The appropriate use of thromboprophylaxis in medical patients admitted to hospital can substantially reduce the overall burden of disease due to venous thromboembolism. However, the use of thromboprophylaxis in medical setting appears to be generally poor leaving at-risk patients unprotected.

We aim to analyse the incidence of symptomatic thromboembolic disease following hospitalisation in medical setting and the efficacy of a multicomponent prevention approach in emergency department including systematic evaluation of thrombosis risk factors and remembers of thrombophylaxis indications and modalities for acutely ill medical patients.

Design: cluster randomized interventional study - Observational study at patient level

Setting: 30 French emergency departments

Patients: Patients over 40 years old admitted in participating emergency departments and hospitalized for acute medical reasons.

Main judgment criteria: the rate of symptomatic thromboembolic events and severe haemorrhage during a formal 3-months follow-up after hospital admission in patients hospitalized at least 48 hours.

Method:

At the end of an observational period of a week, centers will be randomized in two groups: intervention or current practice. In the intervention group, centers will be provided with poster and pocket cards and, if possible, with a computer decision support system remembering venous thromboembolism prophylactic treatment. We will propose no change in current practice in the other group.

Primary outcome: the rate of symptomatic venous thromboembolic events and severe haemorrhage during a formal 3-months follow-up after hospital admission in patients hospitalized at least 48 hours.

All possible thromboembolic events, severe haemorrhages and deaths will be analysed by an adjudication committee blinded of group assignation. Sudden death without obvious cause according to the adjudication committee will be considered as possible fatal pulmonary embolism.

Sample size: We calculated sample size on the basis of primary outcome. Assuming the participation of 30 centers (15 in each group), an intracluster correlation of 0.01, a rate of symptomatic thromboembolic events or severe haemorrhage of 5% in the current practice group, we need a sample of 16170 patients (8085 in each group) to detect a 1.5 percentage absolute difference between the 2 groups (3.5% in the intervention group) with a power of 80% and a significance level of 5%.

Considering a rate of patients hospitalized less than 48 hours around 5% and of lost of follow-up around 3%, we anticipated to include 16500 patients for the main analysis and 18000 patients for the overall study.

Secondary outcomes:

• The appropriateness of thromboprophylaxis in the overall population and according to group assignation:

  • Number of patients needing prevention treatment according to international recommendations and who have an appropriate treatment.
  • Number of patients without indication of thromboprophylaxis and who do not receive a treatment

• The rate of symptomatic venous thromboembolic events during a formal 3-months follow-up after hospital admission

  • in all included patients
  • in patients hospitalized at least 48 hours.
  • inpatients hospitalized less than 48 hours

• The rate of thromboembolic events

  • in patients who had an appropriate thromboprophylactic treatment
  • in patients who had an inappropriate thromboprophylactic treatment
  • in patients who had no thromboprophylactic treatment

• The rate of severe haemorrhage

  • in patients who had an appropriate thromboprophylactic treatment
  • in patients who had an inappropriate thromboprophylactic treatment
  • in patients who had no thromboprophylactic treatment

Inclusion Criteria:

• age over 40 years
• Emergency department admission for non-traumatic reason
• Hospitalization in medical setting

Exclusion Criteria:

• patients less than 40 years old
• patients hospitalized in a facility which doesn't participate to the study
• 3 months follow-up not possible
• patients refusing that their personal data are used for medical research
• patients refusing to be reach for the 3 months follow-up

Eligible centers: Emergency departments previously implicated in research on venous thromboembolism.

Eligible patients: patients over 40 years old admitted in participating emergency departments for non traumatic reason