The demographic features of fatigue in the general population worldwide: a systematic review and meta-analysis

Background

Fatigue is one of the most common subjective symptoms that impairs daily life and predict health-related events. This study aimed to estimate the prevalence of fatigue in the global population.

Methods

PubMed and the Cochrane Library were used to search for relevant articles from inception to December 31, 2021. Studies with prevalence data of fatigue in the general population were selected and reviewed by three authors independently and cross-checked. Regarding subgroups, adults (≥18 years), minors (<18 years), and specific occupation population (participants in each study being limited to a specific occupational group), and fatigue types and severity, meta-analysis was conducted to produce point estimates and 95% confidence intervals (95% CI).

Results

From the initial 3,432 studies, 91 studies accounting for 115 prevalence data points (623,624 participants) were finally selected. The prevalence of general fatigue (fatigue lasting < 6 months, or fatigue of unspecified duration) was 20.4% (95% CI, 16.7-25.0) in adults, 11.7% (95% CI, 5.2-26.6) in minors, and 42.3% (95% CI, 33.0-54.2) in specific occupations. Chronic fatigue (fatigue lasting more than 6 months) affected 10.1% (95% CI, 8.2-12.5) of adults, 1.5% (95% CI, 0.5-4.7) of minors, and 5.5% (95% CI, 1.4-21.6) of subjects in specific occupations. There was an overall female-predominant prevalence for all subgroup analyses, with a total odds ratio of 1.4 (95% CI, 1.3-1.6). Regarding the severity and presence of medical causes, the total prevalence of moderate fatigue [14.6% (95% CI, 9.8-21.8)] was 2.4-fold that of severe fatigue [6.1% (95% CI, 3.4-11.0)], while unexplained fatigue (fatigue experienced by individuals without any underlying medical condition that can explain the fatigue) was ~2.7-fold that of explained fatigue (fatigue experienced by individuals with a medical condition that can explain the fatigue); as proportion of 40.0% of physical, 8.6% of mental, and 28.4% of mixed cause.

Conclusions

This study has produced the first comprehensive picture of global fatigue prevalence in the general population, which will provide vital reference data contributing to fatigue-related research, including the prevention of diseases.

Systematic review registration

Identifier: CRD42021270498.

Effectiveness of Coenzyme Q10 Supplementation for Reducing Fatigue: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Coenzyme Q10 (CoQ10) is a popular nutritional supplement, an antioxidant and an essential component of the mitochondrial electron transport chain. Several clinical studies have suggested that fatigue can be reduced by antioxidant supplementation. However, the data on this topic has been sparse to date. Hence, we conducted this meta-analysis with the aim of investigating the effectiveness of fatigue reduction via CoQ10 supplementation. More specifically, we searched electronic databases for randomized controlled trials (RCTs) published from the database inception to January 2022. A random effects model was implemented to conduct the meta-analysis among 13 RCTs (with a total of 1,126 participants). As compared with the placebo groups evaluated in each RCT, the CoQ10 group showed a statistically significant reduction in fatigue scores (Hedges’ g = −0.398, 95% confidence interval = −0.641 to −0.155, p = 0.001). The directions of the treatment effects were consistent between the healthy and diseased participants. Compared with the placebo group, the effect of reducing fatigue was statistically significant in the subgroup using the CoQ10-only formulation but not in the subgroup using CoQ10 compounds. The results of our meta-regression demonstrate that increases in the daily dose (coefficient = −0.0017 per mg, p < 0.001) and treatment duration (coefficient = −0.0042 per day, p = 0.007) of CoQ10 supplementation were correlated with greater fatigue reduction. There was only one adverse (gastrointestinal) event in the 602 participants who underwent the CoQ10 intervention. Based on the results of this meta-analysis, we conclude that CoQ10 is an effective and safe supplement for reducing fatigue symptoms.

