[Venous thromboembolism's risk assessment: rationale, objectives, and methodology--the ARTE study].

Venous thromboembolism is a frequent clinical condition with high impact on both morbidity and mortality. Venous thromboembolism risk is particularly high in hospitalized patients as well as in oncologic patients, being a factor of poor prognosis for the oncologic disease. Several clinical studies have shown the need to develop effective hospital strategies using a systematic and individualized assessment of venous thromboembolism risk, and additionally to optimize the institution of prophylaxis treatment and its proper use in the context of in-hospital and outpatient management. The ARTE national study is a non-interventional, multicentre, prospective study which is divided in two phases. In the first phase patients are followed in the hospital; in the second phase patients are followed in ambulatory context for a period of 6 months after discharge. Four thousand patients will be included, equally distributed over medical, surgical, oncologic and orthopaedic patients. Data will be collected from the patient's clinical files and through direct clinical evaluation of risk factors for venous thromboembolism, in the departments of medicine, oncology, surgery, and orthopaedics of the participating centres. The main objectives of the study are to assess the risk profile of venous thromboembolism of the study population using a risk assessment model adapted from the Caprini and Khorana et al models, and the validation of the score for the Portuguese population. Simultaneously, the secondary objectives are as follows: to determine the proportion of patients with venous thromboembolism risk, according to the risk assessment model, that are doing prophylaxis; to determine the duration of prophylaxis during the hospitalization; to determine the proportion of patients doing long-term prophylaxis, at the moment of the discharge; to determine the incidence of thromboembolic events (deep venous thrombosis; stroke; pulmonary thromboembolism; transient ischemic attack), haemorrhagic events (major and minor haemorrhages) and death at 6 months after discharge. Each patient will be contacted by telephone at 3 and 6 months after discharge, in order to assess the occurrence of thromboembolic and haemorrhagic events, as well as any readmission. This article describes the ARTE study's rationale, objectives, and methodology.