Systematic reviews and meta-analyses
LO: Describe and compare the design, strengths, limitations and appropriate use of common quantitative research methodologies and explain how these relate to the hierarchy of evidence
Primary prevention - prevent first incident
Secondary prevention - prevent another event with established incident
Systematic review
- Find relevant studies
- Decide which belong
- Judge whether the studies are trustworthy
- Bring findings together
| Strengths | Limitations |
|---|---|
| Multiple studies | Dependent on primary studies |
| Explicit and transparent methods | Miss unpublished evidence |
| Precise estimates | Judgement about inclusion and synthesis |
| Uncertainty and evidence gaps | Poor methods can mislead |
Misleading
- Relevant evidence is missed
- Studies were biased
- Incompatible results combined
Meta-analysis
- Statistically combine compatible numerical results
Forest plot
- Direction - which side is favoured
- Precision - how wide are the confidence intervals
- Consistency - similarities/differences
- Overall estimate - what does pooled result suggest