Tag: critique

Editorial on CFS was biased, inaccurate, and misleading

EDITOR—As a member of the chief medical officer’s working group on chronic fatigue syndrome, I consider that Straus has failed to appreciate the difficulties of deciding what constitutes evidence in an illness as uncertain and heterogeneous as this.1 He also misunderstood, or took out of context, some of the key conclusions and recommendations in the chief medical officer’s report.

Although it was agreed that evidence should not just be limited to the results of randomised controlled trials, the findings of the York systematic review were frequently cited. It was therefore disingenuous of Straus to state that information from this review did not influence the report’s conclusions about a wide range of therapeutic interventions. It did.

Equally, it would have been a serious omission if the report had failed to refer to the feedback from patients contained in three large surveys on attitudes to management, as well as two events where patients and carers met with the working group. All three surveys concluded that graded exercise as is currently being done made more people worse than any other intervention. Pacing, however, was found to be beneficial by around 90% of respondents. By dismissing such views as anecdote, Straus fails to appreciate that the Department of Health is encouraging patients to enter into a therapeutic relationship with the medical profession in the management of chronic conditions such as this.2

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1122848/

 

Source: Shepherd C. Editorial on CFS was biased, inaccurate, and misleading. BMJ. 2002 Apr 13;324(7342):914. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1122848/ (Full article)

 

Chronic fatigue syndrome

Comment in: Chronic fatigue syndrome. [Br J Gen Pract. 2001]

Comment on: Frequency of attendance in general practice and symptoms before development of chronic fatigue syndrome: a case-control study. [Br J Gen Pract. 2001]

 

The study of Hamilton et al in the July issue of the BJGP, 1 claims that a higher consultation rate in people with chronic fatigue syndrome (CFS) before they develop the diagnosis supports the hypothesis that behavioural factors have a role in its aetiology. A similar case-control study of mothers and fathers of Down’s syndrome children showed that both mothers and fathers had significantly more recorded illnesses before the birth of the child and that the mothers had significantly more psychosis, neurosis or self-poisoning.2

The problem with such findings is deciding what they mean. No-one would suggest that Down’s syndrome is caused by ‘behavioural factors,’ so why should anyone believe that of CFS? There is no more evidence that increased frequency of attendance before diagnosis points to behavioural factors in CFS than that it points to non-dysjunction in the germ cells of mothers of Down’s syndrome children.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314117/pdf/11593850.pdf

 

Source: Murdoch JC. Chronic fatigue syndrome. Br J Gen Pract. 2001 Sep;51(470):758. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314117/pdf/11593850.pdf (Full comment)

 

Chronic fatigue in general practice

Comment on: Chronic fatigue in general practice: is counselling as good as cognitive behaviour therapy? A UK randomised trial. [Br J Gen Pract. 2001]

 

Ridsdale and colleagues are to be congratulated on performing a randomised controlled trial of different treatments for chronic fatigue. However, their data do not substantiate their conclusions.

The trial was set up to demonstrate that cognitive behavioural therapy was better than counselling for patients seen in general practice with fatigue symptoms. No difference in the main outcome measures was found between the intervention and control groups. This has been interpreted as showing that the two treatments are equivalent. The sample size required for, and analysis of, equivalence studies are different than those required for trials designed to show differences,2 not least the requirement that equivalence be defined before the trial starts. This trial was not designed to show equivalence. Thus, although the results for the main outcome measures are similar they should not be reported as being equivalent. Without a definition of equivalence, calculating the study’s power to show equivalence is not possible. Also, part of the conclusions depend on a sub-group analysis which, while acknowledged as being underpowered, is given more weight than is justified. If equivalence is defined as six points on the fatigue score then, in this subgroup, the trial only has a power of 36% to show equivalence based on a 95% confidence interval. With a more conservative definition of equivalence even the main study lacks power.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1313987/pdf/11458490.pdf

 

Source: Underwood M, Eldridge S. Chronic fatigue in general practice. Br J Gen Pract. 2001 Apr;51(465):317-8. http://www.ncbi.nlm.nih.gov/pubmed/11458490

 

Cognitive behaviour therapy and chronic fatigue syndrome

Comment on: Chronic fatigue in general practice: is counselling as good as cognitive behaviour therapy? A UK randomised trial. [Br J Gen Pract. 2001]

 

