Block 4 Week 3: Systematic Reviews Flashcards
Define a systematic review
A review of a clearly forumulated question that uses systematic & explicit method to identify, select and critically appraise relavent research & to collect and analyse data from the studies that are included in the rewview
Why have systematic reviews?
Identify which forms of healthcare work and do not work
Busy HCP need quick effective ways of identifying what works best for pt
Health care providers need to be evidence based to ensure practice is up to date
What are the three key functions of a systematic review?
Synthesise the evidence
Understand hetrogeneity in treatment effects
Set the research & practice agenda
What are the steps to a systematic review?
- Rationale/ Familiarise with process
- Question
- Protocol
- Literature search
- Screening
- Eligibility
- Dataabstraction
- Quality assessment
- Analysis
- Summary& Writeup
Systematic review: Rationale/ Familarise with protocol
Rationale
- What is already known
- Someone else already done/ doing review
Familarise with Protocol:
- Start preparing protocol
- Follow reporting guidelines eg: PRISMA-P
SR: Question
PICOS (study design= S)
SPICE (Setting, Population, Intervention, Comparison, Evaluation) for qualitative
SR: Prtocol
Informed by & refined from research question
Include:
- Search strategy
- Inclusion/ Exclusion criteria
- Data extraction
- Risk of bias assessment
- Analysis/ Synthesis plan
- Presentation and Interpretation
SR: Literature Search/ Study Retrieval
- Identify where you plan to search
- Identify search terms
- Search techniques
- Number of records identified through database search/ other sources
SR: Screening
- Number post De-duplicates
- Is the study relevant to research question
- Record number screened (Include (if seems relevant)/ Exclude)
- Record all references
- Assessed by x2 reviewers
SR: Eligibility
- Obtain full text
- Ax against each domain: PICO/SPICE.
No to one domain–> Exclusion. Unsure speak to colleague/ 3rdreviewer
- Inclusion/Exclusion Number recorded
- Excluded record with reason
SR: Data Abstraction
Extract data relavant to question
SR: Quality Assessment
•Suitable tool: Inform analysis & Interpretation
Look for Bias (& summarise for each study)
- Selection
- Performance
- Detection
- Attrition
- Reporting
- Other
Discuss the types of Quality Assessment types of Bias
Selection Bias:
- Systematic bias in the way participants are selected
Performance Bias
- Systematic differences in the care provided to the participants in the comparison groups other than the intervention under investigation
Detection Bias
- Systematic differences between the comparison groups in outcome assessment
Attrition Bias
- Systematic differences between the comparison groups in the loss of participants from the study
Reporting Bias
- Selective reporting of study outcomes
Other Bias
- Funding, error is results
SR: Analysis
Define Meta-Analysis
Quantitative:
- Meta-Analysis if possible
- Results of individual studies combined to produce overall statistic.
- Subject to any biases during selection process –> Mathematically precise bu tclinically misleading result
- ForestPlot
Qualitative:
- Narrative Analysis
Meta-Analysis
What are looking for?
What is hetrogeneity, how is it measured? Why is it importnant?
- Outcome being examined
- Time frame for the outcome?
- Summary effect size being used?
- Number of trials included?
- Heterogeneity in the comparison?
- I2 understand heterogeneity
- Percentage of variation between studies in meta-analysis due to differences between studies & not just sampling error
- 0%, 25% low, 50% moderate, 75% high
- Important:shapesunderstanding pooled effect- Is this true effect or the average effect in a distribution
