The Incidence of Clinical Venous Thromboembolism and Use of Ambulatory Prophylaxis Methods in Bedridden Acutely Ill Medical Outpatients: The ETAPE Study.
Authors: Bosson Jean-Luc , Pouchain Denis , Dubourg Véronique , Dubroca Isabelle , Bergmann Jean-François 
Published: October 2019

Abstract
Introduction Venous thromboembolism (VTE) prophylaxis in hospitalized acutely ill medical patients has become more commonly used in France, especially since the results of the MEDENOX study (Samama et al. N Engl J Med1999;341:793–800) were published. However, the risk for VTE in bedridden acutely ill medical outpatients treated at home by general practitioners is unknown. The aim of the “Evaluation de l’incidence des événements Thromboemboliques veineux et des Modalités Ambulatoires de Prévention du risque thrombo-Embolique en Médecine Générale” ETAPE study was to determine the incidence of clinical VTE in bedridden acutely ill medical outpatients treated at home.
Methods Patients ≥40 years, with an acute medical illness leading to reduced mobility ≥48 h and justifying a medical visit at the patients’ home, were consecutively included in this prospective, multicenter, epidemiological study. Exclusion criteria were: reduced mobility due to a surgical procedure, reduced mobility for >1 month, or use of anticoagulant prior to enrollment. The primary outcome measure was the incidence of clinical deep-vein thrombosis (DVT) between days 1 and 21. The secondary outcome was the incidence of VTE (DVT or pulmonary embolism [PE]). Patients were enrolled by 2895 general practitioners, randomly drawn from a database of 25520 physicians.
Results Of 17194 patients enrolled, 16532 (96.1%) were evaluable. Patients’ median age was 71 years, 61% were female, and 13% were totally bedridden. Patients had one or more of the following medical conditions: hypertension (39%), venous insufficiency of lower limbs with varicose veins (30%), severe infection (29%), acute rheumatologic episode (27%), and diabetes (15%). Patients’ medical histories included prior DVT (14%), cardiac failure (12%), cancer (9%), and myocardial infarction and stroke (5%). Overall, 35% of patients received VTE prophylaxis. Of enrolled patients, 18% were considered to be at major risk, 25% moderate risk, and 57% low risk for VTE based on classical risk factors for VTE described in published guidelines on VTE prevention. Of these patients, 56%, 38% and 27% received prophylaxis, respectively. The incidences of clinical DVT were 1.9%, 0.9% and 0.7%, in patients at major, moderate or low risk for DVT, respectively. A summary of VTE events at follow-up is shown in Table 1.
Conclusion The incidence of clinical VTE (1.1%) observed in this population is similar to that observed in orthopedic surgery patients (1.3–3.3%; Eikelboom JW et al, Lancet2001;358:9–15). Bedridden acutely ill medical outpatients treated at home have a high risk for VTE, a fact that should be considered by physicians when making the decision to provide prophylaxis.
Table 1. Incidence of clinical VTE events at follow-up
CI, confidence interval Patients, n 16532 Median duration of follow-up, days 20 Median time to DVT diagnosis, days 7 DVT diagnosed, % (95% CI) 0.99 (0.84–1.14) DVT confirmed by ultrasonography or venography, % 78 PE, % 0.20 Clinical VTE, % (95% CI) 1.1 (0.94–1.26)