Lecture 4 - measures of occurence Flashcards
Incidence
a new occurrence of an outcome
incidence proportion calculation
incidence prop= #ofnewcases/totalpopatriskofthedisease
Events as expressed per unit time are known as ____
rates
Difference b/w incidence prop and incidence rate?
The incidence rate is not a percentage, it has a unit in terms of time
Point prevalence
the prop of a pop w/ the outcome of interest at a specific point in time
Period prevalence
the prop of a pop w/ the outcome of interest during a specific period of time
A disease with high incidence, but also ___ fatality will show low prevalence
high
a disease with low incidence, with low fatality, will have a —- prevalance
high
The incidence prevalence bathtub
incidence is the faucet
prevalence is the line of bath water
drain is the fatality
Incidence proportions are also sometimes reffered to as
risks
NNT=
1/absolute risk reduction
What is the difference between an absolute difference and a relative difference
absolute difference is a subtraction
relative difference is a ratio
risk ratio
risk in the exposed group/risk in the nonexposed group
odds of outcome
indvs with outcome/individuals without outcome
How can you measure disease occurence in a population?
incidence and prevalence
