[Quality control of printed patient information].

Printed material is an important part in patient information and is called bibliotherapy. It is subject to quality control similar to any other types of treatment. This paper presents an outline of important quality criteria and methods of quality control. Important quality criteria are: (a) Correctness and validity of content evaluated by mentioning the expertise of the authors, appraisal through external experts, reference to scientific literature, and empirical tests of the content, (b) Readability in respect to text structure measured by the "Flesch-Reading-Ease-Formula" supported by fair graphical design including fond and structure of text, (c) Comprehensibility tested by feedback of patients or standardized by the Hamburg comprehensibility rating, (d) Utility including securing availability, acceptance, differential indication and use. Writing and publication of patient leaflets must be accompanied by quality control measures. © Georg Thieme Verlag KG Stuttgart · New York.