TABLE E1.22
Daily Alcohol Consumption
Age 80 þg 0–79 g
25–44
Cases 5 5
Controls 35 270
45–64
Cases 67 55
Controls 56 277
65 þ
Cases 24 44
Controls 18 129(b)Compare the three odds ratios in part (a). When the di¤erence is
confirmed properly, we have an e¤ect modification.
(c) Assuming that the odds ratios for the three age groups are equal (in
other words, age is not an e¤ect modifier), calculate the Mantel–
Haenszel estimate of this common odds ratio.1.23 Postmenopausal women who develop endometrial cancer are on the
whole heavier than women who do not develop the disease. One possi-
ble explanation is that heavy women are more exposed to endogenous
estrogens which are produced in postmenopausal women by conversion
of steroid precursors to active estrogens in peripheral fat. In the face
of varying levels of endogenous estrogen production, one might ask
whether the carcinogenic potential of exogenous estrogens would be the
same in all women. A case–control study has been conducted to examine
the relation among weight, replacement estrogen therapy, and endo-
metrial cancer. The results are shown in Table E1.23.
TABLE E1.23
Estrogen Replacement
Weight (kg) Yes No
< 57
Cases 20 12
Controls 61 183
57–75
Cases 37 45
Controls 113 378
> 75
Cases 9 42
Controls 23 140EXERCISES 43