Pre-PROLOG 1 We wish to identify high pretest likelihood of lung cancer based on the information from the referral to chest x-ray. All patients referred to a chest x-ray examination from General Practice between January 1 and March31, 2005, to the Department of Radiology, Odense University Hospital (OUH), in total 1201 patients. Referral diagnosis and information were registered in this retrospective survey.