number of patients at risk, our data add strength to the argument that VTE prevention should be high on the list of priorities when health care policies are being formed."
Sanofi-Aventis supported this study.
In an accompanying editorial, Samuel Z. Goldhaber, MD, from Harvard University and Brigham and Women's Hospital in Boston, Massachusetts, praises this study for its significant contribution toward raising awareness of VTE and thereby improving prophylaxis for hospitalized patients.
"VTE risk does not simply evaporate when patients are discharged from hospitals," Dr. Goldhaber says. "Anderson and his group have defined a broad 'base of the iceberg' of danger. However,
the fundamental problem is even more profound and goes beyond the millions of hospitalized patients annually that they have identified."
Am J Hematol. Published online July 13, 2007.