Predictors of Fatigue among Patients with Chronic Fatigue Syndrome.

Activity logs involve patients writing down their activities over one or more days. Several studies have found these data collection instruments to accurately describe activities of patients with chronic fatigue syndrome (CFS). The purpose of this study was to utilize the repeated measures available on the ACTRE to evaluate predictors of fatigue at a given timepoint. A random intercept model was tested with the following variables predicting current fatigue: past fatigue (30 mins. prior), current category of activity (e.g., resting, work, recreation, etc.), past category of activity (30 mins. prior), the interaction of past fatigue and past activity, and TH2/TH1 immune shift. These findings and others suggest that activity logs can provide investigators and clinicians with valuable sources of data for understanding patterns of behavior and activity among patients with CFS.