Wk 8 - Rigorous Reviews

Question 1

SYSTEMATIC REVIEW
I) what is it
ii) where does it sit in the evidence hierarchy pyramid?
Iii) when should the protocol of a SR be registered/submitted? What is included in the protocol? (3)
iv) name a registry that the protocol may be registered in
V) what is PRISMA?

Answer 1

I) summary of the medical literature that uses explicit and reproducible methods to systematically search, critically appraise and synthesise on a specific issue. It synthesises results of multiple primary studies related to each other by using strategies that reduce biases and random errors

Ii) sits at the top

Iii) developed and made public before a review is conducted or the results are published
Describes rationale, hypothesis and planned methods

Iv) registry such as PROSPERO

V) PRISMA is s reporting checklist that should be used to ensure high quality in production of protocols and the corresponding report (provide a flowchart to show why records were excluded at each stage etc)

Question 2

REVIEW THE QUESTION
I) what two type of studies is PICO (population, intervention, comparison, outcome) used for?
ii) what two type of studies is SPIDER (sample, phenom of interest, design, evaluation, research type) used for?

Answer 2

I) PICO for quantitative / interventional studies

ii) SPIDER for qualitative / non interventional studies

Question 3

INCLUSION EXCLUSION CRITERIA
I) what do the best systematic reviews contain?
Ii) which two stages are the criteria applied at?
iii) what is it important to do with the criteria before you use it
Iv) name a software that can record decision making

Answer 3

I) contain a small number of very comparable primary studies
Ii) apply criteria at title/abstract stage then at full text stage
iii) pilot it - test and see if you get the expected result
Iv) RAYYAN

Question 4

SYNTHESIS METHODS
I) what is evidence synthesis
ii) what are the three core types of evidence synthesis and what is each used for

Answer 4

I) how you aggregate findings from initial studies to produce a bottom line ie an answer to your research question
Ii) narrative systematic synthesis - descriptive summary of findings, useful for heterogenous studies
Meta synthesis - synthesises qualitative or mixed data to produce summary results
Meta analysis - stat technique for combining quantitative data to produce summary result - can focus on intervention effects ans assoc between variables

Question 5

META ANALYSIS
I) what is it?
Ii) name four key steps
Iii) how are meta analysis results commonly graphically displayed?
Iv) how are binary variables expressed
V) how are continuous measures expressed
Vi) how is publication bias expressed

Answer 5

I) statistical combination of at least two primary studies to produce pooled single estimate of the effect being considered
Ii) data extraction, stat meta analysis, consider heterogeneity, consider bias, interpret results
Iii) meta analysis results displayex in a forest plot
Iv) binary variables expressed as ratios eg risk or odds ratio
V) continuous variables expressed as weighted mean diff between two groups
Vi) publication bias expressed as funnel plot

Question 6

Give two strengths and three weaknesses of the systematic review

Answer 6

Strengths
Provides more robust and reliable conclusions than individual primary studies
Core part of evidence based medicine

Weakness
Limited by avail and quality of evidence
Takes lots of time
Meta anal and synth require lots of expertise
Necessary data may not be included in primary Publications

Question 7

SUMMARY
I) what is a systematic review and what is the core purpose
ii) what are the 7/8 core steps of SR
Iii) where does SR sit in the medical evidence hierarchy
iv) give a strength and weakness

Answer 7

I) summary of medical literature using explicit and reproducible methods to systematically search, critically appraise and synthesise primary research on a spec issue
Core purpose is to collate all available evidence in order to ensure clinical decision making is maximally informed and minimally biased

Ii) core steps are
Set the review question
Search terms and strategy - PICO AND SPIDER
Inclusión exclusion criteria - pilot first
Risk of bias
Data extraction
Evidence synthesis - narrative systematic (descriptive summary), meta anal (statistical pooling), meta synthesis (qualitative analysis)
Writing the report

Iii) top of evidence hierarchy

Iv) strength is robust and reliable conclusions c9mpared to individual studies
Weakness is laborious, specialised