Category: Epidemiology

The definition of disabling fatigue in children and adolescents

Abstract:

BACKGROUND: Disabling fatigue is the main illness related reason for prolonged absence from school. Although there are accepted criteria for diagnosing chronic fatigue in adults, it remains uncertain as to how best to define disabling fatigue and Chronic Fatigue Syndrome (CFS) in children and adolescents. In this population-based study, the aim was to identify children who had experienced an episode of disabling fatigue and examine the clinical and demographic differences between those individuals who fulfilled a narrow definition of disabling fatigue and those who fulfilled broader definitions of disabling fatigue.

METHODS: Participants (aged 8-17 years) were identified from a population-based twin register. Parent report was used to identify children who had ever experienced a period of disabling fatigue. Standardised telephone interviews were then conducted with the parents of these affected children. Data on clinical and demographic characteristics, including age of onset, gender, days per week affected, hours per day spent resting, absence from school, comorbidity with depression and a global measure of impairment due to the fatigue, were examined. A narrow definition was defined as a minimum of 6 months disabling fatigue plus at least 4 associated symptoms, which is comparable to the operational criteria for CFS in adults. Broader definitions included those with at least 3 months of disabling fatigue and 4 or more of the associated symptoms and those with simply a minimum of 3 months of disabling fatigue. Groups were mutually exclusive.

RESULTS: Questionnaires were returned by 1468 families (65% response rate) and telephone interviews were completed on 99 of the 129 participants (77%) who had experienced fatigue. There were no significant differences in demographic and clinical characteristics or levels of impairment between those who fulfilled the narrower definition and those who fulfilled the broader definitions. The only exception was the reported number of days per week that the child was affected by the fatigue. All groups demonstrated evidence of substantial impairment associated with the fatigue.

CONCLUSION: Children and adolescents who do not fulfil the current narrow definition of CFS but do suffer from disabling fatigue show comparable and substantial impairment. In primary care settings, a broader definition of disabling fatigue would improve the identification of impaired children and adolescents who require support.

 

Source: Fowler T, Duthie P, Thapar A, Farmer A. The definition of disabling fatigue in children and adolescents. BMC Fam Pract. 2005 Aug 9;6:33. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1192794/ (Full article)

 

Chronic fatigue syndrome: the need for subtypes

Abstract:

Chronic fatigue syndrome (CFS) is an important condition confronting patients, clinicians, and researchers. This article provides information concerning the need for appropriate diagnosis of CFS subtypes. We first review findings suggesting that CFS is best conceptualized as a separate diagnostic entity rather than as part of a unitary model of functional somatic distress. Next, research involving the case definitions of CFS is reviewed.

Findings suggest that whether a broad or more conservative case definition is employed, and whether clinic or community samples are recruited, these decisions will have a major influence in the types of patients selected. Review of further findings suggests that subtyping individuals with CFS on sociodemographic, functional disability, viral, immune, neuroendocrine, neurology, autonomic, and genetic biomarkers can provide clarification for researchers and clinicians who encounter CFS’ characteristically confusing heterogeneous symptom profiles.

Treatment studies that incorporate subtypes might be particularly helpful in better understanding the pathophysiology of CFS. This review suggests that there is a need for greater diagnostic clarity, and this might be accomplished by subgroups that integrate multiple variables including those in cognitive, emotional, and biological domains.

 

Source: Jason LA, Corradi K, Torres-Harding S, Taylor RR, King C. Chronic fatigue syndrome: the need for subtypes. Neuropsychol Rev. 2005 Mar;15(1):29-58. http://www.ncbi.nlm.nih.gov/pubmed/15929497

 

Epidemiology of chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a controversial disorder with different case definitions, aetiological models and proposed treatments. An epidemiological approach is likely to bring some clarity to the field.

AIM: The aim of this article is to review the literature on the epidemiology of fatigue, chronic fatigue and CFS.

METHOD: A literature search was conducted using the databases Medline and Pubmed as well as the reference lists of recent reviews to identify the relevant studies. The aim was not to do a systematic review but to review the key studies in the area to highlight the methodological issues.

RESULTS: The review is organized according to the following areas: the prevalence of fatigue and chronic fatigue, the prevalence and incidence of CFS, epidemiological associations such as gender, social class and psychiatric co-morbidity and CFS in special groups such as those recovering from a viral infection, specific occupational groups and Gulf War veterans.

