Statistics (bleh) Flashcards
what is a confounding factor?
it is a risk factor to the outcome, it is associated with the exposure, it is not caused by the exposure
what is selection bias?
when comparison groups differ other than the risk factor that you are assessing
what is internal validity?
do the results apply to the people studied?
what is external validity?
do the results apply to the general population?
what is prevalence?
the number of people who have a disease at a certain time
what type of study do you do to get prevalence?
cross-sectional
what type of study do you do to get incidence?
cohort study
what is the equation that shows the relationship between prevalence and incidence?
Prevalence = (Incidence)(Avg. Duration of disease)
what are the assumptions we make in the prevalence equation?
that incidence and disease duration are constant
what is crude death (mortality) rate?
the number of people who died total, out of the population
what is cause-specific mortality rate?
the number of people who died of a specific disease out of the population
what is case fatality rate?
the number of people with the disease who died from it out of the total number of people who had the disease
what is incidence density?
the number of new cases over “person time” in population of candidates
