As background for the remainder of the report, this chapter presents a brief history of ME/CFS, a discussion of the terminology used for this illness, and a summary of the burden it imposes in the United States.
As noted in Chapter 1, “ME/CFS” is an umbrella term that includes myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). For decades, clinicians and researchers developed separate case definitions and diagnostic criteria for ME (Carruthers et al., 2011; Hyde, 2007; Ramsay, 1988a) and CFS (Fukuda et al., 1994; Holmes et al., 1988; Kitani et al., 1992; Reeves et al., 2005; Sharpe, 1991), although the terms describe conditions with similar symptoms and unknown etiology. In the World Health Organization’s International Classification of Diseases, Tenth Revision, which will be implemented in October 2015, both ME and CFS are coded identically and classified as disorders of the nervous system (ICD G93.3). However “fatigue syndrome,” which clinicians may view as synonymous with CFS, is classified under mental and behavioral disorders (ICD F48.0).1
More recent efforts to develop diagnostic criteria for this condition(s) have used the term “ME/CFS” or “CFS/ME” (Carruthers and van de Sande,
1 The World Health Organization’s International Classification of Diseases, Tenth Revision, can be accessed at http://apps.who.int/classifications/icd10/browse/2015/en (accessed February 13, 2015).
2005; Carruthers et al., 2003; Government of South Australia et al., 2004; Jason et al., 2006b, 2010; NICE, 2007). However, there is still disagreement as to whether ME and CFS are separate conditions or are similar enough to belong under an umbrella term such as ME/CFS (Jason et al., 2014).
Beginning in 1934, a series of outbreaks of a previously unknown illness were recorded around the world (Acheson, 1959; Parish, 1978, 1980). The illness was initially confused with poliomyelitis, but it was eventually differentiated and became known as “epidemic neuromyasthenia” (Parish, 1978). The term “benign myalgic encephalomyelitis” was first used in the 1950s to describe a similar outbreak at the Royal Free Hospital in London (Wojcik et al., 2011). The details of each outbreak vary, but in general, patients experienced a variety of symptoms, including malaise, tender lymph nodes, sore throat, pain, and signs of encephalomyelitis (Lancet, 1955). Although the cause of the condition could not be determined, it appeared to be infectious, and the term “benign myalgic encephalomyelitis” eventually was chosen to reflect “the absent mortality, the severe muscular pains, the evidence of parenchymal damage to the nervous system, and the presumed inflammatory nature of the disorder” (Acheson, 1959, p. 593). The syndrome usually appeared in epidemics, but some sporadic cases were identified as well (Price, 1961).
In 1970, two psychiatrists in the United Kingdom reviewed the reports of 15 outbreaks of benign myalgic encephalomyelitis and concluded that these outbreaks “were psychosocial phenomena caused by one of two mechanisms, either mass hysteria on the part of the patients or altered medical perception of the community” (McEvedy and Beard, 1970, p. 11). They based their conclusions on the higher prevalence of the disease in females and the lack of physical signs in these patients. The researchers also recommended that the disease be renamed “myalgia nervosa.” Although these findings were strongly refuted by Dr. Melvin Ramsay, the proposed psychological etiology created great controversy and convinced health professionals that this was a plausible explanation for the condition (Speight, 2013).
Over time, Dr. Ramsay’s work demonstrated that, although this disease rarely resulted in mortality, it was often severely disabling, and as a result, the prefix “benign” was dropped (Ramsay, 1988a; Ramsay et al., 1977; Wojcik et al., 2011). In 1986, Dr. Ramsay published the first diagnostic criteria for ME, a condition characterized by a unique form of muscle fatigability whereby, even after a minor degree of physical effort, 3 or more days elapse before full muscle power is restored; extraordinary variability
or fluctuation of symptoms even in the course of one day; and an alarming chronicity (Ramsay, 1986).
Despite Dr. Ramsay’s work and a U.K. independent report recognizing that ME is not a psychological entity (CFS/ME Working Group, 2002), the health care community generally still doubts the existence or seriousness of this disease. This perception may partly explain the relatively limited research efforts to study ME in fields other than psychiatry and psychology.
