Flashcards in Measures of Association Deck (40)
1
what are measures of association
provide mathematical assessment of the relationship between a given exposure and outcome of interest
2
what 2 things do measures of association do
determine if there is an association
measure the strength of the association
3
what type of studies are MOA used in
analytical
4
when comparing exposure groups we assume the exposure is not associated with the disease if:
same amount of disease found in a group of subjects that has the exposure and dont have the exposure
5
when comparing outcome groups we assume the exposure is not associated with the disease if:
same amount of the exposure is found in a group of diseased subjects as non-diseased subjects
6
why use MOA
to make comparisons
- compare exposure groups
- compare outcome groups
7
4 types of MOA
odds ratio
relative risk
attributable risk
prevalence ratio
8
when is odds ratio used
cross-sectional studies
case-control studies
9
what MOA can be used in prospective studies used to compare outcomes
relative risk (incidence ratio)
attributable risk
- prospective cohort studies
- clinical trials
10
when is prevalence ratio used
retrospective cohort studies
cross-sectional studies
11
T/F incidence can be measured in case-control and cross-sectional studies
false
exposure and disease have already occurred
12
odds ratio
ratio of the odds of exposure in the diseased group to the odds of exposure in the non-diseased group
13
odds
ratio of number exposed to number not exposed
14
how do you calculate odds ratio
odds of exposure in diseased group
---------------------------------------------
odds of exposure in the non-diseased group
15
if OR=1
odds of exposure among cases was equal to that of controls
no association
16
if OR>1
odd of exposure among cases was greater than that of control
positive association (prob. causal)
17
if OR
odds of exposure among cases was greater than that of controls
negative association ( possible protective)
18
T/F OR tells you if there is an association and the magnitude of associate
true
19
which observational study design compares exposed to non-exposed
cohort
clinical trials
cross-sectional studies
20
incidence (risk)
measure used to compare the amount of disease that occurs in the exposed and unexposed groups in prospective studies
21
cumulative incidence (attack rate, risk)
number of new cases at the end of the study divided by population at risk at the beginning of study
22
relative risk
used to compare the risk (or incidence) of disease that occurs in the exposed and unexposed groups
23
how do you calculate relative risk
risk of disease in exposed group
--------------------------------------------
risk of disease in unexposed group
24
if RR=1
risk in exposed = risk in unexposed
no association
25
if RR>1
risk in exposed is greater than unexposed
positive association
26
if RR
risk of disease in exposed is less than risk in unexposed
negative association
27
attributable risk (AR)
amount of proportion of overall disease incidence in a population or group that can be attributed to a specific exposure
28
AR interpreted as
% of the overall disease incidence can be attributed to this particular exposure
29
T/F attributable risk is used to quantify an association
false
used to set priorities in disease control programs
30
how do you calculate attributable risk
risk exposed- risk unexposed
--------------------------------------------
risk exposed
31
prevalence ratio
measure used to compare the amount of disease that occurred in the exposed and unexposed groups in retrospective studies
32
prevalence
probability if being diseased
# of diseased/ total # exposed
33
how to calculate prevalence ratio
prevalence of disease in exposed
--------------------------------------------
prevalence of disease in unexposed
34
PR= 1
no association
35
PR>1
positive association (possible causal)
36
PR
negative association (posible protective)
37
which study design uses odds and OR
case-control
38
which study design(s) use incidence and RR
prospective cohort
clinical trial
39
which study design(s) use prevalence and PR
retrospective cohort
40