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

 

Postinfectious fatigue: prospective cohort study in primary care

Abstract:

The idea that chronic fatigue has an infectious origin has become popular, but the main evidence for such an association has come from retrospective case-control studies, which are subject to ascertainment bias. We report a prospective study of the outcome of clinically diagnosed infections in patients presenting to UK general practitioners.

Questionnaires assessing fatigue and psychiatric morbidity were sent to all patients aged 18-45 years in the study practices. The prevalence of chronic fatigue and chronic fatigue syndrome was then ascertained among 1199 people aged 18-45 who presented to the general practitioners with symptomatic infections and in 1167 people who attended the surgeries for other reasons. 84% were followed up at 6 months. 9.9% of cases and 11.7% of controls reported chronic fatigue (odds ratio 1.0 [95% CI 0.6-1.1]). There were no differences in the proportions who met various criteria for chronic fatigue syndrome. No effect of infection was noted when we excluded subjects who reported fatigue or psychological morbidity at the baseline screening.

The strongest independent predictors of postinfectious fatigue were fatigue assessed before presentation with clinical infection (3.0 [1.9-4.7]) and psychological distress before presentation (1.8 [1.2-2.9]) and at presentation with the acute infection (1.8 [1.1-2.8]). There was no effect of sex or social class. Our study shows no evidence that common infective episodes in primary care are related to the onset of chronic fatigue or chronic fatigue syndrome.

Comment in:

Viral illness and chronic fatigue (syndrome). [Lancet. 1995]

Viral illness and chronic fatigue (syndrome) [Lancet. 1995]

Viral illness and chronic fatigue (syndrome). [Lancet. 1995]

Viral illness and chronic fatigue (syndrome) [Lancet. 1995]

Viral illness and chronic fatigue (syndrome). [Lancet. 1995]

 

Source: Wessely S, Chalder T, Hirsch S, Pawlikowska T, Wallace P, Wright DJ. Postinfectious fatigue: prospective cohort study in primary care. Lancet. 1995 May 27;345(8961):1333-8. http://www.ncbi.nlm.nih.gov/pubmed/7752755

 

Is neurally mediated hypotension an unrecognised cause of chronic fatigue?

Abstract:

Neurally mediated hypotension is now recognised as a common cause of otherwise unexplained recurrent syncope, but has not been reported in association with chronic fatigue. We describe seven consecutive non-syncopal adolescents with chronic post-exertional fatigue, four of whom satisfied strict criteria for chronic fatigue syndrome. Upright tilt-table testing induced significant hypotension in all seven (median systolic blood pressure 65 mm Hg, range 37-75), consistent with the physiology of neurally mediated hypotension. Four had prompt improvement in their chronic fatigue when treated with atenolol or disopyramide. These observations suggest an overlap in the symptoms of chronic fatigue syndrome and neurally mediated hypotension.

Comment in:

Is neurally mediated hypotension an unrecognised cause of chronic fatigue? [Lancet. 1995]

Is neurally mediated hypotension an unrecognised cause of chronic fatigue? [Lancet. 1995]

Is neurally mediated hypotension an unrecognised cause of chronic fatigue? [Lancet. 1995]

 

Source: Rowe PC, Bou-Holaigah I, Kan JS, Calkins H. Is neurally mediated hypotension an unrecognised cause of chronic fatigue? Lancet. 1995 Mar 11;345(8950):623-4. http://www.ncbi.nlm.nih.gov/pubmed/7898182

 

Chronic fatigue: risk factors for symptom persistence in a 2 1/2-year follow-up study

Abstract:

BACKGROUND: The prolonged disability of patients suffering from chronic fatigue may be due to sustaining factors that are independent of the cause and subject to intervention. This study reexamined a cohort of patients with chronic fatigue to define medical and psychiatric predictors of persistent symptoms.

