More than half of adult patients who had a length of stay (LOS) ≥2 days in US-care hospitals met American College of Chest Physicians (ACCP) criteria for consideration of venous thromboembolism prophylaxis, a recent study found. 3 risk assessment algorithms based on 2004, 2008, and 2012 ACCP guidelines for prevention of venous thromboembolism were applied to the 2014 US National Inpatient Sample to derive estimates of the annual number of US inpatients at risk for venous thromboembolism. Researchers found:

• Of 35.4 million discharges from US acute-care hospitals in 2014, 25.3 million (71%) met study inclusion criteria of age ≥18 years and LOS ≥2 days.
• Among 7.5 million patients who underwent a procedure in an operating room, >4.4 million (59%) were at ACCP-defined risk of venous thromboembolism.
• The total annual number of inpatients at risk for venous thromboembolism were 12.8/12.9/11/7 million according to 2004/2008/2014 ACCP guidelines, respectively.