Chronic Fatigue Syndrome
In the mid-1980s, two large outbreaks of an illness in Nevada and New York resembling mononucleosis attracted national attention. The illness was characterized by “chronic or recurrent debilitating fatigue and various combinations of other symptoms, including sore throat, lymph node pain and tenderness, headache, myalgia, and arthralgias” (Holmes et al., 1988, p. 387). The illness was initially linked to Epstein-Barr virus and became known as “chronic Epstein-Barr virus syndrome” (Holmes et al., 1988). In 1987, the Centers for Disease Control and Prevention (CDC) convened a working group to reach consensus on the clinical features of the illness. This group recognized that CFS was not new and had been known by many different names throughout history, “each reflecting a particular concept of the syndrome’s etiology and epidemiology” (Straus, 1991, p. S2). Many of these names were gradually rejected as new research ruled out various causes of the illness, including Epstein-Barr virus. Therefore, the CDC group chose “chronic fatigue syndrome” as a more neutral and inclusive name, noting that “myalgic encephalomyelitis” was the name most accepted in other parts of the world (Holmes et al., 1988). The first definition of CFS was published in 1988, and although the cause of the illness remains unknown, there have been several attempts to update this definition (Fukuda et al., 1994). Chapter 3 provides more information on some of the most recent case definitions and diagnostic criteria.
Although a variety of names have been proposed for this illness, the most commonly used today are “chronic fatigue syndrome,” “myalgic encephalomyelitis,”2 and the umbrella term “ME/CFS.” Reaching consensus on a name for this illness is particularly challenging in part because its etiology and pathology remain unknown (CFS/ME Working Group, 2002).
2 The most commonly used term around the world is “myalgic encephalomyelitis,” although a U.S. consensus group endorsed “encephalopathy” instead. The committee uses the former term throughout this report.
For years, patients, clinicians, and researchers have debated changing the name of the illness.
The term “chronic fatigue syndrome” has been the object of particular criticism from patients, as reflected in hundreds of comments the committee received from the public, both in person and electronically, during the course of this study (FDA, 2013).3 Surveys conducted by ME/CFS advocacy organizations have found that 85 to 92 percent of respondents want that name to be changed (Jason et al., 2004). Their most common complaints are that this name is stigmatizing and trivializing, causing people not to take the disorder seriously (Jason and Richman, 2008). Patients and advocates told the committee that the name “chronic fatigue syndrome” leads others, including clinicians, to think that patients are malingering and to ask whether the illness is “real.” Patients reported that many clinicians are dismissive, making such comments as “I feel tired all the time, too.”4 Many respondents objected specifically to the use of “fatigue” in the name because they do not believe fatigue to be the defining characteristic of this illness.5 For example, the following comment was submitted to the committee:
I believe that the words “Chronic Fatigue” are the kiss of death. Who in this over-wrought, stress-driven society isn’t “fatigued” a good deal of the time? What people don’t get is that this fatigue for people like me keeps me in bed for days at a time and prevents me from doing everyday errands and even simple house tasks on some days.6
In addition to difficult interactions with health care providers, patients have reported several other ways in which the stigmatization of ME/CFS affects them, including financial instability (such as job loss or demotion), social disengagement, and feeling the need to hide their symptoms in front of others (Assefi et al., 2003; Dickson et al., 2007; Green et al., 1999).
Comments submitted to the committee also noted that other illnesses, such as Parkinson’s disease, are not named after their symptoms.7 Patients often pointed out that ME/CFS, which includes symptoms in multiple systems that occur for an extended period of time, involves much more than fatigue, a level of complexity and impact not conveyed by the term “chronic fatigue syndrome.” The term “chronic fatigue syndrome” also may be difficult to understand in populations where English is not the primary language (Bayliss et al., 2014). Many patients prefer “myalgic encephalomyelitis,” a term first used in 1956, because they believe it better reflects the medical
3 Personal communication; public comments submitted to the IOM Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome for meeting 3, 2014.
nature of the illness (Jason et al., 2004; Ramsay, 1988b). However, there are patients and researchers who maintain that ME and CFS are two different illnesses and oppose simply changing the name of CFS to ME (Twisk, 2014).8
Partly in response to the concerns that have been expressed about CFS and to a lesser extent ME, particularly by patients, the committee was asked to recommend whether new terminology for ME/CFS should be adopted, a request that is addressed in Chapter 7. As noted in Chapter 1, the committee uses the umbrella term “ME/CFS” to refer to ME and CFS throughout this report.
