Exam 3: Measures of Impact Flashcards
What are the measures of frequency that describe the frequency of disease in populations?
Incidence (rate or risk: cumulative incidence)
Prevalence (proportion)
What is incidence?
Numerically describes the movement of well to ill/force of disease
What is prevalence?
The “commonness” of disease at a time point/window
What are the measures of association?
Described those factors/exposures related to disease
Compare 2 groups, within the larger population (cohort study, case-control)
What is the measure of association in cohort studies?
Relative risk
What is the measure of association in case-control studies?
Odds ratio
What do measures of impact describe?
The impact of exposures/disease at the population level
What are the measures of impact?
Attributable risk (exposed), also called risk difference
Population attributable risk
Attributable fraction (exposed)
Population attributable fraction
How do you calculate attributable risk (exposed)?
The difference in risk between exposed and unexposed groups
D+/E+) - (D+/E-
What does attributable risk/risk difference express?
The increased incidence of disease, over the baseline, in exposed animals
For every 100 animals exposed, expect an additional x cases
What does attributable risk/risk difference apply to?
Exposed animals only
How do you calculate population attributable risk?
The difference in risk between the total population and unexposed group
(D+/N) - (D+/E-)
What does population attributable risk express?
The amount of disease in the total population attributable to exposure
In (total number) of animals, x cases could be eliminated if exposure is eliminated
What does population attributable risk apply to?
Population
What is attributable proportion (exposed)?
The proportion of incidence in exposed that is attributed to the exposure
