C RITICAL A PPRAISAL OF S CIENTIFIC L ITERATURE ON E MERGENCY M EDICINE Sorana D. Bolboacă Iuliu Hațieganu University of Medicine and Pharmacy Cluj-Napoca 8 July 2016 1
CRITICAL APPRAISAL OF SCIENTIFIC
LITERATURE ON EMERGENCY MEDICINE
Sorana D. BolboacăIuliu Hațieganu University of Medicine and Pharmacy Cluj-Napoca
8 July 2016 1
PubMed (July 5, 2016): Journal article[Article Types]
AND English[Language]) AND Emergency
Medicine[Affiliation]
Number of articles to read by month / day
2015 2014 2013 2012 2011 2010 2009 2008 2007 2006
Month 452 340 237 204 177 164 154 140 132 124
Day 15 11 8 7 6 5 5 5 4 4
8 July 2016 2
WHAT IT WILL BE ABOUT...
• Reading scientific literature: why?
• Critically read emergency scientific literature
• Anatomy of critical appraisal
• Making sense of critical appraisal
8 July 2016 3
READING SCIENTIFIC LITERATURE: WHY?
• Stay in touch with knowledge derived from clinical research1
• EB(E)M = Evidence Based (Emergency) Medicine the
application into daily clinical practice of only those methods,
procedures, medications etc. which are based on scientific
evidence2
• The International Federation for Emergency Medicine:
understand the principles of critical appraisal and skills is
recognized as mandatory in early training of medical students
as well as part of emergency medicine curriculum 3
1. Tonelli MR. The philosophical limits of evidence-based medicine. Acad Med. 1998;73(12):1235.
2. Dick WF. [Evidence-based emergency medicine]. Anaesthesist. 1998 Dec;47(12):957-67.
3. Hobgood C, Anantharaman V, Bandiera G, Cameron P, Halperin P, Holliman J, et al. International Federation for Emergency Medicine Model
curriculum for medical student education in emergency medicine. African Journal of Emergency Medicine 2011;1:139-144.
8 July 2016 4
DIMENSION OF EVIDENCE
Intervention (Dimension of evidence)4: The effect is real? & The size of the
effect is clinically important? & The evidence is relevant for practice?
CRITICALLY READ EMERGENCY SCIENTIFIC
LITERATURE
STRENGTHS WEAKNESSES
GENERALIZABILITY
(can the findings be apply elsewhere?)
VALIDITY
(is the finding true?)
What?5
4. National Health and Medical Research Council. How to use the evidence: assessment and application of scientific evidence. Biotext; Australia,
2000
5. Goodacre S. Critical appraisal for emergency medicine: 1. Concepts and definitions. Emerg Med J 2008;25:219-221.
Research methods Statistical analysis
8 July 2016 7
ANATOMY OF CRITICAL APPRAISAL
Case-Control Cohort Clinical trial
Clear population, exposure and outcome
variables
Clear population, intervention,
comparison group and outcome
variable
Was the design appropriate to answer the research question?
Was blinding possible? Was blinding
employed in the methodology?
Blinding employed? Subjects
randomized (method)? Allocation
concealment?
The follow-up of subjects was complete?
The outcome variable was measured in same way for all subjects?
Screening questions6: clear research question & appropriate study design &
blinding and randomization & subject follow-up & standardization of
outcome measures
6. Guyatt GH, Sackett DL, Cook DJ (1994) Users’ guides to the medical literature. II. How to use an article about therapy or prevention. A. Are
the results of the study valid? Evidence-Based Medicine Working Group. JAMA 271:59-63.
If pass the screening questions is worth to read the full text!
8 July 2016 8
CRITICALLY APPRISAL … GUIDELINES
Different according
with the study design
8 July 2016 9
CRITICALLY APPRISAL … TOOLS
Assist the user in calculation of EBM estimators
Input:
• 0.1% of persons 15-49 years old are HIV+ in
Romania
• 78% of ELISA detect HIV when it is present
• 1% of ELISA incorrectly detect HIV when it
is not present
Interpretation:
→ a positive ELISA only means that the
individual chance of HIV is 50%, rather than
expected 0.1%
8 July 2016 10
CRITICALLY APPRISAL … TOOLS
7. Bolboacă S, Jäntschi L, Achimaş Cadariu A. Creating Diagnostic Critical Appraised Topics. CATRom Original Software for Romanian
Physicians. Appl Med Inform 2004;14:27-34..
8. Bolboacă S, Jäntschi L, Drugan T, Achimaş Cadariu A. Creating Therapy Studies Critical Appraised Topics. CATRom Original Software for
Romanian Physicians. Appl Med Inform 2004;15:26-33.
