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

HIERARCHY OF PREAPPRAISED EVIDENCE

8 July 2016 5

DO NOT GIVE CREDIT TO AN ARTICLE JUST BECAUSE IS

PUBLICHED IN A GOOD JOURNAL!

8 July 2016 6

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

sbolboaca@umfcluj.ro

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