NNT Quiz Flashcards
A registration clinical trial reported results as follows:
Primary efficacy event rate
Test medication: 25%
Reference medication: 20%
Primary hazard event rate
Test medication: 6%
Reference medication: 4%
What is the absolute efficacy improvement for the primary efficacy outcome?
A) 25%
B) 20%
C) 5%
D) None of the above
C (test medication efficacy event rate - reference medication efficacy event rate)
A registration clinical trial reported results as follows:
Primary efficacy event rate
Test medication: 25%
Reference medication: 20%
Primary hazard event rate
Test medication: 6%
Reference medication: 4%
What is the absolute difference in the primary hazard outcome?
A) 2%
B) 4%
C) 6%
D) None of the above
A (test medication primary hazard event rate - reference medication primary hazard event rate)
A registration clinical trial reported results as follows:
Primary efficacy event rate
Test medication: 25%
Reference medication: 20%
Primary hazard event rate
Test medication: 6%
Reference medication: 4%
What is the relative improvement in efficacy?
A) 10%
B) 15%
C) 20%
D) 25%
D (absolute efficacy improvement/reference medication primary efficacy event rate) –> 0.05/0.20 = 0.25 or 25%
A registration clinical trial reported results as follows:
Primary efficacy event rate
Test medication: 25%
Reference medication: 20%
Primary hazard event rate
Test medication: 6%
Reference medication: 4%
What is the relative hazard?
A) 50%
B) 25%
C) 10%
D) 5%
A (absolute change in hazard/primary hazard rates for reference medication) –> (0.02/0.04) = 0.5 or 50%
What is the NNT for the primary efficacy outcome, and what is the number needed to harm for the primary hazard outcome?
A) 5 and 10
B) 50 and 75
C) 20 and 50
D) 1 and 2
NNT = 1/ARR
ARR = difference between test and reference
Efficacy ARR: 0.25 - 0.20 = 0.05
Hazard ARR: 0.06 - 0.04 = 0.02
then plug this in to the NNT equation
NNT efficacy = 1/0.05 = 20
NNT hazard (same as the number needed to harm) = 1/0.02 = 50
