Background: Chronic fatigue syndrome (CFS) is an entity of unknown etiopathogenesis without specific markers. The diagnosis is based on clinical criteria. There are few studies evaluating the natural evolution and prognosis-related factors in CFS.
Objectives: a) to evaluate the outcome of patients suffering from CFS, and b) to detect predictive factors associated with a better prognosis.
Material and methods: Clinical records of all patients diagnosed of CFS between January 1986 and December 1992 were retrospectively reviewed. Of these patients, we included those fulfilling the CDC criteria for CFS, with a follow-up period greater than one year. We evaluated epidemiological, clinical and evolutive data recorded by their usual physicians. Moreover, the patients were interviewed in order to know their own appreciation with respect to their current clinical status, as well as their present working situation.
Results: Twenty-eight patients were included in the present study. Their mean age was 38 +/- 7. Seventy-five percent of them were women. The mean time of clinical follow-up was of 3.2 +/- 1.8 years. According to evaluation, 21% of patients improved or became asymptomatic. A similar percentage (28%) of improvement was obtained from the interview. Forty-eight percent of cases had transitory or definitive laboral incapacity. Regarding to prognostic factors, we could not find any statistical differences among the analyzed variables except for marital status. In this variable, married patients had better outcome than unmarried patients.
Conclusion: CFS is an entity with a poor outcome, since it evolves towards to chronicity in an important number of cases. In addition, strong functional disability may be present, leading frequently to laboral incapacity.