Critical Appraisal Flashcards
What is a cross-sectional survey?
Looks at a snapshot of a population at a point in time. Exposures and outcomes are monitored
Pros of cross-sectional survey?
Ethically safe
Quick
Cheap
Spot general trends
Cons of cross-sectional survey?
Can’t demonstrate cause and effect
Recall bias
What is a case-control study?
Retrospective study
Looks at exposures and outcomes in cases and controls
Calculate Odds Ratio
Pros of case-control study?
Useful in rare diseases
Ethically quite safe
Quick
Cheap
Cons of case-control study?
Relies on accurate record keeping
Can’t demonstrate a temporal association
What is a cohort study?
Prospective study
Looks at exposures and outcomes prospectively
Pros of a cohort study?
Can demonstrate causation
Can demonstrate temporal effect
Minimal ethical issues
Cons of a cohort study?
Expensive
Time-consuming
May lose to follow-up
Not good for studying rare diseases
What is an RCT?
Prospective trial in which patients are randomised to receive either an intervention or a control
Pros of RCT?
Blinding minimises bias
Allows robust statistical analysis
Prospective
Cons of RCT?
Expensive
Ethical issues
Time-consuming
