Disability and chronic fatigue syndrome: a focus on function.

BACKGROUND Evidence was sought in the published literature on how best to measure, monitor, and treat disability in patients with chronic fatigue syndrome (CFS). METHODS A systematic review was performed of English-language literature published between January 1, 1988, and November 15, 2001. Interventional and observational studies of adults with CFS were eligible if they reported measures of disability and employment. A qualitative synthesis of results relating impairment measures to employment was performed. RESULTS Of 3840 studies identified, 37 reported employment status and some measure of mental or physical impairment associated with disability. Most patients with CFS in these studies were unemployed. In 22 studies, the employment status of control subjects was also available. Only depression seemed to be associated with unemployment in patients with CFS. No other measurable impairment seemed to be consistently associated with disability or work outcomes. Only cognitive behavior therapy, rehabilitation, and exercise therapy interventions were associated with restoring the ability to work. No specific patient characteristics were identified as best predictors of positive employment outcomes. No quantitative syntheses of results were performed. CONCLUSIONS For questions of disability and employment in CFS, the limitations inherent in the current literature are extensive. Methodologically rigorous, longitudinal, and interventional studies are needed to determine baseline characteristics that are associated with the inability to work and interventions that are effective in restoring the ability to work in the CFS population. Simple and consistent evaluations of functional capacity in patients with CFS are needed.