Measuring disease occurence

Question 1

What are the two ways to measure incidence?

Answer 1

Cumulative incicence (risk, proportion)
Incidence rate (density)

Question 2

What are the benefits of prevalence?

Answer 2

useful to know for estimating health care burdens

• predict work load
• ongoing drug inventory needed

useful for monitoring control programs
- measures over different time periods to access change in health status of populations

Question 3

What are the limitations for using prevalence?

Answer 3

presents bias of disease by favoring chronic over acute

Can’t use it to measure relation b/w disease and causes - we don’t know if the factor was just a result of disease

Question 4

What is the # range that cumulative incidence has to be in?

Answer 4

0-1

Question 5

What range does incidence rate need to be in?

Answer 5

> 0

Question 6

Can cumulative incidence change over time?

Answer 6

Yes
Can stay the same or increase
NEVER decreases

Question 7

What is the equation for cumulative incidence?

Answer 7

of new cases / # of individuals at risk

Question 8

What is the equation for incidence rate?

Answer 8

of new cases / time

Question 9

When would you want to use incidence rate over cumulative incidence?

Answer 9

To see how fast something happened

If an individual comes into or leaves the study at different times