CRITICAL APPRAISAL OF THE MEDICAL LITERATURE

1
CRITICAL APPRAISAL OF THE MEDICAL LITERATURE

• Hurley Research Center

2
BACKGROUND

• 1992 JAMA Evidence-Based Medicine A New
  Paradigm . . .
• by the McMaster University
  Evidence-Based Medicine Working Group in
  Hamilton, Ontario.
• 1993 JAMA Users Guide to the Medical
  Literature I
• through XIII published in 1997.

3
Evidence-Based Medicine
An approach to clinical decision-making in which
one searches the literature, critically evaluates
the research evidence, and then chooses the most
appropriate intervention or course of action to
take.
4
Critical Appraisal of Literature
Intended to enhance the clinicians skill
to determine whether the results reported in an
article were likely to be . . . .
. . . true
. . . important
. . . applicable to their
patients!
5
KEY QUALITY PARAMETERS

• VALIDITY
• RELIABILITY
• IMPORTANCE

6
VALIDITY

• INTERNAL
• Is the study designed in such a way that I
• can trust the findings?
• EXTERNAL
• Is the study designed in such a way that I
• can generalize the findings?

7
RELIABILITY
If the study was conducted again, would the
results be the same? Usually interpreted as the
accuracy of measurement.
8
IMPORTANCE
What was the effect size or magnitude of
effect? Clinical vs. statistical significance.
9
Tools for Critical Appraisal
EBM simplified approach

• What are the results?
• Are the results valid?
• Will the results help me in patient care?

10
COMMON PROBLEMS
INTRODUCTION

• In concise statement of the problem
• Inadequate review of the literature
• Weak study rationale

11
COMMON PROBLEMS
METHODS

• Inadequate sample size, non-representative
• sample, or biases in subject selection or
  recruitment
• Inadequate controls (random assignment, or
  well-matched controls?)
• Measurement biases (valid tools? blinded?
  timing appropriate? follow-up?)

12
COMMON PROBLEMS
RESULTS

• Selection and/or number of statistical tests
  performed
• Selection of variables for inclusion

13
COMMON PROBLEMS
DISCUSSION

• Failure to link findings to current literature
• Inappropriate inferences
• Failure to critique own work
• Little insight or direction provided

14
APPLICATION TO PRACTICE

• Increase patient trust
• Provide best possible care
• Reduce liability risk

15
EXERCISE