Identifying physical activity patterns in chronic fatigue syndrome using actigraphic assessment

Objective: Changes in physical activity are thought to play an important ro le in maintaining symptoms in chronic fatigue syndrome (CFS). The aim of th is study was to describe intraindividual physical activity patterns in more detail and to identify pervasively passive patients. Methods: With help of a movement-sensing device, physical activity levels were registered contin uously over a 12-day period in 277 CFS patients. Within this registration p eriod, the 10 largest activity peaks were computed. The intensity and durat ion of these activity peaks and their subsequent rest periods were describe d and compared to those of 47 healthy controls. In addition, the patients' 12 daily activity scores were used to identify patients who were characteri sed by low levels of physical activity throughout the registration period. Results: The CFS sample had less intense and shorter activity peaks, while the average rest periods that followed these peaks lasted longer. Approxima tely one-fourth of the CFS sample differed distinctly from the control grou p and was labelled as pervasively passive. Conclusion: The measurements and classification of actual physical activity levels were found to reduce het erogeneity in the CFS population and therefore could provide the opportunit y to optimise behavioural intervention protocols for CFS, (C) 2000 Elsevier Science Inc. All rights reserved.