Thromboembolic Risk Stratification by TRiP(Cast) Score to Guide Physicians in Preventive Treatment Prescriptions for Patients With Lower Limb Trauma Requiring Brace or castING.

Study Overview
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Brief Summary
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Non-surgical traumas to the lower limbs that require orthopedic immobilisation (plaster or splint) are a frequent reason for going to accident and emergency. Due to venous stasis caused by immobilisation, hypercoagulable states and vascular injuries brought on by the trauma, these patients are at risk of developing VTE. For this reason, it is current practice in France and Belgium for the majority of patients to receive a preventative anticoagulant treatment. However, the benefit of this treatment, which has a considerable cost, is controversial. Contrary to French recommendations, American recommendations from 2012 actually advise against systematic preventative medicine, with prevention appearing to be effective primarily in studies with restrictive inclusion criteria. The most significant randomised controlled study on the subject did not show the benefit of low-molecular-weight heparin (LMWH) on the rate of symptomatic VTE among 1,435 non-selected patients. Therefore, in 2017, the Cochrane meta-analysis concluded that stratification of the risk of thromboembolism is required. For this purpose, in collaboration with the Dutch team of Nemeth et al. we have recently developed a risk stratification model that takes into consideration the patient's characteristics, the type of immobilisation and the severity of the trauma: the TRiP(cast) score. This score is applied retrospectively to a large cohort and demonstrates excellent prognostic performances (AUC (area under the curve) of 0.74). In addition, when using a <7 limits, it makes it possible to identify a large group of patients at very low risk of developing VTE (negative predictive value: 99.2%). The aim of the CASTING study is to prospectively demonstrate the reliability and utility of the TRiP(cast) score by showing that patients with orthopaedic immobilisation of a lower limb who are not receiving preventative treatment on the basis of a TRiP(cast) score of <7 have a very low rate of symptomatic VTE, which allows for a significant reduction in prescriptions of anticoagulants in comparison with prior practices.

Official Title
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Thromboembolic Risk Stratification by TRIP Score (Cast) to Guide Physicians in Preventive Treatment Prescriptions for Patients With Lower Limb Trauma Requiring Brace or Casting.

Conditions
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Lower Limb Trauma, Venous Thromboembolism, Stratification

Intervention / Treatment
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* Other: TRIPscore


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consultation in one of the emergency department participating in the study, Isolated trauma from lower limb, Rigid (plaster or resin) or semi-rigid immobilization for an assumed duration of at least 7 days, Adults (18 years), Affiliated patient or beneficiary of a social security, Patient with prior informed consent. Exclusion Criteria: Patient with anticoagulant treatment at the time of trauma, Trauma requiring hospitalization of more than 48 hours, Co-morbidity(s) requiring hospitalization of more than 48 hours at the time of inclusion, Any factor making 90-day follow-up impossible, Pregnant, nursing or childbearing patient, Patient deprived of liberty by judicial or administrative decision, Patient undergoing psychiatric care under duress, Patient subject to a legal protection measure, Patient unable to give free and informed consent.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: neutral<br>No specific instructions for prescribing prophylaxis or not | |
| Active Comparator: TRIPscore<br>calculation of the TRIPcast score and prescription of prophylactic or not according to the result (score > or = 7 : treatment (low molecular weight heparin or fondaparinux); score < 7 : no treatment) | Other: TRIPscore<br>* TRIPcast score calculation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of symptomatic venous thromboembolic events (deep vein thrombosis and / or pulmonary embolism) among patients with a TRiP(cast) score < 7 | To demonstrate the reliability and safety of the decision not to implement thromboprophylaxis in patients with orthopedic immobilization for lower extremity trauma and Trip(cast) < 7 | Day 90 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of prescription for thromboprophylaxis | comparison between the two period | Day 1 | 
| Rate of symptomatic venous thromboembolic events (deep vein thrombosis and / or pulmonary embolism) (whole population) | comparison between the two period | Day 90 | 
| The rate of complications of preventive anticoagulant treatment (bleeding) | comparison between the two period | Day 90 | 
| The direct cost of preventive anticoagulant treatment when the TRiP(cast) score is applied compared to current practices | treatment, nurse, blood test...cost of care | Day 90 | 
| Physicians' satisfaction using likert's scale | 5 level ladder : from totally unsatisfied to totally satisfied | Day 1 |