7 - Systematic Reviews & Meta-Analysis**

Question 1

Define systematic review

Answer 1

• Scientific investigation that focuses on a specific question and uses explicit, pre-specified scientific methods to identify, select, assess, and summarize the evidence
• May include a quantitative synthesis (meta-analysis) depending on the available data

Question 2

Do systematic reviews only contain RCTs?

Answer 2

No

Question 3

Difference between narrative review and systematic review regarding the question

Answer 3

• Narrative = often broad in scope

- Systematic = often a focused clinical question

Question 4

Difference between narrative review and systematic review regarding the sources and searches

Answer 4

• Narrative = not usually specified; potentially biased

- Systematic = comprehensive source and strategy explicitly stated

Question 5

Difference between narrative review and systematic review regarding the selection

Answer 5

• Narrative = not usually specified; potentially biased

- Systematic = criterion-based; uniformly applied

Question 6

Difference between narrative review and systematic review regarding the appraisal

Answer 6

• Narrative = variable

- Systematic = rigorous critical appraisal

Question 7

Difference between narrative review and systematic review regarding the synthesis

Answer 7

• Narrative = qualitative summary common

- Systematic = qualitative summary +/- meta analysis

Question 8

Difference between narrative review and systematic review regarding the inferences

Answer 8

• Narrative = sometimes evidence-based

- Systematic = evidence-based

Question 9

Why are systematic reviews needed?

Answer 9

• Massive number of publications
• Diverse language, different countries
• Studies can appear contradictory
• To establish clinical effectiveness, feasibility of an intervention, and to update guidelines
• To reduce delay of research to clinical practice
• To propose future research agenda

Question 10

Describe the stages of the systematic review process

Answer 10

1. Define a question
2. Search the literature
3. Assess the studies
4. Combine the results
5. Put the findings in context

Question 11

Will a large or a small study produce a large confidence interval?

Answer 11

Small study

Question 12

What is clinical heterogeneity?

Answer 12

Variability in the participants, interventions, and/or outcomes studied

Question 13

What is methodological heterogeneity?

Answer 13

Variability in study design and risk of bias

Question 14

What is statistical heterogeneity?

Answer 14

When observed intervention effects are more different from each other than we would expect due to random error alone

Question 15

Which type of heterogeneity can you quantify?

Answer 15

Statistical

Question 16

What tests can be done to determine if results are similar across studies?

Answer 16

1. Eyeball test (do they look the same)
2. Proportion of variation not due to chance (I squared); now the preferred estimate; 75-100% = considerable heterogeneity
3. Test of “null hypothesis’ of no variation (p-value) – Cochrane chi-square; p < 0.1 = heterogeneity

Question 17

What does n/N mean?

Answer 17

• n = number of px w/ the outcome

- N = total number of px in the group (either treatment or control group)

Question 18

What are funnel plots?

Answer 18

• Detect bias in study selection
• Results of each study plotted against sample size
• In the absence of bias, plot will resemble a symmetrical, inverted funnel

Question 19

Describe the acronym FAITH for determining if a review is good

Answer 19

• F = finding (did they find all studies)
• A = appraisal (did they use appropriate inclusion criteria)
• I = include (did they include valid studies)
• T = total up (did they synthesize similar outcomes)
• H = heterogeneity

Question 20

Where do you report systematic reviews to on the equator network?

Answer 20

Prisma