330-331 / 1676
Breast radiotherapy
Major Coronary Events
Total
number
Cases
(n=963)
Controls
(n=1205)
Left-sided breast cancer
543 (a)
601 (b)
1144
Right-sided breast cancer
420 (c)
604 (d)
1024
Total number
963
1205
2168
•
Association can be tested by the Odds Ratio (OR):
=
ad / bc = 543*604 / 601*420 =
1.30
•
Rare disease assumption (<5%)
33
Case control study: EXAMPLE
Darby, et al. New Engl J Med 2013: 987-998