Evidence Based Medicine Flashcards
5 Key elements of evidence based medicine
- Finding evidence (including asking the right question)
- Assessing the evidence (critical appraisal)
- Synthesising the evidence (bringing it all together)
- Making good decisions
- Evaluating performance against the evidence
Four major study designs as sources of evidence
Cross-sectional survey
Case-control
Cohort
Randomised Controlled Trial (RCT)
What is Evidence Based Medicine?
the conscientious, explicit, and judicious use of the best evidence in making decisions about the care of individual patients.
The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research
Cross-sectional study design
When investigating link (if any) between leg length inequality and back pain:
EITHER
Take a population of people and see how many have LLI and how many have back pain
OR
Take a population of people with one of these and see how many have the other
Case control study design
Take a sample of people with back pain and a sample of matched controls
Compare the prevalence of leg length inequality in the two groups
Cohort study design
Take a sample of unaffected and measure exposure to the risk factor
After a period of time, record how many people in the exposed / unexposed group develop the outcome
But differences may still be due to other factors
Randomised controlled trial (RCT)
Take a sample of patients with condition or risk of interest
Randomisation to intervention exposure / Intervention or control greatly reduces the risk that any difference in outcome is due to unknown or unmeasured factors
Hierarchy of evidence
Best
RCT
Cohort
Case control cross section
Worst
When thinking about the problem use:
Population
Intervention
Comparator
Outcome
