Van der Werf, SP., Prins, JB., Vercoulen, JHMM., van der Meer, JWM and Bleijenberg, G. Identifying physical activity patterns in chronic fatigue syndrome using actigraphic assessment. Journal of Psychosomatic Research, 2000, 49, 5, 373-379.
Changes
in physical activity are thought to play an important role in maintaining
symptoms in CFS. The aim of this study was to describe intraindividual physical
activity patterns in more detail and to identify pervasively passive patients.
With help of a movement-sensing device (actometer), physical activity levels were registered continuously over a 12-day period in 277 CFS patients (CDC criteria '94). Within this registration period, the 10 largest activity peaks were computed. The intensity and duration of these activity peaks and their subsequent rest periods were described and compared to those of 47 healthy controls. In addition, the patients' 12 daily activity scores were used to identify patients who were characterised by low levels of physical activity throughout the registration period. Other measures included the Beck Depression Inventory.
The
CFS sample had less intense and shorter activity peaks, while the average rest
periods that followed these peaks lasted longer. Twenty-four per cent of the CFS
sample differed distinctly from the control group and were labelled as
pervasively passive. (They were “less active compared to other CFS patients
for at least 90% of the total observation period”).
Sixty per cent of the patients were moderately active versus 59% of the
controls. There was no relationship
between levels of activity and either fatigue or mood.
“The measurements and classification of actual physical activity levels were found to reduce heterogeneity in the CFS population and therefore could provide the opportunity to optimise behavioural intervention protocols for CFS”.
With Editorial by PD White, (ibid p. 283-284).
This editorial ignores relevant information inconsistent with the CBT model, e.g. the fact that no study on CFS has so far found evidence that a significant proportion of patients engage in 'prolonged bed rest'. The discussion of the findings in relation to bed rest is therefore pure speculation and conjecture. The editorial also ignores the research consistent with the findings above e.g. Sisto et al 1998, and does not allude to the possibility that in many cases, physical inactivity may be a result of ongoing disease. In relation to the final part of the editorial, it should be noted that the only studies that showed graded exercise to be effective selected broadly defined patients, half of whom were on psychotropic drugs (which may have contributed to their lethargy). The successful trials on CBT also featured broadly defined patients, many of whom had concurrent psychiatric disorders. No study showing the benefits of increasing activity levels has assessed symptoms other than fatigue and emotional distress.]