Systematic Review Registration:https://inplasy.com/inplasy-2022-1-0113/, identifier INPLASY202210113

The Role of Experiential Avoidance in Terms of Fatigue and Pain During COVID-19 Among Latinx Adults

Background

Latinx persons are overrepresented in terms of 2019 Coronavirus (COVID-19) infection rates and constitute a subpopulation at increased risk for COVID-19 related physical ailments. Fatigue and pain are among the most prevalent somatic symptoms among the Latinx population; however, there is little understanding of individual difference factors that are related to fatigue and pain during COVID-19 among this health disparities population. Experiential avoidance (EA) reflects the persistent tendency to avoid aversive internal sensations.

Methods

The current study sought to extend past work by exploring EA in relation to fatigue severity, pain intensity, and pain disability among 182 Latinx adult persons during the COVID-19 pandemic.

Results

Results indicated that EA accounted for a statistically significant amount of variance across the criterion variables.

Conclusions

Overall, the current work provides initial empirical evidence that EA is related to greater fatigue severity and pain severity/disability among Latinx persons during COVID-19.

The influence of nocebo information on fatigue and urge to stop: An experimental investigation

BACKGROUND AND OBJECTIVES

Fatigue is an adaptive state after prolonged effort and often goes hand in hand with changes in behavior and motivation, such as the urge to stop exerting further effort. However, fatigue may become chronic in nature, as seen in multiple psychiatric disorders and chronic diseases, thereby losing its adaptive function. The etiology of fatigue symptoms remains poorly understood. We aimed to investigate whether nocebo information about the fatigue inducing nature of a cognitive task may contribute to the experience of fatigue and the motivational urge to stop.

METHODS

Participants (N = 46) repeatedly rated currently experienced fatigue while engaging in cognitive effort (working memory task). Crucially, half of participants received nocebo instructions prior to this task, whereas the other half only received neutral information.

RESULTS

Over the entire sample, results showed an increase in fatigue and urge to stop as the task progressed. Crucially, participants in the nocebo condition reported a higher urge to stop throughout the task relative to participants in the neutral condition. No significant effects were found for fatigue. Interestingly however, after controlling for baseline differences between conditions in negative affect, there was a significant Condition*Task block interaction effect on fatigue.

LIMITATIONS

Limitations include the relatively short experimental protocol and the underrepresentation of male relative to female participants.

CONCLUSIONS

These findings suggest that heightened awareness among clinicians and therapists about potential nocebo effects in their communication is warranted.

Effects of Fatigue and Grit on Club Sports Coaches

The objective of this research is to identify the level of general fatigue (FG), physical fatigue (FF) and concentration/motivation (C/M) in sports coaches. Two components of grit, consistency of interest (CI) and perseverance in effort (PE), are also assessed. The possible effects of sex, age, marital status, employment contract, work dedication and grit on FG, FF and C/M in sports coaches are examined. This cross-sectional study analyses 335 sports club coaches (21.2% women, 78.8% male) with a mean age of 29.88 (SD = 9.97) years, at a significance level of p < 0.05 for all analyses. Different aspects of fatigue were determined using the Spanish translation of the Multidimensional Fatigue Inventory-20 (IMF-20). The Grit-S scale was used to measure the ability to persevere, have passion and commit. The results indicated that men scored higher in FF, C/M and PE, while women obtained higher values in FG and CI. Non-contract coaches had higher FG, CI and PE, while coaches with contracts scored higher on C/M and FF. In conclusion, coaches with higher CI had higher FG, and high levels of PE were associated with low FG levels.

Prevalence of motor impairment in residents of New South Wales, Australia aged 55 years and over: cross-sectional survey of the 45 and Up cohort

BACKGROUND

The population prevalence of many diseases is known. However, little is known of the population prevalence of motor impairments.

METHODS

The aim of this study was to determine the point prevalence of specific motor impairments (weakness, fatigue, contracture, impaired balance and impaired coordination) in the population aged 55 years and older resident in New South Wales, Australia in 2018. 55,210 members of the 45 and Up cohort were invited to participate in a follow-up survey that included questions on motor impairment. Responses were received from 20,141 people (36%). Calibrated estimates of prevalence of specific motor impairments, and of having at least one motor impairment, were obtained using survey weights based on the known multivariate distributions of age, gender and geographical location (28 regions) in the population.

