Category: Case Definition

A critical analysis of the proposal of the Institute of Medicine to replace myalgic encephalomyelitis and chronic fatigue syndrome by a new diagnostic entity called systemic exertion intolerance disease

Abstract:

The Institute of Medicine (IOM) recently published their report in response to an assignment “to define diagnostic criteria for Myalgic Encephalomyelitis (ME)/chronic fatigue syndrome (CFS), to propose a process for reevaluation of these criteria in the future, and to consider whether a new name for this disease is warranted”.

The basic pre-assumption of the IOM committee for the development of evidence-based diagnostic criteria for ME/CFS was that ME and CFS denote conditions with similar symptoms, hence ME/CFS. The IOM committee recommends: (1) that ME/CFS will be renamed ‘systemic exertion intolerance disease’ (SEID); and that a new code should be assigned to SEID in the International Classification of Diseases (ICD), replacing the existing codes for ME (a neurological disease: G93.3) and CFS (‘signs, symptoms, and abnormal clinical and laboratory findings, not elsewhere classified’: R53.82); (2) that a diagnosis of SEID should be made if the new diagnostic criteria are met; (3) that the Department of Health and Human Services develops a toolkit appropriate for screening and diagnosing patients; and (4) that a multidisciplinary group re-examines the new diagnostic criteria when necessary.

This editorial reviews the working procedure of the IOM and two of the outcomes: the recommendation to introduce a new clinical entity (SEID) and new diagnostic criteria. Based upon the contents of the report, and the arguments of the IOM, a search of PubMed and the archive of the Journal of Chronic Fatigue Syndrome using the search terms ME (and old synonyms) and CFS, and a search of PubMed related to the five core symptoms of SEID was conducted.

Reviewing the working method and the recommendations, it is concluded that the new diagnostic criteria for SEID are based upon important methodological shortcomings and that the introduction of SEID to replace both ME and CFS has several profound negative consequences outweighing the advantages.

 

Source: Twisk FN. A critical analysis of the proposal of the Institute of Medicine to replace myalgic encephalomyelitis and chronic fatigue syndrome by a new diagnostic entity called systemic exertion intolerance disease. Curr Med Res Opin. 2015;31(7):1333-47. doi: 10.1185/03007995.2015.1045472. Epub 2015 May 29. https://www.ncbi.nlm.nih.gov/pubmed/25912615 (Full article)

 

Study findings challenge the content validity of the Canadian Consensus Criteria for adolescent chronic fatigue syndrome

Abstract:

AIM: The 2003 Canadian Consensus Criteria for chronic fatigue syndrome (CFS) are often assumed to suggest low-grade systemic inflammation, but have never been formally validated. This study explored the content validity of the Criteria in a sample of adolescents with CFS selected according to a wide case definition.

METHODS: A total of 120 patients with CFS with a mean age of 15.4 years (range 12-18 years) included in the NorCAPITAL project were post hoc subgrouped according to the Canadian Consensus Criteria. Those who satisfied the criteria (Criteria positive) and those who did not (Criteria negative) were compared across a wide range of disease markers and markers of prognosis.

RESULTS: A total of 46 patients were classified as Criteria positive, 69 were classified as Criteria negative, and five could not be classified. All disease markers were equal across the two groups, except the digit span backward test of cognitive function, which showed poorer performance in the Criteria-positive group. Also, the prognosis over a 30-week period was equal between the groups.

CONCLUSION: This study questions the content validity of the Canadian Consensus Criteria, as few differences were found between adolescent patients with CFS who did and did not satisfy the Criteria.

