Structure and Determinants of Illness Representations in Chronic Disease: A Comparison of Addison's Disease and Chronic Fatigue Syndrome.

Although the clinical relevance of illness representations has been demonstrated in several studies, research on the structure and determinants of illness representations is rare. This article examines the illness representations of chronically ill patients, using a structured interview technique and taking chronic fatigue syndrome (CFS) and Addison's disease (AD) as examples. Considerable differences were found between the group of CFS patients (n = 98) and the group of AD patients (n = 63) with regard to their ideas about the identity, time line, control/cure , and consequences of their illness. Despite these differences, the pattern of correlations among these four dimensions of illness representation was found to be similar for the two groups. Moreover, the strength of the correlations points to the coherent nature of illness representations. The relations between the illness representations, personal variables, and disease- related variables were also explored. Regression analyses showed the dimensions of illness representation to be explained rather well by personal and disease-related variables. Disease-related variables were the most important predictors for the dimensions of identity and consequences; personal variables showed strong associations with time line and control/cure.