1. No category

How to Ask A Good Question
PICO
What is EBM?
How to make a clinical decision?
EBM
• "the conscientious, explicit and judicious use of
current best evidence in making decisions about
the care of the individual patient. It means
integrating individual clinical expertise with the
best available external clinical evidence from
systematic research." (Sackett D, 1996)
• EBM is the integration of clinical expertise,
patient values, and the best evidence into the
decision making process for patient care.
The Steps in the EBM Process
The patient
1. Start with the patient -- a clinical problem or
question arises out of the care of the patient
The question
2. Construct a well built clinical question derived from
the case
The resource
3. Select the appropriate resource(s) and conduct a
search
The evaluation
4. Appraise that evidence for its validity (closeness to
the truth) and applicability (usefulness in clinical
practice)
The patient
5. Return to the patient -- integrate that evidence with
clinical expertise, patient preferences and apply it to
practice
Self-evaluation
6. Evaluate your performance with this patient
Lifelong learning model
• A process of lifelong, self-directed, problembased learning in which caring for one's own
patients creates the need for clinically important
information about diagnosis, prognosis, therapy
and other clinical and health care issues.
• Target your reading to issues related to specific
patient problems. Developing clinical questions
and then searching current databases may be a
more productive way of keeping current with the
literature.
Why is EBM important?
• Physicians reported that their practice generated
about 2 questions for every 3 patients
• Investigators found that physicians had about 5
questions for each patient. 52% of these
question could be answered by the medical
record or hospital information system. 25% could
have been answered by published information
resources such as textbooks or MEDLINE
• Studies have also shown that when clinicians
have access to information, it changes their
patient care management decisions
What is the best way to deliver
2-agonist therapy for the acute
asthma patient in the ED?
MDI with a holding chamber or Nebulizer ?
Physical Methods for Cooling
•
•
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•
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•
Tepid sponging
Bathing
Fanning
Cooling blankets
Rubbing alcohol on the skin
Cool enemas
Ice packs
Is the Evidence Available?
• 145 cases and clinical decisions analyzed:
– 31 could be supported by a randomized
controlled trial
– 65 were supported by a head-to-head trial
(not a placebo-controlled trial)
– 23 were supported by case-control or cohort
studies
– 4 were supported by case series reports
– 22 could not be supported with a study from
the literature
The EBM Process
Pauline is a new patient who recently moved to the area to be
closer to her son and his family. She is 67 years old and has
a history of congestive heart failure brought on by several
myocardial infarctions.
She has been hospitalized twice within the last 6 months for
worsening of heart failure. At the present time she remains in
normal sinus rhythm. She is extremely diligent about taking
her medications (enalapril, aspirin and simvastatin) and wants
desperately to stay out of the hospital. She lives alone with
several cats.
You think she should also be taking digoxin but you are not
certain if this will help keep her out of the hospital. You decide
to research this question before her next visit.
Pauline
Can you construct a well built clinical question ?
Anatomy of a good clinical question
• Patient or problem
– How would you describe a group of patients similar to yours? What are the
most important characteristics of the patient?
• Intervention, prognostic factor, or exposure
– Which main intervention, prognostic factor, or exposure are you
considering? What do you want to do for the patient? Prescribe a
drug? Order a test? Order surgery? What factor may influence the
prognosis of the patient? Age? Co-existing problems? What was
the patient exposed to? Asbestos? Cigarette smoke?
• Comparison
– What is the main alternative to compare with the intervention?
• Outcomes
– What can you hope to accomplish, measure, improve or affect?
Clinical Experience
Foreground knowledge
Background knowledge
Medical
Students
Expert
Practitioners
The structure of the question might
look like this:
Patient / Problem
Intervention
Comparison, if any
Outcome
congestive heart failure,
elderly
digoxin
none, placebo
primary: reduce need for
hospitalization; secondary:
reduce mortality
For our patient, the clinical
question might be:
In elderly patients with
congestive heart failure, is
digoxin effective in reducing
the need for rehospitalization?
Oral, rectal or tympanic
temperature?
