Data from Appendix III of Breslow and Day (1980).  315 records on cases
and controls from the Leisure World Study of estrogen and endometrial
cancer, coded as follows:

Columns      Variable                 Low   High   Missing value
-------      -----------------------  ---   ---    ---
 1- 3        Set number                1     63
 4- 5        Case(1)/Control(0)        0      1
 6- 7        GALL (Gallbladder dis)    0      1
 8 -9        HYP (Hypertension)        0      1
10-11        OB (Obesity)              0      1      0 (coded as 0)
12-13        EST (Estrogen)            0      1
14-15        DOS (Ordinal dose)        0      3      9
16-17        DUR (Ordinal duration)    0      4      9
18-19        NON (Non-estrogen drug)   0      1
20-21        GALL*EST                  0      1
22-23        OB*EST                    0      1      0 
24-25        EST*NON                   0      1
26-27        GALL*OB                   0      1      0
28-29        GALL*NON                  0      1
30-31        DOS1                      0      1      9
32-33        DOS2                      0      1      9
34-35        DOS3                      0      1      9
36-37        DUR1                      0      1      9
38-39        DUR2                      0      1      9
40-41        DUR3                      0      1      9
42-43        DUR4                      0      1      9
44-46        DUR*DOS                   0     12     99
47-49        DURATION (months)         0     96     99
50-52        AGE                      57     83
53-55        ORGINAL SET NUMBER        1     63
56-57        MISSING VALUE (DOS,DUR)   0      1
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