Measures of Association

Question 1

what are measures of association

Answer 1

provide mathematical assessment of the relationship between a given exposure and outcome of interest

Question 2

what 2 things do measures of association do

Answer 2

determine if there is an association

measure the strength of the association

Question 3

what type of studies are MOA used in

Answer 3

analytical

Question 4

when comparing exposure groups we assume the exposure is not associated with the disease if:

Answer 4

same amount of disease found in a group of subjects that has the exposure and dont have the exposure

Question 5

when comparing outcome groups we assume the exposure is not associated with the disease if:

Answer 5

same amount of the exposure is found in a group of diseased subjects as non-diseased subjects

Question 6

why use MOA

Answer 6

to make comparisons

• compare exposure groups
• compare outcome groups

Question 7

4 types of MOA

Answer 7

odds ratio

relative risk

attributable risk

prevalence ratio

Question 8

when is odds ratio used

Answer 8

cross-sectional studies

case-control studies

Question 9

what MOA can be used in prospective studies used to compare outcomes

Answer 9

relative risk (incidence ratio)
attributable risk
- prospective cohort studies
- clinical trials

Question 10

when is prevalence ratio used

Answer 10

retrospective cohort studies

cross-sectional studies

Question 11

T/F incidence can be measured in case-control and cross-sectional studies

Answer 11

false

exposure and disease have already occurred

Question 12

odds ratio

Answer 12

ratio of the odds of exposure in the diseased group to the odds of exposure in the non-diseased group

Question 13

odds

Answer 13

ratio of number exposed to number not exposed

Question 14

how do you calculate odds ratio

Answer 14

odds of exposure in the non-diseased group

Question 15

if OR=1

Answer 15

odds of exposure among cases was equal to that of controls

no association

Question 16

if OR>1

Answer 16

odd of exposure among cases was greater than that of control

positive association (prob. causal)

Question 17

if OR

Answer 17

odds of exposure among cases was greater than that of controls

negative association ( possible protective)

Question 18

T/F OR tells you if there is an association and the magnitude of associate

Answer 18

true

Question 19

which observational study design compares exposed to non-exposed

Answer 19

cohort
clinical trials
cross-sectional studies

Question 20

incidence (risk)

Answer 20

measure used to compare the amount of disease that occurs in the exposed and unexposed groups in prospective studies

Question 21

cumulative incidence (attack rate, risk)

Answer 21

number of new cases at the end of the study divided by population at risk at the beginning of study

Question 22

relative risk

Answer 22

used to compare the risk (or incidence) of disease that occurs in the exposed and unexposed groups

Question 23

how do you calculate relative risk

Answer 23

risk of disease in unexposed group

Question 24

if RR=1

Answer 24

risk in exposed = risk in unexposed

no association

Question 25

if RR>1

Answer 25

risk in exposed is greater than unexposed positive association

Question 26

if RR

Answer 26

risk of disease in exposed is less than risk in unexposed negative association

Question 27

attributable risk (AR)

Answer 27

amount of proportion of overall disease incidence in a population or group that can be attributed to a specific exposure

Question 28

AR interpreted as

Answer 28

% of the overall disease incidence can be attributed to this particular exposure

Question 29

T/F attributable risk is used to quantify an association

Answer 29

false used to set priorities in disease control programs

Question 30

how do you calculate attributable risk

Answer 30

risk exposed- risk unexposed -------------------------------------------- risk exposed

Question 31

prevalence ratio

Answer 31

measure used to compare the amount of disease that occurred in the exposed and unexposed groups in retrospective studies

Question 32

prevalence

Answer 32

probability if being diseased of diseased/ total # exposed

Question 33

how to calculate prevalence ratio

Answer 33

prevalence of disease in exposed -------------------------------------------- prevalence of disease in unexposed

Question 34

PR= 1

Answer 34

no association

Question 35

PR>1

Answer 35

positive association (possible causal)

Question 36

PR

Answer 36

negative association (posible protective)

Question 37

which study design uses odds and OR

Answer 37

case-control

Question 38

which study design(s) use incidence and RR

Answer 38

prospective cohort | clinical trial

Question 39

which study design(s) use prevalence and PR

Answer 39

retrospective cohort

Question 40

T/F there are no measures of exposure or association for case reports/series

Answer 40

true