RESULTS

More than one-third of adults aged over 55 residing in New South Wales have difficulty using their hands, arms or legs. The prevalence of each motor impairment (muscle weakness, fatigue, contracture, impaired balance or impaired coordination) in this population is between 4 and 12%. The prevalence of at least one of these impairments is 21%. The prevalence of at least one impairment in people aged 85 and over is 42%. Women consistently had more difficulty using hands, arms and legs, and more motor impairment, than men. Difficulty using hands, arms and legs and the prevalence of all motor impairments, especially poor balance, greatly increased with age.

CONCLUSION

The prevalence of specific motor impairments in older Australian adults is high - comparable to that of the most prevalent diseases. There may be merit in considering motor impairment as a significant public health problem in its own right.

Healthcare Utilization in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Analysis of US Ambulatory Healthcare Data, 2000-2009

Background: ME/CFS is a complex and disabling illness with substantial economic burden and functional impairment comparable to heart disease and multiple sclerosis. Many patients with ME/CFS do not receive appropriate healthcare, partially due to lack of diagnostic tests, and knowledge/attitudes/beliefs about ME/CFS. This study was to assess the utility of US ambulatory healthcare data in profiling demographics, co-morbidities, and healthcare in ME/CFS. Methods: Data came from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) in the U.S. Weighted analysis was performed. We examined 9.06 billion adult visits from 2000 to 2009 NAMCS/NHAMCS data. ME/CFS-related visits were identified by ICD-9-CM code, 780.71, up to tertiary diagnosis. Results: We estimated 2.9 million (95% CI: 1.8-3.9 million) ME/CFS-related visits during 2000-2009, with no statistical evidence (p-trend = 0.31) for a decline or increase in ME/CFS-related visits. Internists, general and family practitioners combined provided 52.12% of these visits. Patients with ME/CFS-related visits were mostly in their 40 and 50 s (47.76%), female (66.07%), white (86.95%), metropolitan/urban residents (92.05%), and insured (87.26%). About 71% of ME/CFS patients had co-morbidities, including depression (35.79%), hypertension (31.14%), diabetes (20.30%), and arthritis (14.11%). As one quality indicator, physicians spent more time on ME/CFS-related visits than non-ME/CFS visits (23.62 vs. 19.38 min, p = 0.065). As additional quality indicators, the top three preventive counseling services provided to patients with ME/CFS-related visits were diet/nutrition (8.33%), exercise (8.21%), and smoking cessation (7.24%). Compared to non-ME/CFS visits, fewer ME/CFS-related visits included counseling for stress management (0.75 vs. 3.14%, p = 0.010), weight reduction (0.88 vs. 4.02%, p = 0.002), injury prevention (0.04 vs. 1.64%, p < 0.001), and family planning/contraception (0.17 vs. 1.45%, p = 0.037). Conclusions: Visits coded with ME/CFS did not increase from 2000 to 2009. Almost three quarters of ME/CFS-related visits were made by ME/CFS patients with other co-morbid conditions, further adding to complexity in ME/CFS healthcare. While physicians spent more time with ME/CFS patients, a lower proportion of ME/CFS patients received preventive counseling for weight reduction, stress management, and injury prevention than other patients despite the complexity of ME/CFS. NAMCS/NHAMCS data are useful in evaluating co-morbidities, healthcare utilization, and quality indicators for healthcare in ME/CFS.

Prevalence of Fatigue in Head and Neck Cancer Survivors

Introduction:

In head and neck cancer (HNC) patients, fatigue is present throughout the course of treatment and during follow-up. There are limited data about the prevalence and factors associated with fatigue in HNC survivors. The objectives of this study were to assess the prevalence of fatigue and its interference with daily life activities and examine the association between fatigue and gender, age, primary tumour site, Human Papillomavirus (HPV) status, previous oncologic therapy, and time since end of treatment.