©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

 

Source: Asprusten TT, Fagermoen E, Sulheim D, Skovlund E, Sørensen Ø, Mollnes TE, Wyller VB. Study findings challenge the content validity of the Canadian Consensus Criteria for adolescent chronic fatigue syndrome. Acta Paediatr. 2015 May;104(5):498-503. doi: 10.1111/apa.12950. Epub 2015 Mar 23. https://www.ncbi.nlm.nih.gov/pubmed/25640602

 

Chronic fatigue syndrome versus sudden onset myalgic encephalomyelitis

Abstract:

A revised sudden onset case definition for Myalgic Encephalomyelitis (ME) has been developed (Jason, Damrongvachiraphan, et al., 2012 ) based on past case definitions. In a prior study, Jason, Brown, and colleagues ( 2012 ) compared patients recruited using the 1994 case definition of chronic fatigue syndrome (CFS) to contrast those meeting criteria for the revised ME criteria.

They found that this revised ME case definition identified patients with more functional impairments and physical, mental, and cognitive problems than those meeting the CFS criteria. The study by Jason, Brown, et al. ( 2012 ) only selected individuals who first met the CFS criteria, and it only relied on one Chicago-based data set. The current study replicated this comparison with two distinct data sets with different case ascertainment methods. Results indicate that the ME criteria identified a group of patients with more functional disabilities as well as more severe post-exertional malaise symptoms.

 

Source: Jason LA, Evans M, Brown A, Sunnquist M, Newton JL. Chronic fatigue syndrome versus sudden onset myalgic encephalomyelitis. J Prev Interv Community. 2015;43(1):62-77. doi: 10.1080/10852352.2014.973233. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295655/ (Full article)

 

Complications in operationalizing lifelong fatigue as an exclusionary criterion

Abstract:

The case definitions for chronic fatigue syndrome (CFS) and chronic fatigue syndrome/Myalgic Encephalomyelitis (ME) stipulate that the experience of lifelong fatigue is an exclusionary criterion (Carruthers et al., 2003 ; Fukuda et al., 1994 ). This article examines the lifelong fatigue construct and identifies potential validity and reliability issues in using lifelong fatigue as an exclusionary condition.

Participants in the current study completed the DePaul Symptom Questionnaire (Jason et al., 2010 ), and responses were examined to determine if they had experienced lifelong fatigue. This article discusses the extensive process that was needed to confidently discern which participants had or did not have lifelong fatigue. Using the most rigorous standards, few individuals were classified as having lifelong fatigue. In addition, those with and without lifelong fatigue had few significant differences in symptoms and functional areas. This article concludes with a recommendation that lifelong fatigue should no longer be used as an exclusionary criterion for CFS or ME/CFS.

 

Source: Sunnquist M, Jason LA, Brown A, Evans M, Berman A. Complications in operationalizing lifelong fatigue as an exclusionary criterion. J Prev Interv Community. 2015;43(1):42-53. doi: 10.1080/10852352.2014.973238. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295633/ (Full article)

 

Measuring substantial reductions in activity

Abstract:

The case definitions for Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), ME, and CFS each include a disability criterion requiring substantial reductions in activity in order to meet diagnostic criteria. Difficulties have been encountered in defining and operationalizing the substantial reduction disability criterion within these various illness definitions.

The present study sought to relate measures of past and current activities in several domains including the SF-36, an objective measure of activity (e.g., actigraphy), a self-reported quality of life scale, and measures of symptom severity.

Results of the study revealed that current work activities had the highest number of significant associations with domains such as the SF-36 subscales, actigraphy, and symptom scores. As an example, higher self-reported levels of current work activity were associated with better health. This suggests that current work related activities may provide a useful domain for helping operationalize the construct of substantial reductions in activity.

 

Source: Schafer C, Evans M, Jason LA, So S, Brown A. Measuring substantial reductions in activity. J Prev Interv Community. 2015;43(1):5-19. doi: 10.1080/10852352.2014.973242. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295629/ (Full article)

 

Examining the Institute of Medicine’s Recommendations Regarding Chronic Fatigue Syndrome: Clinical Versus Research Criteria

Abstract:

The Institute of Medicine (2015) has proposed a new clinical case definition for what had been known as chronic fatigue syndrome (CFS). This new criteria involved the following domains: substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities; post-exertional malaise; unrefreshing sleep; and at least one of the two following symptoms: cognitive impairment or orthostatic intolerance.

