Lecture 7.1: RCTs Flashcards
Definition of a Clinical Trial
Any research study that prospectively assigns human participants or groups of humans to one or more health-related intervention to evaluate the effects on health outcomes
Purpose of a Clinical Trial
To provide reliable EVIDENCE of treatment EFFICACY and SAFETY
In order to ensure clinical trials are safe and efficient, they need to be…? (3)
- Fair: unbiased and without confounding
- Controlled: a comparison of interventions
- Reproducible: in experimental conditions
Double Blind Trials
Preventing a person involved in the study from
knowing which treatment a participant is
receiving:
* Participants
* Clinicians or staff carrying out treatments
* Research team involved in data
collection/analysis
Why is Double Blinding important?
Minimises measurement bias
Allocation Concealment
- Person randomising the participant does not
know what the next treatment allocation will be - Avoids allocation bias
What is the Placebo Effect?
Even if the therapy is irrelevant to the
patient’s condition, the patient’s attitude to
his or her illness, and indeed the illness
itself, may be improved by a feeling that
something is being done about it
What is a Placebo?
- A placebo is an inert substance made to
appear identical in every way to the active
formulation with which it is to be compared, - e.g. appearance, taste, texture, dosage regime,
warnings, etc
Why are Placebos important?
To cancel out any ‘placebo effect’ that may
exist in the active drug
Losses to Follow-Up
- Not every participant remains in the trial
- This could lead to Follow-Up bias
How to minimise Losses to Follow-Up (4)
- Make the follow-up practical and minimise
inconvenience - Be honest about the commitment required from
participants - Avoid coercion or inducements
- Maintain contact with participants
Advantages of RCTs (3)
- Unbiased distribution of confounders
- Blinding
- Randomisation
Disadvantages of RCTs (3)
- Expensive: time and money
- Volunteer bias
- Ethically problematic at times