Ridsdale and colleagues state that there is evidence that cognitive behaviour therapy (CBT) is effective for patients with chronic fatigue syndrome (CFS), but fail to point out that such evidence derives only from studies performed in the United Kingdom, where CFS is diagnosed on the basis of the Oxford criteria. There is no evidence that CBT is beneficial to patients fulfilling the Australian criteria for CFS or the American ones, namely, the original criteria of the Centers for Disease Control.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1313986/pdf/11458489.pdf

 

Source: Baschetti R. Cognitive behaviour therapy and chronic fatigue syndrome. Br J Gen Pract. 2001 Apr;51(465):316-7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1313986/ (Full comment)

 

Patient education to encourage graded exercise in chronic fatigue syndrome. Trial has too many shortcomings

Comment on: Randomised controlled trial of patient education to encourage graded exercise in chronic fatigue syndrome. [BMJ. 2001]

 

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? They could have discussed anything but chronic fatigue.

Thirdly, frequent early contacts with patients in the three intervention groups (and not the control group) might have confounded the outcome measures by positively influencing the results. This view is supported by the maximum difference emerging as early as three months among patients who had had the illness for an average of over four years, with little change thereafter. By speaking to the patients Powell et al might have provided them with a coping strategy that the control group could not access. Furthermore, did the authors ask the patients to keep an activity diary to record the intensity (mild/moderate) and duration (minutes/hours a day) of physical exercise so that they could note any difference across the intervention groups?

Because no objective measures of physical activity (for example, exercise endurance) were included before and after the interventions for assessing outcome in this study, the reported beneficial effects of graded physical exercise are based on weak evidence. Moreover, the authors did not use the current diagnostic criteria to select patients with chronic fatigue syndrome. Why are we reading this in the BMJ?

You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1120585/

 

Source: Chaudhuri A. Patient education to encourage graded exercise in chronic fatigue syndrome. Trial has too many shortcomings. BMJ. 2001 Jun 23;322(7301):1545-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1120585/ (Full comment)

 

On the epidemiology of ‘mysterious’ phenomena

Abstract:

In the field of epidemiology, research topics are favored or dismissed depending on whether respective variables under investigation are believed to exist according to current scientific theories. Unconventional independent variables or exposures, such as religiousness and spirituality, and controversial dependent variables or outcomes, such as chronic fatigue syndrome, may be considered unacceptable topics for researchers because they do not fit comfortably into the consensus clinical perspectives of mainstream medical scientists or physicians.

Disapproval of research in these and other taboo areas is generally masked by claims that such studies are “pseudoscientific,” despite hundreds or thousands of peer-reviewed publications on these topics. In reality, seemingly “mysterious” variables are equally as amenable to epidemiologic research as any other exposure or disease. Similarly, alternative therapies are able to be investigated using existing methods, despite claims to the contrary. Such research is vital for scientific understanding to be expanded into new areas of inquiry.

 

Source: Levin J, Steele L. On the epidemiology of ‘mysterious’ phenomena. Altern Ther Health Med. 2001 Jan;7(1):64-6. http://www.ncbi.nlm.nih.gov/pubmed/11191044

 

Diagnose and be damned. Corroboration is important when children’s illnesses are diagnosed

EDITOR—Marcovitch’s arguments about treatment of the chronic fatigue syndrome (myalgic encephalomyelitis) in children are illogical.1 He writes of the “hatchet job” performed by Panorama in the programme of 8 November and refers to the Washington Post’s policy that news requires corroboration.

One of the responses to his article, by Wessely [published here, p 1005], states, “contrary to the message of the programme, the management of chronic fatigue syndrome in children is not contentious.”2 In referring to a case reported by Panorama Marcovitch states that “parents’ views and those of the local medical team were in conflict.” Yet the programme made clear that the dispute was between the parents supported by their own medical advisers and the local medical team, so perhaps there is greater disagreement than has been asserted.

Marcovitch discussed at length Munchausen’s syndrome by proxy; Panorama labelled one of the cases of myalgic encephalitis as being a case of this syndrome. No one likes receiving emotional, intemperate outbursts, even from people who think they have been wrongly accused. But what is sauce for the goose is surely sauce for the gander. Even doctors sometimes make mistakes, yet Marcovitch disregards the possibility that parents, knowing themselves innocent, may feel themselves to have been receiving exactly the same type of vituperative attack that he objects to when doctors are on the receiving end. Such allegations turn on fact rather than clinical opinion so should be subject to Marcovitch’s own test of corroboration.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1117876/

 

