Clinical Trials

Question 1

What are the purpose of clinical trials?

Answer 1

To provide evidence that the drugs is safe and effective before it is licensed for use

They also allow us to determine the most cost-effective drug and that it is also best fit for its purpose

Question 2

What are observational studies?

Answer 2

In observational studies, an independent variable that already exists within the study population is selected

Question 3

What are the advantages of observational studies?

Answer 3

Study long-term effects

Detect correlations between two variables, which can be positive or negative

Question 4

What are the disadvantages of observational studies?

Answer 4

Unable to tightly control the composition of the experimental groups, bias potential as a results

Unable to determine causation

Question 5

What happens before clinical trials? What is the purpose of this?

Answer 5

Drug is tested on cell cultures and animals in the lab.

Allows researchers a better understanding on how the treatment works and if there are any side effects.

Question 6

What does phase one of clinical trials involve?

Answer 6

Small dose of treatment being tested on a small number of volunteers (100)

Question 7

What is the purpose of phase one clinical trials?

Answer 7

Gather pharmacokinetic, metabolic and pharmacodynamic data

Question 8

What does phase two of clinical trials?

Answer 8

Treatment being tested on a larger number of people (500) who have the illness.

Question 9

What is the purpose of phase two clinical trials?

Answer 9

Confirm data from phase one.

Confirms that the drug is safe, effective and the optimum dosage.

Question 10

What does phase three of clinical trials?

Answer 10

Treatment being tested on a very large number of people (1,000-3,000) who have the illness. Patients split into a test and control group.

Question 11

What is the purpose of phase three clinical trials?

Answer 11

Confirm data from phase one and two.

Confirm it is best suited to treat this condition

Question 12

What is a placebo trial? What is its purpose?

Answer 12

Real drug prescribed to test group and a fake/pre-exisisting drug is prescribed to the control group.

Results not due to psychological effects.

Question 13

What is cross over design?

Answer 13

Cross over design occurs in placebo trials. Patients who were prescribed the drug switch after a period of time and are prescribed the control drug.

Question 14

What is the benefits of cross over design?

Answer 14

Less patients needed

Question 15

What is the disadvantage of cross over design?

Answer 15

Difficult to manage

Question 16

What is a double-blind trial? What is its purpose?

Answer 16

Neither the subjects nor doctors know who is in the control and test group.

Prevent biasses

Question 17

What is a prospective trial?

Answer 17

Watches for outcomes during a long study period and relates this to other factors.

Question 18

What is a retrospective trial? What is the disadvantage of this trial?

Answer 18

Compares two groups of people, with the disease and a similar group of people without the disease.

Open to biasses

Question 19

Why is phase three randomised?

Answer 19

Prove drug works on everyone. Prevents biasses.

Question 20

What are the disadvantages of phase three being randomised?

Answer 20

Subjects may not represent general patient population.

Patients better at complying, more likely to take the drugs

Need twice as many patients, to form placebo and drug group.

Not all patients receive treatment.

Question 21

What does phase four of clinical trials involve?

Answer 21

Post-marketing surveillance to produce evidence of long term safety of the treatment.

Question 22

What is a pilot study?

Answer 22

A short experiment carried out before investigation.

Question 23

What is the aim of a pilot study?

Answer 23

To evaluate and modify experimental protocols

Question 24

What is a superiority trial?

Answer 24

Proves new treatment is better than the control or standard

Question 25

What is a non-inferiority trial?

Answer 25

Proves new treatment is not worse than the standard and better than the control

Question 26

What do we need to consider when designing a trial?

Answer 26

Number of subjects. Needs to be large enough to detect a difference between control. Depends on the frequency of the outcome measurement.

Control drug.

Mixed group of patients.

Question 27

What is statistical test used to analyse trials?

Answer 27

T-test

Question 28

What does the t-test prove?

Answer 28

Whether two sets of data are significantly different enough to make a valid conclusion.

It produces a p-value. Generally, a p-value less than or equal to 0.05 is considered significant as there is less than a 5% chance the difference is due to random variation.