Category: Prevalence

Chronic fatigue and the chronic fatigue syndrome: prevalence in a Pacific Northwest health care system

Abstract:

OBJECTIVES: To investigate the point prevalence of the chronic fatigue syndrome and unexplained debilitating chronic fatigue in a community-based sample of persons and to describe demographic, clinical, and psychosocial differences among those with the chronic fatigue syndrome, those with chronic fatigue, and healthy controls.

DESIGN: Prospective cohort study.

SETTING: A health maintenance organization in Seattle, Washington.

PARTICIPANTS: A random sample of 4000 members of the health maintenance organization was surveyed by mail for the presence of chronic fatigue.

MEASUREMENTS: Persons with chronic fatigue were evaluated using a questionnaire that requested information about medical history and fatigue and related symptoms; validated measures of functional status and psychological distress; a physical examination; and standardized blood tests. A structured psychiatric interview was done in persons who appeared to meet the original Centers for Disease Control and Prevention (CDC) criteria for the chronic fatigue syndrome. Participants completed self-report measures at 12 and 24 months. Those with chronic fatigue were reevaluated in person 1 year after study enrollment.

RESULTS: 3066 (77%) of the 4000 members surveyed responded. Chronic fatigue was reported by 590 persons (19%). Of these, 388 (66%) had a medical or psychiatric condition that could account for the fatigue. Of the 74 persons (37%) with chronic fatigue who were enrolled in the study, only 3 met the CDC criteria for the chronic fatigue syndrome. The remaining 71 persons were designated as having chronic fatigue alone. Seventy-four healthy, age- and sex-matched controls who were drawn from the same sample but who denied having chronic fatigue were also studied. Demographic characteristics were similar in persons with the chronic fatigue syndrome, persons with chronic fatigue alone, and controls. Those with the chronic fatigue syndrome or chronic fatigue alone had more frequent cervical and axillary adenopathy, poorer functional status, and greater psychological distress than controls. Women and minorities were not overrepresented among cases with chronic fatigue.

CONCLUSIONS: Using different assumptions about the likelihood that persons who did not participate in the study had the chronic fatigue syndrome, the estimated crude point prevalence of the syndrome in this community ranged from 75 to 267 cases per 100,000 persons. The point prevalence of chronic fatigue alone was strikingly higher; it ranged from 1775 to 6321 cases per 100,000 persons.

 

Source: Buchwald D, Umali P, Umali J, Kith P, Pearlman T, Komaroff AL. Chronic fatigue and the chronic fatigue syndrome: prevalence in a Pacific Northwest health care system. Ann Intern Med. 1995 Jul 15;123(2):81-8. http://www.ncbi.nlm.nih.gov/pubmed/7778839

 

Chronic fatigue syndrome in the community. Prevalence and associations

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a poorly understood condition, apparently related to both psychiatric disturbance and infectious illness. Little progress has been made in identifying aetiology, owing to a lack of epidemiological studies using case-definition criteria.

METHOD: A community postal survey of a random sample of over 1000 patients registered at a local health centre comprised a fatigue questionnaire and the 12-item General Health Questionnaire (GHQ).

RESULTS: Total fatigue scores were modestly higher in women than men. Fatigue was most frequently attributed to psychosocial factors. Fatigue and GHQ scores were strongly correlated. Two men and two women satisfied British criteria for CFS, a prevalence of 0.56% (95% Cl 0.16-1.47%); three were probable psychiatric cases.

CONCLUSIONS: Previously reported sociodemographic associations of CFS may reflect medical referral patterns. A strong association exists with psychological morbidity, but relabelling CFS as a psychiatric disorder is not justified.

 

Source: Lawrie SM, Pelosi AJ. Chronic fatigue syndrome in the community. Prevalence and associations. Br J Psychiatry. 1995 Jun;166(6):793-7. http://www.ncbi.nlm.nih.gov/pubmed/7663830

 

Prevalence of chronic fatigue syndrome in Italian patients with persistent fatigue

Abstract:

Our study was carried out to determine the prevalence of chronic fatigue syndrome (CFS) within a selected population of patients suffering from persistent fatigue. We studied subjects with recurrent or persistent fatigue lasting 6 months and fulfilling at least four minor Center for Disease Control (CDC) criteria for the diagnosis of CFS.

