3. Why? – to save time
• In order to keep up to date,
clinicians would have to read
17 articles a day, 365 days a
year
• Research is of variable
quality
• Only an estimated 1% is
judged clinically relevant
• Need to find the 1%
4. Publication bias
Papers with “interesting” results are more
likely to be:
• Submitted and accepted for publication
• Published in a major journal
• Published in English
• Quoted by authors
• Quoted in newspapers
5. Brainstorm
What factors should you be bearing in
mind when reading an article?
Think about
• the research described
• how it is reported
13. Forest plots
Line of no effect
Confidence interval
Best estimate
less than 1
1
more than 1
14. Forest plots
Line of no effect
Confidence interval
Best estimate
less than 1
1
more than 1
15. Forest plots
Line of no effect
Confidence interval
Best estimate
Pooled result
less than 1
1
more than 1
16. P-value
Could the result have
occurred by chance?
p = 0.001
(1 in 1000)
p = 0.2
(1 in 5)
A p-value of less than 0.05 (1 in 20) is
considered to be statistically significant
17. How it works
• Involves answering a short questionnaire
• We use the CASP questionnaires at
http://www.sph.nhs.uk/what-we-do/publichealth-workforce/resources/critical-appraisalsskills-programme
• The questionnaires were devised by
doctors for doctors