Purpose of Critical Appraisal
• Evaluate level of evidence and quality of
evidence to support clinical decision-making
– How certain are we about the results? (validity)
– How applicable are the results to the practice?
(applicability; translational capacity)
• Schemas exist for critically appraising
quantitative research and qualitative research
• Take advantage of tools to permit RAPID
critical appraisal of evidence
More Practical Reasons for Critical
Appraisal of Evidence
• Judge worthiness of study
• Understand reliability and relevance for
practice
• Make objective decisions about patient care
• Make sense of the results
TO EFFECTIVELY PRACTICE AS AN EVIDENCE
BASED PRACTICE PROVIDER…
Critical Appraisal of Evidence:
Key Questions to Consider
• Are the results of the study valid?
• What are the results?
• Do the results apply to my patients?
Let’s Use Appraisal Tools to GUIDE
Response to the KEY Questions…
For N513…
• Johns Hopkins Rating System
– Aggregates evaluative criteria as
• Research
• Non-research
– Because JH system captures qualitative research as “nonresearch,” we are using Melnyk, et al. Rapid Critical Appraisal
Form for Qualitative Studies in addition to JH tools
– Rate Level of Evidence first
– Rate Quality of Evidence second
For N513…
• If you need additional guidance to determine
level of evidence and quality rating
– Use Appendix D from Melnyk & Fineout-Overholt
textbook
• Checklists specifically address
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Case-control studies
Cohort studies
Randomized clinical trials
Systematic reviews
Qualitative evidence
Evidence-based clinical practice guidelines
Here is How I Would Approach Rapid
Critical Appraisal of Evidence…
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Read the study (more than one read is necessary)
Determine the study design FIRST
Prepare a JH Rating System form for the study
Access Appendix D to guide quality evaluation of
study
• Refer to textbook chapters 5-8 for detailed
considerations addressing validity, interpretation
of results, and clinical applicability
Case Control Studies
• Examines why certain people develop disease,
experience adverse event, or behave in a certain
way (CASES)
– By selecting cases and comparing these cases to
“controls” (those without the
characteristic/condition/behavior) of interest,
differences are assumed to explain why CASES ARE
CASES and CONTROLS ARE CONTROLS
– Remember though…no manipulation or intervention
so CAUSE AND EFFECT cannot be conclusively
determined with such a design
Go to Appendix D
• To address the 3 overarching questions for rapid critical
appraisal…
– Are the results of the study valid?
• How were cases obtained?
• Were appropriate controls selected?
• Were data collection methods same for both?
– What are the results?
• Is an estimate of effect given (do numbers add up)?
• Are there multiple comparisons of data?
• Is there any possibility of bias or confounding?
– Will the results help me in caring for my patients?
• Were the study patients similar to my own?
• How do the results compare with previous studies?
• What values/expectations do my patients have for the outcome?
Go to JH Rating System for Research
Form
• Because Case Control Studies have two groups
for comparison, these studies should be
evaluated as research
– The checklist should guide your evaluation of the
LEVEL
– Then QUALITY
– Place overall rating at top of JH Rating System
form for each study