1.5: Binary response data

Question 1

Risk difference and relative risk:

Odds ratio:

Answer 1

• p1 and p2 denote respective risks (success probabilities) for treatment and control groups
• Risk difference: p1-p2
• Relative risk: p1/p2
• Odds ratio: disease odds(1)/disease odds(2)

….FC 1a

Question 2

Assumption in intervals for binary response data:

Answer 2

• Based upon normal approximation

Question 3

CIs for binary response data:

Answer 3

• Estimated in log form for RR and OR
• FC 2a

Question 4

What is NNT?

Answer 4

• A further measure of treatment effectiveness
• Number needed to treat
• NNT = -1/RD
• Particularly useful to communicate benefit of preventative interventions for rare diseases

Question 5

Interpreting clinical relevance:

Answer 5

• Whole confidence interval must be above or below the clinically relevant measure (delta*) to make a conclusion of clinical relevance or otherwise
• If delta* lies within the lower and upper bound, a conclusion cannot be established