Statistics

Question 1

Sensitivity

Answer 1

Proportion of patients with the condition who have a positive test result

TP/(TP+FN)

Question 2

Specificity

Answer 2

Proportion of patients without the condition who have a negative test result

TN/TN+FP

Question 3

Positive predictive Value

Answer 3

The chance that the patient has the condition if the diagnostic test is positive

TP/TP+FP

Question 4

Negative Predictive Value

Answer 4

The chance that the patient does not have the condition if the test is negative

TN/TN+FN

Question 5

Likelihood ratio for a positive test result

Answer 5

How much the odds of the disease increase when a test is positive

sensitivity/ 1- specificity

Question 6

Likelihood ratio for a negative test result

Answer 6

how much the odds of the disease decrease when a test is negative

1-sensitivity/specificity

Question 7

NNT

Answer 7

1/absolute risk reduction

Question 8

Absolute risk reduction

Answer 8

experimental event rate - control event rate