Measures of Association

Question 1

List all of the M.O.A.

Answer 1

Risk ratio (cumulative incidence ratio)
• Odds ratio
• Incidence rate ratio

Question 2

How to calculate relative risk/risk ratio

Answer 2

R exposed= a/a+b
R unexposed= c/c+d
RR=a/a+b/c/c+d

Question 3

If RR=1 then…

Answer 3

− Risk in exposed = Risk in non-exposed − No

association

Question 4

If RR>1 then…

Answer 4

Risk in exposed > Risk in non-exposed −

Positive association; ? causal

Question 5

• If RR<1 then…

Answer 5

− Risk in exposed < Risk in non-exposed −

Negative association; ? protective

Question 6

What does risk (ratio) mean

Answer 6

• Probability of developing a given disease
-Risk =
Number of new cases of disease/Number of persons followed/at risk

Question 7

What is the null hypothesis for RR

Answer 7

RR = 1

Question 8

What is odds ratio

Answer 8

Odds ratio is a ratio of the odds of an event under contrasting conditions (exposed and unexposed)

Question 9

How do you calculate odds ratio

Answer 9

OD|E / OD|UE = (a/b)/(c/d) = ad/bc

Question 10

What is the null hypothesis for odds ratio

Answer 10

OR=1

Question 11

What is the MOA used for cross sectional studies

Answer 11

prevalence OR

Question 12

What is the MOA fro case control studies

Answer 12

OR

Question 13

What is the MOA used for RCT

Answer 13

RR