Measures of disease frequency

Question 1

What is cumulative incidence?

Answer 1

the number of newly detected cases that develop during follow-up, divided by the number of disease-free subjects available at the start of follow-up.

Question 2

speed at which new cases emerge?

Answer 2

incidence rate

Question 3

Incidence rate calculation?

Answer 3

IR = I/PT
I = new case of disease in cohort
PT = the total time, called person-time (PT), that disease-free individuals in the cohort are observed over the study period

Question 4

denominator of the cumulative incidence?

Answer 4

number of disease-free subjects available at the start of follow-up.

Question 5

Point prevalence equation?

Answer 5

number of cases in a defined population / number of people in a defined population at the same time

Question 7

Period prevalence = what

Answer 7

number of identified cases during a specified period of time / total number of people in that population

Question 8

Another term for incidence rate?

Answer 8

Incidence density