Trial has too many shortcomings

EDITOR—Powell et al's controlled trial of graded physical exercise in chronic fatigue syndrome has several shortcomings.1

Firstly, the only tool that was used to assess the level of physical activity was entirely subjective. This was a single item (the third item) of the 11 item standardised SF-36 health survey questionnaire. Use of this single item alone as a valid measure of physical fitness is hardly acceptable in the absence of objective data.

Secondly, in a randomised study one can only compare like with like. In this case, all patients in the intervention arms had a minimum of three telephone contacts during the first three months. Patients in the control group were abandoned to primary care after the randomisation. Why did the investigators not maintain the same number of telephone contacts with the control group? …