In addition, in August of 2015, the CFS Advisory Committee, which makes recommendations to the Secretary of US Department of Health and Human Services, proposed that the Canadian 2003 criteria should serve as the research case for CFS. Up to now, there have not been any published investigations comparing these clinical and research criteria.

Using patient samples collected in the United States, Great Britain, and Norway, the current study compared and contrasted patients who met the clinical and research criteria. Overall findings indicated that those meeting the research criteria in comparison to those meeting the clinical criteria were significantly more impaired on a wide variety of symptoms and functional areas. The implications of these findings are discussed.

 

Source: Jason LA, McManimen S, Sunnquist M, Brown A, Newton JL, Strand EB. Examining the Institute of Medicine’s Recommendations Regarding Chronic Fatigue Syndrome: Clinical Versus Research Criteria. J Neurol Psychol. 2015;2015(Suppl 2). pii: http://www.avensonline.org/wp-content/uploads/JNP-2332-3469-S2-0002.pdf. Epub 2015 Nov 25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5008852/ (Full article)

 

Variability in Symptoms Complicates Utility of Case Definitions

Abstract:

BACKGROUND: Ambiguities in case definitions have created difficulties in replicating findings and estimating the prevalence rates for chronic fatigue syndrome (CFS) and Myalgic Encephalomyelitis (ME).

PURPOSE: The current study examined differences in occurrence rates for CFS and ME cardinal symptoms (i.e. post-exertional malaise, unrefreshing sleep, and neurocognitive deficits).

RESULTS: Findings indicated that there is a wide range of occurrence rates on critical symptoms of the case definition, suggesting that either the types of patients recruited differ in various settings or the questions assessing core symptoms vary in their wording or criteria among different researchers.

CONCLUSIONS: The polythetic nature of the case definition may contribute to the wide ranges of symptom occurrence that was found. In order to increase assessed reliability of the symptoms and case definitions, there is a need to better standardize data collection methods and operationalization of symptoms. This solution would reduce the heterogeneity often seen in populations of CFS patients.

 

Source: McManimen SL, Jason LA, Williams YJ. Variability in Symptoms Complicates Utility of Case Definitions. Fatigue. 2015;3(3):164-172. Epub 2015 May 12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831632/ (Full article)

 

What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia

Abstract:

The current study had two objectives. (1) to compare objective and self-report measures in patients with chronic fatigue syndrome (CFS) according to the 1994 Center for Disease Control (CDC) criteria, patients with multiple sclerosis (MS), and healthy controls, and (2) to contrast CFS patients who only fulfill CDC criteria to those who also fulfill the criteria for myalgic encephalomyelitis (ME), the 2003 Canadian criteria for ME/CFS, or the comorbid diagnosis of fibromyalgia (FM).

One hundred six participants (48 CFS patients diagnosed following the 1994 CDC criteria, 19 MS patients, and 39 healthy controls) completed questionnaires assessing symptom severity, quality of life, daily functioning, and psychological factors. Objective measures consisted of activity monitoring, evaluation of maximal voluntary contraction and muscle recovery, and cognitive performance. CFS patients were screened whether they also fulfilled ME criteria, the Canadian criteria, and the diagnosis of FM.

CFS patients scored higher on symptom severity, lower on quality of life, and higher on depression and kinesiophobia and worse on MVC, muscle recovery, and cognitive performance compared to the MS patients and the healthy subjects. Daily activity levels were also lower compared to healthy subjects. Only one difference was found between those fulfilling the ME criteria and those who did not regarding the degree of kinesiophobia (lower in ME), while comorbidity for FM significantly increased the symptom burden.

CFS patients report more severe symptoms and are more disabled compared to MS patients and healthy controls. Based on the present study, fulfillment of the ME or Canadian criteria did not seem to give a clinically different picture, whereas a diagnosis of comorbid FM selected symptomatically worse and more disabled patients.