Methods:

Consecutive locally advanced HNC patients having completed curative treatment at least 1 year earlier and free of disease were asked to fill in the Brief Fatigue Inventory (BFI) questionnaire. Fatigue was categorized according to BFI average score as absent (0), mild (>0 to <4), moderate (≥4 to ≤6), and severe (>6 to ≤10).

Results:

From February 2015 to July 2016, 129 patients (median age = 60 years old; 67% male) were evaluated. Primary sites of cancer were oropharynx (46%, with 4/5 patients HPV positive), nasopharynx (22%), larynx/hypopharynx (14%), oral cavity (13%), and paranasal sinus or salivary gland (5%). Oncologic treatment was completed 12 to 96 months earlier (median = 34 months). Fatigue was reported as absent in 15% of the patients, mild in 67%, moderate in 11%, and severe in 7%. No association between BFI average score and the analyzed variables was identified.

Discussion:

Moderate and severe fatigue was reported in 18% of HNC survivors. Further research is needed to assess its causes and improve the management.

Fatigue in Parkinson's disease: A systematic review and meta-analysis

We conducted a systematic review and meta-analysis aimed at establishing robust prevalence estimates and identifying clinical correlates of fatigue in PD. From 2,459 titles and abstracts, we selected 44 relevant studies (n = 7427 patients). Overall, the meta-analysis showed a prevalence of fatigue of 50% in PD. This prevalence estimate, however, was significantly moderated by study heterogeneity in measurement scales and cut-off thresholds. In contrast, demographic features, disease severity, cognitive impairment, and depression did not moderate prevalence estimates. Moreover, fatigue prevalence did not differ between de novo and treated PD patients. Compared to nonfatigued patients, fatigued patients had sligthly higher age (1.44 years), disease duration (0.93 years), l-dopa equivalent daily dose (50.89 units), UPDRS-III (4.99 points), and H & Y (0.33 points), as well as risk of comorbid depression (risk ratio = 1.89) and had a little lower MMSE score (-0.66 points). Fatigue was moderately associated with apathy (Hedges' g = 0.55), anxiety (Hedges' g = 0.67), daytime somnolence (Hedges' g = 0.43), sleep disturbances (Hedges' g = 0.66), and poorer quality of life (Hedges' g = 1.23). Our analyses suggest that fatigue is a frequent, independent nonmotor symptom in PD appearing early and persisting throughout the disease course, and that establishing uniform diagnostic criteria for PD-related fatigue is critical. In addition, several nonmotor symptoms appear to be associated with fatigue and negatively impact quality of life. Pharmacological and nonpharmacological interventions targeting fatigue and associated symptoms may improve quality of life in patients with PD. © 2018 International Parkinson and Movement Disorder Society.

A reexamination of the cognitive behavioral model of chronic fatigue syndrome

OBJECTIVE

The cognitive behavioral model of chronic fatigue syndrome (CFS) suggests that cognitions and reduced activity level perpetuate the fatigue and impairment that individuals with CFS experience. The two empirical evaluations of this model resulted in conflicting findings. The current study examines the influence of case definition fulfillment on the applicability of this model to CFS.

METHOD

A moderated mediation analysis was conducted on 990 individuals with CFS to reexamine the behavioral pathway of this model. Case definition fulfillment was entered as a moderator.

RESULTS

Findings were generally inconsistent with the cognitive behavioral model of CFS. Case definition fulfillment significantly moderated the relation between activity level and physical impairment (β = -0.08, p = 0.03); individuals who met more stringent case definitions demonstrated a weaker relation between activity level and impairment.

CONCLUSIONS

This model may not accurately represent the experience of individuals with CFS, particularly those who fulfill more stringent case definitions.

