Measures of Association

Question 1

counterfactual theory

Answer 1

all else being equal (in the same group), the outcome if the exposure didn’t occur. requires assumption of exchangeability.

Question 2

exchangeability

Answer 2

comparability with respect to all other determinants of outcome

Question 3

absolute differences

Answer 3

subtracting frequencies. [A-B]

Question 4

relative difference

Answer 4

division of frequencies. [B/A]

Question 5

probability of outcome in the exposed

Answer 5

A/(A+B)

Question 6

probability of outcome in the non exposed

Answer 6

C/(C+D)

Question 7

Number needed to Treat/Harm

Answer 7

NNT/NNH # of patients needed to be treated to receive the stated benefit/harm