Perceived fatigue is comparable between different disease groups

Studies have established that levels of fatigue vary between different patient groups. It is less clear whether the nature, as opposed to severity of fatigue differs between groups.

To examine descriptions of fatigue by patients with a range of chronic diseases and determine the relationship between symptom domains.

Retrospective review of Fatigue Impact Scale (FIS) data.

Fatigue Research Group.

Six hundred subjects in five chronic disease groups and one (n = 45) normal control group.

Statistical analysis was performed to assess the effect of increasing fatigue and the overlap of FIS domain scores between disease groups by calculation of geometric means as proportions summed to 1 in each FIS domains, whilst controlling for total score.

Those with lower scores exhibit relatively higher physical scores than patients with higher total scores. In contrast, as total score increases, so does the proportion accounted for by the cognitive and psychosocial scores. This was not related to a threshold effect as the maximum total score of 40 in the physical domain was only achieved in three patients (<1%). Average domain proportions between patient groups did not vary to any degree among physical (0.30-0.39), cognitive (0.15-0.23) and psychosocial (0.42-0.47) domain proportions of the patient groups.

Perceived fatigue is similar between patient groups. Increasing scores were not related to simply reaching the maximum threshold in the physical domain. Studies have confirmed a positive-structured approach to symptom management in one fatigue-associated chronic disease, primary biliary cirrhosis, leads to significant improvements in quality of life. We suggest that, with a similar approach, the same might be true in other chronic diseases where moderate fatigue is a significant problem.