Clinical Trial Design

Question 1

Why are clinical trials important?

Answer 1

They provide evidence - practice is evidence based

Question 2

What is defined as pre-clinical development?

Answer 2

Investigating animal pharmacology

Investigating animal toxicology

Tissue culture

Question 3

How many phases are there to clinical trials?

Answer 3

Four

Question 4

What is phase 1 of a clinical trial?

Answer 4

Clinical pharmacology in normal ‘healthy’ volunteers generating pharmacokinetic, metabolic and pharmacodynamic data.

100 subjects

Question 5

What drugs are not seen in phase 1 in clinical trials?

Answer 5

Certain cytotoxic drugs - that cause harm to the individual

Question 6

What happens in phase 2 of clinical trials?

Answer 6

Evidence of efficacy and identifies a likely dosage range

Confirms kinetics and dynamics

Involves up to 500 patients

Question 7

What happens in phase 3 of clinical trials?

Answer 7

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

Question 8

What is phase 4 of clinical development of a drug?

Answer 8

Post marketing surveillance to produce evidence of long term safety

Question 9

How many people are involved in the stages of clinical trials?

Answer 9

Stage One: 100
Stage Two: Up to 500
Stage Three: 1000-3000

Question 10

What is the purpose of a pilot study?

Answer 10

To test study design

Question 11

What are the different methods of trials?

Answer 11

Double blind
Single blind
Prospective
Retrospective

Question 12

What are the stages of a prospective clinical trial?

Answer 12

Design the study, recruit, then follow up

Question 13

What is a retrospective clinical trial?

Answer 13

When data is collected from case records after treatment is given

Question 14

What is a cross over study?

Answer 14

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

Question 15

What is the difference between a superiority VS a Non-inferiority trial?

Answer 15

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

Question 16

Who might you exclude from a clinical trial?

Answer 16

Pregnant women
Children
Seriously ill
Elderly
Patients at risk of side effects

Question 17

What is the purpose of statistical significance?

Answer 17

Helps quantify whether a result is likely due to chance or to some factor of interest that different subjects were exposed to

Question 18

What is the process of establishing statistical significance?

Answer 18

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.

Question 19

What P value indicated statistical significance?

Answer 19

A p-value less than 0.05 (typically ≤ 0.05) is statistically significant.

Question 20

What does a p-value of less than 0.05 mean?

Answer 20

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.

Question 21

What p-value is not statistically significant?

Answer 21

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.

Question 22

Can you accept a null hypothesis?

Answer 22

You cannot accept the null hypothesis, we can only reject the null or fail to reject it.

Question 23

What is a null hypothesis?

Answer 23

The null hypothesis of a test always predicts no effect or no relationship between variables.

Question 24

What is an alternative hypothesis?

Answer 24

The alternative hypothesis states your research prediction of an effect or relationship.