EAB - stats in practise

Question 1

What is randomisation?

Answer 1

• Random allocation into an experimental group and a control
  group
• Avoids selection bias
• Successful randomisation makes different groups have similar characteristics at baseline

Question 2

What is blinding?

Answer 2

• A blind experiment is an experiment in which information about the test is masked (kept) from the participants
• Aim: to reduce or eliminate bias
• Bias may be intentional or unconscious

Question 3

What are the 4 types of blinding?

Answer 3

Question 4

What is intention to treat (ITT) analysis?

Answer 4

• ITT analysis includes every subject who is randomised according to randomised treatment assignment
• Ignores noncompliance, protocol deviations, withdrawal, and anything that happens after randomisation
• ITT analysis maintains prognostic balance generated by randomisation
• Estimate of treatment effect is generally conservative.
• A better application of the ITT approach is possible if complete outcome data are available for all randomised subjects.

Question 5

What is per protocol analysis?

Answer 5

A subset of the ITT (Intention to treat) population who completed the study
without any major protocol violations

Question 6

What is skin prick testing?

Answer 6

• This involves a small amount of the allergen being placed onto the skin and then pricking the skin (it does not draw blood)
• If the child is allergic to any of the allergens being tested a small bump (hive) will develop within 5-15 minutes.
• This disappears after about 30 minutes.