CONCLUSION: While fatigue as a symptom is very common, CFS is relatively rare. Many of the epidemiological associations seen in specialist clinics are not found in community samples. It is unlikely that one specific causal factor can explain CFS. Future studies should go beyond estimating the prevalence to testing more complex aetiological models.

 

Source: Ranjith G. Epidemiology of chronic fatigue syndrome. Occup Med (Lond). 2005 Jan;55(1):13-9. http://occmed.oxfordjournals.org/content/55/1/13.long (Full article)

 

Incidence of fatigue symptoms and diagnoses presenting in UK primary care from 1990 to 2001

Erratum in: J R Soc Med. 2005 Feb;98(2):88.

 

Abstract:

Little is known about whether the incidence of symptoms of fatigue presented in primary care, and the consequent diagnoses made, change over time. The UK General Practice Research Database was used to investigate the annual incidence of both fatigue symptoms and diagnoses recorded in UK primary care from 1990 to 2001. The overall incidence of all fatigue diagnoses decreased from 87 per 100 000 patients in 1990 to 49 in 2001, a reduction of 44%, while postviral fatigue syndromes decreased from 81% of all fatigue diagnoses in 1990 to 60% in 2001. Chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) together increased from 9% to 26% of all fatigue diagnoses. The incidence of fibromyalgia increased from less than 1 per 100 000 to 35 per 100 000. In contrast, there was no consistent change in the incidence of all recorded symptoms of fatigue, with an average of 1503 per 100 000, equivalent to 1.5% per year. CFS/ME and fibromyalgia were rarely diagnosed in children and were uncommon in the elderly. All symptoms and diagnoses were more common in females than in males. The overall incidence of fatigue diagnoses in general has fallen, but the incidence rates of the specific diagnoses of CFS/ME and fibromyalgia have risen, against a background of little change in symptom reporting. This is likely to reflect fashions in diagnostic labelling rather than true changes in incidence.

Comment in: Brain imaging in fatigue syndromes. [J R Soc Med. 2005]

 

Source: Gallagher AM, Thomas JM, Hamilton WT, White PD. Incidence of fatigue symptoms and diagnoses presenting in UK primary care from 1990 to 2001. J R Soc Med. 2004 Dec;97(12):571-5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1079668/ (Full article)

 

Factors influencing the diagnosis of chronic fatigue syndrome

Abstract:

BACKGROUND: Most of what is believed about chronic fatigue syndrome (CFS) is based on clinic-based studies. These studies may not reflect CFS cases in the population.

METHODS: We used data from a population-based study of CFS to identify factors associated with receiving a CFS diagnosis. Wichita, Kan, residents were screened by random-digit dialing. Eligible individuals completed a telephone interview. Respondents meeting CFS criteria were invited for a clinical evaluation to confirm CFS. We analyzed all persons with confirmed CFS. The main outcomes of this study, prevalence and incidence of CFS, are published elsewhere. Herein, we present an exploratory analysis with previous CFS diagnosis as the outcome, predicted by demographic and symptom characteristics.

RESULTS: We confirmed CFS in 90 subjects; 14 (16%) had been previously diagnosed as having CFS. Persons in the middle- vs the higher-income group were more likely to have been diagnosed as having CFS (9 [29%] of 31 subjects vs 3 [8%] of 39 subjects; P = .03), as were those with sudden vs gradual fatigue onset (7 [41%] of 17 subjects vs 4 [6%] of 64 subjects; P < .01), those reporting tender lymph nodes (7 [33%] of 21 subjects vs 7 [10%] of 69 subjects; P = .02), and those reporting a sore throat (6 [35%] of 17 subjects vs 8 [11%] of 73 subjects; P = .02). Only 17 (21%) of 81 subjects had sudden fatigue onset, and tender lymph nodes (reported in 21 [23%] of 90 subjects) and a sore throat (reported in 17 [19%] of 90 subjects) were the least common symptoms.

CONCLUSION: Most cases of CFS in the population are unrecognized by the medical community; persons diagnosed as having CFS may be different from persons with CFS in the general population.

