At enrollment, participants completed a four page questionnaire on medi
cation use. smoking history, diet, alcohol intake, physical activity, occupation,
height, weight, current medical illnesses, family history of cancer, and other
characteristics. For each of 15 categories of medications, the questionnaire
asked two questions: "How many times in the last month have you used the
following [medications]'.'" and "How long (in years) have you used them?"The
first category listed was "Aspirin, Bufferin, and Anacin" and the second was "Tylenol (acetaminophen)." The other categories included vitamins, trunquilizers.
and medications for specific medical conditions.