Methods: From our cohort (n=608) we identified those with comorbidities associated with fatigue, and those taking medications associated with drowsiness. We constructed dummy variables, permitting the contribution of these potentially assignable causes of fatigue to be assessed. Using multiple regression analysis, we modelled the relationship between Profile of Fatigue and Discomfort (PROFAD) physical and mental fatigue scores and potentially related variables.
Results: Pain, depression, and daytime sleepiness scores were closely associated with both physical and mental fatigue (all p≤0.0001). In addition, dryness was strongly associated with physical fatigue (p≤0.0001). These effects were observed even after adjustment for co-morbidities associated with fatigue or medications associated with drowsiness.
Conclusions: These findings support further research and clinical interventions targeting pain, dryness, depression and sleep to improve fatigue in PSS patients.