Category: Case Definition

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

 

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

 

Psychiatric illness in patients with chronic fatigue and those with rheumatoid arthritis

Abstract

OBJECTIVES: To identify psychiatric differences between patients with chronic fatigue and those with rheumatoid arthritis and to investigate whether patients meeting Centers for Disease Control (CDC) criteria for chronic fatigue syndrome (CFS) can be differentiated from patients with chronic fatigue on measures of disability and psychosocial distress.

DESIGN: Cross-sectional study comparing 98 patients with chronic fatigue with 31 patients with rheumatoid arthritis on structured psychiatric interviews and patient questionnaires. Nineteen patients meeting CDC criteria for CFS were compared with 79 patients with chronic fatigue not meeting CDC criteria on questionnaires measuring disability and psychosocial distress.

SETTING: Consecutive patients with chronic fatigue were selected from a chronic fatigue clinic at the University of Washington, and 31 consecutive patients with rheumatoid arthritis were sampled from a private rheumatology practice.

MAIN RESULTS: Patients with chronic fatigue had a significantly higher prevalence of lifetime major depression and somatization disorder than did patients with rheumatoid arthritis. Patients with chronic fatigue also had a significantly higher prevalence of current and lifetime psychiatric diagnoses. Only 19 of 98 patients with chronic fatigue met CDC criteria for CFS. Patients meeting CDC criteria for CFS could not be differentiated from the larger group of patients with chronic fatigue on any study variable.

CONCLUSIONS: Patients with chronic fatigue have a significantly higher burden of psychiatric illness than do patients with rheumatoid arthritis. The psychiatric illness preceded the development of chronic fatigue in over half the patients. Centers for Disease Control criteria for CFS did not select a subset of chronic fatigue patients who could be differentiated on disability or psychosocial parameters from patients with chronic fatigue who did not meet CDC criteria.

Comment in The trouble with chronic fatigue. [J Gen Intern Med. 1991]

 

Source: Katon WJ, Buchwald DS, Simon GE, Russo JE, Mease PJ. Psychiatric illness in patients with chronic fatigue and those with rheumatoid arthritis. J Gen Intern Med. 1991 Jul-Aug;6(4):277-85. http://www.ncbi.nlm.nih.gov/pubmed/1890495

 

A report–chronic fatigue syndrome: guidelines for research

Introduction:

Patients who present with a principal complaint of disabling fatigue of uncertain cause have received much attention in recent years. Correspondingly there has been an increasing amount of research into this problem. The findings have however often been contradictory. Resolution of these contradictions depends on the ability to compare research studies, but such constructive comparison has rarely been possible. This is largely because research has been carried out by investigators trained in different disciplines, using different criteria to define the condition. Whilst such an eclectic approach is to be welcomed, agreement on case definition, and assessment methods is necessary if progress is to be made.

You can read the rest of this article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1293107/pdf/jrsocmed00127-0072.pdf

 

Source: Sharpe MC, Archard LC, Banatvala JE, Borysiewicz LK, Clare AW, David A, Edwards RH, Hawton KE, Lambert HP, Lane RJ, et al. A report–chronic fatigue syndrome: guidelines for research. J R Soc Med. 1991 Feb;84(2):118-21. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1293107/

 

Chronic fatigue syndrome: issues in the diagnosis and estimation of incidence

Abstract:

This article critiques the current working definition of chronic fatigue syndrome. The concerns raised about the current working definition are the following: prolonged or excessive exertion is not addressed explicitly; duration and quality of bed rest are not specified; a socioeconomic ascertainment bias is present; data from history and physical findings are not clearly separated and are relegated to minor criteria; and the rigor of neurologic and psychiatric evaluations is not specified.

We propose a flow chart that addresses the possible modes of evolution of chronic fatigue syndrome for patients; this chart may yield more homogeneous subgroups of individuals with this syndrome or enable some patients to avert the syndrome.

 

Source: Armon C, Kurland LT. Chronic fatigue syndrome: issues in the diagnosis and estimation of incidence. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S68-72. http://www.ncbi.nlm.nih.gov/pubmed/2020804

 

Defining the chronic fatigue syndrome

Abstract:

The recently published working definition of the chronic fatigue syndrome (CFS) is a necessary first step toward a consistent effort to research this controversial illness. Before this definition was developed, cases often were defined vaguely, according to the perceptions and biases of the individual researchers, so that the results of some studies were unclear. However, few specific diagnostic parameters for CFS exist, and the new definition may not delineate a single clinicopathologic entity.

Future efforts at researching this illness should be aimed at identifying parameters that differentiate CFS from psychiatric conditions such as major depression and from other defined chronic diseases. Because CFS may be the result of multiple disease processes, the separate study of well-defined subgroups of patients with CFS is appropriate.

Such subgroups of patients are probably more likely to have common pathogenetic features than are patients with CFS as a whole group.

 

Source: Holmes GP. Defining the chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S53-5. http://www.ncbi.nlm.nih.gov/pubmed/2020802

 

The chronic fatigue syndrome (myalgic encephalomyelitis)–myth or mystery?

Abstract:

The chronic fatigue syndrome (CFS) or myalgic encephalomyelitis has caused great confusion, misunderstanding and perhaps even mismanagement of many persons presenting with a variety of combinations of ill-defined complaints. The history, possible pathogenesis and clinical features, of what is probably in most instances a post-viral infection syndrome, are reviewed. The recent Centers for Disease Control case definition is summarised and simplified. The need for such uniformity of definition, acceptable to most workers in the field, is emphasised in order to facilitate further studies into the cause, diagnosis, course and treatment of CFS. The difficulty in treating this condition and the currently recommended management are described. Double-blind controlled studies are essential in assessing any proposed new treatment.

 

Source: Spracklen FH. The chronic fatigue syndrome (myalgic encephalomyelitis)–myth or mystery? S Afr Med J. 1988 Nov 5;74(9):448-52. http://www.ncbi.nlm.nih.gov/pubmed/3055363

 

Chronic fatigue syndrome: a working case definition

Abstract:

The chronic Epstein-Barr virus syndrome is a poorly defined symptom complex characterized primarily by chronic or recurrent debilitating fatigue and various combinations of other symptoms, including sore throat, lymph node pain and tenderness, headache, myalgia, and arthralgias.

Although the syndrome has received recent attention, and has been diagnosed in many patients, the chronic Epstein-Barr virus syndrome has not been defined consistently. Despite the name of the syndrome, both the diagnostic value of Epstein-Barr virus serologic tests and the proposed causal relationship between Epstein-Barr virus infection and patients who have been diagnosed with the chronic Epstein-Barr virus syndrome remain doubtful.

We propose a new name for the chronic Epstein-Barr virus syndrome–the chronic fatigue syndrome–that more accurately describes this symptom complex as a syndrome of unknown cause characterized primarily by chronic fatigue. We also present a working definition for the chronic fatigue syndrome designed to improve the comparability and reproducibility of clinical research and epidemiologic studies, and to provide a rational basis for evaluating patients who have chronic fatigue of undetermined cause.

 

Source: Holmes GP, Kaplan JE, Gantz NM, Komaroff AL, Schonberger LB, Straus SE, Jones JF, Dubois RE, Cunningham-Rundles C, Pahwa S, et al. Chronic fatigue syndrome: a working case definition. Ann Intern Med. 1988 Mar;108(3):387-9. http://www.ncbi.nlm.nih.gov/pubmed/2829679