Clinical Trial Design Flashcards
Why are clinical trials important?
They provide evidence - practice is evidence based
What is defined as pre-clinical development?
Investigating animal pharmacology
Investigating animal toxicology
Tissue culture
How many phases are there to clinical trials?
Four
What is phase 1 of a clinical trial?
Clinical pharmacology in normal ‘healthy’ volunteers generating pharmacokinetic, metabolic and pharmacodynamic data.
100 subjects
What drugs are not seen in phase 1 in clinical trials?
Certain cytotoxic drugs - that cause harm to the individual
What happens in phase 2 of clinical trials?
Evidence of efficacy and identifies a likely dosage range
Confirms kinetics and dynamics
Involves up to 500 patients
What happens in phase 3 of clinical trials?
Evidence of safety
If the drug works for the condition we are testing
All data collected and used to request a license to sell the drug
1000-3000 patients
What is phase 4 of clinical development of a drug?
Post marketing surveillance to produce evidence of long term safety
How many people are involved in the stages of clinical trials?
Stage One: 100
Stage Two: Up to 500
Stage Three: 1000-3000
What is the purpose of a pilot study?
To test study design
What are the different methods of trials?
Double blind
Single blind
Prospective
Retrospective
What are the stages of a prospective clinical trial?
Design the study, recruit, then follow up
What is a retrospective clinical trial?
When data is collected from case records after treatment is given
What is a cross over study?
When patients receive both methods of treatment, one after the other with a cross over stage in the middle called a “wash out period” - removes all the old drug
What is the difference between a superiority VS a Non-inferiority trial?
Superiority - Shows that a new treatment is better then control (standard or placebo)
Non-inferiority - shows that the new treatment is not worse than the standard by much
Shows that the new treatment would have beaten a placebo arm
Who might you exclude from a clinical trial?
Pregnant women
Children
Seriously ill
Elderly
Patients at risk of side effects
What is the purpose of statistical significance?
Helps quantify whether a result is likely due to chance or to some factor of interest that different subjects were exposed to
What is the process of establishing statistical significance?
Mixing the data from both sets randomly to create a new range of mean values.
Repeated many times, you can determine how likely the chances are of experiencing a similar difference in measurements between the randomised mean values and the actual difference obtained.
What P value indicated statistical significance?
A p-value less than 0.05 (typically ≤ 0.05) is statistically significant.
What does a p-value of less than 0.05 mean?
It indicates strong evidence against the null hypothesis, as there is less than a 5% probability the null is correct (and the results are random).
Therefore, we reject the null hypothesis, and accept the alternative hypothesis.
What p-value is not statistically significant?
A p-value higher than 0.05 (> 0.05) is not statistically significant and indicates strong evidence for the null hypothesis.
This means we retain the null hypothesis and reject the alternative hypothesis.
Can you accept a null hypothesis?
You cannot accept the null hypothesis, we can only reject the null or fail to reject it.
What is a null hypothesis?
The null hypothesis of a test always predicts no effect or no relationship between variables.
What is an alternative hypothesis?
The alternative hypothesis states your research prediction of an effect or relationship.