 

Source: Solomon L, Reeves WC. Factors influencing the diagnosis of chronic fatigue syndrome. Arch Intern Med. 2004 Nov 8;164(20):2241-5. http://www.ncbi.nlm.nih.gov/pubmed/15534161

 

Development of the chronic fatigue syndrome in severely fatigued employees: predictors of outcome in the Maastricht cohort study

Abstract:

STUDY OBJECTIVE: To identify risk factors of the development of the chronic fatigue syndrome (CFS), the persistence or recurrence of fatigue, or recovery from fatigue in a large sample of fatigued employees.

DESIGN: Analyses were based on the Maastricht cohort study (MCS), a prospective population based cohort study among more than 12 000 employees. Multiple regression models were used to identify predictors of CFS-like caseness (meeting research criteria for CFS), non-CFS fatigue caseness, or no fatigue caseness.

SETTING: The working population in the Netherlands.

PARTICIPANTS: 1143 employees with medically unexplained fatigue were followed up prospectively for 44 months.

MAIN RESULTS: At 44 month follow up, 8% of the employees were CFS-like cases (none of who reported to have received a CFS diagnosis), 40% were non-CFS fatigue cases, and 52% were no longer fatigue cases. Factors that predicted CFS-like caseness compared with non-CFS fatigue caseness were high age, exhaustion, female sex, low education, and visits to the general practitioner. Factors that predicted CFS-like caseness compared with no fatigue caseness were fatigue, exhaustion, low education, visits to the GP and occupational physician, and bad self rated health. Factors that predicted non-CFS fatigue caseness compared with no fatigue caseness were fatigue, low self perceived activity, exhaustion, anxious mood, and bad self rated health.

CONCLUSIONS: Unexplained fatigue among employees in some instances is a precursor of the development of CFS. The prognostic role of self rated health suggests that prevention and treatment of chronic fatigue should be aimed at changing the perception of health or illness. Less clear is the role of health care seeking or receiving a CFS diagnosis.

 

Source: Huibers MJ, Kant IJ, Knottnerus JA, Bleijenberg G, Swaen GM, Kasl SV. Development of the chronic fatigue syndrome in severely fatigued employees: predictors of outcome in the Maastricht cohort study. J Epidemiol Community Health. 2004 Oct;58(10):877-82. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1763327/

 

Unloading the trunk: neurasthenia, CFS and race

Abstract:

The aetiologies of both chronic fatigue syndrome (CFS) and its predecessor neurasthenia, have been linked to technological advances in ‘developed’ countries. This paper discusses how this has led to a form of race thinking within discussions about fatigue which has persisted for more than a century. We review the historical development of this race thinking from neurasthenia to CFS and describe how it is manifested in both the lay- and medical literature. We also review the epidemiological literature on CFS and ethnicity to better understand the relatively low percentage of non-white patients seen in tertiary referral clinics for CFS. The aim of this paper is to act as a starting point for a debate on race and CFS.

 

Source: Luthra A, Wessely S. Unloading the trunk: neurasthenia, CFS and race. Soc Sci Med. 2004 Jun;58(11):2363-9. http://www.ncbi.nlm.nih.gov/pubmed/15047091

 

A comparison of pregnancies that occur before and after the onset of chronic fatigue syndrome

Abstract:

BACKGROUND: Many women with chronic fatigue syndrome (CFS) fear that pregnancy will worsen their condition, increase the risks of maternal complications of pregnancy, or threaten the health of their offspring. Little empirical evidence, however, has been published on this matter.

METHODS: A detailed questionnaire was administered to 86 women regarding 252 pregnancies that occurred before or after the onset of CFS and the outcomes of these pregnancies were observed.

RESULTS: During pregnancy, there was no change in CFS symptoms in 29 (41%), an improvement of symptoms in 21 (30%), and a worsening of symptoms in 20 (29%) of 70 subjects. After pregnancy, there was no change in CFS symptoms in 21 (30%), an improvement of symptoms in 14 (20%), and a worsening of symptoms in 35 (20%) of the subjects. The rates of many complications were similar in pregnancies occurring before the onset and in those occurring after the onset of CFS. There was a higher frequency of spontaneous abortions in the pregnancies occurring after, vs before, the onset of CFS (22 [30%] of 73 pregnancies after vs 13 [8%] of 171 before; P<.001), but no differences in the rates of other complications. Developmental delays or learning disabilities were reported more often in the offspring of women who became pregnant after, vs before, the onset of CFS (9 [21%] of 43 children vs 11 [8%] of 139 children; P =.01).