Epistemic injustice in healthcare encounters: evidence from chronic fatigue syndrome

Chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) remains a controversial illness category. This paper surveys the state of knowledge and attitudes about this illness and proposes that epistemic concerns about the testimonial credibility of patients can be articulated using Miranda Fricker's concept of epistemic injustice. While there is consensus within mainstream medical guidelines that there is no known cause of CFS/ME, there is continued debate about how best to conceive of CFS/ME, including disagreement about how to interpret clinical studies of treatments. Against this background, robust qualitative and quantitative research from a range of countries has found that many doctors (and medical students) display uncertainty about whether CFS/ME is real, which may result in delays in diagnosis and treatment for patients. Strikingly, qualitative research evinces that patients with CFS/ME often experience suspicion by healthcare professionals, and many patients vocally oppose the effectiveness, and the conceptualisation, of their illness as psychologically treatable. We address the intersection of these issues and healthcare ethics, and claim that this state of affairs can be explained as a case of epistemic injustice (2007). We find evidence that healthcare consultations are fora where patients with CFS/ME may be particularly vulnerable to epistemic injustice. We argue that the (often unintentional) marginalisation of many patients is a professional failure that may lead to further ethical and practical consequences both for progressive research into CFS/ME, and for ethical care and delivery of current treatments among individuals suffering from this debilitating illness.

Heart rate variability biofeedback therapy and graded exercise training in management of chronic fatigue syndrome: An exploratory pilot study

OBJECTIVE

Chronic fatigue syndrome (CFS) is characterised by persistent fatigue, exhaustion, and several physical complaints. Research has shown cognitive behavioural therapy (CBT) and graded exercise training (GET) to be the most effective treatments. In a first step we aimed to assess the efficacy of heart rate variability biofeedback therapy (HRV-BF) as a treatment method comprising cognitive and behavioural strategies and GET in the pilot trial. In a second step we aimed to compare both interventions with regard to specific parameters.

METHODS

The study was conducted in an outpatient treatment setting. A total of 28 women with CFS (50.3±9.3years) were randomly assigned to receive either eight sessions of HRV-BF or GET. The primary outcome was fatigue severity. Secondary outcomes were mental and physical quality of life and depression. Data were collected before and after the intervention as well as at a 5-month follow-up.

RESULTS

General fatigue improved significantly after both HRV-BF and GET. Specific cognitive components of fatigue, mental quality of life, and depression improved significantly after HRV-BF only. Physical quality of life improved significantly after GET. There were significant differences between groups regarding mental quality of life and depression favouring HRV-BF.

CONCLUSION

Both interventions reduce fatigue. HRV-BF seems to have additional effects on components of mental health, including depression, whereas GET seems to emphasise components of physical health. These data offer implications for further research on combining HRV-BF and GET in patients with CFS.

TRIAL REGISTRATION

The described trial has been registered at the International Clinical Trials Registry Platform following the number DRKS00005445.

Chronic fatigue syndrome: comparing outcomes in White British and Black and minority ethnic patients after cognitive-behavioural therapy

BACKGROUND

Cognitive-behavioural therapy (CBT) is one of the most promising treatments for chronic fatigue syndrome (CFS). It is unclear whether CBT is effective for Black and minority ethnic (BME) groups.

AIMS

To assess the effectiveness of CBT in BME patients compared with White British patients presenting to a specialist CFS service.

METHOD

Data from 67 (19.0%) BME participants and 285 (81.0%) White British participants referred to a specialist CFS service in the UK were collected at baseline and after CBT treatment.

RESULTS

Pairwise comparisons revealed that both BME participants and White British participants significantly improved on measures of fatigue severity (P<0.001), physical functioning (P<0.001) and work/social adjustment (P<0.001). Independent samples t-tests showed that BME participants improved despite exhibiting significantly higher baseline damage beliefs (P = 0.009), catastrophising (P = 0.024), all-or-nothing behaviour (P = 0.036) and avoidance/resting behaviour (P = 0.001), compared with White British participants.

CONCLUSIONS

To our knowledge, this study is the first to indicate that CBT is effective for treating CFS in a group of patients from diverse BME backgrounds.

