Inclusion Criteria:

Trauma patients who arrive at the respective trauma centers for evaluation for acute injuries will be considered for enrollment:

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• Male and female patients 18 years of age or older (no upper age limit)
• Male and female patients < 18 years of age or older (who have assented to inclusion and whose parents or legally authorized representatives have signed consent)
• Blunt trauma patients including those with closed head injury
• Penetrating trauma patients
• Subjects meeting all of the above criteria but who are pregnant will also be enrolled but will first require informed consent prior to blood draws

Exclusion Criteria: 

Trauma patients who arrive to ED who:

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• Are on therapeutic anticoagulation, such as Coumadin or antiplatelet agents (excluding aspirin or ibuprofen).
• Have preexisting coagulopathy (cirrhosis and inherited thrombophilia)
• Are patients greater than 12 hours from time of injury
• Are patients who do not have a blood sample at 12 or less hours, relative to time of injury
• Have active malignancy, active sepsis, or renal failure requiring dialysis
• Are patients with burn  or electrical injuries
• Have known prior history of VTE
• Are patients who have experienced significant traumatic injuries or major surgery within the past year
• Are patients on high dose steroids or autoimmune medications
• Are prisoners
• Have current injuries from known suicide attempt
• Do not meet trauma criteria despite initial classification as Yellow or Red trauma.

Eligibility last updated 8/24/122. Questions regarding updates should be directed to the study team contact.