Tag: critique

Chronic fatigue syndrome: a clinical and laboratory study with a well-matched control group

Comment on: Chronic fatigue syndrome: a clinical and laboratory study with a well matched control group. [J Intern Med. 1995]

 

Dear Sir,

It is an ongoing debate whether concurrent occurrence of particular additional symptoms should be part of the definition of chronic fatigue syndrome (CFS) [1–5] or not. Studies on the similarities and differences between patients satisfying the various definitions are indispensable to solve this dispute.

Swanink et al. [6] studied CFS patients satisfying the criteria described by Sharpe et al. [3], i.e. additional symptoms may be present but are not required. Part of the group also satisfied the more stringent CFS criteria by the Centers for Disease Control (CDC) [1], which require the additional presence of at least eight specific symptoms. When the number of complaints was included as the covariate, no significant differences on fatigue severity, depression and functional impairment were found between CFS patients who fulfilled the CDC criteria and who did not. Furthermore, the authors remarked that the sole effect of applying the CDC symptom criteria to their study group is separating patients with few symptoms from patients with many symptoms.

These results are very misleading and have often been misinterpreted. The authors’ analysis of variance (anova) yielded a lot of significant differences between CDC–CFS and non-CDC–CFS patients. That these were lost in their subsequent analysis of covariance (ancova) is because the level of the covariate and the treatment (fulfilment of the CDC criteria) are highly dependent, as fulfilment of the CDC criteria requires the presence of at least nine symptoms (fatigue included). Because the ancova assumption that the covariate is statistically independent of the treatment is not met, the ancova results are artificial and have little practical meaning [7, 8].

What happened* is illustrated in Fig. 1. anova checks whether CDC–CFS and non-CDC–CFS patients have equal test score means  and inline image and inline image. ancova, however, checks the equality of adjusted test score means  and inline image and inline image. These are obtained by transporting inline image and inline image from the treatment covariate means  inline image and inline image and  along parallel regression lines to the grand covariate mean inline image. Thus ancova predicts if test score means of CDC–CFS and non-CDC–CFS patients would have been equal if both groups had exactly the same mean number of complaints. It provides an answer to a question that has no relevance – the mean number of complaints is inherently different for these two groups. In particular, Table 1 of the article learns that the grand covariate mean as reported with the standardized questionnaire equals  = 674/88 = 7.66: the adjusted mean  corresponds to a group of CDC–CFS patients that does not even exist in reality!

Figure 1.

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Difference between analysis of variance (anova) and analysis of covariance (ancova).anova compares the treatment means  and , whereas ancova compares the adjusted treatment means  and  corresponding to the same level of the covariate for both groups. Note that the grand covariate mean corresponds to a group of CDC–CFS patients that does not exist in reality.

Although their ancova was inappropriate, the authors’anova did result in valuable information.anova of CDC–CFS versus non-CDC–CFS yielded significant differences (at least P < 0.05) in concentration, activity, sleep and rest, ambulation, alertness behaviour, and recreation and pastimes, which according to the authors means that CDC–CFS patients are significantly more impaired in daily functioning. As the subjective fatigue subscale of the checklist individual strength (CIS-fatigue) easily reaches the extreme end of its scale in CFS samples (see e.g. [9, 10]), it is obvious that no significant differences in fatigue severity as measured by CIS-fatigue could be found. Generally speaking, assessing fatigue severity using a scale without this flaw may well result in different outcomes (see e.g. [10]).

Because the inadequate ancova made it appear that there are no clinical differences between CDC–CFS and non-CDC–CFS patients, this study has often been cited to permit leaving out additional symptom criteria when considering CDC–CFS. This has had major consequences for scientific research as well as for clinical practice. In scientific literature, non-CDC–CFS patients are labelled as having ‘a diagnosis of CFS according to the CDC criteria’ [10] or fulfilling ‘the CDC criteria for CFS’ [11], although other sources by the same authors explicitly state that they do not [12, 13]. In a large randomized study on cognitive behaviour therapy for CFS [14], one of the two reasons that patients without the required number of additional symptoms were included is that ‘patients who fulfilled the CDC-criteria did not differ concerning the severity of the complaints from patients who did not satisfy the CDC criteria’ [13]. The CFS definition used for clinical practice in large parts of the Netherlands [15] is based on CDC criteria, but patients without the required additional symptoms are also diagnosed CFS because ‘clinically this distinction has no meaning, as it has turned out from Dutch research’ [16]. This means that if the mistakes above would have been noted at an earlier stage, literally thousands of chronically fatigued patients might have had a different diagnosis in the Netherlands.