Fatigue Severity among African Americans: Gender and Age Interactions

The present study investigated the relationship between fatigue, age, and gender in a multiculturally and socioeconomically diverse community-based urban sample. The impact of age and gender on fatigue severity was examined in a group of 3,692 African Americans and then compared to results from 9,717 Caucasians and 3,450 Latinos. Findings indicated that for African Americans, there was a significant gender by age interaction. African American women had significantly higher rates of fatigue when compared to African American men. Older African American men had significantly higher rates of fatigue than younger African American men. However, there was no significant difference in the levels of fatigue reported by younger and older African American women. An age and gender interaction was also present for the Caucasian sample but not for the Latino sample. Findings suggest that age and gender are important in predicting the severity of fatigue in an African American sample.

Chronic Fatigue Syndrome

Fifty-three chronic fatigue syndrome patients treated at a complementary medical centre were assessed over 12 months. Measures included the Chalder Fatigue scale, the General Health Questionnaire (GHQ) and positivity in illness (Silver Lining Questionnaire, SLQ). The SLQ measured at 6 and 9 months predicted ( p < .01) mental (but not physical) fatigue at 12 months independently of current mental fatigue, initial mental fatigue, duration since diagnosis and time between start of treatment and entry to the study. The GHQ did not predict fatigue at any time point. The results suggest that a caring therapeutic intervention increases positive interpretations of illness prior to improvements in mental fatigue, but that positivity does not play a causal role in the reduction of fatigue.

Understanding the Association of Fatigue With Other Symptoms of Fibromyalgia: Development of a Cluster Model

OBJECTIVE

To develop a symptoms cluster model that can describe factors of fibromyalgia syndrome (FMS) associated with fatigue severity as reported by the sample and to explore FMS clinical symptom subclusters based on varying symptom intensities.

METHODS

FMS individuals (n = 120, 82% ages 31-60 years, 90% women, 59% white) diagnosed with the 1990 or 2010 American College of Rheumatology diagnostic criteria were enrolled. Participants completed multiple validated self-report questionnaires to measure fatigue, pain, depression, anxiety, pain catastrophizing, daytime sleepiness, cognitive function, and FMS-related polysymptomatic distress. Cluster analysis using SPSS 19.0 and structural equation modeling using AMOS 17.0 were used.

RESULTS

Final structural equation modeling the symptoms cluster model showed good fit and revealed that FMS fatigue was associated with widespread pain, symptoms severity, pain intensity, pain interference, cognitive dysfunction, catastrophizing, anxiety, and depression (χ(2)  = 121.72 (98df), P > 0.05, χ(2) /df = 1.242, comparative fit index = 0.982, root mean square error of approximation = 0.045). Two distinct clinical symptom subclusters emerged: subcluster 1 (78% of total subjects), defined by widespread pain, unrefreshed waking, and somatic symptoms, and subcluster 2 (22% of total subjects), defined by fatigue and cognitive dysfunction with pain being a less severe and less widespread occurrence.

CONCLUSION

Overall, subcluster 1 had more intense symptoms than subcluster 2. FMS symptoms may be categorized into 2 clinical subclusters. These findings have implications for an illness whose diagnosis and management are symptom dependent. A longitudinal study capturing the variability in the symptom experience of FMS subjects is warranted.

Problems in defining post-exertional malaise

Post-exertional malaise (PEM) is a cardinal symptom of the illnesses referred to as Myalgic Encephalomyelitis (ME), Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), and chronic fatigue syndrome (CFS). PEM is reported to occur in many of these patients, and with several criteria (e.g., ME and ME/CFS), this symptom is mandatory (Carruthers et al., 2003 , 2011 ). In the present study, 32 participants diagnosed with CFS (Fukuda et al., 1994 ) were examined on their responses to self-report items that were developed to capture the characteristics and patterns of PEM. As shown in the results, the slight differences in wording for various items may affect whether one is determined to have PEM according to currently used self-report criteria to assess CFS. Better understanding of how this symptom is assessed might help improve the diagnostic reliability and validity of ME, ME/CFS, and CFS.

