12 - Drug development and clinical trials

Question 1

ABCS of clinical trial design

Answer 1

Assignment - First come first served (loss of blinding) , Randomised

Blinding - open, single, double, triple (if randomisation sequence lost) (reduces bias)

Comparison

• Active - dose, conc (measure conc) or biomarker control
• Placebo (good to compare against - if there is genuine uncertainty)
• Standard treatment (if it is known to be effective)

Sequence

• parallel (good to work out -does the drug work?)
• cross-over deigns (carryover effect is a negative - half life)
• titration (increase dose - to figure out dose-response relationship)

Question 2

Pros and Cons of intention to treat analysis

Answer 2

Does not take into account if the subject took the medication or not

• Means that size of treatment effect will be underestimated if some subjects did not take their medication
• useful for making pharmacoeconmic decision where the cost of drug has to be paid wheather it is actually taken or not

-As treated - take into accoun this information - less likely to have the underestimation bias that is associated with the intenition to treat approach - more suitable for makign sicentific decisions