Estimating the prevalence of chronic fatigue syndrome and associated symptoms in the community

Abstract:

Chronic fatigue syndrome is a poorly understood disease characterized by debilitating fatigue and neuromuscular and neuropsychological symptoms. Despite numerous studies on the subject, the epidemiology of the syndrome in the community remains largely unexplored.

An estimate of the prevalence in the population is presented, approximating the Centers for Disease Control criteria as well as the prevalence estimates of the fatigue symptom complex that include fatigue, disability, and neuromuscular and neuropsychological symptoms. The study population consisted of a very large, multicenter, stratified, and random sample of a general population health survey known as the Epidemiologic Catchment Area Program.

Data used for this study were gathered between 1981 and 1984. The Diagnostic Interview Schedule, a highly structured mental health interview, was used to assess the lifetime prevalence of medical and psychological symptoms. Chronic fatigue was common.

A total of 23 percent of the subjects reported having experienced the symptom of persistent fatigue sometime during their lives. Chronic fatigue syndrome, however, as defined by the Centers for Disease Control, appeared to be quite rare in the general population. Only 1 of 13,538 people examined was found to meet a diagnosis of the syndrome with an approximation of the CDC criteria. Fatigue symptom complex was frequently related to medical or psychiatric illness or substance abuse; thus, persons meeting partial criteria of chronic fatigue syndrome were also found to be rare when psychiatric or medical exclusions were applied.

 

Comment in: Taking exception to chronic fatigue syndrome prevalence findings by Price, et al. [Public Health Rep. 1993]

 

Source: Price RK, North CS, Wessely S, Fraser VJ. Estimating the prevalence of chronic fatigue syndrome and associated symptoms in the community. Public Health Rep. 1992 Sep-Oct;107(5):514-22. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1403692/ (Full article)

 

Alleged link between hepatitis B vaccine and chronic fatigue syndrome

I thought it fitting that Mr. Andrew House’s letter “Alleged link between  and chronic fatigue syndrome” saw the light of day in your Apr. 1 issue (page 1145), sharing space with “Psychopharmacology of lycanthropy.”

It was an appropriate debut for a letter that unblushingly ridiculed sick human beings. The disparaging tone and point of view reminded me of the way psychiatric patients used to be discussed in the bad old days.

You can read the full comment as well as the author’s reply here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1336231/pdf/cmaj00257-0021c.pdf

 

Source: O’Sullivan SJ. Alleged link between hepatitis B vaccine and chronic fatigue syndrome. CMAJ. 1992 Aug 15;147(4):399, 402. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1336231/

 

NIH conference. Chronic fatigue syndrome research. Definition and medical outcome assessment

Abstract:

A workshop was held 18 to 19 March 1991 at the National Institutes of Health to address critical issues in research concerning the chronic fatigue syndrome (CFS). Case definition, confounding diagnoses, and medical outcome assessment by laboratory and other means were considered from the perspectives of key medical specialties involved in CFS research.

It was recommended that published Centers for Disease Control (CDC) case-definition criteria be modified to exclude fewer patients from analysis because of a history of psychiatric disorder. Specific recommendations were made concerning the inclusion or exclusion of other major confounding diagnoses, and a standard panel of laboratory tests was specified for initial patient evaluation.

The workshop emphasized the importance of recognizing other conditions that could explain the patient’s symptoms and that may be treatable. It was viewed as essential for the investigator to screen for psychiatric disorder using a combination of self-report instruments followed by at least one structured interview to identify patients who should be excluded from studies or considered as a separate subgroup in data analysis.

Because CFS is not a homogeneous abnormality and because there is no single pathogenic mechanism, research progress may depend upon delineation of these and other patient subgroups for separate data analysis. Despite preliminary data, no physical finding or laboratory test was deemed confirmatory of the diagnosis of CFS.

For assessment of clinical status, investigators must rely on the use of standardized instruments for patient self-reporting of fatigue, mood disturbance, functional status, sleep disorder, global well-being, and pain. Further research is needed to develop better instruments for quantifying these domains in patients with CFS.

 

Source: Schluederberg A, Straus SE, Peterson P, Blumenthal S, Komaroff AL, Spring SB, Landay A, Buchwald D. NIH conference. Chronic fatigue syndrome research. Definition and medical outcome assessment. Ann Intern Med. 1992 Aug 15;117(4):325-31. http://www.ncbi.nlm.nih.gov/pubmed/1322076

 

Outcome in the chronic fatigue syndrome

Comment in: Self help organization’s advice on myalgic encephalomyelitis. [BMJ. 1992]

Comment on: Follow up of patients presenting with fatigue to an infectious diseases clinic. [BMJ. 1992]

 

EDITOR,-Michael Sharpe and colleagues’ paper confirms what many clinicians have long suspected -namely, that the prognosis for those with a chronic fatigue syndrome who reach specialist care is poor.’ The paper also suggests that membership of a self help organisation is associated with a poor outcome. Although the authors emphasise that this association is not necessarily causal, I fear that the self help organisations may interpret this as another attack on their credibility, which will further sour relations between the organisations and the profession.

