Category: Prevalence

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

 

Prevalence of chronic fatigue syndrome-related symptoms among nurses

Abstract:

Chronic Fatigue Syndrome is an illness that is characterized by debilitating fatigue and a group of other related symptoms. Few epidemiological studies have been conducted, and none have focused on a nursing population. The present study is the first to assess the prevalence of Chronic Fatigue Syndrome-related symptoms in a sample of nurses. Demographic characteristics, symptoms, and possible prevalence rates are presented and discussed. When using both narrow and more inclusive criteria to define this symptom complex, higher rates of this disorder were found than in previous epidemiological studies. The implications of these findings are discussed.

 

Source: Jason LA, Taylor SL, Johnson S, Goldston SE, Salina D, Bishop P, Wagner L. Prevalence of chronic fatigue syndrome-related symptoms among nurses. Eval Health Prof. 1993 Dec;16(4):385-99. http://www.ncbi.nlm.nih.gov/pubmed/10130552

 

Chronic fatigue in primary care attenders

Abstract:

From 686 patients attending primary care physicians, 77 were identified by a screening procedure as having chronic fatigue. Of these, 65 were given a comprehensive psychological, social and physical evaluation.

Seventeen cases (26%) met criteria for the chronic fatigue syndrome. Forty-seven (72%) received an ICD-9 diagnosis of whom 23 had neurotic depression, with a further 5 meeting criteria for neurasthenia.

Forty-nine were ‘cases’ as defined by the revised Clinical Interview Schedule (CIS-R), and 42 if the fatigue item was excluded. Psychiatric morbidity was more related to levels of social stresses than was severity of fatigue.

The main difference between these subjects and those examined in hospital settings is that the former are less liable to attribute their symptoms to wholly physical causes, including viruses, as opposed to social or psychological factors. Identification and management of persistent fatigue in primary care may prevent the secondary disabilities seen in patients with chronic fatigue syndromes.

 

Source: McDonald E, David AS, Pelosi AJ, Mann AH. Chronic fatigue in primary care attenders. Psychol Med. 1993 Nov;23(4):987-98. http://www.ncbi.nlm.nih.gov/pubmed/8134522

 

Taking exception to chronic fatigue syndrome prevalence findings by Price, et al.

Comment on: Estimating the prevalence of chronic fatigue syndrome and associated symptoms in the community. [Public Health Rep. 1992]

 

We would like to address some serious methodological issues in the article, “Estimating the Prevalence of Chronic Fatigue Syndrome and Associated Symptoms in the Community,” by Rumi K. Price, et al., published in the September-October issue of Public Health Reports. We believe that because of the deficiencies in the design of this research, the authors’ conclusions are totally illogical and invalid.

In this article, the authors conclude that Chronic Fatigue Syndrome (CFS), as defined by the Centers for Disease Control (CDC) Diagnostic Criteria, might be “quite rare” in the general population, as only 1 of 13,538 individuals studied was deemed to have CFS. The official CDC Diagnostic Criteria, however, were not utilized to diagnose cases of CFS. Instead, the researchers reviewed interview questionnaire data collected between 1981 and 1984 for a purpose unrelated to diagnosing CFS. In fact, the CDC Diagnostic Criteria were not formulated and published until 1988.

You can read the rest of this comment as well as the rely from the authors here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1403345/pdf/pubhealthrep00069-0137c.pdf

 

Source: Robin R, Lipkin DM, Hume GW. Taking exception to chronic fatigue syndrome prevalence findings by Price, et al. Public Health Rep. 1993 Jan-Feb;108(1):135-7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1403345/

 

Epidemiology of chronic fatigue syndrome: the Centers for Disease Control Study

Abstract:

The US Centers for Disease Control initiated physician-based chronic fatigue syndrome (CFS) surveillance systems in four cities in September 1989 to determine the prevalence, incidence, course and impact of the illness. The participating physicians have referred to our surveillance system 590 patients who were ill during the first two years of surveillance with severe, debilitating, unexplained fatigue for at least the preceding six months.

Referred patients were screened for psychiatric disorders preceding, concurrent with, and subsequent to the onset of their fatigue by specially trained nurses using a modified Diagnostic Interview Schedule. Complete health histories were obtained by interview and review of medical records and a basic panel of standard laboratory diagnostic tests were conducted. Four physicians have independently reviewed the health information of 337 of the patients for classification.

Approximately 26% of patients referred to the surveillance system met the CFS case definition in all regards, 14% lacked one or more of the required eight symptom criteria, 15% were judged to have another possible or known medical illness which could account for the severe fatigue, and the remaining 45% did not meet the case definition because of histories of psychiatric disorders preceding the onset of fatigue.

Minimum prevalence rates for the period 1 September 1989 to 1 September 1991 ranged from 2.0 to 7.3 per 100,000 of the general population across the four study sites and rates based on prorated data ranged from 4.6 to 11.3 per 100,000. More than 80% of the CFS cases were female, most were white, and their average age at onset was approximately 30 years.

 

Source: Gunn WJ, Connell DB, Randall B. Epidemiology of chronic fatigue syndrome: the Centers for Disease Control Study. Ciba Found Symp. 1993;173:83-93; discussion 93-101. http://www.ncbi.nlm.nih.gov/pubmed/8387910

 

Allergy among Japanese patients with chronic fatigue syndrome

Abstract:

Allergy is a common feature of patients with chronic fatigue syndrome (CFS). Because of this strong association, we attempted to explore the prevalence of allergies among Japanese patients with CFS.