Type of question
Diagnosis
how to select and interpret diagnostic tests
Therapy
how to select treatments to offer patients that do
more good than harm and that are worth the efforts
and costs of using them
Prognosis
how to estimate the patient's likely clinical course
over time and anticipate likely complications of
disease
Harm/ Etiology
how to identify causes for disease (including
iatrogenic forms)
Type of Study
MetaAnalysis
Systematic Review
Randomized Controlled Trial
Cohort studies
Case Control studies
Case Series/Case Reports
Animal research/Laboratory studies
The type of question is important and can
help lead you to the best study design
Type of
Question
Suggested best type of Study
Therapy
RCT>cohort > case control > case series
Diagnosis
prospective, blind comparison to a gold standard
Harm/Etiology RCT > cohort > case control > case series
Prognosis
cohort study > case control > case series
Prevention
RCT>cohort study > case control > case series
Clinical Exam
prospective, blind comparison to gold standard
Cost
economic analysis
For our patient, the clinical question is:
In elderly patients with congestive heart
failure, is digoxin effective in reducing the
need for rehospitalization
It is a therapy question and the best
evidence would be a randomized controlled
trial (RCT). If we found numerous RCTs,
then we might want to look for a systematic
review.
Clinical
question
Patient
Population
Intervention
Clinical
MEDLINE
Scenario
strategy
congestive heart heart failure,
failure, elderly
congestive
Limit to Aged
digoxin
digoxin
Comparison (if
any)
Outcome
none or placebo
rate of
hospitalization
Type of question therapy
hospitalization
Type of study
RCT
Limit to randomized
controlled trial as
publication type
Select a resource
• Colleagues
• Summaries of the primary evidence
ACP Journal Club | Clinical Evidence | eMedicine |
FPIN Clinical Inquiries | InfoPOEMs| UpToDate
• Databases
MEDLINE | Cochrane Library
• Electronic textbooks and libraries
ACP Medicine | Harrisons | MD Consult | Stat!Ref
• Meta-Search Engines
SUMSearch | TRIP Plus: Turning Research into Practice
• ACP Online: http://www.acpjc.org/
• Clinical Evidence:
http://www.clinicalevidence.com/
• eMedicine: http://www.emedicine.com
• FPIN: http://www.fpin.org
• InfoPOEMS: http://www.infopoems.com/
• UpToDate: http://www.uptodate.com
• MEDLINE Access PubMed at:
http://www.pubmed.gov
Clinical Questions
Textbook
or other
source
Map to
resource
Choose
database
within
resource
Background
Clinical
query
ForeForeground ground Map to
or
question
background
type
question?
Map to
study
designs
Design
and
execute
search
Appraise evidence and make
decision
Henry is an active 5 year old boy. His mother
brought him in for a check-up because Henry has
had a fever and a sore throat for several days.
You suspect Strep and take a throat culture. The
standard treatment for Streptococcal Pharyngitis
is oral Penicillin three times a day. However, for
Henry and his mother, you are concerned about
compliance and the expense of this medication.
You recall that a drug representative recently told
you that a daily dose of amoxicillin is just as good
as penicillin, but costs less. You want to review
the literature before you decide on amoxicillin for
Henry and possibly changing your standard
practice.
Based on this scenario, choose the best,
well-built clinical question:
A. In children with strep throat, is amoxicillin
as effective as penicillin for relief of
symptoms?
B. What is the best treatment for relieving
the symptoms of a sore throat?
C. Is amoxicillin better than penicillin for
young children?
Experience on The Application
of EMB
Evidence-Based Case
Conference
Modified PBL
History
• A 68 year-old female is brought to the ED
by her husband who is concerned that she
is “not acting right”.
• The patient has been not eating well for
several days, and has been increasingly
confused.
• Intermittent “stomach pains” intermittently
and vomiting
Vital signs
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Blood Pressure - 78/60 mmHg
Heart Rate - 120 beats/minute
Respiratory Rate - 24 breaths/minute
Temperature 38.50 C
Oxygen Saturation (SaO2): 100% on 2
liters via nasal cannula
Physical Exam
• General: patient responds verbally, but is weak
appearing and somewhat confused
• HEENT: possible scleral jaundice
• Neck: Soft, no JVD, no meningismus
• Heart: Increased rate, no murmurs or rubs.
