Magnitude of Venous Thromboembolism Risk in US Hospitals: Impact of Evolving National Guidelines for Prevention of Venous Thromboembolism.

BACKGROUND: The annual number of US hospital discharges at risk for venous thromboembolism and the impact of evolving American College of Chest Physicians (ACCP) consensus guidelines for prevention of venous thromboembolism are unknown.

METHODS: Three 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.

RESULTS: 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 length of stay (LOS) ≥2 days. Among 7.5 million patients who underwent a procedure in an operating room, more than 4.4 million (59%) were at ACCP-defined risk for venous thromboembolism, irrespective of which version of the ACCP guidelines applied. With an additional 8.4/8.5/7.3 million eligible discharges meeting criteria for venous thromboembolism prophylaxis due to medical risk factors, the total annual numbers of inpatients at risk for venous thromboembolism were 12.8/12.9/11.7 million according to 2004/2008/2012 ACCP guidelines, respectively.

CONCLUSIONS: Over half of adult patients who had an LOS ≥2 days in US acute-care hospitals met ACCP criteria for consideration of venous thromboembolism prophylaxis based on risk factors associated with surgery or acute medical illness. These data provide an objective basis for estimating the potential impact of venous thromboembolism prevention on patient care, together with associated costs, risks, and benefits.