Venous Thromboembolism Risk Huge for Hospitalized Patients

WORCESTER, Mass., July 13 -- More than 12 million hospitalized patients, 31% of U.S. hospital discharges in 2003, were at risk of venous thromboembolism, researchers reported.

But it still remains unclear whether this large group of medical as well as surgical patients received recommended prophylaxis, Frederick A. Anderson Jr., Ph.D., of the University of Massachusetts, and colleagues at the Mayo Clinic and in London reported online in the American Journal of Hematology.

With 5% to 10% of hospital deaths a direct result of pulmonary embolism, for example, venous thromboembolism is a major U.S. health problem, the researchers wrote.

However, they said, the total number of hospital patients at risk was not known.

To estimate that number, the researchers used the 2003 Nationwide Inpatient Sample from the Healthcare Cost and Utilization Project and treatment criteria set by the Seventh American College of Chest Physicians (ACCP) Consensus Conference on Antithrombotic and Thrombolytic Therapy.

The Nationwide Inpatient Sample included patients who'd had major surgery patients and were age 18 and older with a hospital stay of two or more days and medical patients age 40 or older with a similar-length hospital stay.

Of an estimated 38,220,659 discharges in 2003, 7,786,390 (20%) were surgical patients. Of these, 44% were at low risk for venous thromboembolism, 15% were at moderate risk, 24% were at high risk, and 17% were at very high risk, respectively.

Of the 15,161,586 medical patients, 7,742,419 (51%) met ACCP risk criteria, the researchers reported.

Although their study was not able to determine whether at-risk patients received prophylaxis, the researchers said, there are reports from the U.S. and elsewhere of poor levels of prophylactic therapy.

The researchers also acknowledged that their study was unable to assess whether antithrombotic therapies, when used, were given appropriately.

The large number of hospitalized patients at risk for this disorder provides support for developing and monitoring compliance with hospital protocols and national guidelines for prevention, the researchers said.

Furthermore, they added, considering the large number of patients at risk, the data add strength to placing prevention high on the list of priorities when health care policies are being formed.

In an accompanying editorial, Samuel Z. Goldhaber, M.D., of Harvard, wrote that Dr. Anderson and his group have defined a

broad ''base of the iceberg'' of a risk he called "staggering."

However, he noted, what happens in the hospital (such as lapses in good hospital practice) does not necessarily stay in the hospital.

Failure to protect against venous thromboembolism, he said, may have potentially devastating implications for months after hospital discharge.

Those who do not receive preventive measures, Dr. Goldhaber said, will more than likely develop deep vein thrombosis or pulmonary embolism within the ensuing 90 days, either in a skilled nursing facility or at home in the community.

In fact, he said, immobility and clot risk might increase after discharge because fewer nurses and therapists are available to ensure ambulation and exercise.

Do patients who continue to require prophylaxis receive prescriptions for preventive measures when they are discharged from the hospital? If prophylaxis is ordered, what is the duration of the prophylaxis prescription? Are patients properly instructed about the risk upon discharge?

These questions mark the final frontier of venous thromboembolism prevention, Dr. Goldhaber wrote.

Dr. Goldhaber had no financial disclosures to report.