9. Bolboacă S, Jäntschi L, Achimaş Cadariu A. Creating Etiology/Prognostic Critical Appraised Topics CATRom Original Software for Romanian
Physicians. Appl Med Inform 2003;13:11-16.
8 July 2016 11
Centre for Evidence
Based Medicine
University of Oxford
Romanian online tool for Critical Appraisal Topics
MAKING SENSE OF CRITICAL APPRAISAL
IF2015 = 5.008
8 July 2016 12
MAKING SENSE OF CRITICAL APPRAISAL
Population &
Exposure &
Outcome
Study Objective: Out-of-hospital cardiac arrest has an overall poor prognosis. We
sought to identify what temporal trends and influencing factors existed for this
condition in one region.
Methods: We studied consecutive out-of-hospital cardiac arrest patients from 2007
to 2011 with attempted resuscitation in Copenhagen. From an Utstein database, we
assessed survival to admission and comorbidity with the Charlson comorbidity
index from the National Patient Registry and employment status from the Danish
Rational Economic Agents Model database. We used logistic regression analyses to
identify factors associated with outcome.
Primary endpoint
8 July 2016 13
MAKING SENSE OF CRITICAL APPRAISALAppropriate design?
Study Objective: Out-of-hospital cardiac arrest has an overall poor prognosis. We
sought to identify what temporal trends and influencing factors existed for this
condition in one region.
Methods: We studied consecutive out-of-hospital cardiac arrest patients from 2007
to 2011 with attempted resuscitation in Copenhagen. From an Utstein database, we
assessed survival to admission and comorbidity with the Charlson comorbidity
index from the National Patient Registry and employment status from the Danish
Rational Economic Agents Model database. We used logistic regression analyses to
identify factors associated with outcome.
Evidence level: III-2
Was blinding
possible? Was
blinding employed
in the
methodology?
8 July 2016 14
MAKING SENSE OF CRITICAL APPRAISAL The follow-up
of subjects was
complete?
No detailed information in regards of follow up!
Selection of Participants …Successful resuscitation defined as
admission to the hospital was the primary endpoint of this study, with
survival to hospital discharge as the secondary endpoint.
How many days/months were follow-up?
8 July 2016 15
MAKING SENSE OF CRITICAL APPRAISAL The outcome
variable was
measured in same
way for all
subjects?
No information is provided!
8 July 2016 16
MAKING SENSE OF CRITICAL APPRAISAL
RESULTS: Of a total of 2,527 attempted resuscitations in out-of-hospital cardiac
arrest patients, 40% (n=1,015) were successfully resuscitated and admitted to the
hospital. The strongest independent factors associated with successful resuscitation
were shockable primary rhythm (multivariate odds ratio [OR]=3.9; 95%CI: 3.1 to
5.0), witnessed arrest (multivariate OR=3.5; 95% CI: 2.7 to 4.6), and out-of-hospital
cardiac arrest in a public area (multivariate OR=2.1; 95% CI: 1.6 to 2.8) …
The number of patients with a high comorbidity burden (Charlson comorbidity index
≥3) increased during the study period (P<0.001), from 18% to 31% (P<0.001),
whereas the percentage of out-of-hospital cardiac arrest patients with successful
resuscitation to hospital admission increased by 3% per year during the study period,
from 37% in 2007 to 43% in 2011 (P<0.001).
The effect is real? &
The size of the effect is
clinically important? & The
evidence is relevant for
practice?
8 July 2016 17
MAKING SENSE OF CRITICAL APPRAISAL
CONCLUSION: Our observations confirm the importance of key features
that influence out-of-hospital cardiac arrest survival to hospital admission but are not highly influenced by public health actions. Despite increased illness burden, this short term outcome from cardiac arrest improved as care system efforts matured.
The effect is real? &
The size of the effect is
clinically important? &
The evidence is relevant
for practice?
It is worth to read the full text?
Could reading this article improve the EM practice?
8 July 2016 18
7 Indian Pediatrics 2011;48::277-287.
?• Today EM evidence is not necessary tomorrow EM
evidence
Continuing education
• http://ebem.org/index.php • http://www.tamingthesru.com/emergencykt
EM Evidence
• Clinical protocols
• Guidelines
New media
• Cell phones, smartphones, texting, social media
• the Internet, health care or monitoring apps
KEY MESSAGE!
8 July 2016 19
Research Evidence Practice
Not all of us need
to do research
Critical appraisal
of scientific
literature need
specific skills
AND knowledge
The latest EM knowledge
that change practice are in
the scientific literature
Critical appraisal of EM scientific literature is like riding a bicycle … It needs practice
8 July 2016 20