clinical trial design

Question 1

Discuss the uses of a clinical study

Answer 1

EFFICACY
EVIDENCE
SAFETY
Superiority trial: 
-drug is better than control
Non-inferiority trial:
-not worse than standard 
-would be worse than placebo

Question 2

discuss the basic considerations involved in trial design.

Answer 2

-subjects; age, gender, other disease, compliancy
-choice of control: placebo, drug of known effect
-choice of stats test; differences due to chance, p<0.5
-Exclusion principle:
pregnant women, children, elderly

Question 3

Discuss the importance of statistical power.

Answer 3

Shows how much results are down to chance.

Differences between correlation and causation

Question 4

phases

Answer 4

phase 1- 100 patients. pharmacokinetics/dynamic
Phase 2- 500 patients. likely dosage range
phase 3- 100/300 patients whether it works for conditions
phase 4- tens/hundrends of thousands of patients- long term efficacy

Question 5

problems which may arise from randomised trails

Answer 5

Randomised: patients randomly assigned to drug or placebo

• Do patients represent general population
• Doctors may refuse
• Need twice as many patients