Source: Pheby D. Diagnose and be damned. Corroboration is important when children’s illnesses are diagnosed. BMJ. 2000 Apr 8;320(7240):1004. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1117876/ (Full article)

 

Chronic fatigue syndrome and depression

Comment on: Cerebral perfusion in chronic fatigue syndrome and depression. [Br J Psychiatry. 2000]

 

I found MacHale et al’s (2000) discussion of their results confusing. According to the abstract and methods, they screened their patients with chronic fatigue syndrome (CFS) to exclude those with depression. Then they examined this group further using a standardised psychiatric interview (Schedule for Affective Disorders and Schizophrenia), in order to “ exclude subjects with current psychiatric illness, with a particular emphasis on depression”. The data from the Hamilton Rating Scale for Depression are difficult to interpret given the number of illnessrated items, but the scores did not indicate a significant degree of depression either. So, having excluded “subjects with depression or anxiety”, why did the authors claim in their discussion that “the main limitation of the present study is that our CFS subjects had high levels of depression”?

You can read the rest of this comment here: http://bjp.rcpsych.org/content/177/5/470.long

 

Source: Goudsmit E. Chronic fatigue syndrome and depression. Br J Psychiatry. 2000 Nov;177:470. http://bjp.rcpsych.org/content/177/5/470.long

 

Chronic fatigue syndrome: is it physical?

Comment on: Strength and physiological response to exercise in patients with chronic fatigue syndrome. [J Neurol Neurosurg Psychiatry. 2000]

 

It is increasingly recognised that chronic fatigue syndrome (CFS) is heterogeneous. A significant proportion of patients fulfilling operative criteria for a diagnosis of CFS will also fulfill criteria for a psychiatric disorder, such as depression or somatisation. Failure to recognise this heterogeneity prejudices attempts to understand CFS in cross sectional studies. In this issue (pp 302–307) Fulcher et al report a study of muscle strength, aerobic exercise capacity, and functional incapacity in a group of patients with CFS without concurrent psychiatric disorder, compared with patients with major depression and a group of normal but sedentary subjects.1 In an incremental treadmill exercise test, patients with CFS and depressed patients had lower peak oxygen consumption rates, maximal heart rates, and plasma lactate concentrations than the sedentary controls; but this reflected the shorter duration of exercise tolerated by these patients. At submaximal work rates, patients with CFS and depressed patients experienced greater perception of eVort than sedentary controls at the same level of work. This is in keeping with the finding that such patients show greater sensitivity to bodily sensations than normal subjects. Overall, there was little difference between the patients with CFS and the depressed patients in exercise characteristics, yet the patients with CFS reported significantly greater degrees of physical fatigue and physical incapacity.

You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1737076/pdf/v069p00289.pdf

 

Source: Lane R. Chronic fatigue syndrome: is it physical? J Neurol Neurosurg Psychiatry. 2000 Sep;69(3):289. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1737076/

 

Treating chronic fatigue with exercise. Exercise, and rest, should be tailored to individual needs

Comment on: Putting the rest cure to rest–again. BMJ. 1998

 

 

Editor – While I welcome Sharpe and Wessely’s reminder about the dangers of bed rest,1 I am concerned about the blanket advice regarding activity levels for patients with chronic fatigue. Chronic fatigue syndrome is now generally acknowledged to be a heterogeneous condition, not a single entity with a single cause. Accordingly, what may suit one person may be totally inappropriate for another. As research has shown, most patients with chronic fatigue syndrome remain ambulant, spend relatively few daytime hours resting, are no more inactive than people with mild multiple sclerosis, and tend to perform at or near their activity ceiling.2 What these patients need is not a strict programme in which rest is allowed according to a predetermined plan but a flexible approach that does not ignore current energy levels or make people feel guilty if they increase rest periods when they consider this to be right for them.

From a theoretical perspective, inactivity may well be an important factor in chronic fatigue syndrome, but I note that Sharpe and Wessely did not provide a single reference to back their claim that many patients simply “go home and rest,” let alone that most resort to “excessive rest.” Does this mean that the theory that “excessive inactivity” perpetuates chronic fatigue syndrome is based largely on anecdotal reports and articles in magazines? Moreover, in this age of evidence based medicine, discussions of a treatment should mention the negative reports of its efficacy as well as the positive.3,4

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1113801/

 

Source: Goudsmit E. Treating chronic fatigue with exercise. Exercise, and rest, should be tailored to individual needs. BMJ. 1998 Aug 29;317(7158):599; author reply 600. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1113801/