What are the possible explanations for these disturbing findings? Sharpe and colleagues suggest that patients’ beliefs are an important mediator of disability, a view I share.2 An article written by a sufferer illustrates how this might happen: “These living viruses are erratic and unpredictable. The prickly-edged ones pierce their way into the body cells. If disturbed by the patient’s activity they become as aggressive as a disturbed wasps’ nest, and can be felt giving needle-like jabs (or stimulating the nerves to do so).” It is easy to understand how such beliefs, regardless of their scientific accuracy, amplify disability.

You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882994/pdf/bmj00086-0047b.pdf

 

Source: Wessely S. Outcome in the chronic fatigue syndrome. BMJ. 1992 Aug 8;305(6849):365. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882994/

 

Outcome in the chronic fatigue syndrome

Comment on: Follow up of patients presenting with fatigue to an infectious diseases clinic. [BMJ. 1992]

 

EDITOR,-Michael Sharpe and colleagues’ follow up study of 177 patients with chronic fatigue of uncertain origin raises several important unanswered questions, which require further investigation. Factors such as a belief that their illness followed an infection, intolerance to alcohol, and membership of a support group for patients with myalgic encephalomyelitis were all associated with an adverse prognosis. Could it be that the authors had identified patients belonging to a distinct postinfectious subgroup as many doctors maintain they do? Clearly, if this is the case future studies of this nature will have to include more objective analysis of persisting viral infection (for example, analysis of muscle biopsy specimens with the polymerase chain reaction rather than tests for VP1 antigen); immune function (for example, function of natural killer cells rather than white cell counts); and hypothalamic-pituitary-axis activity (for example, up regulation of serotonin- I receptors and basal cortisol concentrations) to see if there are characteristic abnormalities that distinguish the postinfectious subgroup.

The high incidence of intolerance to alcohol is noted as intriguing, but from personal experience, as well as from seeing many patients with a classic postinfectious fatigue syndrome, I regard this observation as an important diagnostic feature. In these patients even small amounts of alcohol cause a further deterioration in cognitive function, and I suggest that a physiological explanation may lie in the fact that alcohol increases the concentration of the neurotransmitter y-aminobutyric acid, which in turn reduces the availability of calcium ions and hence depresses brain function still further.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1883001/pdf/bmj00086-0047c.pdf

 

Source: Shepherd C. Outcome in the chronic fatigue syndrome. BMJ. 1992 Aug 8;305(6849):365. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1883001/

 

Outcome in the chronic fatigue syndrome

Comment on: Follow up of patients presenting with fatigue to an infectious diseases clinic. [BMJ. 1992]

 

EDITOR,-Michael Sharpe and colleagues report that most patients with the chronic fatigue syndrome rate contact with medical services as unhelpful or only slightly helpful. Many sufferers turn to alternative health care, again with varied success. Such dissatisfaction with medical care is well documented, and self help organisations flourish to provide the support, advice, and education that is not, or cannot be, provided by the medical profession; they potentially fulfil an important role.

The authors conclude that for patients with the chronic fatigue syndrome membership of a self help organisation is associated with a poorer outcome (although whether members were more functionally impaired at the outset is not known). Adopting coping strategies, particularly with regard to exercise and “stress,” and a belief in the persistence of a viral infection are also associated with continuing disability.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1883006/pdf/bmj00086-0047d.pdf

 

Source: Cope H, David AS. Outcome in the chronic fatigue syndrome. BMJ. 1992 Aug 8;305(6849):365. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1883006/

 

Immunologically mediated fatigue: a murine model

Abstract:

Chronic fatigue syndrome (CFS) is an idiopathic disorder in which the chief symptoms is profound fatigue. To explore the relationship between immune stimulation and fatigue, we developed a murine model for quantifying fatigue: reduction in voluntary running and delayed initiation of grooming after swimming.

Inoculation of female BALB/c mice with Corynebacterium parvum antigen or the relatively avirulent Me49 strain of Toxoplasma gondii induced fatigue: baseline running reduced to less than 50 and 30% for 8 and 14 days, respectively, and delayed initiation of grooming after swimming in both immunologically stimulated groups.

A threefold evaluation of serum transforming growth factor-beta levels, a cytokine increased in CFS patients, was found in fatigued C. parvum- and T. gondii-inoculated mice. This murine model appears promising for investigation of the pathogenesis of immunologically mediated fatigue.

 

Source: Chao CC, DeLaHunt M, Hu S, Close K, Peterson PK. Immunologically mediated fatigue: a murine model. Clin Immunol Immunopathol. 1992 Aug;64(2):161-5. http://www.ncbi.nlm.nih.gov/pubmed/1643746

 

Chronic fatigue syndrome criteria. A critique of the requirement for multiple physical complaints

Abstract:

OBJECTIVE: The purpose of this study was to test the hypothesis that the patients with chronic fatigue who have the highest number of medically unexplained physical symptoms over their lifetime would also have the highest prevalence of current and lifetime affective and anxiety disorders, lifetime affective symptoms, and the most functional disability. A further goal was to use this information to modify the current case definition to better identify a subgroup of patients with chronic fatigue syndrome who are less likely to have psychiatric illness.