• Respiratory: Mild basilar rhonchi in both lung
fields, no retractions
• Abdomen: Soft, non-distended, RUQ tenderness
with deep palpation, no rebound or guarding
• Extremities: no appreciable edema, rash, or
erythema
Labs
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WBC: 22,000/mm3
HCT: 30%
HCO3: 17 mEq/L
BUN: 60 mg/dL
Cr: 2.1 mg/dL
Total Bilirubin: 4.6 mg/dl
Alkaline Phosphatase: 223 U/L
Coagulation values: normal
Urinalysis: (+) urobilinogen
Blood, Urine, Sputum Cultures pending
Imaging
• ECG: sinus tachycardia with an old LBBB
• Head CT: no acute changes
• Chest x-ray: normal
Clinical Course
• Within the first 3hs: 2 liters NS, Ceftriaxone
1g IV, and 500mg metronidazole 500 mg IV
Repeat BP: 88/30 mmHg norepinephrine
at 3 mcg/kg/min, BP increased to 105/60
with HR115, and she appeared somewhat
improved
Admitted to the ICU and arrived about 3
hours later when a bed became available
She died shortly after arriving to the ICU
Mortality Conference
Patient Profile 16:27
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Age: 76 years old
Sex: male
Arrival: walk by himself
Vital signs: BT 37.6
PR 118 RR16
BP 132/78
• Triage III
History
• A 76 y/o male suffered from progressive
abdominal pain since yesterday afternoon after
“painless” colonoscopy in a medical center
• Nausea(+), vomiting(+), no stool passage for 1
day
• Denied fever, tarry stool
• PH: irritable bowel disease, constipation, GU,
appendicitis s/p op, denied hypertension and
DM
PE
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Consciousness: clear E4M6V5
HEENT: no icteric, no anemic
Chest and heart: no specific findings
Abdomen: Soft, distended, mild diffuse
tenderness, no rebound pain, hypoactive
bowel sound
• Extremities: no edema, warm, no rash
Management
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IV fluid with NS
Morphine 5mg IV st
CBC+DC/PL, BCS
KUB, CXR (Standing)
Lab 17:57
• WBC 24070 with Seg 87%, Band 2%
• Hb: 16.3 Platelet: 175k
Management 18:20
• Primperan 10mg IV st
• Fleet enema 1 BT st: Fail
• Fleet enema 1 BT st again
Lab 18:43
• Na 132 K 4.5 Sugar 171 GOT 50
• BUN 27 Cr 2.5
• CRP 23.7
Progression (19:15)
• Abdominal pain exacerbation after the 2nd
enema
• Vital signs: PR 116 RR 14 BP 104/56
• On Monitor, 12-lead ECG, Cardiac
enzyme and D-dimer
• Plain abdomen (Left decubitous view) and
Abdomen CT
Progression (20:00)
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Vital signs: PR 120, RR 36 BP 98/62
Intubation (RSI)
Fluid resuscitation and Inotropic agents
Antibiotics
Consult surgeon
No ICU bed available
Lab (20:10)
• ABG 7.301/35.7/205.1/17.8 (O2 mask
6L/min)
• TnT: neg, D-dimer 708
Progression 21:00
• Vital signs: PR 118 RR 22 BP 85/57
• Admitted to ICU
• Operation was performed until 00:50 due
to
– Unstable hemodynamics
– No key family member could make decision
OP Findings
• A huge perforation hole about 6x4cm was found
on the anterior wall of the rectosigmoid area at
the distance 18~20cm from the anal verge
• A marked gangrene change with impending
perforation was seen on a segment about 50cm
of small bowel, 80cm away from the ileocecal
valve
• There were multiple spots to patches of ischemic
changes spreading on the whole colon and
small bowel.
• The whole colon was congested, edematous.
thick-walled and erythematous changes
What was happened?
• General surgeon: Colon perforation
complicated with intestinal necrosis
( ischemic bowel disease)
• Operator of colonoscopy: colon perforation
by enema, not related to colonoscopy
• EP?????
!
!
