A simple formula for calculating the risk faced by acutely ill patients for venous thromboembolism was validated in a case-control study with more than 400 patients. This VTE risk-calculator formula “is the first [risk-assessment model (RAM)] to be validated on a large scale in hospitalized medical patients,” Charles E. Mahan, PharmD, said at the congress of the International Society on Thrombosis and Haemostasis. “Applying this RAM could spare 20%-30% of these patients from getting unnecessary prophylaxis” with an anticoagulant, said Dr. Mahan, director of outcomes research at the New Mexico Heart Institute in Albuquerque. He cautioned that the new evidence he presented still needs to be published, and a prospective test of the risk formula should also be done. “This gives us some information that we can comfortably use,” Dr. Mahan said in an interview. Other formulas for estimating VTE risk in patients hospitalized for medical reasons include the Padua Prediction Score. The validation used the risk formula developed by the IMPROVE (International Medical Prevention Registry in Venous Thromboembolism) study, which included more than 15,000 medical patients seen at 52 hospitals in 12 countries (Chest 2011;140:705–14). Editor's NoteWhile this study was performed in acute-care hospital patients, it's reasonable to presume that it has at least some applicability to postacute patients. In the nursing home setting, we do not always do a great job with VTE prophylaxis – sometimes we don't provide it to someone who probably should get it, while other times we keep a patient on prophylaxis (e.g., with subcutaneous enoxaparin) for far longer than is indicated, with adverse effects. I would encourage you to consider using a tool like this to assess risk and to try to keep VTE risk on your radar for all nursing home residents, be they skilled or custodial.—Karl Steinberg, MD, CMD,Editor in Chief While this study was performed in acute-care hospital patients, it's reasonable to presume that it has at least some applicability to postacute patients. In the nursing home setting, we do not always do a great job with VTE prophylaxis – sometimes we don't provide it to someone who probably should get it, while other times we keep a patient on prophylaxis (e.g., with subcutaneous enoxaparin) for far longer than is indicated, with adverse effects. I would encourage you to consider using a tool like this to assess risk and to try to keep VTE risk on your radar for all nursing home residents, be they skilled or custodial. —Karl Steinberg, MD, CMD, Editor in Chief The IMPROVE RAM includes seven risk factors, each scoring 1-3 points. A history of VTE scores 3; immobilization for a week or more, intensive care unit stay, and age over 60 score 1 each; and three other factors score 2 points each. The validation cohort came from the more than 130,000 patients aged 18 years or older who were hospitalized for at least 3 days during 2005-2011 at a McMaster University–affiliated hospital in Hamilton, Ont. Excluding patients with VTE at the time of admission and some others, the investigators identified 139 patients who developed VTE within 90 days of hospital admission and matched them with 278 patients who did not develop a VTE. The IMPROVE RAM showed “good” discrimination in the validation cohort, Dr. Mahan reported. The incidence of VTE during the 90 days following hospitalization in the validation cohort was 0.20% in patients with low scores, 0 or 1; 1.04% in patients with moderate scores, 2 or 3; and 4.15% in those with high scores, 4 or greater. By comparison, in the first IMPROVE cohort the VTE rates for 90 days were 0.45% in patients with low scores, 1.30% in those with moderate scores, and 4.74% in those with high scores. In 2011, the IMPROVE authors suggested that clinicians apply VTE prophylaxis to patients who scored 2 points or higher on the risk formula, which represented 31% of the more than 15,000 patients in the derivation cohort. In the validation cohort, 37% of the patients had a score of 2 or more. The new data suggest that a score of 3 or more may be an even better cutoff for starting VTE prophylaxis with heparin or low-molecular-weight heparin, Dr. Mahan said, but he added that this needs more analysis. “In the United States especially, we are over-prophylaxing … a large group of U.S. hospital patients who don't need it,” Dr. Mahan said. He disclosed being a consultant to or speaker for several drug companies.