Formulas

Question 1

ratio

Answer 1

dividing one by the other
X:Y = X/Y

Question 2

proportion

Answer 2

relationship to part to whole
160 boys and 240 total = 160/240 = 67%

Question 3

rate

Answer 3

number of conditions or events within a designated period of time
/
population at risk during same period of time

Question 4

incidence

Answer 4

number of new cases in given time peroid
/
population at risk

(- people who already a have it, not at risk)

Question 5

incidence density

Answer 5

new cases occurring during the study period
/
person - time units accumulated by subjects during study period

Question 6

prevalence

Answer 6

number of existing cases
/
total population

Question 7

sensitivity

Answer 7

+
/
+ pause false -

Question 8

attack rate

Answer 8

divide part by whole
EX: 1000 students at lunch, 650 got ill = 650/1000

Question 9

infant mortality rate

Answer 9

number of infant death <1 year of age
/
number of births in same year

Question 10

age specific

Answer 10

number of cases in a specific age category in a population at a specified time
/
population in a same age category at the same specified time

Question 11

PMR

Answer 11

number of death resulting from a specific cause in a specific time peroid
/
total number of deaths in same time peroid