Prognostic factors for persons with idiopathic chronic fatigue

Background: The simultaneous examination of a large number of patient chara cteristics in a prospective study of patients with chronic fatigue. Objective: To compare the relative importance of these characteristics as p rognostic factors. Methods: The data analyzed were from 199 subjects in a registry of persons who were aged 18 years or older and had idiopathic fatigue for at least 6 m onths. All subjects completed an extensive baseline questionnaire that prov ided information about fatigue, demographic characteristics, medical condit ions, lifestyle, sleeping habits, psychological characteristics, and the pr esence of criteria for chronic fatigue syndrome. Changes in fatigue severit y from baseline to 2-year follow-up were tested for an association with ris k factors at baseline and with changes in symptoms other than fatigue durin g the follow-up period. Results: The following characteristics at baseline significantly and indepe ndently predicted greater fatigue improvement: less unclear thinking, fewer somatoform symptoms not used to define chronic fatigue syndrome, infrequen t awakening, fewer hours sleeping, and being married. Of 29 subjects who at baseline reported no somatoform symptoms unrelated to chronic fatigue synd rome and who thought clearly most of the time, 8 substantially improved, co mpared with 1 of 29 Subjects who had more than 2 somatoform symptoms and ne ver thought clearly (P =.01). Improvements in the following symptoms were s ignificantly and independently associated with improvements in fatigue: unc lear thinking, depression, muscle aches, and trouble falling asleep. Conclusions: This study identified characteristics of subjects that seem to be of prognostic importance for idiopathic chronic fatigue. Symptoms that change concomitantly with changes in fatigue may be intrinsically linked to fatigue.