Symptom fluctuations and daily physical activity in CFS (Meeus et al, 2011)

[mtnbibliophile]

My concern about this study (and others) is that the control group is composed of sedentary people. I don't understand why.
For one thing, those people may be sedentary because of unknown, undiagnosed illnesses.
For another, I don't know about you all, but I was far from sedentary when I contracted this illness. I think the control group should more appropriately match the average pre-morbid activity level of the CFS patients being studied. Compare me to someone who's sedentary because of an unknown illness or genetic disposition or whatever, and our symptom fluctuations may not differ much. Compare me to someone who works in a stressful job 60 hours a week, as I did, and I bet there's a lot more difference.
Can anyone explain why sedentary controls are used?
thanks

 

[WillowJ]

welcome to the forum, mtnbibliophile

the strategy behind using sedentary controls is to sort out what is from this specific illness (or illness spectrum) as opposed to what might be from being generally less active than other people.

in experimental design there is something which is called a 'confounding effect'. What you described as the difference between really any sick or even any inactive person and someone who works 60 hours a week is a real difference, but it isn't necessarily due to the exact thing being studied. In order to sort out what specifically is due to the exact thing being studied, controls are sought which are as similar as possible to the people being studied.

Thus it's useful to use in some studies presumed healthy sedentary people, and in others you'll see people with MS, rheumatoid arthritis, major depressive disorder, etc. as controls (as well as healthy controls). It's most often a mark of a poorly-designed or poorly-interpreted study to compare sick people to only healthy people (there are some like this), because then one can't tell whether something is due to illness in general, due to some indirect effect of being ill or some shared risk factor to being ill, or whether it indeed relates directly to the specific thing which is being studied.

 

[mtnbibliophile]

Thank you for your prompt response, Willow. I'm glad to have discovered this forum, where the levels of both civility and knowledge far exceed what I have seen elsewhere. I understand your reasoning, Willow, but I still think it was inappropriate to use sedentary controls in this case. I don't care that my symptom fluctuations are similar to those of similarly sedentary people. My concern is, when I try to explain to a healthy person that "yes, I look fine now, but my symptoms vary tremendously and I didn't feel this well yesterday", and the healthy person dismisses my illness by saying, "Oh, everybody has good days and bad days" or something similar, I want to be able to cite peer-reviewed scientific research that shows that the fluctuation in symptom severity in CFS patients during a day or from one day to the next far exceeds the amplitude of fluctuation in feelings of wellness in normally healthy people. Does such a study exist amd if so, can someone point me to it? We all have plenty of anecdotal evidence, but hard data would be much more convincing to the skeptical.

 

[WillowJ]

you're welcome.

Maybe what you need are these studies:

Anderson JS, Ferrans CE. "The quality of life of persons with chronic
fatigue syndrome." J Nerv Ment Dis. 1997 Jun;185(6):359-67.

Overall scores on the quality of life index were significantly lower in CFS
than for other chronic illness groups. Subjects reported the lowest quality
of life scores in health and functioning domain.

Indepth interviews provided
a more complete understanding of the quality of life in CFS and further
explained the low ratings that were found on the quality of life index.

The findings suggest that quality of life is particularly and uniquely
disrupted in CFS.

Komaroff AL, Fagioli LR, Doolittle TH, Gandek B, Gleit MA, et al. "Health
status in patients with chronic fatigue syndrome and in general population
and disease comparison groups." Am J Med. 1996 Sep;101(3):281-90.

PATIENTS: The subjects of the study were patients with CFS (n = 223) from a
CFS clinic, a population-based control sample (n = 2,474), and disease
comparison groups with hypertension (n = 2,089), congestive heart failure (n
= 216), type II diabetes mellitus (n = 163), acute myocardial infarction (n
= 107), multiple sclerosis (n = 25), and depression (n = 502).

RESULTS: Patients with CFS had far lower mean scores than the general
population control subjects on all eight SF-36 scales. They also scored
significantly lower than patients in all the disease comparison groups other
than depression on virtually all the scales. When compared with patients
with depression, they scored significantly lower on all the scales except
for scales measuring mental health and role disability due to emotional
problems, on which they scored significantly higher.

Buchwald D, Pearlman T, Umali J, Schmaling K, Katon W. "Functional status in
patients with chronic fatigue syndrome, other fatiguing illnesses, and
healthy individuals." Am J Med. 1996 Oct;101(4):364-70.

Chronic fatigue syndrome (CFS) is a condition that may be associated with
substantial disability. Our objectives were to describe the usefulness of
the SF-36 in CFS patients and to determine if subscale scores could
distinguish patients with CFS from subjects with unexplained chronic fatigue
(CF), major depression (MD), or acute infectious mononucleosis (AIM), and
from healthy control subjects (HC).

A strikingly consistent pattern was
found for the physical functioning, role functioning, social functioning,
general health, and body pain subscales, with the lowest scores in CFS
patients, intermediate scores in AIM patients, and the highest scores in the
HC subjects. The CFS patients had significantly lower scores than patients
with CF alone on the physical functioning (P < or = 0.01), role functioning
(P < or = 0.01), and body pain (P < or = 0.001) subscales. The emotional
functioning and mental health scores were worst among those with MD.

Patients with CFS and CF have marked impairment of their functional status.

And this essay series with references:

http://cfids.org/cfidslink/2010/pem-series.asp

I hope that helps.

 

[mtnbibliophile]

Thank you for the effort, but no. I'm very specifically looking for something that addresses the swings between our best times and our worst times, and how those swings are far wider than the usual ups and downs that a healthy person undergoes. Dr. Bell, in his "Faces of CFS" book, had a wonderful example of a patient who lay in bed 22 hours a day, but played basketball the other two hours. Unfortunately, that's anecdotal evidence, not as convincing as research studies, especially if you're trying to explain to your disability insurer that their 15 minutes of videotaped activity does not mean that they have evidence that I'm no longer severely disabled.

 

[Little Bluestem]

What does subscribe to post mean? I usually bookmark things but sometimes on boards it will only save the front page of the board.

Obviously, not computer literate here. :>)

I think ‘subscribe to post’ was the terminology of the old board and that the current equivalent is ‘watch thread’. You do that clicking the button at the upper right of the thread. You can choose whether or not to get e-mails. You can see your watched threads by clicking on ‘Watched Threads’ on the bar across the top of the thread.

 

[barbc56]

Thanks!!!!

 

[WillowJ]

perhaps this might be of some use, mtnbibliophile :
http://www.prohealth.com/library/showarticle.cfm?libid=13474

ETA: the link from there to the text doesn't work. Full text may be found here:
http://www.name-us.org/MECFSExplainPages/2007CiccolellaLegalStressTest.pdf

 

[Enid]

Peculiar research this and off real medical biological/pathology findings now apparent. Who the bh knows quite what one is capable of from day to day until the pathophysiolgy (well on the way) understood and indeed treated. How much longer do we have to go into useless studies of eg fatigue especially now the BIOLOGICAL pathology is now being revealed.

Oh and symptom fluctations - how about passings out one minute or upright (just) remembering names. Any whizz solution here.

 

[mtnbibliophile]

Willow, Dolphin, a belated thank you for your help. I got sidetracked onto different CFS issues - for some of which I went right back to this thread for information - but never remembered to thank you. Now that I'm two days away from filing my appeal of my disability insurer's denial of benefits, I'm tying up loose ends, and you two were among them. It is a joy to be on Phoenix Rising and see all the knowledge available here.