Jackson: Anatomy and Physiology of a Randomised Controlled Trial

Question 1

Why do a Randomised Control Trial?

Answer 1

They are considered to be the gold standard in determining whether a drug or treatment actually works. It is a gold standard because by randomising the trial participants into groups you reduce confounding factors.

Question 2

Draw a GATE frame for this abstract…

Answer 2

Question 3

Why would you randomise high and low-risk patients separately?

Answer 3

Because with randomisation there is a 50% chance that the individual will be placed in either the exposure or control group. As a result, if the two groups were randomised together there is the possibility that there would be more high-risk individuals in one group just by chance which will cause confounding.

• The process of separately randomising high and low-risk individuals is known as stratified random sampling.

Question 4

What is block randomisation?

Answer 4

The experimenter divides subjects into subgroups called blocks, such that the variability within blocks is less than the variability between blocks. Then, subjects within each block are randomly assigned to treatment conditions.

Question 5

What is concealed allocation?

Answer 5

Concealed allocation is a procedure implemented in a randomized control trial where the individuals screening and separating the candidates into two (or more) arms of a study are blinded. This is a consideration beyond blinding the practitioner delivering the care or the patients receiving the care.

Question 6

What is double blind?

Answer 6

Of or relating to an experiment or clinical trial in which neither the subjects nor the researchers know which subjects are receiving the active medication, treatment,etc., and which are not: a technique for eliminating subjective bias from the test results.

Question 7

How do you calculate EGO and CGO?

Answer 7

EGO = a/EG

CGO = b/CG

• Can be differentiated into “intended to treat groups” and “on treatment groups” to account for non-compliance etc.

Question 8

What are the strengths and weaknesses of RCTs?

Answer 8

• Strengths
  
  • Addresses confounding.
• Weaknesses
  
  • Too expensive
  • Usually too small so lots of random error
  • Usually not “real world”
  • Poor compliance