METHODS: Seventy-eight patients with chronic fatigue present for 6 months or more (not required to meet the Centers for Disease Control case definition for chronic fatigue syndrome [CFS]) completed a self-report, follow-up questionnaire to measure the overall improvement or worsening of their condition at a mean of 2.5 years after their initial examination. At the time of initial evaluation, patients underwent a structured psychiatric examination, physical examination, laboratory studies, and self-report measures of psychological distress and functional disability. The psychiatric examination queried the patient about 28 somatic symptoms that are separate from those associated with CFS. Discriminant analysis was used to determine which variables present at the initial examination were significant predictors of persistent symptoms and disability at 2.5 years.

RESULTS: The factors most important at the time of initial presentation in predicting persistent illness were: (1) more than eight medically unexplained physical symptoms separate from those associated with CFS case definition; (2) lifetime history of dysthymia; (3) duration of chronic fatigue symptoms greater than 1.5 years; (4) less than 16 years of formal education; and (5) age older than 38 years. None of the results of the initial physical examination, or immunologic, general laboratory, or viral antibody measurements were significant in predicting persistence of symptoms. Recovery rates for those who met the criteria for CFS by either of two case definitions were lower than the rate of noncases, but the differences were not statistically significant. The five aforementioned variables formed a significant discriminative function, correctly classifying 78% of those who recovered and 74% of those with persistent symptoms.

CONCLUSIONS: At initial examination, patients with chronic fatigue, more than eight medically unexplained physical symptoms (excluding symptoms in the case criteria for CFS), a lifetime history of dysthymic disorder, longer than 1.5 years of chronic fatigue, less than 16 years of formal education, and who were older than 38 years were the most likely to have persistence of symptoms of chronic fatigue at the 2.5-year follow-up.

 

Source: Clark MR, Katon W, Russo J, Kith P, Sintay M, Buchwald D. Chronic fatigue: risk factors for symptom persistence in a 2 1/2-year follow-up study. Am J Med. 1995 Feb;98(2):187-95. http://www.ncbi.nlm.nih.gov/pubmed/7847436

 

Case control study of chronic fatigue in pediatric patients

Abstract:

OBJECTIVE: To determine the demographic characteristics, medical features, psychological profile, and natural history of children with chronic fatigue.

DESIGN: Case control study.

SETTING: Pediatric Infectious Diseases Clinic of Kosair Children’s Hospital, 1990 to 1992.

PARTICIPANTS: Forty-four patients referred for persistent fatigue were evaluated. Twenty patients participated in a psychological study; 20 healthy controls of similar age and gender were recruited from community pediatric practices and 20 matched depressed controls were recruited from university psychiatry services (subjects were treated as groups in the analyses).

MEASURES: Demographic data were obtained for all referred patients. Those with fatigue for at least 2 months and no alternative diagnosis received a detailed history, physical, and battery of laboratory tests (complete blood count, sedimentation rate, chemistry panel, chest X-ray thyroid stimulating hormone, thyroxine, anti-nuclear antibodies, urinalysis, immunoglobulins, and Epstein-Barr virus (EBV), toxoplasma, and cytomegalovirus serologies). Psychological study participants completed the following: background structured interview; Kaufman Brief Intelligence Test; Children’s Depression Inventory; Child Behavior Checklist; Youth Self Report; Diagnostic Interview for Children and Adolescents-Revised; mail-in follow-up survey.

RESULTS: The median age of fatigue patients was 14.3 years; 60% were female, 96% white, and 87% from the mid/upper socioeconomic status (SES). Fatigue patients were demographically similar to 21 patients referred for infectious mononucleosis (IM) but were older than other clinic patients (P < .0001). White race (P = .0568) and mid/upper SES (P = .0403) were over-represented among fatigue patients compared to patients referred for other diagnoses. Of 36 patients meeting criteria for further study, 5 had an IM-like illness including evidence of recent EBV infection. For the remaining 31 patients, clinical and laboratory evaluations were unrevealing. Psychological study subjects reported marked declines in quality-of-life and scored high on measures of internalizing, withdrawal, and social isolation. Nine met diagnostic criteria for depression, although depressive symptoms were not as prominent as those reported by depressed controls. Fatigue subjects scored higher on somatization than both control groups. The follow-up survey indicated symptomatic improvement in most patients.

