1. EVIDENCE BASED MEDICINE
CRITICAL APPRAISAL THERAPY

3. Steps of practicing EBM
Assess your patient
Clinical examinatio (local , abdominal …ect) then determine the CC and the nedd for EBM
Ask clinical question
Best diagnosis modality,treatment, prognosis, and the harm that may affect the pt.
Acquire the evidence
Ebm resources( ready made evidence, un ready appraised evidence)
Appraise the evidence
Appraise the primary research that you cant depend on it ( methodology)
Apply the evidence to pt. care

5. Ask clinical questions
Build a question with 4 main components
P opulation / Situation
I ntervention / Exposure
C ounter intervention
O utcome
T imeframe

7. Types of questions
Background questions Foreground questions

8. Bachground questions
Where to find the answers? Mainly for students

9. Foreground questions
Where to find the answers? Mainly for practioner

10. Evidence pyramide

11. Levels of evidence
Graded according to its power 1- systemic reviews of well conducted RCT or large RCTs. 2-systemic reviews of well conducted observational studies or large observational studies. 3- systemic reviews of descriptive studies or large descriptive studies. 4- opinion of respected authorities.

12. Put In Mind
- There is no perfect trial - Prestigious journal or authors are never a seal of guarantee of quality ( Appraise the Evidence ) - A badly conducted or biased research is hazardous to one’s practice and patient as much as a good one is useful to them.

13. Why we need to do Critical Appraisal

14. The effect of the 2500 most common used drugs

15. Why A systematic review
(Williamson, 1986) From 4235reachers articles published in 30 journals 9among them BMJ, JAMA, NEJM, Lancet) only 20% met the validity criteria. (McKibbon et al.,2004) From 60,352 articles published in 170 journals in year 2000 Only 4132 (6.8%) were of high quality and clinical relevant.

16. Etiology and risk factors cohort and case control
Question Study
Therapy RCTs
Harm Cohort
Etiology and risk factors cohort and case control
Diagnosis Cross- sectional
Different research questions require different
study designs.
For example the best design for studies
evaluating the effectiveness of an intervention or
treatment is a Randomized controlled trial.

17. Studies are also subject to Bias, Confounders and it is important that researchers take steps to minimize this bias &confounders. For example, use of a Control group, Randomization and blinding.

18. Important aspects about the RCTS
Randomization Bliniding Allocation concelment Intention to treat analysis

19. Critical appraisal
Critical appraisal is the process of systematically examining research to assess its: - Validity - Results - Relevance Before using it in decision making. The Critical Appraisal aims to help people develop the necessary skills to make sense of scientific evidence based on validity, results and relevance.

20. Research involves gathering of data ,
collection of data and analysis of the data to
produce meaningful information.
However, many of the research are not in
good quality and many studies are biased and
their results are untrue.
This can lead us to draw false conclusions

21. The triangle of Appraisal
Relevance Validity Results
Triangle of Critical appraisal
Is the article relevant to my practice and my patient
Is the article of good methodology
What is the treatment effect

22. Validity depends on the methodological quality of the research
The degree to which the results of a study are likely to be true and free from bias.
Validity depends on the
methodological quality of the research

23. Randomly assigned Outcome compared Experimental group
Follow up
Control group
Outcome compared
Control group
Follow up

24. Always Remember
Minimize Bias by Randomization Allocation concealment Double blinding Intention to treat analysis R A D I

25. Results
how large was the treatment effect? * EER Experimental Event Rate * CER Control Event Rate * NNT Number Needed to Treat How precise was the estimate of the treatment effect? * p: P Value * 95% C.I: 95% Confidence Interval?

27. Example 1
A RCT was done to evaluate a new drug claimed to prevent common cold in children child received placebo and 1000 received the drug. During 6 months follow-up cold occurred in 200 of the kids on active treatment and 300 of the kids on placebo.

28. Results Tabulation
1000 child received placebo and 1000 received the drug on 6 months follow-up cold occured in 200 of the kids on active treatment and 300 on placebo
No common cold
Common cold
800
200
GI: Drug
700
300
GII: Placebo

29. EER= 20% CER= 30% 10% ARR NNT=100/ ARR NNT= 100/10 NNT= 10
Event-Ve
Event +Ve
800
200
EXP GRP
700
300
CTL GRP
EER= 20% CER= 30% 10% ARR NNT=100/ ARR NNT= 100/10 NNT= 10

30. Example 2
In the Coronary Primary Prevention trial (1985); patient with high serum cholesterol level were randomized to receive either cholestyramine or an equally foul-tasting placebo and the outcome was cardiac death after 7-10 years. In the cholestyramine group; there were 30 cardiac deaths out of 1900 participants and in the placebo group; there were 38 cardiac deaths out of 1906 participants

31. Result Tabulation
Cholestyramine group: 30 cardiac deaths out of 1900 Placebo group: 38 cardiac deaths out of 1906 EER= 30/1900X100= 1.58% CER= 38/1906X100= 1.99% ARR= 0.41% NNT= 100/ ARR 100/0.41= 244

32. Relevance
The degree to which the result can be applied to one’s own patients. * Different patient * Relevant outcomes not considered * Intervention can not be applied to my patient ( Availability, Cost, Harm/Benefit ratio)

33. Clinical Scenario
It is the croup season and you have a large pediatric population in your practice. You have been taught that the use of corticosteriods for croup is controversial and should be used only as a parenteral therapy or with a nebulizer in hospitalized patients. But you wonder wether you can use oral corticosteriods for children with croup!

35. The PICO
P Children with croup I Oral corticosteriods C Parenteral or nebulized corticosteriods O Croup score In children with croup; what is the effectiveness of oral corticosteriods compared to parenteral corticosteriods in reducing symptoms.

36. Steps to find Evidence 1- Determine the domain of the question
2- Determine the best study type to answer it
3- Formulate the search strategy
1- What are the key words
2- Where to search
3- How to search
4- Perform the search
1- Pre-appraised sites
2- Primary research ( PubMed)
5-Choose relevant studies for appraisal ( Largest, best methodology)

37. Or Parenteral (IV, IM) )AND
The Search
Synonym 2
Synonym 1
Primary term
Or distress) AND
Or respiratory s
( Croup P
Or ) AND Or
( Corticosteriods
Mesh I
Or Parenteral (IV, IM) )AND
Or Nebulized
(Oral Or C
Or improvement
Or recovery
Croup score O

38. The Cochrane Library
Clinical Evidence
EB- Guidlines
PubMed

39. Critical Appraisal work sheet
Are the results of the study valid? Are the valid of this randomized important ? Can you apply this result on your patient?

40. Now you can drink your Coffee