Clinical Guidline
When to Perform Head CT in The
Patients with Mild Head Injury
Yi-Kung Lee MD
Department of Emergency Medicine
Buddish Tzu Chi Dalin General
Hospital
Guidelines
• Clinical Policy: Neuroimaging and
Decisionmaking in Adult Mild Traumatic Brain
Injury in the Acute Setting (ACEP)
• Pratice Management Guidelines For The
Management Of Mild Traumatic Brain Injury
(Eastern Association for the Surgery of Trauma)
• New Orleans and Canadian Criteria
• NICE Head Injury Guideline
• NCWFNS Proposal
• Results of The WHO Collaborating Center Task
Force on Mild Traumatic Brain
Clinical Policy: Neuroimaging and
Decisionmaking in Adult Mild
Traumatic Brain Injury in the
Acute Setting
Ann Emerg Med. August 2002;40:231-249
Inclusion Criteria
• Blunt trauma to the head within 24 hours
of presentation to the ED
• Any period of posttraumatic LOC or of
posttraumatic amnesia
• A GCS score of 15 on initial evaluation in
the ED
• Age older than 15 years
Exclusion Criteria
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•
•
•
Presence of a bleeding disorder
Penetrating trauma
Patients with multisystem trauma
Focal neurologic findings
Core Questions
• Is there a role for plain film radiographs in
the assessment of acute MTBI in the ED?
• Which patients with acute MTBI should
have a noncontrast head CT scan in the
ED?
• Can a patient with MTBI be safely
discharged from the ED if a noncontrast
head CT scan shows no evidence of acute
injury?
Outcome
• Presence of an acute intracranial
abnormality on noncontrast head CT scan
• Is there a role for plain film radiographs
in the assessment of acute MTBI in the
ED?
• Recommendation B:
– Skull film radiographs are not recommended
in the evaluation of MTBI.
– Although the presence of a skull fracture
increases the likelihood of an intracranial
lesion, its sensitivity is not sufficient to be a
useful screening test. Indeed, negative
findings on skull films may mislead the
clinician.
• Which patients with acute MTBI should have
a noncontrast head CT scan in the ED?
• Recommendation A: (New Orleans low risk
criteria)
– A head CT scan is not indicated in those patients with
MTBI who do not have
•
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•
•
headache,
vomiting,
age greater than 60 years,
drug or alcohol intoxication,
deficits in short-term memory,
Physical evidence of trauma above the clavicle, or
seizure.
• Can a patient with MTBI be safely
discharged from the ED if a
noncontrast head CT scan shows no
evidence of acute injury?
• Recommendation C:
– Patients with MTBI who present 6 hours after
sustaining the injury, have a normal clinical
examination, and who have a head CT scan
that does not demonstrate acute injury can be
safely discharged from the ED.
– Patients can be discharged after a shorter
period of observation if they are under the
care of a responsible third party.
Pratice Management Guidelines
for The Management of Mild
Traumatic Brain Injury
The EAST Practice Management Guidelines Work
Group
Copyright 2001 Eastern Association for the Surgery of
Trauma
Mild Traumatic Brain Injury
• An injury caused by blunt
acceleration/deceleration forces which
produce a period of unconsciousness for
20 minutes or less and/or brief retrograde
amnesia, a Glasgow Coma Scale score of
13 to 15, no focal neurological deficit, no
intracranial complications (e.g. seizure
activity), and normal computed
tomography (CT) findings.
Recommendation
• CT of the brain is the gold standard
diagnostic study for MTBI patients and
should be performed on all patients
sustaining a transient neurologic deficit
secondary to trauma. A patients with a
normal hCT has a 0 to 3% probability for
neurologic deterioration, usually in patients
with a GCS 13 and 14.
(N Engl J Med 2000;343:100-5.)
Low Risk Criteria Study
• Objective: To develop and validate a set of
clinical criteria that could be used to identify
patients with minor head injury who do not need
to undergo CT
• Prospective cohort study (Dec 1997 ~ Jun 1999)
• Two Phases study
• Minor head injury, >3 y/o, <24 hours after the
injury
Definition of Minor Head Injury
• Loss of consciousness
– witness or
– the patient reported loss of consciousness
– the patient could not remember the traumatic event
• Normal findings on a brief neurologic
examination
– normal cranial nerves and normal strength and
sensation in the arms and legs
• A score of 15 on the Glasgow Coma Scale
Phase I
6.9%
X
Definition of Items
• Headache: any head pain, whether diffuse or local.