Apparently [13] the incorrect results of the article have also been presented during a recent meeting held for revising the latest CDC–CFS definition (presentation Bleijenberg, CDC consensus meeting, Atlanta 2000). To prevent more scientific research on CDC–CFS that disregards additional symptoms and more CFS definitions that are based on statistical errors rather than on data, it is important that the mistakes in the article are corrected as soon as possible.

You can read the rest of this comment here: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2004.01378.x/full

 

Source: Stouten B. Chronic fatigue syndrome: a clinical and laboratory study with a well-matched control group. J Intern Med. 2004 Sep;256(3):265-7; author reply 268-9. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2004.01378.x/full (Full article)

 

Patient organisations in ME and CFS seek only understanding

Comment on: General practitioners’ perceptions of chronic fatigue syndrome and beliefs about its management, compared with irritable bowel syndrome: qualitative study. [BMJ. 2004]

 

Editor—To compare general practitioners’ attitudes to patients with chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) and those with irritable bowel syndrome was disappointing in the study by Raine et al.1 Particularly disappointing was that the study was conducted in the months after the chief medical officer recognised—with considerable attendant publicity—the severity and impact of chronic fatigue syndrome or myalgic encephalomyelitis on the lives of those affected.2

One outcome of the study was that pressure groups were perceived as influencing clinical encounters, making it harder to legitimise the symptoms. That the authors labelled patients’ organisations “pressure groups” was interesting in itself.

The organisations cover a range of views on the illness and the solutions needed. This organisation carries out an information role for patients and professionals and provides a range of services no different from that of any other medium sized charity (www.afme.org.uk). We campaign vigorously of course for recognition of chronic fatigue syndrome and myalgic encephalomyelitis and for funding to remedy years of neglect in this field.

We are not “antidoctor” and our members mostly view their general practitioners as supportive and understanding but faced with a complex illness and lacking a toolkit to help.

Far from patients’ organisations wishing to politicise the consulting room, we simply ask for a little more understanding, mixed with a little humility and matched with an eagerness to obtain training and information about diagnosis and treatment.

You can read the rest of this comment here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC449878/

 

Source: Clark C. Patient organisations in ME and CFS seek only understanding. BMJ. 2004 Jul 10;329(7457):112-3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC449878/ (Full article)

 

Harmful psychiatrization

Ulrik Fredrik Malt’s response( 1 ) to my post about myalgic encephalomyelitis / chronic fatigue syndrome in the journal no. 9/2004 ( 2 ) and what he calls the ME group, is irrelevant to the core issue. Is the response really an apologia for his own views and practices, a practice that does not conform with practices at other university hospitals? Other universities conform correctly to ICD-10, which classifies myalgic encephalomyelitis / chronic fatigue syndrome as a neurological disorder (diagnostic code G93.3), and have introduced the new clinical criteria ( 3 ). It is not up to individual doctors to classify a disorder in the category that suits them. It is evident that the Malt places himself above ICD-10.

Myalgic encephalomyelitis / chronic fatigue syndrome has more than 30 years been classified as a neurological disorder and will remain so in the upcoming revision of the ICD. The psychiatrization which has been ongoing for many years, has caused major problems for those affected. Patients are ignored, rejected, distrusted, persecuted, mistreated, not taken seriously and suspected of malingering. Contagion and disability are downplayed, and many patients do not get Social Security benefits and assistance on a par with other seriously ill patients. Under the auspices of the US Department of Health a declaration has been adopted which states that “patients have been harmed as a result of disrespect, indifference and ignorance of the medical community” ( 4 ). According to the statement, one must “aggressively embark on disrespect that these patients meet both the general population and the medical community.” It stressed further that there is an urgent need for training of health professionals. In this connection healthcare professionals are advised not to read about myalgic encephalomyelitis / chronic fatigue syndrome in textbooks of psychiatry and instead read other research and literature ( 5 ).

