Randomised Control Trials

Question 1

Phase 1 of a clinical trial

Answer 1

Is it safe?

Investigates the safety of a drug, on a small sample of healthy volunteers.
Starting with the lowest dose, the dose is increased to the max dose tolerated.

Question 2

Phase 2 of a clinical trial

Answer 2

What is the right dose? What are the side effects?

Investigating:
2a - the right dose in a patient population who have the disease
2b - the side effects

Question 3

Phase 3 of a clinical trial

Answer 3

Now that the drug has been deemed safe, a dose has been calculated, and we know about some side effects, it can be compared against current gold standard treatment or a placebo

Question 4

Stage 4 of a clinical trial

Answer 4

Monitoring of a drug post marketing

Question 5

Advantages of an RCT

Answer 5

Investigating a single variable
Can minimise bias with good design and randomisation
if adequately powered, it can minimise Typ1 and Type 2 error
Blinding can reduce performance bias

Question 6

Disadvantages of an RCT

Answer 6

Expensive - often funded by a pharmacetuical company
Often underpowered - needs a large smaple size
Needs clinical equipoise for ethical randomisation