PROGNOSIS IN CHRONIC FATIGUE SYNDROME - A PROSPECTIVE-STUDY ON THE NATURAL COURSE

Objective-To determine spontaneous improvement after a follow up inter val of 18 months in patients with chronic fatigue syndrome and to iden tify factors that predict improvement. Methods-A longitudinal study wa s used. Of 298 initially assessed self referred patients fulfilling cr iteria for chronic fatigue syndrome, 246 patients completed self repor t questionnaires at follow up (response rate 83%). A multidimensional assessment method was used, measuring behavioural, emotional, cognitiv e, and social functioning. Comparison data from 53 healthy subjects ma tched for age, sex, and educational level were available. Results-Thre e per cent of patients reported complete recovery and 17% reported imp rovement. At follow up, there were considerable problems at work and c onsumption of medication was high. Subjective improvement was confirme d by dimensional change: at follow up recovered patients had similar s cores to healthy subjects and improved patients showed significant imp rovement on four out of seven outcome measures and had higher scores t han healthy subjects in all dimensions. Sociodemographic variables or treatment by specialists and alternative practitioners did not predict improvement. Predictors of improvement were: subjective sense of cont rol over symptoms, less fatigue, shorter duration of complaints, and a relative absence of physical attributions. Conclusion-The improvement rate in patients with a relatively long duration of complaints is sma ll. Psychological factors are related to improvement, especially cogni tive factors.