• Vomiting: any emesis after the traumatic event.
• Drug or alcohol intoxication :on the basis of the history
obtained from the patient or a witness and suggestive
findings on physical examination, such as slurred speech
or the odor of alcohol on the breath. Measurements of
blood alcohol and toxicologic tests were ordered at the
discretion of the physician.
• A deficit in short-term memory : persistent
anterograde amnesia in a patient with an otherwise
normal score on the GCS
• Physical evidence of trauma above the
clavicles: any external evidence of injury,
including contusions, abrasions, lacerations,
deformities, and signs of facial or skull fracture.
• Seizure : a suspected or witnessed seizure after
the traumatic event.
• Coagulopathy : a history of bleeding or a
clotting disorder or current treatment with
warfarin.
Phase II
Sensitivity 100%!
(95-100%)
Positive CT Findings
Conclusion
JAMA. 2005;294:1511-1518
Lancet 2001; 357: 1391–96
Clinical Decision Rule
• To develop a highly sensitive clinical
decision rule for use of CT in patients with
minor head injuries
• Prospective cohort study
• Adults who presented with a GCS score of
13–15 after head injury
• From 1996 to 1999
Inclusion Criteria
• Blunt trauma to the head resulting in
witnessed loss of consciousness, definite
amnesia, or witnessed disorientation; and
• Initial emergency department GCS score
of 13 or greater as determined by the
treating physician; and
• Injury within the past 24 h
• 3121 patients
Exclusion criteria
• < 16 years old
• Minimal head injury (ie, no loss of consciousness,
amnesia, or disorientation)
• No clear history of trauma as the primary event (eg,
primary seizure or syncope)
• Obvious penetrating skull injury or obvious depressed
fracture
• Acute focal neurological deficit
• Unstable vital signs associated with major trauma
• A seizure before assessment in the emergency
department
• Bleeding disorder or used oral anticoagulants (ie,
coumadin)
• Returned for reassessment of the same head injury
• Pregnancy
Outcome Measure
• The primary outcome was need for neurological
intervention (3121/3121)
– either death within 7 days secondary to head injury or
the need for any of the following procedures within 7
days:
• craniotomy, elevation of skull fracture, intracranial pressure
monitoring, or intubation for head injury (shown on CT).
• The secondary outcome was clinically important
brain injury, on CT. (2078/3121, 67%)
– Any acute brain finding revealed on CT and which
would normally require admission to hospital and
neurological follow-up
Lancet 2001; 357: 1391–96
Lancet 2001; 357: 1391–96
Variables
Lancet 2001; 357: 1391–96
Lancet 2001; 357: 1391–96
Lancet 2001; 357: 1391–96
External Validity
• External Validation of
the Canadian CT
Head Rule and the
New Orleans Criteria
for CT Scanning in
Patients With Minor
Head Injury
• Dutch prospective
study
• >16 y/o
JAMA. 2005;294:1519-1525
CT Findings
JAMA. 2005;294:1519-1525
Validation
JAMA. 2005;294:1519-1525
Comparison of the CCHR and NOC
• Canadian prospective study
• (1) blunt trauma to the head resulting in
witnessed loss of consciousness, definite
amnesia, or witnessed disorientation; (2)
initial ED GCS score of 13 or greater as
determined by the treating physician, and
(3) injury within the previous 24 hours
JAMA. 2005;294:1511-1518
Clinical Outcome
JAMA. 2005;294:1511-1518
JAMA. 2005;294:1511-1518
Sensitivity and Specificity
JAMA. 2005;294:1511-1518
Sensitivity and Specificity
JAMA. 2005;294:1511-1518
Realities
Before application
of CCHR
Emerg. Med. J. 2004;21;420-425
Realities
After application
of CCHR
Emerg. Med. J. 2004;21;420-425
Compliance
Emerg. Med. J. 2004;21;420-425
Compliance
Emerg. Med. J. 2004;21;420-425
Impaction
Emerg. Med. J. 2004;21;426-428
NICE (National Institute for
Clinical Excellence) Head
Injury Guideline
Head injury
Triage, assessment, investigation and early
management of head injury in infants,
children and adults
June 2003
Developed by the National
Collaborating Centre for Acute Care
Definitions
• Infants<1 y/o, children 1–15 y/o and adults
>16 y/o, the ‘infants and young children’ <
5y/o
• ‘Head injury’: any trauma to the head,
other than superficial injuries to the face.
