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National Collaborating Centre for Primary Care (UK). Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (or Encephalopathy): Diagnosis and Management of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (or Encephalopathy) in Adults and Children [Internet]. London: Royal College of General Practitioners (UK); 2007 Aug. (NICE Clinical Guidelines, No. 53.)

Cover of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (or Encephalopathy)

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (or Encephalopathy): Diagnosis and Management of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (or Encephalopathy) in Adults and Children [Internet].

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1Introduction to chronic fatigue syndrome/myalgic encephalomyelitis (or encephalopathy)

1.1. Introduction

Chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (or encephalopathy) (ME) is a relatively common illness. The physical symptoms can be as disabling as multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, congestive heart failure and other chronic conditions. CFS/ME places a substantial burden on people with the condition, their families and carers, and hence on society.

Many different potential aetiologies for CFS/ME – including neurological, endocrine, immunological, genetic, psychiatric and infectious – have been investigated, but the diverse nature of the symptoms can not yet be fully explained. The World Health Organization (WHO) classifies CFS/ME as a neurological illness (G93.3), and some members of the Guideline Development Group (GDG) felt that, until research further identifies its aetiology and pathogenesis, the guideline should recognise this classification. Others felt that to do so did not reflect the nature of the illness, and risked restricting research into the causes, mechanisms and future treatments for CFS/ME.

In 1998, the Chief Medical Officer for England convened an Independent Working Group which reported in 2002.4 In the report, the Working Group stated that CFS/ME is a genuine illness, and that health and social care professionals should therefore recognise it as such. The CMO working group called for a consensus to be reached on terminology and definition, and while awaiting this, suggested that the composite term CFS/ME is used and that it is considered as one condition or a spectrum of disease for the purpose of the report. This is the approach also adopted in this guideline. As a result of the report,4 the Medical Research Council was commissioned to develop a research strategy, and has made research on CFS/ME a priority.

1.2. Clinical need for the guideline

CFS/ME comprises a range of symptoms that includes fatigue, malaise, headaches, sleep disturbances, difficulties with concentration and muscle pain. A person’s symptoms may fluctuate in intensity and severity, and there is also great variability in the symptoms different people experience. CFS/ME is characterised by debilitating fatigue that is unlike everyday fatigue and can be triggered by minimal activity. This raises especially complex issues in adults and children with severe CFS/ME.

CFS/ME, like other chronic conditions for which the causes and disease processes are not yet fully understood, poses significant problems for healthcare professionals. It can cause profound, prolonged illness and disability, which has a substantial impact on people with CFS/ME and their carers. Uncertainties about diagnosis and management, and a lack of clinical guidance for healthcare professionals, have exacerbated this impact.

1.3. Aetiology

Currently, the aetiology of CFS/ME remains unknown, although several factors have been suggested, including immunological, genetic, viral, neuroendocrine and psychological.5 Indeed, there is growing evidence that the condition is heterogeneous, and may not have a single or simple aetiology. It may be best regarded as a spectrum of illness that is triggered by a variety of factors in people who have an underlying predisposition. This is the view of aetiology taken by the GDG, pending the findings of ongoing research.

1.4. Diagnosis

The clinical practice guidelines on chronic fatigue syndrome developed by the Royal Australian College of Physicians define CFS as ‘a descriptive term used to define a recognisable pattern of symptoms that cannot be attributed to any alternative condition’.6 There is ongoing debate about the most appropriate diagnostic criteria to be applied. Please see Chapter 5 for a full discussion of diagnosis.

Because of the potential educational and social disruption, it has been generally agreed that for children and adolescents 6 months of fatigue before diagnosis is too long. For this reason fatigue durations of 8 weeks7 and 3 months8 have been proposed.1 The Royal College of Paediatrics and Child Health guideline stated that a patient who is referred with debilitating fatigue for assessment should be given an initial opinion of ‘generalised fatigue’.

At present, there are no physical signs that identify CFS/ME specifically. In addition, there are no diagnostic laboratory tests or other diagnostic criteria that can, as yet, confirm a diagnosis of CFS/ME,9 although research is ongoing. The diagnosis of CFS/ME is therefore made on the basis of a recognisable pattern of characteristic symptoms, and on the exclusion of other known causes.

