Chronic fatigue, chronic fatigue syndrome, and fibromyalgia. Disability and health-care use.

OBJECTIVES: Disabling chronic fatigue that does not meet criteria for chronic fatigue syndrome (CFS) or fibromyalgia (FM) is a condition thought to be associated with substantial disability and an apparently high use of health-care services. The authors compare patients who have chronic fatigue, CFS, FM, or CFS and FM together (CFS+FM) on employment status, self-reported disability, number of medical care visits, type of services obtained, and other diagnoses received.

METHODS: The authors studied 402 patients from a university-based chronic fatigue clinic. All patients underwent an initial structured diagnostic assessment. One hundred forty-seven patients met case criteria for CFS, 28 for FM, 61 for CFS+FM, and 166 fell in the residual chronic fatigue group. Of these patients, 388 completed a follow-up questionnaire an average of 1.7 years later. Chi-squared tests and analysis of variance were used to compare groups on follow-up measures of health-care use and disability.

RESULTS: Patients with chronic fatigue, CFS, FM, and CFS+FM were similar in terms of disability and health-care use, though those with CFS+FM were significantly more likely to be unemployed and to use more chiropractic and "other" provider services. Rates of unemployment ranged from 26% (chronic fatigue) to 51% (CFS+FM). Overall, patients reported a mean of 21 visits to a wide variety health-care providers during the previous year, with no significant differences between groups.

CONCLUSIONS: Chronic fatigue, CFS, and FM are associated with considerable personal and occupational disability and low rates of employment. The potentially large economic burden of these disorders underscores the need for accurate estimates of direct and indirect costs, the relative contribution of individual factors to disability, and the need to develop targeted rehabilitation programs.