In: Math
2,006 persons are cross classified by disease and exposure.
Our outcome of interest is having the disease.
Use the following 2 x 2 table to answer questions below.
Disease |
No Disease |
|
Exposed |
9 |
992 |
Not Exposed |
16 |
989 |
a. What percent of people have disease?
b. What percent of the exposed persons have disease?
c. What is the odds of disease among the exposed?
d. What is the odds of disease among the unexposed?
e. What is the odds ratio of disease among the exposed and unexposed. Interpret the odds ratio and comment whether the exposure is deleterious or protective.
a)
diseased people = (9+16)/2006 = 1.25%
b)
percent of the exposed persons have disease = 9/(9+992)*100= 0.90%
c)
odds of disease among the exposed = 9/992 = 0.00907
d) odds of disease among the unexposed=16/989= 0.0162
e) odds ratio = (9/992)/(16/989) = 0.5608
This means
that the odds of developing the disease for those exposed to the
risk factor is 0.56 times the odds of
developing the condition for those that were not exposed to the
risk factor