CONCLUSIONS: Pregnancy did not consistently worsen the symptoms of CFS. Most maternal and infant outcomes were not systematically worse in pregnancies occurring after the onset of CFS. The higher rates of spontaneous abortions and of developmental delays in offspring that we observed could be explained by maternal age or parity differences, and should be investigated by larger, prospective studies with control populations.

Comment in: Chronic fatigue syndrome, pregnancy, and Addison disease. [Arch Intern Med. 2004]

 

Source: Schacterle RS, Komaroff AL. A comparison of pregnancies that occur before and after the onset of chronic fatigue syndrome. Arch Intern Med. 2004 Feb 23;164(4):401-4. http://www.ncbi.nlm.nih.gov/pubmed/14980991

 

Functional status of persons with chronic fatigue syndrome in the Wichita, Kansas, population

Abstract:

BACKGROUND: Scant research has adequately addressed the impact of chronic fatigue syndrome on patients’ daily activities and quality of life. Enumerating specific problems related to quality of life in chronic fatigue syndrome patients can help us to better understand and manage this illness. This study addresses issues of functional status in persons with chronic fatigue syndrome and other fatiguing illnesses in a population based sample, which can be generalized to all persons with chronic fatigue.

METHODS: We conducted a random telephone survey in Wichita, Kansas to identify persons with chronic fatigue syndrome and other fatiguing illnesses. Respondents reporting severe fatigue of at least 1 month’s duration and randomly selected non-fatigued respondents were asked to participate in a detailed telephone interview. Participants were asked about symptoms, medical and psychiatric illnesses, and about physical, social, and recreational functioning. Those meeting the 1994 chronic fatigue syndrome case definition, as determined on the basis of their telephone responses, were invited for clinical evaluation to confirm a diagnosis of chronic fatigue syndrome. For this analysis, we evaluated unemployment due to fatigue, number of hours per week spent on work, chores, and other activities (currently and prior to the onset of fatigue), and energy level.

RESULTS: There was no difference between persons with chronic fatigue syndrome and persons with a chronic fatigue syndrome-like illness that could be explained by a medical or psychiatric condition for any of the outcomes we measured except for unemployment due to fatigue (15% vs. 40%, P <.01). Persons with chronic fatigue syndrome and other fatiguing illnesses had substantially less energy and spent less time on hobbies, schooling, or volunteer work than did non-fatigued controls (P <.01).

CONCLUSIONS: Persons with chronic fatigue syndrome are as impaired as persons whose fatigue could be explained by a medical or psychiatric condition, and they have less energy than non-fatigued controls.

Comment in: Chronic fatigue and chronic fatigue syndrome in the general population. [Health Qual Life Outcomes. 2003]

 

Source: Solomon L, Nisenbaum R, Reyes M, Papanicolaou DA, Reeves WC. Functional status of persons with chronic fatigue syndrome in the Wichita, Kansas, population. Health Qual Life Outcomes. 2003 Oct 3;1:48. http://www.ncbi.nlm.nih.gov/pubmed/14577835

 

Epidemiology of chronic fatigue syndrome and self reported myalgic encephalomyelitis in 5-15 year olds: cross sectional study

Chronic fatigue syndrome is characterised by severe physical and mental fatigue associated with disability, which by definition markedly affects people’s lives. At one end of the spectrum, newspaper headlines imply that chronic fatigue syndrome or myalgic encephalomyelitis in children is of epidemic proportions, whereas at the other end the existence of the disorder is refuted. Attempts have been made to assess the size of the problem in the community, general practice, schools, and secondary care.w1-w5 Methodological problems, however, such as selection biases and poor response rates make it difficult to draw conclusions from these studies. We are unaware of any population studies in the United Kingdom that examine the prevalence of and factors associated with chronic fatigue syndrome in children. We determined the prevalence of chronic fatigue, chronic fatigue syndrome, and reported myalgic encephalomyelitis in 5-15 year olds and examined demographic and psychiatric associations.

You can read the rest of this article here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC196393/

 

Source: Chalder T, Goodman R, Wessely S, Hotopf M, Meltzer H. Epidemiology of chronic fatigue syndrome and self reported myalgic encephalomyelitis in 5-15 year olds: cross sectional study. BMJ. 2003 Sep 20;327(7416):654-5.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC196393/ (Full article)