CAT

Question 1

2 advantages of SR

Answer 1

• SR: rigorous summary of all research evidence that relates to a specific question
• By bringing together all the relevant evidence disadvantages of single studies can be guarded against
• individual studies may have inadequate sample sizes to detect important differences -> FN results

Question 2

What is the problem with only searching one database

Answer 2

Fails to identify all releavnt studies whicch may have influenced the results of the review

Question 3

Problem with only looking at studies published in English

Answer 3

• Trial reports that are translated for publication in English language journals tend to have bigger effect sizes (i.e. so English-language only searches tend to overstate the effect of an intervention

Question 4

Importance of assessing quality of studies

Answer 4

• Assessing quality is important because studies with weaker designs will be less valid and can overestimate effects.
• Using two independent reviewers to assess quality makes it less likely that errors will be made.
• Using pre-agreed criteria helps make the process objective and transparent.

Question 5

Why are RCT less impacted by bias

Answer 5

• RCT: groups similar due to randomisation -> can be sure obs differences due to intervention
• obs: patient/ clinician decides which gr patient allocatied to -> imbalance of condounders

Question 6

Meta analysis =

Answer 6

A statistical technique for quantitatively combining the results of multiple studies that measure the same outcome into a single pooled or summary estimate.

Question 7

definition of odds ratio

Answer 7

A ratio of the odds of an event in an exposed group to the odds of the same event in a group that is not exposed