Risk of venous thromboembolism among hospitalized medically ill patients

Abstract

The 90-day risk of venous thromboembolism (VTE) among medically ill patients admitted to a hospital was estimated and is discussed. Patients aged > or =40 years who were hospitalized between January 1, 1998, and June 30, 2002, for reasons other than traumatic injury, labor and delivery, mental disorder, or VTE and who did not undergo surgery were identified in a large U.S. healthcare claims database. Patients receiving anticoagulants in the 90-day period preceding hospital admission were excluded. We estimated the percentage of study subjects who developed clinical deep-vein thrombosis (DVT) or pulmonary embolism (PE) within 90 days of hospital admission using Kaplan-Meier methods. We also estimated hazard ratios (HRs) for potential risk factors for VTE using univariate and stepwise multivariate Cox proportional hazards regression models. Among 92,162 study subjects, 1468 (1.59%) developed clinical DVT or PE within 90 days of hospital admission; 18% of these events occurred postdischarge. In multivariate analyses, significant risk factors for clinical VTE included: 1) history of cancer (HR, 1.67; 95% confidence interval [CI], 1.45-1.93); 2) history of VTE within six months of index admission (HR, 6.14; 95% CI, 4.74-7.96); 3) operating room procedure within 30 days of index admission (HR, 1.81; 95% CI, 1.47-2.24); 4) peripheral artery disease during index admission (HR, 1.68; 95% CI, 1.28-2.21); and 5) heart failure during index admission (HR, 1.72; 95% CI, 1.52-1.95). The risk of clinical VTE among medically ill patients admitted to a hospital, although less than that of patients undergoing major surgery, is not negligible. Patients with a history of recent VTE or surgery, those who are admitted to the intensive care unit, those with an admitting diagnosis of heart failure, and those with active cancer are at especially high risk of VTE and deserve increased consideration for prophylaxis.