First, to verify the feasibility of a population-based study in the Lombardy region of Italy and study the characteristics related to potential subjects' participation, we conducted a phone survey of 1053 healthy subjects from the catchment area, selected from the rosters of the Regional Health Service, to have the age, gender and geographic distribution expected in the lung cancer cases. We asked the contacted subjects whether they would agree to participate in a study of lung cancer that would require an interview and donation of a blood sample. Only 320 (30%) of the subjects responded "Yes". There was only modest variation in response by municipality, age, gender, tobacco use, and educational level. From this effort, we obtained valuable information about preferred location for blood drawing, days of the week, and times most convenient for participation. This information was used in a series of pilot studies in which we first contacted the selected individuals by mail with follow-up by telephone, offering participation in the study at the closest hospitals of the catchment area. Then, we advertised the study on the local
