AK Knudsen, LV Lervik, SB Harvey, CMS Løvvik, AN Omenås, and A Mykletun
Comparison of chronic fatigue syndrome/myalgic encephalopathy with
other disorders: an observational study
J R Soc Med Sh Rep May 2012 3:32; doi:10.1258/shorts.2011.011167
The study is on internet usage
For this journal there is a 400-word, 5-reference limit to e-letters
or otherwise I would have written more.
Dear AK Knudsen
Robert J Longworth, Retired
Dear AK Knudsen
I note that in the discussion section, 3rd paragraph, 9th line the
authors acknowledge that a previous study had shown that multiple
sclerosis had a higher online activity than me/cfs.
"The results from this study are in line with findings from Davison et
al.,20 who found CFS to have the second highest level of online
activity, after multiple sclerosis."
Why then did the authors design a study that did not include multiple
sclerosis as a comparison? Especially as the authors have concluded
that me/cfs has ten times the relative online activity of any other
disorder or condition.
Do the authors think that by not including multiple sclerosis as a
comparison to me/cfs, they were achieving best practise for a
scientific study? I note also that there is not mention of this matter
as being a weakness in their study.
Since the authors have acknowledged a possibility that online activity
for multiple sclerosis may be higher than for me/cfs, do the authors
think that the possible explanations for this high activity is the
same for both illnesses.
Do the authors consider a possible explanation for people with
multiple sclerosis having a high online activity, is due to being
isolated with a debilitating physical illness, loneliness and seeking
companionship. I note these possible explanations were not listed for
the high online activity of me/cfs people.
Conflict of Interest: None declared
Published 24 July 2012
RE: Comparison of chronic fatigue syndrome/myalgic encephalopathy with
other disorders: an observational study
Irish ME/CFS Association
Knudsen and colleagues raise an interesting issue. However, I believe
they could have helped ensure better matching by using other groups of
patients with chronic illnesses such as multiple sclerosis which, as
the authors highlighted, had previously been found to have higher
online activity than Myalgic encephalomyelitis/chronic fatigue
syndrome (ME/CFS). Perhaps in time the field will develop and
statistical tools like regression could help isolate which independent
variables predict online activity, and hence help isolate communities
with unusual patterns.
It would have been interesting if the authors had gathered qualitative
information on the topics discussed, to see if there were differences
not just in the quantity of activity but also in terms of the range of
topics discussed, and how they were discussed in different groups.
ME/CFS is often said to be a heterogeneous condition (1); similarly in
my experience, users of ME/CFS online forums are not all the same in
terms of their interests (what they like to discuss or read about).
This can be seen in the different types of groups that show up in a
search of www.yahoogroups.com, for example: there are chat groups;
groups interested in experimental therapies; groups interested in
activism of one sort or another; groups interested in discussing
research findings, etc.
The authors suggest that the high level of activity in ME/CFS could be
explained by action proneness (2). However that study was
retrospective and thus could be affected by recall bias. Research that
utilised an "action proneness" questionnaire, when individuals were
actually ill with ME/CFS, found lower levels compared to the general
The paper also mentions the "boom-bust" theory with regard to activity
levels in ME/CFS. However, there is evidence that activity levels in
ME/CFS patients don't fluctuate any more than control groups (3,4).
We are told that "research on support group participation for CFS/ME
sufferers indicates that active members report greater symptom
severity and less improvement of the disorder than inactive members
(5)". However the study, which also involved fibromyalgia, found that
employment rates, an important measure of overall functioning was not
statistically different between the two groups.
If there are particular issues in ME/CFS that are driving patients to
internet forums, perhaps in time they will improve e.g. the
stigmatisation mentioned. Also, more effective therapies for ME/CFS
may become available - currently there are no FDA approved drugs for
the condition, which can lead patients to be interested in numerous
(1) Kindlon T. Reporting of Harms Associated with Graded Exercise
Therapy and Cognitive Behavioural Therapy in Myalgic
Encephalomyelitis/Chronic Fatigue Syndrome. Bulletin of the IACFS/ME.
(last accessed: January 4, 2013)
(2) Van Houdenhove B, Onghena P, Neerinckx E, Hellin J. Does high
'action-proneness' make people more vulnerable to chronic fatigue
syndrome? A controlled psychometric study. J Psychosom Res. 1995
(3) Meeus M, van Eupen I, van Baarle E, et al. Symptom fluctuations
and daily physical activity in patients with chronic fatigue syndrome:
a case-control study. Arch Phys Med Rehabil. 2011 Nov;92(11):1820-6.
(4) van der Werf SP, Prins JB, Vercoulen JH, van der Meer JW,
Bleijenberg G. Identifying physical activity patterns in chronic
fatigue syndrome using actigraphic assessment. J Psychosom Res. 2000
(5) Friedberg F, Leung DW, Quick J. Do support groups help people with
chronic fatigue syndrome and fibromyalgia? A comparison of active and
inactive members. J Rheumatol 2005;32:2416-20
Conflict of Interest:
I am the Assistant Chairperson and Information Officer of the Irish
ME/CFS Association. All my work for the Association is unpaid.
Published 10 January 2013