Evaluation included both clinical examination and laboratory testing. All subjects filled out a questionnaire specifically designed to gain information about the length and severity of symptoms, and patients with a previously diagnosed illness associated with fatigue were excluded.

The study was carried out at the Fatigue Clinic of an internal medicine unit (Clinica Medica I) of the University of Rome “La Sapienza”. Sixty-three subjects, residents of the Lazio region (central Italy), completed the diagnostic assessment. Alternative diagnoses were established in 37 (59%) of the 63 patients. A diagnosis of CFS based on the CDC criteria was established in only 6 cases.

In 2 subjects, CFS had appeared following infectious mononucleosis, and no definitive diagnosis could be formulated for 18 patients. In Italy, CFS seems to be an infrequent cause of severe and persistent fatigue in a selected population. Numerous morbid conditions may be responsible for a clinical picture closely resembling CFS. We recommend that patients suffering from fatigue be thoroughly evaluated.

 

Source: Conti F, Priori R, De Petrillo G, Rusconi AC, Arpino C, Valesini G. Prevalence of chronic fatigue syndrome in Italian patients with persistent fatigue. Ann Ital Med Int. 1994 Oct-Dec;9(4):219-22. http://www.ncbi.nlm.nih.gov/pubmed/7893570

 

Chronic fatigue syndrome and myalgic encephalomyelitis

Comment on:

Chronic fatigue syndrome. Distinguish between syndromes… [BMJ. 1994]

Chronic fatigue syndrome. Role of psychological factors overemphasised. [BMJ. 1994]

 

Editor,-Our recent editorial on the chronic fatigue syndrome and myalgic encephalomyelitis prompted considerable correspondence,’ which raised issues of case definition, clinical management, and attitudes towards people with psychiatric illnesses. Sadly, many of our critics show that the editor of the BMJ is wrong to state in the “editor’s choice” in the issue of 14 May that “only the naivest medical students think that diseases have some independent, objective reality.” Medical students show greater intellectual sophistication in tackling the classification of ill defined illnesses than many patients and doctors-and particularly medical practitioners with self diagnosed myalgic encephalomyelitis.

Case definition-Ellen M Goudsmit’ and Nick Anderson’ assert that research criteria for the chronic fatigue syndrome fail to distinguish myalgic encephalomyelitis and exaggerate psychiatric associations. The best replicated research finding, however, is that patients suffer substantial emotional morbidity, whether the chronic fatigue syndrome is defined by British or, as patient groups prefer, Australian or American criteria. All three sets of criteria can be used to identify cases on a continuum of fatigue, which includes myalgic encephalomyelitis. We did not cite DO Ho-Yen’s prevalence study as it used an idiosyncratic definition of cases of the ‘chronic fatigue syndrome and surveyed doctors’ diagnoses rather than patients.

You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540769/pdf/bmj00450-0067b.pdf

 

Source: Lawrie SM, Pelosi AJ. Chronic fatigue syndrome and myalgic encephalomyelitis. BMJ. 1994 Jul 23;309(6949):275. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540769/

 

Chronic fatigue syndrome. Prevalence study overlooked

Comment on: Chronic fatigue syndrome: prevalence and outcome. [BMJ. 1994]

 

Editor,-It is sad that, in an issue in which Tony Delamothe considers biased reporting of the chronic fatigue syndrome, S M Lawrie and A J Pelosi’s editorial on the subject should be so one sided. The editorial’s title mentions the prevalence of the chronic fatigue syndrome, but the editorial fails to mention the most complete British study. In this study all general practices in two health boards were circulated with a questionnaire. There was a 91% response rate, with most respondents (71%) accepting the existence of the chronic fatigue syndrome when a strict definition was used. The doctors reported a prevalence among their patients of 1-3/1000 patients (range 0-3-2/1000 for the 10 areas surveyed). The higher prevalences were found in more populated areas.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540208/pdf/bmj00440-0055a.pdf

 

Source: Ho-Yen DO, Shanks M. Chronic fatigue syndrome. Prevalence study overlooked. BMJ. 1994 May 14;308(6939):1299. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540208/

 

Chronic fatigue syndrome. Distinguish between syndromes…

Comment in: Chronic fatigue syndrome and myalgic encephalomyelitis. [BMJ. 1994]

Comment on: Longitudinal study of outcome of chronic fatigue syndrome. [BMJ. 1994]

 

EDITOR,-I note that several people writing in the BMY are still confusing myalgic encephalomyelitis with the chronic fatigue syndrome. I wish to clarify matters. From a scientist’s point of view, the main problem is not the term chronic fatigue syndrome but the various diagnostic criteria that go with it. For instance, the strict Australian definition adopted by Wilson et al is similar to that for myalgic encephalomyelitis.2 As a result, it is reasonably certain that in this article the two names probably refer to the same disease.