 

Source: Meeus M, Ickmans K, Struyf F, Kos D, Lambrecht L, Willekens B, Cras P, Nijs J. What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia. Clin Rheumatol. 2016 Jan;35(1):191-203. doi: 10.1007/s10067-014-2793-x. Epub 2014 Oct 14. https://www.ncbi.nlm.nih.gov/pubmed/25308475

 

A comparison of health status in patients meeting alternative definitions for chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

BACKGROUND: Several diagnostic definitions are available for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) that varies significantly in their symptom criteria. This pilot study was conducted to determine whether simple biological and clinical measures differed between CFS/ME patients meeting the 1994 Centres for Disease Control and Prevention (CDC) criteria, the International Consensus Criteria (ICC), as well as healthy controls.

METHODS: A total of 45 CFS/ME patients and 30 healthy controls from the South East Queensland region of Australia provided a blood sample, reported on their current symptoms, as well as aspects of their physical and social health using the Short-Form Health Survey (SF-36), and the World Health Organisation Disability Adjustment Schedule 2.0 (WHO DAS 2.0). Differences were examined using independent sample t-testing.

RESULTS: Patients fulfilling the ICC definition reported significantly lower scores (p < 0.05) for physical functioning, physical role, bodily pain, and social functioning than those that only fulfilled the 1994 CDC definition. ICC patients reported significantly greater (p < 0.05) disability across all domains of the WHO DAS 2.0.

CONCLUSIONS: These preliminary findings suggest that the ICC identifies a distinct subgroup found within patients complying with the 1994 CDC definition, with more severe impairment to their physical and social functioning.

 

Source: Johnston SC, Brenu EW, Hardcastle SL, Huth TK, Staines DR, Marshall-Gradisnik SM. A comparison of health status in patients meeting alternative definitions for chronic fatigue syndrome/myalgic encephalomyelitis. Health Qual Life Outcomes. 2014 Apr 30;12:64. doi: 10.1186/1477-7525-12-64. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008489/ (Full article)

 

The status of and future research into Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: the need of accurate diagnosis, objective assessment, and acknowledging biological and clinical subgroups

Abstract:

Although Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS) are used interchangeably, the diagnostic criteria define two distinct clinical entities. Cognitive impairment, (muscle) weakness, circulatory disturbances, marked variability of symptoms, and, above all, post-exertional malaise: a long-lasting increase of symptoms after a minor exertion, are distinctive symptoms of ME. This latter phenomenon separates ME, a neuro-immune illness, from chronic fatigue (syndrome), other disorders and deconditioning.

The introduction of the label, but more importantly the diagnostic criteria for CFS have generated much confusion, mostly because chronic fatigue is a subjective and ambiguous notion. CFS was redefined in 1994 into unexplained (persistent or relapsing) chronic fatigue, accompanied by at least four out of eight symptoms, e.g., headaches and unrefreshing sleep. Most of the research into ME and/or CFS in the last decades was based upon the multivalent CFS criteria, which define a heterogeneous patient group.

Due to the fact that fatigue and other symptoms are non-discriminative, subjective experiences, research has been hampered. Various authors have questioned the physiological nature of the symptoms and qualified ME/CFS as somatization. However, various typical symptoms can be assessed objectively using standardized methods. Despite subjective and unclear criteria and measures, research has observed specific abnormalities in ME/CFS repetitively, e.g., immunological abnormalities, oxidative and nitrosative stress, neurological anomalies, circulatory deficits and mitochondrial dysfunction.

However, to improve future research standards and patient care, it is crucial that patients with post-exertional malaise (ME) and patients without this odd phenomenon are acknowledged as separate clinical entities that the diagnosis of ME and CFS in research and clinical practice is based upon accurate criteria and an objective assessment of characteristic symptoms, as much as possible that well-defined clinical and biological subgroups of ME and CFS patients are investigated in more detail, and that patients are monitored before, during and after interventions with objective measures and biomarkers.

 

Source: Twisk FN. The status of and future research into Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: the need of accurate diagnosis, objective assessment, and acknowledging biological and clinical subgroups. Front Physiol. 2014 Mar 27;5:109. doi: 10.3389/fphys.2014.00109. eCollection 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3974331/ (Full article)