Most evaluations of cognitive behavioural therapy to treat people with chronic fatigue syndrome/myalgic encephalomyelitis rely exclusively on subjective self-report outcomes to evaluate whether treatment is effective. Few studies have used measures appropriate to assessing whether cognitive behavioural therapy changes in more objective measures. A review of studies incorporating objective measures suggests that there is a lack of evidence that cognitive behavioural therapy produces any improvement in a patient's physical capabilities or other objective measures such as return to work. Future studies of chronic fatigue syndrome/myalgic encephalomyelitis should include some objective assessments as primary outcomes. If this is to include activity monitors, we first need a sound baseline dataset.
Keywords: chronic fatigue syndrome; cognitive behaviour therapy; effectiveness; qualitative methods; quantitative methods.