A qualitative study to explore the concept of fatigue/tiredness in cancer patients and in healthy individuals.

Interest in fatigue research has grown since the finding that fatigue/tiredness is the most frequently reported symptom of cancer and its treatment. But even though several authors have tried to conceptualise fatigue, its mechanisms are still poorly understood. The aim of this study was twofold: (a) to explore fatigue in cancer patients inductively, and (b) to compare experiences of fatigue/tiredness of healthy individuals with those of cancer patients to identify cancer-specific fatigue/tiredness and related concepts. A qualitative research strategy was adopted using a grounded-theory approach. The prospective study took place in the oncology department of the Kantonsspital, St. Gallen, Switzerland, with samples of 20 cancer patients and 20 healthy individuals. Unstructured, tape-recorded interviews were conducted to collect data. The transcripts of the interviews were analysed using content analysis and constant comparison. Different themes emerged between the two groups although both fitted a classification system that categorised fatigue into physical, affective and cognitive expressions of fatigue/tiredness. Physical signs were more frequent than affective and cognitive signs in both groups. In the cancer patients, fatigue involved decreased physical performance, extreme, unusual tiredness, weakness and an unusual need for rest, which was distinctly different for healthy persons. Affective and cognitive distress was also more prominent in cancer patients. Interestingly, the concept of malaise was not identified by either sample and not understood as an expression of fatigue by this German-speaking population. Linguistic differences in the description of fatigue/tiredness between healthy and ill individuals revealed different perceptions of the phenomenon. A step-like theory, explaining the production of fatigue/tiredness was tentatively put forward involving nociception, perception and expression of tiredness. The emerging concepts break tiredness/fatigue into an expression of physical, affective and cognitive tiredness/fatigue. The experience is different between healthy individuals and cancer patients. Care must be taken when drawing generalised conclusions but the results of the study identify and clarify ideas that might form an important basis for further, controlled studies.