The “Oxford” criteria used in Britain, however, are far broader, covering all patients whose severe, unexplained fatigue has been present for at least half of the time and for at least six months. The only other requirements are that the fatigue must have had a definite onset and that it affects both physical and mental functioning. Unlike with the strict Australian definition, no immunological criteria have to be met.2 Moreover, there do not have to be appreciable fluctuations in symptoms still a major criterion for myalgic encephalomyelitis.

In terms of prevalence, a recent study found that 17 of 686 (2-5%) attenders in general practice fulfilled the Oxford criteria for the chronic fatigue syndrome.3 When a further four patients who did not meet the criterion of a definite onset were also included the estimated prevalence increased to 3%. In contrast, the prevalence of myalgic encephalomyelitis rarely exceeds 1-5 per 1000.4

Most patients who fulfil the Oxford criteria suffer not from myalgic encephalomyelitis but from more common conditions, notably depression, anxiety states, sleep disorders, and fibromyalgia. None of these disorders occur in epidemics …

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540201/pdf/bmj00440-0053c.pdf

 

Source: Goudsmit EM. Chronic fatigue syndrome. Distinguish between syndromes… BMJ. 1994 May 14;308(6939):1297-8. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540201/

 

Chronic fatigue syndrome: prevalence and outcome

This week’s journal contains two papers from multidisciplinary teams that shed light on syndromes of chronic fatigue and so move us towards resolving the often bitter controversy over myalgic encephalomyelitis. A large community survey by Pawlikowska and colleagues provides estimates of the prevalence of the symptom of fatigue,’ operationally defined chronic fatigue syndrome,2 and self declared (possibly self diagnosed) chronic fatigue syndrome in young and middle aged adults in south east England (p 763).1

They found that fatigue was common, occurred as a continuum, and was highly correlated with emotional distress. Most people attributed their fatigue to social or psychological factors. While 02% of the respondents reported that they had chronic fatigue syndrome, as many as 1% of respondents satisfied several of the criteria for the syndrome. As with many illnesses, the cases were found at the severe end of the continuum of fatigue, without any sharp cut off. Associations of self reported chronic fatigue syndrome with female sex and upper social class confirm what has been found in primary care and hospital studies 34 but are less typical in community surveys.’ 6 Previous studies have consistently identified a strong association between emotional morbidity and chronic fatigue syndrome,7 but this “is inevitable given the similarities of the criteria and the measures used to define them.”‘ Interestingly, the closer cases fulfil the definition of chronic fatigue syndrome the stronger the association with emotional morbidity.

Comment in:

Chronic fatigue syndrome. Prevalence study overlooked. [BMJ. 1994]

Chronic fatigue syndrome. …and study them separately. [BMJ. 1994]

Chronic fatigue syndrome. ME Association is honest about prognosis. [BMJ. 1994]

Comment on: Professional and popular views of chronic fatigue syndrome. [BMJ. 1994]

 

Source: Lawrie SM, Pelosi AJ. Chronic fatigue syndrome: prevalence and outcome. BMJ. 1994 Mar 19;308(6931):732-3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539646/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539646/pdf/bmj00432-0006.pdf

 

Population based study of fatigue and psychological distress

Abstract:

OBJECTIVES: To determine the prevalence of fatigue in the general population and the factors associated with fatigue.

DESIGN: Postal survey.

SETTING: Six general practices in southern England.

SUBJECTS: 31,651 men and women aged 18-45 years registered with the practices.

MAIN OUTCOME MEASURES: Responses to the 12 item general health questionnaire and a fatigue questionnaire which included self reported measures of duration, severity, and causes of fatigue.

