Cognitive behavioural treatment for chronic fatigue syndrome in a rehabilitation setting: effectiveness and predictors of outcome.

Cognitive behavioural therapy (CBT) was combined with graded exercise therapy (GET) for patients with chronic fatigue syndrome (CFS) in an uncontrolled implementation study of an inpatient multidisciplinary group therapy. During the intake procedure, 160 CFS patients completed a questionnaire on fatigue related measurements, physical impairment, depression, somatic and psychological attributions, somatic focus, and sense of control over symptoms. Pre-treatment physical activity level was measured with an actometer. At baseline, post-treatment and 6-month follow-up individual strength, subjective fatigue and physical impairment, were reassessed. Large effect sizes were found on subjective fatigue (1.2 post-treatment; 1.2 follow-up) and physical impairment (-.9 post-treatment; -.9 follow-up), Clinically significant improvement was found in 33.8% of the participants at post-treatment and 30.6% at follow-up. Individual strength at post-treatment was predicted by level of physical activity before treatment, and by sense of control over symptoms and physical activity at follow-up. Clinically significant improvement in subjective fatigue was predicted by not receiving a disablement insurance benefit, shorter duration of fatigue, higher sense of control over symptoms and, at follow-up by more pre-treatment physical activity. In conclusion, the intervention was effective for CFS patients. Cognitive behavioural factors that perpetuate fatigue symptoms are also predictors of treatment outcome.