A positive diagnosis of CFS/ME should be made after other known causes for the symptoms have been excluded and where the symptoms are causing functional impairment.1

1.5. Management

Early research into CFS/ME focused on possible causes, diagnostic criteria and natural history of the illness, with research into the treatment or management of the condition increasing only in recent years. Results are now available from a number of studies that have assessed the effectiveness of interventions used in the treatment or management of CFS/ME or have considered the support and information needs of healthcare professionals, patients and carers.

Guidelines on the management of CFS/ME have been published in Canada, the USA and Australia; in the UK, the Royal College of Paediatrics and Child Health published guidelines on the management of CFS/ME in children and young people in December 2004.1;6;10;11 An evidence-based report on the diagnosis and management of CFS/ME was also adopted in the Netherlands.12

The approach taken in this guideline is that of managing CFS/ME as a condition. Detailed guidance about the management of every potential symptom has not been included since the management of symptoms should follow established principles. For example, the principles of pain management should be applied in managing pain in someone with CFS/ME.

1.6. Prognosis

The CMO’s report concluded that the natural course of CFS/ME is such that:

  • most patients will show some degree of improvement over time, especially with treatment
  • a substantial number of patients will pursue a fluctuating course with periods of relative remission and relapse, and
  • a significant minority become severely, and perhaps permanently, disabled.4

Overall, there is considerable variation reported in both the severity and the duration of symptoms. The US Centers for Disease Control (CDC) cited a review of published studies reporting recovery rates of 8–63% (median 40%), with full recovery being rare (5–10% achieving total remission).9

1.7. Epidemiology

1.7.1. Incidence and prevalence

Overall, the evidence suggests a population prevalence of at least 0.2–0.4%,4 which means that a general practice with a population of 10,000 patients is likely to have up to 40 patients with CFS/ME, half of whom will need input from specialist CFS/ME services. However, there is a lack of epidemiological data for the UK, which means that population estimates are based on extrapolations from other countries. The estimated annual prevalence is approximately 4000 cases per million of the population.13

The CDC reported that:

  • people of every age, gender, ethnicity and socioeconomic group can have CFS/ME
  • CFS/ME affects women at four times the rate of men
  • it is most common in people aged in their 40s and 50s
  • although CFS/ME is much less common in children than in adults, children can develop the illness, particularly during adolescence.9

1.8. Existing service provision

CFS/ME can cause profound, prolonged illness and disability. Uncertainties about diagnosis and management, and lack of clinical guidance for healthcare professionals have created problems in the care of people with CFS/ME, including lack of access to appropriate care.

The 2002 CFS/ME Working Group Report highlighted that the provision of services specifically tailored for patients with CFS/ME in England is limited, and may be non-existent in some areas. Specialist CFS/ME services for children and young people, including inpatient facilities, are limited across the UK. Referrals from primary care have been to one or more of several specialties, such as general medicine, immunology, neurology, haematology, rheumatology and psychiatry. The CFS/ME Working Group Report suggested that the lack of locally based specialist CFS/ME services could pose a problem ‘to both patients who need a service and to commissioners of health services who wish to reduce the cost of out of area treatments’.4

The 2004–2006 CFS/ME Service Investment Programme, which was set up to address major gaps in service provision across England, has led to the phased establishment of 13 clinical network coordinating centres, 36 local teams for adults’ services and 11 specialist CFS/ME care teams for children and young people. The new CFS/ME services now cover 65% of the population of England whilst some of the remaining 35% of the population are covered by the pre-existing services. Within the first 2 years of the project, 11,040 adult patients were seen and enrolled into treatment programmes. The children and young people teams have seen 669 children and have established multiagency arrangements for treatment and support.14 However, the initial set-up phase of the Investment Programme has now ended and the extension and even the continuance of some of these services is at risk, even though the NHS has been given the necessary funding to continue them. Questions therefore remain about access to appropriate care for all who need it.

Copyright © 2007, Royal College of General Practitioners.
Bookshelf ID: NBK53583


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