Prevalence of fatigue in patients 3 months after stroke and association with early motor activity: a prospective study comparing stroke patients with a matched general population cohort

BACKGROUND

Fatigue is a common complaint after stroke. Reasons for higher prevalence are still unclear. This study aimed to determine if fatigue prevalence in stroke patients is different to that of age and gender matched general population controls, and to explore whether early motor activity was associated with reduced likelihood of fatigue three months after stroke.

METHODS

This was a prospective multicenter cohort study of stroke patients admitted to eleven regional Norwegian hospitals, within 14 days after stroke. Stroke patients (n = 257) were age and gender matched to participants in a general population health survey (HUNT3-survey) carried out in a regional county of central Norway. The single-item fatigue questionnaire from the HUNT3-survey was administered to both groups to compare prevalence. The association between early motor activity (time in bed, time sitting out of bed, and time upright) and fatigue at three months after stroke (Fatigue Severity Scale) was tested with logistic regression. Simple models including each activity outcome, with adjustment for stroke severity and pre-stroke function, were tested, as well as a comprehensive model that included additional independent variables of depression, pain, pre-stroke fatigue, age and gender.

RESULTS

Prevalence was higher after stroke compared with the general population: 31.1% versus 10.9%. In the simple regression models, none of the early motor activity categories were associated with fatigue three months after stroke. In the comprehensive model, depression, pain and pre-stroke fatigue were significantly associated with post-stroke fatigue. Time in bed through the daytime during hospital stay approached statistical significance (p = 0.058) with an odds ratio for experiencing fatigue of 1.02 (95% CI 1.00-1.04) for each additional 5.4 minutes in bed.

CONCLUSIONS

Stroke patients had higher prevalence of fatigue three months after stroke than the age and gender matched general population sample, which may be partly explained by the stroke population being in poorer health overall. The relationship between early motor activity (and inactivity) and fatigue remains unclear. Further research, which may help drive development of new treatments to target this challenging condition, is needed.

Validity of the multidimensional fatigue symptom inventory-short form in an African-American community-based sample

OBJECTIVES

This study examined the psychometric properties of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) in a community-based sample of African-Americans.

DESIGN

A sample of 340 African-Americans (116 men, 224 women) ranging in age from 18-81 years were recruited from the community (e.g., churches, health fairs, and beauty salons). Participants completed a brief demographic survey, the MFSI-SF and the Positive and Negative Affect Schedule.

RESULTS

The structural validity of the MFSI-SF for a community-based sample of African-Americans was not supported. The five dimensions of fatigue (General, Emotional, Physical, Mental, Vigor) found for Whites in prior research were not found for African-Americans in this study. Instead, fatigue, while multidimensional for African-Americans, was best represented by a unique four-four profile in which general and emotional fatigue are collapsed into a single dimension and physical fatigue, mental fatigue, and vigor are relatively distinct. Hence, in the absence of modifications, the MFSI-SF cannot be considered to be structurally invariant across ethnic groups. A modified four-factor version of the MFSI-SF exhibited excellent internal consistency reliability and evidence supports its convergent validity. Using the modified four-factor version, gender, and age were not meaningfully associated with MFSI-SF scores.

CONCLUSION

Future research should further examine whether modifications to the MFSI-SF would, as the findings suggest, improve its validity as a measure of multidimensional fatigue in African-Americans.

Fatigue in healthy and diseased individuals

OBJECTIVES

Although fatigue is experienced by everyone, its definition and classification remains under debate.

METHODS

A review of the previously published data on fatigue.

RESULTS

Fatigue is influenced by age, gender, physical condition, type of food, latency to last meal, mental status, psychological conditions, personality type, life experience, and the health status of an individual. Fatigue may not only be a symptom but also a measurable and quantifiable dimension, also known as fatigability. Additionally, it may be classified as a condition occurring at rest or under exercise or stress, as physiologic reaction or pathologic condition, as spontaneous phenomenon or triggerable state, as resistant or irresistant to preconditioning, training, or attitude, as prominent or collateral experience, and as accessible or inaccessible to any type of treatment or intervention. Fatigue may be the sole symptom of a disease or one among others. It may be also classified as acute or chronic. Quantification of fatigability is achievable by fatigue scores, force measurement, electromyography, or other means. Fatigue and fatigability need to be delineated from conditions such as sleepiness, apathy, exhaustion, exercise intolerance, lack of vigor, weakness, inertia, or tiredness. Among neurological disorders, the prevalence of fatigue is particularly increased in multiple sclerosis, amyotrophic lateral sclerosis, Parkinson disease, traumatic brain injury, stroke, and bleeding and also in neuromuscular disorders. Fatigue may be influenced by training, mental preconditioning, or drugs.

