Systematic Reviews

Question 1

What is a systematic review

Answer 1

Identifies, appraises and summarises all of the evidence on a particular topic, with pre-defined eligibility criteria

Question 2

Difference between a systematic review and meta analysis

Answer 2

SR tells you what the result is

Meta-analysis gives you average magnitude by summarising results of other studies

Question 3

Limitations of meta-analyses

Answer 3

Only high quality if they’re based on unbiased studies, so appraisal is important

Question 4

Heterogeneity

Answer 4

Inconsistency in results/design of the studies, combining studies with high heterogeneities in a meta-analysis would be very inappropriate

Question 5

How to measure heterogeneity

Answer 5

I^2 statistic, lower means less variation

Question 6

Publication bias effect on meta-analyses

Answer 6

More interesting results are more likely to be published, effect accumulates when using studies in meta-analysis

Question 7

Funnel plot key points

Answer 7

y axis has measure of how precise studies are
More precise studies should cluster around true effect, pyramid shape
Asymmetry of studies around true effect line may indicate publication bias