Psychiatrization and trivialization of this suffering must end and textbooks corrected. Health authorities should urgently address this issue as they have done in England.

You can read the rest of this comment here: http://tidsskriftet.no/article/1045776

 

Source: Stormorken E.  Harmful psychiatrization. Tidsskr Nor Laegeforen. 2004 Jul 1;124(13-14):1826-7; author reply 1827. [Article in Norwegian] http://tidsskriftet.no/article/1045776 (Full article)

 

Cost-effectiveness of cognitive behaviour therapy for patients with chronic fatigue syndrome

Comment on: Cost-effectiveness of cognitive behaviour therapy for patients with chronic fatigue syndrome. [QJM. 2004]

 

Sir,

I read Severens et al.’s article on the cost-effectiveness of cognitive behaviour therapy for patients with unexplained chronic fatigue1 with interest, although as several subjects met the CDC criteria for ‘idiopathic chronic fatigue’ rather than ‘chronic fatigue syndrome’,2,,3 I prefer to use the term ‘unexplained chronic fatigue’ as defined by Fukuda et al.3 to describe the patient sample under consideration.

To be able to regard the presented cost estimates as a valid reflection of the medical costs of patients with unexplained chronic fatigue, it is imperative to demonstrate that there are no differences between participants who are included in the analysis and participants who are excluded from the analysis.

According to the authors: ‘An extensive comparison between participants in the cost-effectiveness analyse (n = 171) and the remaining clinical study participants (n = 99) did not reveal any statistically significant differences regarding age, duration of CFS complaints, and scores for Sickness Impact Profile, Karnofsky score, physical activity, a self-efficacy scale, a causal attribution list, and functional impairment.’ (pp. 158–9).

Although details are lacking in the article, baseline data of the included and excluded participants are available from a publication of the Health Care Insurance Board of the Netherlands (College voor zorgverzekeringen).4 Comparing baseline variables of the two groups using two-tailed independent sample t-tests yields the results that are presented in Table 1. The table shows that physical activity (measured by a motion-sensing device called the actometer), self-efficacy, and psychological well-being (measured by the symptom checklist 90) are significantly different at the 0.05 level. The p values for physical activity (p = 0.0081) and self-efficacy (p = 0.0046) are particularly small.

You can read the rest of this comment here: http://qjmed.oxfordjournals.org/content/97/6/379.long

 

Source: Stouten B. Cost-effectiveness of cognitive behaviour therapy for patients with chronic fatigue syndrome. QJM. 2004 Jun;97(6):379-80. http://qjmed.oxfordjournals.org/content/97/6/379.long (Full article)

 

Heresies in textbook on psychiatry

In journal no. 5/2004( 1 ) reported Textbook of Psychiatry by Ulrik Fredrik Malt et al ( 2 ). This book contains erroneous information relating to the description of neurasthenia. The authors classify chronic fatigue syndrome (CFS), post-viral fatigue syndrome (PVFS) and myalgic encephalomyelitis (ME) as neurasthenia, diagnosis code F48.0, and has thus reclassified suffering from a neurological condition to be a psychiatric condition. This was done in Malts first textbook of psychiatry, published in 1994.

WHO has since 1969 classified Thurs the 1st as neurological disease and is not going to change that in the upcoming revision. The English psychiatrists Simon Wessely, Michael Sharpe and their counterparts, often called Wessely School, has spent countless publications in more than a decade trying to to psychiatric ME / CFS, which in part has been internationally condemned.

Leading Norwegian psychiatrists are influenced by Wessely School doctrine, and this doctrine has been continued in Textbook of Psychiatry ( 2 ). In WHO’s Guide to mental health in primary care , which Wessely has helped to develop, is ME / CFS wrongly classified under mental disorders, F48.0. Wrong classification has been debated in the British House several times. WHO were involved and confirmed that ME / CFS should continue to be classified under G93.3 and that no disease can be classified in more than one category. According to ICD-10 is to be post-viral fatigue syndrome specifically excluded before the diagnosis neurasthenia set. Secretary of State for the UK Department of Health, Lord Warner, had in the House of Lords regret their statements in support of Wessely misclassification.

