Measures of Association Flashcards
Any relationship btwn 2 measured quantities that renders them dependent is…
an association (ass.)
What does a dependent (associated) relationship mean?
when one quantity changes, so does the other
What does an independent relationship mean?
when one quantity changes, the other does not change
Measures of association are used to make comparisons between…
- exposure groups
2. outcome groups
What tests are used to measure associations?
Odds ratio
Relative risk (incidence ratio)
Attributable risk
Prevalence ratio
Retrospective studies comparing exposure in diseased groups utilize what test in what scenarios?
Retrospective studies: Cross-Sectional and Case-Control
Utilize Odds Ratio
Prospective studies comparing disease in exposure groups utilize what tests in what scenarios?
Prospective studies: Pros. Cohort and Clinical Trials
Utilize Relative risk and Attributable Risk
Retrospective studies comparing disease in exposure groups utilize what test in what scenarios?
Retrospective studies: Retro. Cohort and Cross-Sectional
Utilize Prevalence Ratio
How do you calculate the odds ratio?
Odds of exposure in the diseased/ odds of exposure in the non-diseased
If the OR = 1…
the odds of exposure among cases was equal to that of the controls
No association!
If the OR >1…
Odds of exposure among cases was greater than that of controls.
Positive association, possibly causal!
If the OR
Odds of exposure among cases was less than that of controls.
Negative association, possible protective.
What does the Odds Ratio tell you?
OR tells you if there is an association and the magnitude of the association.
The Relative Risk is used to compare…
the Risk (incidence) of disease that occurs in the exposed and unexposed groups.
It is the ratio of incidence of disease in the exposed to the incidence of disease in the unexposed.
How do you calculate Relative Risk (RR)?
Risk (incidence) of disease in the Exposed/ Risk (incidence) of disease in the Unexposed
