Venous thrombosis (VTE), the formation of blood clots in a vein, is a major health problem for hospitalized patients in the United States.
In the short term, VTE can lead to
deep vein thrombosis (DVT), typically in the legs, and
pulmonary embolism (PE), which occurs when a piece of the
blood clot migrates into an artery of the lungs.
Evidence implicates PE in up to 10 percent of sudden in-hospital deaths. In the long term, VTE can lead to post-thrombotic syndrome (PTS), marked by persistent leg pain, swelling, and cramps, or pulmonary hypertension. Fortunately, such dire complications are easy to avoid through preventive strategies, from compression boots to anti-clotting medications. Unfortunately, inpatients at risk for VTE are routinely overlooked.
To provide a clear, quantitative sense of the scope of this problem, researchers at the University of Massachusetts Medical School and Mayo Clinic College of Medicine set out to estimate the total number of US inpatients at risk for VTE , a crucial figure previously unknown. Their results, which will be published online in the American Journal of Hematology ( http://www.interscience.wiley.com/journal/ajhstrongly support the need for reinforcing established national guidelines for identifying patients at risk for VTE, as well as monitoring compliance with hospital protocols for VTE prevention.
"Our findings suggest that each year, almost one-third of hospitalized patients are at risk of VTE," notes the study's lead author, Dr. Frederick Anderson. "This highlights the magnitude of the US public health risk posed by this potentially preventable condition."
To determine the number of hospitalized patients at 'substantial risk, for developing VTE, Dr. Anderson and his colleagues used criteria defined by the American College of Chest Physicians (ACCP) , widely respected guidelines that have been available to physicians across the country for 15 years. They applied them to the Nationwide Inpatient Sample (NIS), the largest all-payer inpatient care database in the US, containing information on over 8 million hospital stays, for 2003. That year, an estimated 38,220,659 patients were discharged from roughly 6,000 acute-care hospitals. 56 percent of these patients (21, 574, 294 individuals) met the study's inclusion criteria for age and length of hospital stay: two days or more, sufficient time to diagnose and prescribe VTE prevention. Of the study population, 20 percent (7,786,390 individuals) were surgical patients ages 18 and older, and 40 percent (15,161,586 individuals) were patients ages 40 and older hospitalized for a serious medical condition.