Randomised Control Trials Flashcards
What two things are tested in a clinical trial?
Efficacy: whether new treatment improves health
Safety: new treatment is not detrimental to health
What three features are needed in a clinical trial? It must be….
Controlled, fair and reproducible.
What is a non randomised control trial and what are the problems with these?
These are where patients are give a new treatment and then compared to those receiving the old treatment. This can lead to allocation bias as well as confounding.
What is important to ensure that maximum gain of knowledge is acquired from a RCT?
Losses to the trial must be minimised, and treatment compliance must be maximised.
List the stages in an RCT.
Define what you are studying, identify a source of patients, gain consent from patients, allocate patients, follow up patients.
What is the primary outcome in a RCT?
This is the outcome which we are looking for. It can only be one outcome and is what we use to calculate sample size.
What are secondary outcomes in an RCT?
These are other outcomes of interest such as side effects.
What must a randomised control trial not do?
It must not disadvantage one group of patients. This means that measurements must be made regularly to ensure that this is not happening.
Give an example of how random allocation can occur.
Allocate each patient a number and use a random number generator. This will help to reduce allocation bias.
What is blinding, and what are the different types?
Blinding is where either the patient, clinician or investigator does not know which treatment the patient is being given. Single is when one of these does not know and double is where 2 or 3 do not know.
What is a placebo?
This is when treatment is compared with no treatment to see whether some of the effect is caused just because care is given.
What are the ethics surrounding a placebo?
The trial population must be aware that they may receive a placebo.
Why can losses happen in the follow up of clinical trials?
They can be appropriate if someone’s condition means they have to leave the trial or they can be unfortunate when someone decides to withdraw.
What is the difference between the as treated and intention to treat analysis?
The as treated analysis will only include members of the trial who were compliant with treatment whilst the intention to treat will include all members. This is more representative of the general population because some people will not comply.
What does clinical equipoise mean?
This means that there is reasonable uncertainty as to which treatment is the best, this makes a clinical trial ethical.