• The primary patient outcome of concern
throughout the guideline is “clinically
important brain injury’.
Selection of patients for CT
imaging of the head
•
Patients who have sustained a head injury and present with any one
of the following risk factors should have CT scanning of the head
immediately requested.
–
–
–
–
–
–
–
–
GCS < 13 at any point since the injury.
GCS = 13 or 14 at 2 hours after the injury.
Suspected open or depressed skull fracture.
Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes,
cerebrospinal fluid otorrhoea, Battle’s sign).
Post-traumatic seizure.
Focal neurological deficit.
More than one episode of vomiting (clinical judgement should be used
regarding the cause of vomiting in those aged <12 y, and whether
imaging is necessary).
Amnesia for greater than 30 minutes of events before impact. The
assessment of amnesia will not be possible in pre-verbal children and is
unlikely to be possible in any child aged under 5 years.
Selection of patients for CT
imaging of the head
• CT should also be immediately requested in
patients with any of the following risk factors,
provided they have experienced some loss of
consciousness or amnesia since the injury:
– Age 65 years.
– Coagulopathy (history of bleeding, clotting disorder,
current treatment with warfarin).
– Dangerous mechanism of injury (a pedestrian struck
by a motor vehicle, an occupant ejected from a motor
vehicle or a fall from a height of greater than 1 metre
or five stairs). A lower threshold for height of falls
should be used when dealing with infants and young
children (that is, aged under 5 years).
Evaluate the impact of the NICE
head injury guidelines
• Before/ after study
• month A, six months
before the
implementation of NICE
(Nov 2002 at NTGH and
May 2003 at Hope), and
month B, one month after
the implementation of
NICE (May 2003 at
NTGH and Jan 2004 at
Hope).
Emerg. Med. J. 2005;22;845-849
Emerg. Med. J. 2005;22;845-849
Conclusion
• cost
effectiveness
should not be a
barrier for the
implementation
of the NICE head
injury guidelines
in UK EDs
Clinical Performance of NICE
Recommendations versus
NCWFNS Proposal in Patients
with Mild Head Injury
JOURNAL OF NEUROTRAUMA
Volume 22, Number 12, 2005
• Over a 5-year
period, the
clinical data of
7,955
adolescent and
adult patients
with mild head
injury were
prospectively
collected
Results
• Three hundred fifty-four patients (6.8%)
had intracranial lesions on computed
tomography (CT) scan;
• Neurosurgical intervention was needed in
108 patients (1.3%), and
• An unfavorable outcome occurred in 54
patients (0.7%) at 6-month follow-up.
Favor!
Favor!
Meta-Analysis
(for Risk Factor Analysis)
• Cohort or nested cohort studies
• MEDLINE and EMBASE were searched from
01/1990 to 06/2002
• Grey literature
• The reference lists of guidelines developed by
the American Academy of Pediatrics, The
Eastern Association for the Surgery of Trauma,
The Scottish Intercollegiate Guidelines Network,
and The Royal College of Surgeons of England
JOURNAL OF NEUROTRAUMA,21(7),877-885 2004
• 83,636 patients from 35 papers
• Present relative risk ratios for 23 clinical
variables that may predict the presence of
significant intracranial injury in adults
sustaining minor head injury
Clinical History
JOURNAL OF NEUROTRAUMA,21(7),877-885 2004
Mode of Injury
JOURNAL OF NEUROTRAUMA,21(7),877-885 2004
Clinical Exam&Imaging
JOURNAL OF NEUROTRAUMA,21(7),877-885 2004
JOURNAL OF NEUROTRAUMA,21(7),877-885 2004
DIAGNOSTIC PROCEDURES IN MILD TRAUMATIC
BRAIN INJURY: RESULTS OF THE WHO
COLLABORATING CENTRE TASK FORCE ON MILD
TRAUMATIC BRAIN INJURY
J Rehabil Med 2004; Suppl.
43: 61–75