Of the present 18 patients, 78% had allergies during their premorbid and/or postmorbid conditions. Their allergies were mainly cutaneous reactions including drug allergies and 43% of the patients had 2 or more allergic reactions.

In the case of a premorbid condition, allergies improved spontaneously after onset of CFS. Clinical manifestations of CFS, however, became worse during the period of an association with allergies.

Immunologic tests, including peripheral blood lymphocyte-subsets, blastogenesis, natural killer-cell functions and cytokine-assays, were not any correlation between both patients with and without allergies.

Source: Matsumoto Y, Ninomiya S. Allergy among Japanese patients with chronic fatigue syndrome. Arerugi. 1992 Dec;41(12):1722-5. [Article in Japanese] http://www.ncbi.nlm.nih.gov/pubmed/1290417

 

The economic impact of chronic fatigue syndrome

Abstract:

OBJECTIVE: To estimate the economic impact of chronic fatigue syndrome (CFS) on the individual, the government, and the community.

DESIGN: The financial burden produced by CFS was studied by calculating the direct and indirect costs arising from the disorder. Data regarding use of health resources, income and employment were obtained by questionnaire from patients with CFS. In addition, aggregate Medicare data on the incidence and fees charged for each Schedule item for these patients was obtained.

SETTING: The Richmond Valley, New South Wales.

PARTICIPANTS: Forty-two patients with CFS identified in our population-based prevalence study.

RESULTS: The conservative estimate of the per annum costs of CFS in the Richmond Valley, with a prevalence of 37.1 cases per 100,000, was $396,000. If extrapolated to the Australian population, we estimate CFS would generate an annual cost of at least $59 million.

CONCLUSION: This disorder constitutes a large but neglected area of health resource utilisation and economic burden.

Comment in: The economic impact of chronic fatigue syndrome. [Med J Aust. 1993]

 

Source: Lloyd AR, Pender H. The economic impact of chronic fatigue syndrome. Med J Aust. 1992 Nov 2;157(9):599-601. http://www.ncbi.nlm.nih.gov/pubmed/1406420

 

Estimating the prevalence of chronic fatigue syndrome and associated symptoms in the community

Abstract:

Chronic fatigue syndrome is a poorly understood disease characterized by debilitating fatigue and neuromuscular and neuropsychological symptoms. Despite numerous studies on the subject, the epidemiology of the syndrome in the community remains largely unexplored.

An estimate of the prevalence in the population is presented, approximating the Centers for Disease Control criteria as well as the prevalence estimates of the fatigue symptom complex that include fatigue, disability, and neuromuscular and neuropsychological symptoms. The study population consisted of a very large, multicenter, stratified, and random sample of a general population health survey known as the Epidemiologic Catchment Area Program.

Data used for this study were gathered between 1981 and 1984. The Diagnostic Interview Schedule, a highly structured mental health interview, was used to assess the lifetime prevalence of medical and psychological symptoms. Chronic fatigue was common.

A total of 23 percent of the subjects reported having experienced the symptom of persistent fatigue sometime during their lives. Chronic fatigue syndrome, however, as defined by the Centers for Disease Control, appeared to be quite rare in the general population. Only 1 of 13,538 people examined was found to meet a diagnosis of the syndrome with an approximation of the CDC criteria. Fatigue symptom complex was frequently related to medical or psychiatric illness or substance abuse; thus, persons meeting partial criteria of chronic fatigue syndrome were also found to be rare when psychiatric or medical exclusions were applied.

 

Comment in: Taking exception to chronic fatigue syndrome prevalence findings by Price, et al. [Public Health Rep. 1993]

 

Source: Price RK, North CS, Wessely S, Fraser VJ. Estimating the prevalence of chronic fatigue syndrome and associated symptoms in the community. Public Health Rep. 1992 Sep-Oct;107(5):514-22. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1403692/ (Full article)

 

Chronic fatigue syndrome

Comment on: General practitioners’ experience of the chronic fatigue syndrome. [Br J Gen Pract. 1991]

 

Sir, Ho-Yen and McNamara give an interesting account of general practitioners’ experience of the chronic fatigue syndrome (August Journal, p.324). However, many of the conclusions which they draw are not supported by their study.

The problem lies in the method by which cases were identified. It seems unlikely that the doctors who responded to the questionnaire would have screened every patient on their practice lists for the condition. Even to screen only those patients who attended the surgery would have been a massive undertaking. There is no evidence that the practices involved kept a case register for this illness. I presume therefore that the cases reported were identified from memory by the doctors who responded to the survey. Thus, for patients who meet the criteria for this illness to be identified as a ‘case’ they must: decide that they are ill, decide to visit the doctor, be correctly identified as a case by the general practitioner and leave such an impression on the doctor’s mind as to be easily recalled later. It is very unlikely that, having passed through such a selection procedure, the cases identified would represent either the true number or display the typical characteristics of patients with this condition in the general population.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1371804/pdf/brjgenprac00062-0042b.pdf

 

Source: Plummer WP. Chronic fatigue syndrome. Br J Gen Pract. 1991 Nov;41(352):480. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1371804/