[Definition, significance and measurement of disease concepts of patients. The Disease Concept Scale for schizophrenic patients].

Illness concepts represent cognitive interpretations, explanations and predictions of health status. Illness concepts are a consequence and an expression of the patient's cultural background, view of the world, value system, way of living, and personal life experiences. Illness concepts are significant in that they influence patient's informed consent and compliance behavior. Illness concepts have been formulated in phenomenological-descriptive, formal-structural and psychological approaches. Based on these alternative conceptualizations, a scale was developed to measure seven dimensions of illness concepts. including trust in medication, trust in the treating physician, negative treatment expectations, guilt, chance control, susceptibility, and idiosyncratic assumptions. The reliability and validity of the scale (KK-scale) was tested in a group of schizophrenic patients in different treatment settings. The psychometric properties of the scale were found to be satisfactory. Support for the discriminant validity of the scale was found in relation to patient's age, education, sex, and compliance treatment institution.