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Access to Data

The Schema is a timeline of the study. It indicates start/end points, visits expected, major testing to be done, and any other information that is crucial to understanding how the study was completed.

Schema Description

The study enrolled 10,828 at-risk males. At study entry, all subjects completed a questionnaire that elicited information regarding demographics, smoking history, and exposure to other lung cancer risk factors. Eligible participants were randomized by computer to either a dual-screen or x-ray only group. Each group completed an annual questionnaire and exam during which posterior-anterior and lateral chest x-rays were obtained. In the dual-screen group, sputum was collected at the annual exam after saline aerosol induction. Immediately following each annual exam and at four and again eight months later, dual-screen participants were instructed to collect at home their first sputum upon rising for three consecutive morning. Screening continued for 5-7 years. For all deaths identified during follow-up, death certificates were requested, as were relevant clinical records pertaining to cause of death.