CONCLUSIONS: Chronic fatigue was a common reason for referral, with over-representation of white children from mid/upper SES. After exclusion of EBV-associated IM, screening laboratory tests were not helpful in establishing specific organic diagnoses. Whereas the natural history was favorable, chronic fatigue resulted in major quality-of-life changes and was associated with significant levels of psychosocial distress.

IMPLICATIONS: Psychological evaluation is warranted in these patients, as some may have treatable psychological conditions. Given the absence of proved medical therapies, psychosocial interventions to improve quality-of-life should be studied.

 

Source: Carter BD, Edwards JF, Kronenberger WG, Michalczyk L, Marshall GS. Case control study of chronic fatigue in pediatric patients. Pediatrics. 1995 Feb;95(2):179-86. http://www.ncbi.nlm.nih.gov/pubmed/7838632

 

Psychobehavioral and immunological characteristics of adult people with chronic fatigue and patients with chronic fatigue syndrome

Abstract:

The psychobehavioral responses and cellular immune function were investigated in healthy people (control, N = 21), adult people with chronic fatigue (fatigue-non-CFS group, N = 24), and patients with chronic fatigue syndrome (CFS, N = 10).

Based on psychobehavioral responses, the fatigue-non-CFS group had low general activity levels (p < .05) and slightly depressive tendencies (p < .01) compared with the control. They had many life event stresses (p < .05) and sleep disturbances (p < .01), and they could not cope appropriately with stresses.

The fatigue-non-CFS group also showed significantly lower natural killer (NK) cell activity (p < .01) and decreased numbers of CD16+ and CD56+ cells (p < .05). Compared with the fatigue-non-CFS group, patients with CFS had higher degrees of physical fatigue (p < .01) and more life event stresses (p < .05).

They had lower general activity levels and social introversion. They were also in a depressive state. NK cell activity and the numbers of CD16+ and CD56+ cells were significantly reduced in patients with CFS (p < .01).

These findings suggest that adult people with chronic fatigue may be in an intermediate state between the healthy control and patients with CFS in terms of psychobehavioral responses and low NK cell activity. We observed three cases in such an intermediate state in whom CFS subsequently developed.

 

Source: Masuda A, Nozoe SI, Matsuyama T, Tanaka H. Psychobehavioral and immunological characteristics of adult people with chronic fatigue and patients with chronic fatigue syndrome. Psychosom Med. 1994 Nov-Dec;56(6):512-8. http://www.ncbi.nlm.nih.gov/pubmed/7871106

 

Chronic fatigue: a peculiar evolution of eosinophilia myalgia syndrome following treatment with L-tryptophan in four Italian adolescents

Abstract:

We describe four Italian adolescents in whom a persistent, debilitating fatigue appeared after therapeutic ingestion of products containing L-tryptophan and subsequent to the development of a transient rise in eosinophil count and severe myalgia (Eosinophilia Myalgia Syndrome-EMS). Their clinical picture was indistinguishable from that of the so-called Chronic Fatigue Syndrome. A chronic fatigue may occur after diverse triggering agents and its represents the peculiar clinical evolution of these four paediatric cases of EMS.

 

Source: Priori R, Conti F, Luan FL, Arpino C, Valesini G. Chronic fatigue: a peculiar evolution of eosinophilia myalgia syndrome following treatment with L-tryptophan in four Italian adolescents. Eur J Pediatr. 1994 May;153(5):344-6. http://www.ncbi.nlm.nih.gov/pubmed/8033924

 

Alpha-delta sleep in patients with a chief complaint of chronic fatigue

Abstract:

Our prospective, standardized cohort study was designed to assess the presence of alpha wave intrusions during non-rapid eye movement sleep (alpha-delta sleep) and its relationship to fibromyalgia, major depression, and chronic fatigue syndrome (CFS) in patients with a chief complaint of chronic fatigue.

