In a small cohort study investigating the effect of a rare exposure ( E), the following results were found:
Table 1 Disease
Yes
No
Yes 60
180
No 60
180
Exposure
A- Is there an association between exposure and disease? Show the way you reached the conclusion. [2 points]
B- A stratified analysis by Age-groups shows the following:
Younger adults Older adults
Disease Disease
Exposure
Yes
No Exposure Yes No
Yes
30 90 Yes 40 80
No
40 80 No 30 90
What is the relative risk (RR) of exposure causing disease in younger adults and what is the RR in older adults? [ 4 points]
c- How do you explain this result? (No more than 60 words) [4 points]