Deep vein thrombosis in elderly patients hospitalized in subacute care facilities: a multicenter cross-sectional study of risk factors, prophylaxis, and prevalence.

BACKGROUND The efficacy of venous thromboembolism prophylaxis has not been established, to our knowledge, in elderly patients hospitalized in subacute care facilities. OBJECTIVES To describe risk factors and physician practices in the prevention of venous thromboembolism and to estimate the prevalence of deep vein thrombosis. METHODS A multicenter cross-sectional study was conducted in the subacute care departments of 36 French hospitals. The study population included 852 inpatients older than 64 years. Systematic ultrasound examination was performed by angiologists. RESULTS Of the 852 inpatients, 178 (20.9%; 95% confidence interval [CI], 18.2%-23.8%) had 3 or more risk factors other than age, while 144 patients (16.9%; 95% CI, 14.4%-19.6%) had none. The rate of prophylactic anticoagulant treatment was 56.1%, ranging from 20.0% to 86.9%, depending on the department. In multivariate analysis, prophylaxis use was associated with acute immobilization (odds ratio [OR], 4.17; 95% CI, 2.48-7.01), chronic immobilization (OR, 3.19; 95% CI, 2.22-4.60), major surgical procedure (OR, 6.81; 95% CI, 4.26-10.88), and congestive heart failure (OR, 1.65; 95% CI, 1.02-2.67). Prophylaxis use was low in patients who had cancer (OR, 0.49; 95% CI, 0.29-0.84) or myocardial infarction (OR, 0.39; 95% CI, 0.14-1.00). It was not significantly associated with paralytic stroke or history of venous thromboembolism. Deep vein thrombosis was detected in 135 patients (15.8%; 95% CI, 13.4%-18.5%): 50 (5.9%; 95% CI, 4.4%-7.7%) had proximal vein thrombosis and 85 (10.0%; 95% CI, 8.0%-12.2%) had calf vein thrombosis. CONCLUSIONS The prevalence of deep venous thrombosis is high in these patients, despite wide use of prophylaxis. Further prospective studies assessing the clinical benefit of extended duration prophylaxis are needed in elderly patients hospitalized in subacute care settings.