Fatigue in Parkinson's disease: prevalence and associated factors.

The purpose of this study was to examine the prevalence of fatigue in Parkinson's disease (PD) patients and compare this to the general population. Factors associated with fatigue were investigated by linear regression. Fatigue was assessed by the fatigue questionnaire. The mean age of the 176 PD patients (41% women) was 69 years (range 35-90), and the mean UPDRSIII was 22.3 (SD 11.7). Fatigue levels (means) were significantly higher in PD patients compared with the general population; however, effect sizes were moderate for women for physical and total fatigue indicating clinically significant differences here only. Only female PD patients had more chronic fatigue than the general population. Fatigue was related to characteristics of PD but also to sleep disturbance, depression, and gender. This population-based study demonstrates that fatigue is a common symptom in PD patients, but compared with the general population, clinically significant differences were only found for female PD patients.