RCT Flashcards
How do you analyse a paper on TREATMENT using the RABITFuR mnemonic
Randomisation
Allocation concealment
Blinding
Intention to treat analysis
Treatment Effect
Follow up Rate
Results
What are the types of randomisation
Simple randomisation
Block Randomisation
Stratified Block randomisation
What is randomisation
The allocation of participants to groups by chance to ensure that both groups have equal known and unknown prognostic factors (1 mark) so that the results from the trial is attributed to the intervention alone (1 mark)
What is allocation concealment
The process of ensuring that the person who is making the decision about enrolling a patient is unaware of whether the next patient enrolled will be entered into the intervention or control group (1 mark) to prevent selection bias (1 mark)
What is blinding
The process of ensuring that the personnel (patients, care giver or outcome assessor) are unaware of which patients have been assigned to the intervention or control group
What is the difference between blinding and allocation concealment
- Allocation concealment can always be achieved, whereas blinding may not in some instances
- Allocation concealment occurs before and up to the point of allocation, whereas blinding occurs after allocation
- Allocation concealment prevents selection bias, whereas blinding prevents performance or measurement bias
What is intention to treat analysis
Patients are analysed based on the group they are randomised to irrespective of what treatment they receive
Why is Allocation concealment important
- Protects the integrity of the randomization process, protects the assignment sequence before and until treatment allocation to
facilitate blinding downstream - Minimizes effect of selection bias. Whereby knowledge of the next treatment allocation might influence clinicians’ decision to include/exclude patient or Influence patient’s decision to withhold consent or to participate in the trial
- Uphold principle of justice – all patients have equal chance of receiving either intervention or control
Why is intention to treat analysis important
- In reality, patients adherence to treatment is an important marker or the failure or success of a treatment. Excluding such patients would be omitting important information about the performance of the treatment
- Removal of patients post randomisation, from analysis disturbs the prognostic balance achieved during the randomisation process
What is an adjusted analysis
A statistical analytical tools (eg regression) used to take into account differences in baseline characteristics and prognostic factors between groups that may influence outcomes
What is 95% confidence interval in lay man terms
There is 95% certainty that the point estimate lies between the ranges of the confidence interval
What is the purpose of an inclusion criteria
Identifies the population of interest and focusses the research study on this population of interest
What is the purpose of an exclusion criteria
- Removes populations that have a confounder that affects the outcome of interest
- Remove vulnerable populations who are high risk of a negative outcome
- Limit the size of the study population
What is an open label trial?
- A trial where participants and care givers are not blinded. This is often due to practical or ethical reasons. It is open to performance bias
How do you limit the reduction in internal validity from an open label trial
- Have outcome assessors that are blinded
- Have objective outcomes