DESIGN: Two hundred eighty-five consecutive patients with chronic fatigue were interviewed with the National Institute of Mental Health Diagnostic Interview Schedule and completed four self-rating questionnaires measuring psychologic distress, functional disability, and the tendency to amplify symptoms. Based on previously published data, patients were divided into four groups with a progressively higher number of lifetime medically unexplained physical symptoms. The prevalence of current and lifetime psychiatric disorders, lifetime psychologic symptoms, and extent of functional impairment was then compared in these four groups of patients.

MAIN RESULTS: The prevalence of current and lifetime psychiatric diagnosis and lifetime depressive symptoms increased linearly with the number of lifetime physical symptoms that the patient experienced. The extent of impairment in activities of daily living and the tendency to amplify symptoms also increased linearly with the number of medically unexplained physical symptoms.

CONCLUSION: The patients with the highest numbers of medically unexplained physical symptoms had extraordinarily high rates of current and lifetime psychiatric disorders. These data suggest that the current case definition for chronic fatigue syndrome inadvertently selects for patients with the highest prevalence of lifetime psychiatric diagnoses. A recommendation based on these results is to modify the case criteria for chronic fatigue syndrome to include patients with fatigue and few physical symptoms and to identify and consider excluding patients with high numbers of physical complaints.

Comment in: Defining the chronic fatigue syndrome. [Arch Intern Med. 1992]

 

Source: Katon W, Russo J. Chronic fatigue syndrome criteria. A critique of the requirement for multiple physical complaints. Arch Intern Med. 1992 Aug;152(8):1604-9. http://www.ncbi.nlm.nih.gov/pubmed/1497394

 

The chronic fatigue syndrome

Introduction

Waging war requires ….. energy, which in the end, depletes the operator and concerns the relationship between energy and stress. When the operators are human beings, it may happen that a stage is reached such that the demands being made exceed their resources to cope ….. the symptoms of such resultant stress have been given a variety of labels – shellshock, lack of moral fibre, twitch, war neurosis, battle fatigue and now post-traumatic stress disorder ……’. This is a paraphrased account of Norman Dixon’s penetrating assessment of post-Gulf War battle stress in The Times Saturday Review of the 26 January 1991. It would apply equally to the chronic fatigue syndrome (CFS), which also has a variety of labels including the post-viral fatigue syndrome, myalgic encephalomyelitis, Royal Free disease, fibromyalgia, epidemic neuromyaesthenia, yuppy ‘flu disease, chronic Epstein-Barr virus syndrome and Iceland disease. The major clinical feature is of incapacitating fatigue, often accompanied by widespread myalgia and low-spiritedness.

You can read the rest if this article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2399560/pdf/postmedj00068-0012.pdf

 

Source: James DG1, Brook MG, Bannister BA. The chronic fatigue syndrome. Postgrad Med J. 1992 Aug;68(802):611-4. http://www.ncbi.nlm.nih.gov/pubmed/1448399

 

Clinical, epidemiologic, and virologic studies in four clusters of the chronic fatigue syndrome

Abstract:

BACKGROUND: The purpose of this study is to provide a case definition of chronic fatigue syndrome in an outbreak occurring in the Nevada-California region to evaluate candidate etiologic agents and observe the natural history of the illness.

METHODS: Patients diagnosed as having chronic fatigue syndrome were studied by repeated interviews, questionnaires, and blood collection over a 3-year period. Serum samples were tested for antibodies to Epstein-Barr virus, human herpesvirus-6, and human T-lymphotropic viruses I and II. Leukocytes from typical cases were also assayed for human T-lymphotropic viruses I and II.

RESULTS: Cases were defined as persons who had: (1) severe persistent fatigue following an acute illness appearing in an individual with no previous physical or psychological symptoms; (2) presenting signs and symptoms of an acute infection; (3) severe and persistent headache and/or myalgias; and (4) abrupt change in cognitive function or the appearance of a new mood disorder. After 3 years of follow-up, almost all study subjects were able to return to pre-illness activity. None of the viruses evaluated–human T-lymphotropic viruses I and II, Epstein-Barr virus, or human herpesvirus-6–could be etiologically linked to these outbreaks.

CONCLUSION: Clinical features of outbreaks of chronic fatigue syndrome differ sufficiently to suggest different etiologic agents. Giardiasis appears to have precipitated one of the four clusters in this study but the cause(s) of the other three outbreaks is as yet uncertain. The overall prognosis ofchronic fatigue syndrome is usually favorable.

Comment in: Human herpesvirus type 6 and chronic fatigue syndrome. [Arch Intern Med. 1993]

 

Source: Levine PH, Jacobson S, Pocinki AG, Cheney P, Peterson D, Connelly RR, Weil R, Robinson SM, Ablashi DV, Salahuddin SZ, et al. Clinical, epidemiologic, and virologic studies in four clusters of the chronic fatigue syndrome. Arch Intern Med. 1992 Aug;152(8):1611-6. http://www.ncbi.nlm.nih.gov/pubmed/1323246