L05 - AAAA systematic reviews Flashcards
(38 cards)
What does ‘assess’ in the AAAA framework constitute?
- Formulate a clear clinical question (PICO framework)
- Identify the study design that would provide the most accurate answer
What does ‘access’ in the AAAA framework constitute?
- Search for and retrieve the research
What does ‘identify’ in the AAAA framework constitute?
- Identify the strengths and weaknesses of the research you find and understand what the results mean
What does ‘act’ in the AAAA framework constitute?
- Apply the evidence, taking into account its limitations, alongside other information (e.g. patient pref)
What is positive results bias?
When authors are more likely to submit, or editors accept, positive than negative or inconclusive results
What is outcome reporting bias?
When several outcomes within a trial are measured but are reported selectively depending on the strength and direction of those results
What is the PICO framework?
P = Patient popn - how describe group of patients I = Intervention or issue C = comparator - main alt intervention (comparison intervention) O = Outcomes - context
Advantages of systematic reviews?
- Can be best source of evidence on effects and effectiveness of healthcare interventions
- Assimilation of large amounts of research evidence
- Provide reliable unbiased estimates of effect
- Inc precision of estimates of effects
- Proc inf about the generalisability and consistency of effect
- Identify what info is missing
- Useful for making decisions
What is evidence based medicine?
- Mix of indiv clinical expertise, best external evidence and patient values/ expectations
- Optimise dec making by using best available research
What are some reasons for differences between RCT’s?
- Chance
- Reporting of available evidence
- Selection from available evidence
Differences in: - Ppl
- Intervention/ comparator
- Care other than what being investigated
- Assessment of treatment effects
- Follow-up
What is publication bias?
The outcome of an experiment or research study influences the decision whether to publish or otherwise distribute it.
What are the different types of publication bias?
- +VE results bias
- Outcome reporting bias
What is positive results bias?
When authors more likely to submit or editors accept, positive than negative or inconclusive results
What is outcome reporting bias?
When several outcomes within a trial are measured but are reported selectively depending on the strength and direction of those results
What are the benefits of reviews?
- Vol of lit condensed
- New info made accessible
- Relevant info
- Saves time?
What is a systematic review?
The research method used to synthesis multiple pieces of research evidence on the effectiveness of a treatment
- Review of all lit
- On one particular topic
- Using scientific methods
List the hierarchy or evidence (for effectiveness)
- Systematic reviews
- RCT’s
- Cohort studies
- Case control studies
- Case series and reports
- Expert opinion ‘anecdotal’ evidence
What are the stages in a systematic review?
- Define question (what/ why/ PICO)
- Write protocol - desc of methods
- Search for evidence/ studies - comprehensive identification of relevant studies
- Select relevant studies from search - unbiased selection of studies for review
- Appraise studies - unbiased assessment of methodological quality of each study
- Extract, analyse and summarise data - unbia extraction
- Interpret review results
- Discussion and conclusions
Why is writing a protocol an important stage of writing a systematic review?
- Desc of methods
- Ensures methods and problems are considered a priority
- Avoids introducing bias
How might you search f for evidence/ studies in a systematic review?
- Bibliographic databases
- MEDLINE, EMBASE
- Non-eng lang lit
- Grey lit hard to identify)
How would you select relevant studies from the search in a systematic review?
Two reviewers independently using pre-defined criteria (based on PICO) to select relevant studies from the search
- reduces errors
How would you appraise studies in a systematic review?
Two reviewers independetly using checklist (e.g. CASP - critical appraisal skills programme)
- reduces errors
How would you extract, analyse and summarise data in a systematic review?
Two reviewers independently using predefined approach to identify relevant data
- Predefined analysis of data
- Use of validated appropriate methods of numerical data synthesis (meta-analysis)
- Predefined exploration of possible effect modifiers
What is a meta-analysis?
A statistical analysis that combines the results of multiple scientific studies that address the same question (each study has some degree of error reported)
