Randomised Controlled Trials Flashcards
Efficacy?
Test an intervention in ideal conditions
Effectiveness?
Does the intervention work in the real world
What limits confounding?
Randomisation
Internal validity?
Extent to which the observed difference between 2 groups can be correctly attributed to the intervention tested
External validity?
Extent to which outcomes observed in the study apply to people outside the sample included in the trial ie. generalisability
Bias?
A tendency of an estimate to deviate in one direction away from true value
Observer and detection bias?
Outcome measure does not adequately capture outcome of interest and does it measure equally between 2 groups
Selection bias e.g?
Allocated groups different at outset
Study sample does not represent target population
Solution to observer bias?
Blinding to exposure intervention disease status or hypothesis
Attrition bias?
Participants dropping out of an RCT
Performance bias?
Different treatment of different arms in an RCT i.e one get paid
Publication bias?
RCTs do not find between group differences less likely to be published
Clinical Equipoise?
Ethical basis for medical research that involves assigning patients to different treatments i.e is one treatment better than other
Steering committee?
Individuals who come together throughout the trial to provide an independent oversight on the efficacy and validity of the trial
So only which type of study provides experimental evidence for Bradford Hill criteria?
RCT