Study Designs: RCTs Flashcards
(27 cards)
When would you use a controlled trial over a regular trial?
To test whether something works better than something else
What does the ‘controlled’ section of RCT mean?
It has a comparison group
In a trial, what does representativeness mean?
How well the participants in a trial reflect the broader population for whom the treatment is intended
Which 2 types of population are relevant in RCTs?
Reference population
Experimental population
In RCTs, what is meant by the reference population?
The group to which results are applicable
In RCTs, what is meant by the experimental population?
The group in which the trial is conducted
What are the components of the research triad?
Population
Sample
Results
What is meant by external validity?
The sample must be representative of the population to allow generalisation
What is meant by internal validity?
The trial must be systematic and repeatable, such that repeating it in the same way would give similar results
What is the requirement of a trial for the results to be applied to the population?
It needs to be internally and externally valid
List 5 sampling methods used in RCTs.
Simple random
Systematic
Stratified
Cluster
Disproportional
Which type of sampling involves the population being first divided into subgroups, then random samples taken from each?
Stratified sampling
Which type of sampling involves selecting every nth individual from a list?
Systematic sampling
What is meant by cluster sampling?
Population divided into clusters (e.g. GP practices or hospitals) and entire clusters are randomly selected
Do participants consent before or after random allocation?
Before
What is the main randomisation method in RCTs?
Computer generated random numbers
Which method ensures treatments groups in RCTs are kept equal in number?
Block randomisation
Which term describes the order in which participants are to be allocated to treatment
Allocation sequence
Which terms describes not disclosing to patients and those involved in recruiting trial participants the allocation sequence before random allocation occurs?
Allocation concealment
At what point in the trial does allocation concealment occur?
Enrolment
Which term describes not disclosing to participants and outcome assessors the treatment allocations after random allocation?
Blinding
What are the 2 analysis options in RCTs?
Per protocol analysis
Intention-to-treat analysis
In per protocol analysis, are dropouts included or excluded?
Excluded
