Flashcards in Critical Appraisal - Systematic Reviews & Meta-Analysis Deck (18)

1

## What is a systematic review?

### A literature review focused on a single question with well defined criteria for review. It is the highest level of evidence.

2

## What is a meta-analysis?

### The statistical analysis aspect of systematic review - analyses combined data from multiple studies. Done using statistical software.

3

## What are the purposes of a meta-analysis?

### Increase power, resolve uncertainty, improve estimates, answer other questions (such as secondary outcomes)

4

## What are the inclusion and exclusion criteria used to select studies for a systematic review?

### The PICOT parameters plus other relevant criteria such as sample size

5

## How might bias be introduced when selecting studies?

### By selecting only studies which are in English, or by selecting only studies which have been published

6

## What is the CONSORT checklist?

### A checklist of items that should be included in a randomised trial

7

## What is the Cochrane guidelines?

### A guide which looks at various types of bias to judge whether or not the individual study accounted for it

8

## What are the key statistical issues in a meta-analysis?

### outcome, weighting and heterogeneity

9

## What does the outcome look at?

### The average of each of the studies - such as the relative risk. Can be either a relative or absolute measure.

10

## What determines the weighting of each study?

### The number of outcomes - which is usually an indirect measure of the sample size

11

## Why is heterogeneity important?

### Because only studies which are not heterogenous should be combined

12

## How is the information presented in a meta-anaysis?

### In a forest plot

13

## What does the vertical line in the forest plot represent?

### The line of null effect

14

## What does the size of the square in the forest plot represent?

### The size of each of the studies

15

## What does the horizontal line in the forest plot represent?

### The confidence interval

16

## What does the diamond in the forest plot represent?

### The pooled result of all the studies - the vertical line of the diamond shows the point estimate and the horizontal width of the diamond shows the confidence interval

17

## How is statistical heterogeneity determined?

### Using a p value. If the p value is greater than 0.05 then the studies are not heterogenous so can be combined.

18