3.8 Flashcards
Why are clinical trials carried out?
to establish the safety and effectiveness of vaccines and drugs prior to them being licensed for use
Give three methods that aid in the design of clinical trials
- double-blind trials
- randomised trials
- placebo-controlled protocols
How can statistical significance be improved in clinical trials?
Increasing sample (group) size to establish statistical significance
What happens before a clinical trial is carried out?
Before a clincial trial is carried out, the potential treatment undergoes extensive testing on cells and on animals in the laboratory.
What happens in phase one of clinical trials?
small doses of treatment are tested on a very small number (e.g. 25-50) of volunteers to check that is safe.
What happens in phase two of clinical trials?
treatment is tested on a large number (e.g. 150-300) of people who have the illness to test if the treatment is safe and effective and to find out what the optimum dose may be
What happens in phase three of clinical trials?
treatment is tested on a very large number (e.g. 1000-2000) of people who have the illness using a randomised, placebo-controlled, double-blind protocol
What happens if phase three is successful?
results are submitted and licence sought to manufacture the new treatment.
In phase two, what are the two groups made from the target population?
test group - who will receive the treatment
control group - who will not receive the treatment
What is a placebo?
This is a ‘fake’ treatment that takes the same form as the real treatment except that it lacks the active ingredient being tested
What does the placebo allow?
the use of placebo allows a valid comparison to be made between the test group and the control group to assess the effect of the new treatment.
What is a blind trial?
one in which the human subjects do not know whether they are receiving the active treatment or the placebo.
What is a double-blind trial?
one in which neither the subjects nor the doctors know who is receiving what treatment
What does double-blind trial eliminate?
eliminates bias
What is randomisation?
Subjects in a clinical trials are divided into groups in a randomised way to reduce bias in the distribution of characteristics such as age and gender