RESULTS: 15,283 valid questionnaires were returned, giving a response rate of 48.3%, (64% after adjustment for inaccuracies in the practice registers). 2798 (18.3%) of respondents reported substantial fatigue lasting six months or longer. Fatigue and psychological morbidity were moderately correlated (r = 0.62). Women were more likely to complain of fatigue than men, even after adjustment for psychological distress. The commonest cited reasons for fatigue were psychosocial (40% of patients). Of 2798 patients with excessive tiredness, only 38 (1.4%) attributed this to the chronic fatigue syndrome.

CONCLUSION: Fatigue is distributed as a continuous variable in the community and is closely associated with psychological morbidity.

Comment in:

Patients with a self diagnosis of myalgic encephalomyelitis. [BMJ. 1995]

Twists in the tale of impossible means. The reviewer shows that the gremlins might have attacked on several fronts. [BMJ. 2000]

Twists in the tale of impossible means. In which a copy of the original manuscript is found safe in Norway. [BMJ. 2000]

Fatigue and psychological distress. Statistics are improbable. [BMJ. 2000]

 

Source: Pawlikowska T, Chalder T, Hirsch SR, Wallace P, Wright DJ, Wessely SC. Population based study of fatigue and psychological distress. BMJ. 1994 Mar 19;308(6931):763-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539651/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539651/pdf/bmj00432-0041.pdf

 

Chronic fatigue syndrome: have flawed assumptions been derived from treatment-based studies?

Abstract:

Chronic fatigue syndrome is a disabling disorder that has been studied primarily in clinical settings. In the absence of an adequate epidemiological database, cultural stereotypes have influenced the characterization of chronic fatigue syndrome as “the yuppie flu,” similar to the 19th century characterization of neurasthenia as a disease of the affluent. The limited epidemiological data available and the overall medical-sociological literature call this assumption into question. Only a community “true” prevalence study that is unbiased by help seeking and access to health care can provide an accurate assessment of the risk factors for and the public health ramifications of this disease.

 

Source: Richman JA, Flaherty JA, Rospenda KM. Chronic fatigue syndrome: have flawed assumptions been derived from treatment-based studies? Am J Public Health. 1994 Feb;84(2):282-4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1615008/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1615008/pdf/amjph00453-0124.pdf

 

 

Prevalence of fatigue and chronic fatigue syndrome in a primary care practice

Abstract:

BACKGROUND: Our goals were to determine the prevalence of unusual, debilitating fatigue and the frequency with which it was associated with the chronic fatigue syndrome (CFS) or other physical or psychological illness in an outpatient clinic population.

METHODS: We prospectively evaluated a cohort of 1000 consecutive patients in a primary care clinic in an urban, hospital-based general medicine practice. The study protocol included a detailed history, physical examination, and laboratory and psychiatric testing.

RESULTS: Five patients who came because of CFS studies were excluded. Of the remaining 995, 323 reported fatigue, and 271 (27%) complained of at least 6 months of unusual fatigue that interfered with their daily lives. Of the 271, self-report or record review revealed a medical or psychiatric condition that could have explained the fatigue in 186 (69%). Thus, 85 (8.5%) of 995 patients had a debilitating fatigue of at least 6 months’ duration, without apparent cause. Of these patients, 48 refused further evaluation, and 11 were unavailable for follow-up; 26 completed the protocol. Three of the 26 were hypothyroid, and one had a major psychiatric disorder. Of the remaining 22 patients, three met Centers for Disease Control and Prevention criteria for CFS, four met British criteria, and 10 met the Australian case definition. The point prevalences of CFS were thus 0.3% (95% confidence interval [CI], 0% to 0.6%), 0.4% (95% CI, 0% to 0.8%), and 1.0% (95% CI, 0.4% to 1.6%) using the Centers for Disease Control and Prevention, British, and Australian case definitions, respectively. These estimates were conservative, because they assumed that none of the patients who refused evaluation or were unavailable for follow-up would meet criteria for CFS.

CONCLUSIONS: While chronic, debilitating fatigue is common in medical outpatients, CFS is relatively uncommon. Prevalence depends substantially on the case definition used.

 

Source: Bates DW, Schmitt W, Buchwald D, Ware NC, Lee J, Thoyer E, Kornish RJ, Komaroff AL. Prevalence of fatigue and chronic fatigue syndrome in a primary care practice. Arch Intern Med. 1993 Dec 27;153(24):2759-65. http://www.ncbi.nlm.nih.gov/pubmed/8257251