SYSTEMATIC REVIEWS Flashcards
Give 3 features of a systematic review?
- Review of all literature
- Focuses on one particular topic/ question
- Uses scientific methods
What are some possible reasons for differences between RCTs? (4)
- Chance
- Differences in people
- Differences in follow up
- Selection from available evidence
What is positive result bias?
When authors are more likely to 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
Give 2 possible issues that can arise with systematic reviews
- Large volumes of information
- Low quality info drowns out high quality info
Define the term review
Any attempt to summarise information
Give 3 benefits of reviews?
- Large amounts of literature can be condensed
- New info is made easily accessible
- Provide goof quality reviews of the topic
What is a systematic review?
A research method that is generally used to synthesise multiple pieces of research evidence of the effectiveness of a research question
Draw the flow chart to show the stages of producing a systematic review
Give two ways in which bias is avoided in the stages of creating a systematic review
- Writing the protocol and description of methods
- Using two independent reviewers to result in an unbiased selection of studies
Define a meta analysis study
Uses statistical techniques to combine the quantitative results from a number of studies
Give 3 advantages of systematic reviews
- Assimilation of large amounts of research evidence
- Provide reliable unbiased estimates of effects
- Can be the best source of evidence on effectiveness
What are internal validity and external validity?
Internal validity - The extent to which the effect that is observed is attributable to the experimental condition not other confounding factors
External validity - The extent to which the conclusions and results can be applied to other people, places and times
What does critical appraisal involve?
- Is the review trustworthy/ valid?
- What were the review’s results?
- How will the results help external validity?
What are the 10 questions that critical appraisal should ask?
1) Did the review ask a clearly focused question?
2) Did the review include the right type of question?
3) Did the reviews try to identify all relevant studies?
4) How did the reviewers decide which studies to include and did they assess the quality of the included studies?
5) Have the results of the studies been combined together (meta analysis) and if so, why?
6) How are the results presented and what is the main result?
7) How precise are the results?
8) Can the results be applied to the local population?
9) Were all important outcomes considered?
10) Should policy or practice be changed as a result of the evidence contained in this review?
