S1.2 Clinical Trials Flashcards
What is a clinical trial?
Any form of planned experiment which involves patients and is designed to find the most appropriate method of treatment for future patients with a given medical condition.
What is the purpose of a clinical trial?
To provide reliable evidence of treatment efficacy and safety
Efficacy - the ability of a healthcare to improve the health of a defined group
Safety - the ability of a healthcare not to harm a defined group
What are the disadvantages of non-randomised clinical trials?
Non RCT compares patients receiving new or standard treatment.
It can lead to allocation bias and confounding variables
What is comparison with historical controls?
The comparison of a group of patients who had the standard treatment with a group receiving a new treatment.
But, the standard treatment group is often flawed as: selection process less rigorous they are treated differently
What are the steps involved in a randomised controlled trial?
Definition of factors
Conduct of the trial
Comparison of outcomes
What are the advantages of random allocation?
Minimal allocation bias: each participant has an equal chance of being allocated to each of the treatments
Minimal confounders: leads to treatment groups that are likely to be similar in size and characteristics
What are the advantages of blinding?
Don’t know the treatment allocation so prevents bias
What is the placebo affect?
A placebo is an inert substance made to appear identical to the active formulation which it is meant to be.
Participants should be informed that they MAY receive a placebo
How do we minimise ‘losses to follow-up’ and ‘non-compliance’?
Need to maintain contact with patients and simplify instructions.
What is an explanatory trial?
As treated analysis
Analyses only those who completed follow-up and complied with treatment.
This allows the comparison of psychological effects of treatment but loses effects of randomisation.
What is a pragmatic trial?
Intention to treat analysis
Analyses treatment groups regardless of whether they completed follow-up or complied with treatment.
This preserves the effects of randomisation.
Describe the issues that should be considered for a clinical trial to be regarded as ethical
Scientifically robust
Ethical recruitment: no inappropriate exclusion or inclusion
Valid consent: written
Describe the purpose of a Research Ethics Committee
Conduct of study
Informed consent
