[Validity of retro- and prospective data analysis (authors' translation)].

Retrospective chart analysis of 88 operated patients with bronchial carcinoma showed grave deficiencies. In 15% the reason for admission to hospital was not available and the exact smoking habits of 74% were not known. Retrospective TNM-classification was possible in only 59%. It was known in 67% whether a radiotherapy and in 17% whether a cytostatic therapy was additionally performed. Only 13 of the 20 surviving patients participated in the follow-up. In contrast with these figures, a prospective collection of data (44 patients) has an effectiveness of 95% or more for all parameters.