Director of WHO’s Collaborating Centre at King’s College London, Professor Rachel Jenkins has had to bow and accept the WHO’s official position, namely that ME / CFS should be classified under G93.3. The book is stopped and will come in a revised edition. When a country has accepted WHO’s regulations, it is mandatory to follow ICDs classification.

Malt and employee classification of ME / CFS in Textbook of Psychiatry ( 2 ) is contrary to the WHO system. It is highly regrettable that new generations healthcare are taught in heresy by reading the chapter on psychosomatic disorders in this book. In my view, the discussion of ME / CFS is removed, the book withdrawn and come out in a revised edition.

A consensus panel of medical experts has developed new clinical criteria for ME / CFS ( 3 ) These criteria provide a more accurate description of reality.

You can read the full letter here: http://tidsskriftet.no/article/1015463

 

Source: E. Stormorken. Heresies in textbook on psychiatry. Tidsskr Nor Laegeforen. 2004 May 6;124(9):1277; author reply 1277. [Article in Norwegian] http://tidsskriftet.no/article/1015463 (Full article)

 

Chronic fatigue syndrome: an endocrine disease off limits for endocrinologists?

Abstract:

Endocrinologists were not included in the multidisciplinary working groups that prepared two recent reports on chronic fatigue syndrome, despite its unequalled clinical overlap with Addison’s disease, which is a classic endocrine disorder. The failure to include at least one endocrinologist in those panels may explain why in their extensive reports there is not a single word about the 42 clinical features that chronic fatigue syndrome shares with Addison’s disease, including all the signs and symptoms listed in the case definition of this syndrome.

Comment in: Dr Baschetti rides/writes again. [Eur J Clin Invest. 2004]

 

Source: Baschetti R. Chronic fatigue syndrome: an endocrine disease off limits for endocrinologists? Eur J Clin Invest. 2003 Dec;33(12):1029-31. http://www.ncbi.nlm.nih.gov/pubmed/14636284

 

Review: cognitive behavioural interventions may be effective for chronic fatigue syndrome and chronic back pain

Comment on: Systematic review of mental health interventions for patients with common somatic symptoms: can research evidence from secondary care be extrapolated to primary care? [BMJ. 2002]

 

Psychological disorders have a high financial burden with many indirect costs. Behavioural strategies and cognitive behavioural interventions may be effective for a range of mental disorders, including some of the most chronic, severe and costly mental health problems.1 Very few medical professionals are adequately trained to deliver such treatments, however. This article is both timely and important because it emphasises the need to disseminate cognitive behaviour therapies more widely.

Raine et al conducted a thorough review of the efficacy of psychological treatments for common somatic symptoms: chronic fatigue syndrome, irritable bowel syndrome and chronic back pain. The results were consistent with the findings by the American Psychological Association’s Task Force on Promotion and Dissemination of Psychological Procedures:2 cognitive behaviour interventions and behaviour therapy are effective for treating chronic back pain and chronic fatigue syndrome. Raine et al found that treatment effects were stronger in secondary care compared with primary care settings. Furthermore, antidepressants were effective in both settings for treating irritable bowel syndrome.

The review has some limitations. First, as in all secondary analyses, the review is based only on published studies (that are more likely to report positive outcomes). There may also be problems with how interventions were defined and implemented. The majority of studies did not follow a treatment manual and did not measure adherence to the therapy protocol. The distinction between “behaviour therapy” and “cognitive-behaviour therapy” therefore remains elusive. This leaves important questions unanswered about how and why these treatments work (ie the mechanisms and mediators of change).3

You can read the rest of this comment here: http://ebmh.bmj.com/content/6/2/55.long

 

Source: Hofmann SG. Review: cognitive behavioural interventions may be effective for chronic fatigue syndrome and chronic back pain. Evid Based Ment Health. 2003 May;6(2):55. http://ebmh.bmj.com/content/6/2/55.long (Full article)

 

Diverse etiologies for chronic fatigue syndrome

Comment on: Markers of viral infection in monozygotic twins discordant for chronic fatigue syndrome. [Clin Infect Dis. 2002]

 

SIR—Koelle et al.  recently studied 22 pairs of identical twins discordant for chronic fatigue syndrome and concluded that there was no major contribution for viral infections in the perpetuation of chronic fatigue syndrome (CFS). The authors should be commended for their methodology and the use of well-matched control subjects. However, the study raised several issues.

