Critical appraisal is the process of carefully examining research to judge its validity, relevance, and applicability. It is important to ensure research findings are valid and applicable to one's own population before incorporating them into clinical practice. While research is peer-reviewed, critical appraisal is still needed to avoid misinterpreting results. When critically appraising research, one should examine aspects like the research question, methodology, results, discussion and conclusions to determine the overall quality and implications. Checklists exist to standardize the critical appraisal of different study designs.

1. Critical appraisal
Research module – Basic research I
Dr Tan Chai Eng
Dept of Family Medicine
UKM

2. What is critical appraisal?
• “The process of carefully and systematically
examining research to judge its
trustworthiness and its value and relevance in
a particular context” (Burls 2009)

3. Why is critical appraisal important?
• To ensure that what is presented by the
authors are valid
• To determine whether the study results are
applicable to your population
• To ensure you are practising evidence-based
medicine in your clinical practice.

4. Controversies in medical research
• Research findings need to be evaluated
carefully to avoid making inaccurate
conclusions!
http://i.dailymail.co.uk/i/pix/2012/01/17/article-2087649-0F7E35C600000578-
697_468x242.jpg
Wakefield, 1998. Lancet
Autism and MMR
HRT and breast cancer

5. Common misconception about
research articles
• It was published in a scientific journal so it
must be correct...right? (MYTH)
TRUTH
• It should have undergone peer review but needs
to be appraised to avoid misinterpreting the
results
• Some journals get payment from authors to
publish, irregardless of quality of research

6. Oh, rats! I should have paid
attention in biostatistics and
epidemiology class!

7. Critical appraisal – How to do it?
Research question
Literature search (PICO)
Select titles relevant to your study
Read the abstract to get a rough idea about
the study setting, methodology and findings
It doesn’t stop
here!!!

8. Critical appraisal - How to do it?
Obtain the full-text of the research
article
Read the whole article!
•Introduction – background and objectives of study
•Methodology – study population, setting, study design, data
collection
•Results – analysis, any confounding factors
•Discussion – compare and contrast findings, supported by
literature
•References – reliable references? Any potential articles to be
snowballed?

9. • Does it relate to the topic you are searching
for? Does it contain the important keywords?
• Does it mention where the study was done?
• Does it mention what type of study design
was used?
• Does it mention what outcome it has studied?
1: Title of the paper

10. 2: Author of the paper
• Who are the authors?
• What are the affiliations of these authors? –
relevant expertise, location of institution
• Who is the corresponding author? -
important to obtain permissions etc.

11. 3: Abstract
• Can be structured or unstructured, depending
on requirements of journal.
• Should have:
• Brief introduction of research problem / question and
study objectives
• Summary of methodology
• Summary of results
• Discussion or conclusion
• Length of abstract depends on journal
requirements.

12. 4: Introduction
• Should provide a background of why the study
was conducted, relevant literature regarding
the topic.
• Final paragraph usually states the objective /
aim of the study.
• May content several key references that you
should search for and read as well!

13. 5: Methodology
• Study population: where and what type of
population? E.g. community setting, primary
care setting, specialist setting? Specific
disease conditions? Asian or Western?
• The above will affect whether the findings can
be comparable with your own results.
• If no local studies, or regional studies, then
international studies / foreign studies are
useful.

14. 5: Methodology
• Study design
– Cross-sectional?
– Prospective / retrospective cohort?
– Case-control (retrospective)?
– Clinical trial?
– Systematic review?
– Qualitative?
• Different study designs will have different
checklists for rigor (quality) of methodology

15. Critical appraisal checklist for various
study designs
• Critical appraisal skills programme, UK:
http://www.casp-uk.net/#!casp-tools-
checklists/c18f8
• Qualitative research :
http://intqhc.oxfordjournals.org/content/intq
hc/19/6/349.full.pdf

16. 6: Results
• Presentation of data in tables, charts that are
easy to understand.
• Statistical significance? p value < 0.05?
• Strength of correlation? r (correlation
coefficient) value?
• Prediction? Adjusted OR?

17. 7: Discussion
• Comparing (same findings) and contrasting
(different findings) results with other studies
• Reasonable and logical explanation for the
differences if any
• What are the strengths and limitations of the
study? Are there other strengths and
limitations not declared by the authors?

18. 8: Conclusion
• Is the conclusion from the study valid
(appropriate methodology, valid tools, correct
analysis)?
• Is the conclusion based on the findings of the
study?
• Is the findings of the study relevant to your
research topic? Can it be applied for your
research proposal?

19. Finally…
• What have I learnt from reading this paper?
• What are the things that can be improved
from this study? Can I overcome the
limitations and improve it in my research?
• Enter the relevant information into your
literature review table.
• Skills from critical appraisal can help you in
preparing your proposal as well as in writing
up your research dissertation.

20. To ensure comprehension…
• Try to appraise the papers in the assignments
section.
• Any queries can be discussed in the discussion
section.