Definitions for the strength of evidence (Class I-III) and strength of recommendations (Level A-C) are repeated at the end of the "Major Recommendations" field.
- Which patients with mild traumatic brain injury (TBI) should have a noncontrast head computed tomography (CT) scan in the emergency department (ED)?
Recommendations
Level A recommendations. A noncontrast head CT is indicated in head trauma patients with loss of consciousness or posttraumatic amnesia only if one or more of the following is present: headache, vomiting, age greater than 60 years, drug or alcohol intoxication, deficits in short-term memory, physical evidence of trauma above the clavicle, posttraumatic seizure, Glasgow Coma Scale (GCS) score less than 15, focal neurologic deficit, or coagulopathy.
Level B recommendations. A noncontrast head CT should be considered in head trauma patients with no loss of consciousness or posttraumatic amnesia if there is a focal neurologic deficit, vomiting, severe headache, age 65 years or greater, physical signs of a basilar skull fracture, GCS score less than 15, coagulopathy, or a dangerous mechanism of injury.*
*Dangerous mechanism of injury includes ejection from a motor vehicle, a pedestrian struck, and a fall from a height of more than 3 feet or 5 stairs.
Level C recommendations. None specified.
- Is there a role for head magnetic resonance imaging (MRI) over noncontrast CT in the ED evaluation of a patient with acute mild TBI?
Recommendations
Level A recommendations. None specified.
Level B recommendations. None specified.
Level C recommendations. None specified.
- In patients with mild TBI, are brain-specific serum biomarkers predictive of an acute traumatic intracranial injury?
Recommendations
Level A recommendations. None specified.
Level B recommendations. None specified.
Level C recommendations. In mild TBI patients without significant extracranial injuries and a serum S-100B level less than 0.1 micrograms/L measured within 4 hours of injury, consideration can be given to not performing a CT.*
*This test has not yet received Food and Drug Administration approval for clinical use in the United States.
- Can a patient with an isolated mild TBI and a normal neurologic evaluation result be safely discharged from the ED if a noncontrast head CT scan shows no evidence of intracranial injury?
Recommendations
Level A recommendations. None specified.
Level B recommendations. Patients with an isolated mild TBI who have a negative head CT scan result are at minimal risk for developing an intracranial lesion and therefore may be safely discharged from the ED.*
*There are inadequate data to include patients with a bleeding disorder; who are receiving anticoagulation therapy or antiplatelet therapy; or who have had a previous neurosurgical procedure in this population.
Level C recommendations. Mild TBI patients discharged from the ED should be informed about postconcussive symptoms.
Definitions:
Strength of Evidence
Literature Classification Schema^
Design/
Class
|
Therapy* |
Diagnosis** |
Prognosis*** |
| 1 |
Randomized, controlled trial or meta-analyses of randomized trials |
Prospective cohort using a criterion standard |
Population prospective cohort |
| 2 |
Nonrandomized trial |
Retrospective observational |
Retrospective cohort
Case control
|
| 3 |
Case series
Case report
Other (e.g., consensus, review)
|
Case series
Case report
Other (e.g., consensus, review)
|
Case series
Case report
Other (e.g., consensus, review)
|
^Some designs (e.g., surveys) will not fit this schema and should be assessed individually.
*Objective is to measure therapeutic efficacy comparing >2 interventions.
**Objective is to determine the sensitivity and specificity of diagnostic tests.
***Objective is to predict outcome including mortality and morbidity.
Approach to Downgrading Strength of Evidence*
| |
Design/Class |
| Downgrading |
1 |
2 |
3 |
| None |
I |
II |
III |
| 1 level |
II |
III |
X |
| 2 levels |
III |
X |
X |
| Fatally flawed |
X |
X |
X |
*See "Description of Methods Used to Analyze the Evidence" field for more information.
Strength of Recommendations
Level A recommendations. Generally accepted principles for patient management that reflect a high degree of clinical certainty (i.e., based on strength of evidence Class I or overwhelming evidence from strength of evidence Class II studies that directly address all of the issues).
Level B recommendations. Recommendations for patient management that may identify a particular strategy or range of management strategies that reflect moderate clinical certainty (i.e., based on strength of evidence Class II studies that directly address the issue, decision analysis that directly addresses the issue, or strong consensus of strength of evidence Class III studies).
Level C recommendations. Other strategies for patient management that are based on preliminary, inconclusive, or conflicting evidence, or, in the absence of any published literature, based on panel consensus.
There are certain circumstances in which the recommendations stemming from a body of evidence should not be rated as highly as the individual studies on which they are based. Factors such as heterogeneity of results, uncertainty about effect magnitude and consequences, strength of prior beliefs, and publication bias, among others, might lead to such a downgrading of recommendations.