First, similar to previous studies, the approach of Koelle et al.  was to look for statistical differences among the well-matched pairs with respect to the presence of viral antibodies and, more specifically, the presence of DNA of the viruses studied. Although these viruses were no more prevalent among the patients with CFS than among their healthy twins, one cannot conclude that these viruses are not the cause of CFS in a small subset of patients. CFS has been described in a small number of patients who had had well-documented acute Epstein-Barr virus (EBV), cytomegalovirus (CMV), and parvovirus B19 infections, and many of the patients responded to specific antiviral therapy. Of the first 200 patients with CFS who we evaluated for viral etiologies , only ∼10% had etiologies that were attributed to the viruses studied by Koelle et al. Chlamydia pneumoniae infection, an uncommon, although treatable, cause of CFS, was also dismissed in a previous, smaller study .

You can read the rest of this comment here: http://cid.oxfordjournals.org/content/36/5/671.long

 

Source: Chia JK, Chia A. Diverse etiologies for chronic fatigue syndrome. Clin Infect Dis. 2003 Mar 1;36(5):671-2; author reply 672-3. http://cid.oxfordjournals.org/content/36/5/671.long (Full article)

 

Chronic fatigue syndrome/ME

Comment on: Chronic fatigue syndrome/myalgic encephalitis. [Br J Gen Pract. 2002]

 

In previous correspondence,1 I challenged the trivialisation of chronic fatigue syndrome (CFS), and the generalisation and speculation in an editorial on chronic fatigue.2 The authors dismissed my arguments as, in their opinion, I had not demonstrated that I ‘was prepared and able accurately to read and interpret a scientific article’.3 I consider this remark to be unfair and unjustified.

I shall discuss each of their points in turn. First, they denied that by referring to the illness as ‘fatigue or its synonyms’, they were trivialising ‘the suffering of patients with PUPS (persistent unexplained physical symptoms)’. The authors must be aware of the controversy surrounding the word ‘fatigue’. As one affected surgeon wrote: ‘there is nothing in your experience in medical school, residency, or practice with its gruelling hours and sleep deprivation that even approaches the fatigue you feel with this illness. Fatigue is the most pathetically inadequate term’.4 Other writers on the subject recognise this, which is probably why most tend to describe the main symptom as profound, debilitating or disabling fatigue. But this was not the case here. The authors clearly equated CFS with (normal) tiredness and chronic fatigue. Elsewhere, they referred to ‘commonplace symptoms’ and in their response, again wrote about ‘fatigue and its synonyms’

You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314477/pdf/12528593.pdf

 

Source: Goudsmit E. Chronic fatigue syndrome/ME. Br J Gen Pract. 2002 Dec;52(485):1023-4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314477/pdf/12528593.pdf

 

Chronic unexplained fatigue

Comment on: Chronic unexplained fatigue. [Postgrad Med J. 2002]

 

I found the editorial on chronic fatigue syndrome by White both surprising and disappointing, because he used the title “Chronic unexplained fatigue” and the subtitle “A riddle wrapped in a mystery inside an enigma”, but his editorial, by ignoring very important facts about chronic fatigue syndrome, actually perpetuates that riddle, rather than helping to solve it.

If a puzzling and poorly manageable condition shares more than 40 features, including all of its diagnostic criteria, with a well known and easily treatable disease, this astounding clinical overlap should not be ignored, because reason not only suggests that the mysterious illness may simply be a form of the well known disease, but also hints that it is worthwhile assessing whether the classic therapy for that treatable disease could be effective for the enigmatic condition as well.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1757928/pdf/v078p00763a.pdf

 

Source: Baschetti R. Chronic unexplained fatigue. Postgrad Med J. 2002 Dec;78(926):763; author reply 763. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1757928/pdf/v078p00763a.pdf