The study group comprised 30 consecutive patients seen at a university hospital referral clinic for evaluation of chronic fatigue. All patients had nocturnal polysomnography, dolorimetric tender point assessment for fibromyalgia, a comprehensive history, physical, and laboratory evaluation, and a structured psychiatric interview. Alpha-delta sleep was identified in 8 of the 30 patients (26%), major depression in 20 (67%), CFS in 15 (50%), and fibromyalgia in 4 (13%). Ten of the 30 patients (33%) had a primary sleep disorder (sleep apnea, periodic limb movements, or narcolepsy).

Alpha-delta sleep was not significantly correlated with fibromyalgia, CFS, major depression, or primary sleep disorders, but was significantly more common among patients who had chronic fatigue without major depression. We conclude that primary sleep disorders are relatively common among patients with chronic fatigue and must be diligently sought and treated. Alpha-delta sleep is not a marker of fibromyalgia or CFS, but may contribute to the illness of nondepressed patients with these conditions.

Comment in: Sleep disorders and chronic fatigue. [South Med J. 1994]

 

Source: Manu P, Lane TJ, Matthews DA, Castriotta RJ, Watson RK, Abeles M. Alpha-delta sleep in patients with a chief complaint of chronic fatigue. South Med J. 1994 Apr;87(4):465-70. http://www.ncbi.nlm.nih.gov/pubmed/8153772

 

Measuring the functional impact of fatigue: initial validation of the fatigue impact scale

Abstract:

The fatigue impact scale (FIS) was developed to improve our understanding of the effects of fatigue on quality of life. The FIS examines patients’ perceptions of the functional limitations that fatigue has caused over the past month. FIS items reflect perceived impact on cognitive, physical, and psychosocial functioning.

This study compared 145 patients referred for investigation of chronic fatigue (ChF) with 105 patients with multiple sclerosis (MS) and 34 patients with mild hypertension (HT). Internal consistency for the FIS and its three subscales was > .87 for all analyses. Fatigue impact was highest for the ChF group although the MS group’s reported fatigue also exceeded that of the HT group. Discriminant function analysis correctly classified 80.0% of the ChF group and 78.1% of the MS group when these groups were compared.

This initial validation study indicates that the FIS has considerable merit as a measure of patient’s attribution of functional limitations to symptoms of fatigue.

 

Source: Fisk JD, Ritvo PG, Ross L, Haase DA, Marrie TJ, Schlech. Measuring the functional impact of fatigue: initial validation of the fatigue impact scale. Clin Infect Dis. 1994 Jan;18 Suppl 1:S79-83. http://www.ncbi.nlm.nih.gov/pubmed/8148458

 

Sleep disorders in patients with chronic fatigue

Abstract:

This prospective, cohort study examined the prevalence of sleep disorders among highly selected patients with chronic fatigue. On the basis of responses suggestive of sleep pathology on a screening questionnaire, 59 patients from a university-based clinic for chronic fatigue who had undergone a medical and psychiatric evaluation underwent polysomnography.

Criteria for chronic fatigue syndrome (CFS) were met by 64% of patients and those for a current psychiatric disorder were met by 41%. Overall, 41% of patients had abnormal results for a multiple sleep latency test and 81% had at least one sleep disorder, most frequently sleep apnea (44%) and idiopathic hypersomnia (12%).

In comparing patients who did and did not meet CFS criteria, no significant differences were found in individual sleep symptoms or sleep disorders. Likewise, symptoms and sleep disorders were unrelated to psychiatric diagnoses. In conclusion, chronically fatigued patients with suggestive symptoms may have potentially treatable coexisting sleep disorders that are not associated with meeting criteria for CFS or a current psychiatric disorder.

 

Source: Buchwald D, Pascualy R, Bombardier C, Kith P. Clin Infect Dis. 1994 Jan;18 Suppl 1:S68-72. http://www.ncbi.nlm.nih.gov/pubmed/8148456