1. Systematic reviews and meta-analyses
Both really very interesting topics once again

2. Critical Appraisal Systematically examining evidence for:
Validity
Results
relevance
Essential for practice of EBM

3. What is????
SR:
Apply same level of rigour in reviewing evidence as should have gone into producing it in first place
Take care to find ALL relevant studies
Explicit statement of objectives, materials & methods
Synthesis all findings in an unbiased way
Explicit & reproducible methodology

4. When is a SR needed?
When there is a substantive therapeutic question, several primary studies (with variable findings?) and substantial uncertainty

5. SR Advantages: Limit bias Reliable & accurate
Compare different studies (heterogeneity)

6. SR Disadvantages May be done badly GIGO Inappropriate combinations
Drown out important effects
Findings not always in keeping with findings from single large RCT

7. The evidence Hierarchies I-1 SR of several DBRCT I-2 1+ DBRCT
II-1 1+ good cohort
II-2 1+ case control
II-3 1 uncontrolled experiment
III expert opinion
IV mikey likes it

8. Assessing a SR VIAD VALID? IMPORTANT APPLICABLE? (DISCUSSION)
methodology
IMPORTANT
What are ORs & CIs?
APPLICABLE?
To my patients / practice?
(DISCUSSION)

9. What’s a MA? Statistical combination of results of several trials
SR may contain a MA
Usually presented as pooled OR with CI
Some argue that if evidence needs a MA to find the answer probably not worth doing…..