My personal experience of having ME/CFS feels like permanently having the flu, a hangover, and jet lag while being continually electrocuted (which means that pain plays at least as much of a role in my condition as fatigue).9
As noted in Chapter 1, ME/CFS affects between 836,000 and 2.5 million people in the United States (Jason et al., 1999, 2006a; Reynolds et al., 2004). It affects more women than men, and although many seeking care for ME/CFS are Caucasian, the illness may be more common in minority groups (Jason et al., 1999, 2009, 2011; Reyes et al., 2003). The average age of onset is 33, although ME/CFS may begin as early as age 10 and as late as age 77 (NIH, 2011). Symptoms can persist for years, and most patients never regain their premorbid level of health or functioning (Nisenbaum et al., 2000; Reyes et al., 2003; Reynolds et al., 2004). The duration of ME/CFS and the potentially debilitating consequences of symptoms can be an enormous burden for patients, their caregivers, the health care system, and society.
Disability and Impairment
Several ME/CFS symptoms—including fatigue, cognitive dysfunction, pain, sleep disturbance, post-exertional malaise, and secondary depression or anxiety—may contribute to impairment or disability (Andersen et al., 2004; Tiersky et al., 2001). Patients with ME/CFS have been found to be more functionally impaired than those with other disabling illnesses, including type 2 diabetes mellitus, congestive heart failure, hypertension, depression, multiple sclerosis, and end-stage renal disease (Jason and Richman,
2008; Twisk, 2014). Symptoms can be severe enough to preclude patients from completing everyday tasks, and 25-29 percent of patients report being house- or bedbound by their symptoms. Many patients feel unable to meet their family responsibilities and report having to reduce their social activities (NIH, 2011). However, these data include only patients who were counted in clinics or research studies and may underrepresent the extent of the problem by excluding those who are undiagnosed or unable to access health care (Wiborg et al., 2010). More information on disability in ME/CFS can be found in Appendix C.
Health Care Costs and Utilization
Patients with ME/CFS spend considerably more on health care than the general medical patient population (Twemlow et al., 1997). They also see more physicians and visit their health care providers more often relative to the general medical patient population (Thanawala and Taylor, 2007; Twemlow et al., 1997). Many patients report barriers to accessing health care as well, including the nature of their illness and financial considerations (Lin et al., 2009; Thanawala and Taylor, 2007).
ME/CFS symptoms often are so debilitating that patients are unable to work or attend school full-time (Crawley et al., 2011; Solomon et al., 2003; Taylor and Kielhofner, 2005; Twemlow et al., 1997). A review of 15 studies conducted between 1966 and 2004 showed that unemployment rates among those with the disorder ranged from 35 to 69 percent in 13 of these studies (Taylor and Kielhofner, 2005). ME/CFS was found to account for $8,554 in lost household earnings, 19 percent of which was attributable to lower educational attainment (Lin et al., 2011). Another study, conducted among ME/CFS patients in Kansas, found that ME/CFS resulted in reduced household and labor force productivity that caused individual income losses of approximately $20,000 annually (Taylor and Kielhofner, 2005). Reductions in employment and productivity per hour resulted in a 37 percent reduction in household productivity and a 54 percent reduction in labor force productivity (Reynolds et al., 2004).
As noted, ME/CFS often lasts for many years, and beyond lost income, inflicts substantial economic costs at both the individual and the societal level. In one study, annual direct medical costs per ME/CFS patient ranged from $2,342 in a community-based sample (previously undiagnosed) to
$8,675 in a tertiary sample (already diagnosed) (Jason et al., 2008). Another study found that individuals with ME/CFS incurred $3,286 in annual direct medical costs (Lin et al., 2011). The direct and indirect economic costs of ME/CFS to society are estimated to be approximately over $18 to $24 billion annually (Jason et al., 2008).
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Bayliss, K., L. Riste, L. Fisher, A. Wearden, S. Peters, K. Lovell, and C. Chew-Graham. 2014. Diagnosis and management of chronic fatigue syndrome/myalgic encephalitis in black and minority ethnic people: A qualitative study. Primary Health Care Research & Development 15(2):143-152.
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