CONCLUSIONS

Fatigue needs to be recognized as an important condition that is not only a symptom but may also be quantified and can be modified by various measures depending on the underlying cause.

Fatigue and fatigability in neurologic illnesses: proposal for a unified taxonomy

Fatigue is commonly reported in many neurologic illnesses, including multiple sclerosis, Parkinson disease, myasthenia gravis, traumatic brain injury, and stroke. Fatigue contributes substantially to decrements in quality of life and disability in these illnesses. Despite the clear impact of fatigue as a disabling symptom, our understanding of fatigue pathophysiology is limited and current treatment options rarely lead to meaningful improvements in fatigue. Progress continues to be hampered by issues related to terminology and assessment. In this article, we propose a unified taxonomy and a novel assessment approach to addressing distinct aspects of fatigue and fatigability in clinical and research settings. This taxonomy is based on our current knowledge of the pathophysiology and phenomenology of fatigue and fatigability. Application of our approach indicates that the assessment and reporting of fatigue can be clarified and improved by utilizing this taxonomy and creating measures to address distinct aspects of fatigue and fatigability. We review the strengths and weaknesses of several common measures of fatigue and suggest, based on our model, that many research questions may be better addressed by using multiple measures. We also provide examples of how to apply and validate the taxonomy and suggest directions for future research.

Racial/ethnic differences in the prevalence of internalizing symptoms: do Latin-American immigrant show more symptomatology than Spanish native-born adolescents?

This study mainly compared the prevalence of internalizing symptoms of 834 Spanish and 159 Latin-American immigrant adolescents. Participants completed self-report measures about depression, anxiety and somatic symptoms and a socio-demographic questionnaire. The results indicated that being Latin-American was associated with higher levels of depressive symptoms and being female was related to higher depressive and anxiety symptoms. Gender differences were more prevalent in Spaniards than in Latinos, with girls showing more symptoms than boys. High socio-economic status was negatively related to depressive symptoms and anxiety. The results may alert clinicians of the importance of assessing depressive symptoms in Latino adolescents in order to treat this group of youths effectively.

Characterizing Fatigue: The Effects of Ethnicity and Acculturation

It is unknown if fatigue measures like the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF; Stein, Jacobsen, Blanchard, & Thors, 2004) appropriately describe fatigue in Hispanics or if acculturation plays a role in fatigue. This study compared fatigue in community samples of Hispanics and Anglos. The MFSI-SF and pertinent questionnaires were administered to adults in San Diego County via telephone survey. Some differences in fatigue were observed in initial comparisons between Hispanics and Anglos, including when acculturation was considered. When age and education were controlled, Hispanics reported less general fatigue than Anglos, regardless of acculturation status, p = < .01. Exploratory factor analyses indicate that the MFSI-SF general-fatigue subscale was problematic for Hispanics. Implications, limitations, and future directions are discussed.

Phenomenological dimensions of sensory gating

Contemporary sensory gating definitions are generally tied to the perceptual and attentional phenomenology described by McGhie and Chapman, including abnormalities in the quality of sensory input, heightened awareness of background noises, and poor selective attention reported by individuals with schizophrenia. Despite these explicit phenomenological origins, little is known about the experiential phenomena underlying contemporary operationalizations of the sensory gating construct, such as whether the construct is restricted to experiences associated with the modulation of sensory percepts includes selective attention and distractibility or even whether the construct is accessible via self-report. Because clarification of these issues has important implications for the development and testing of psychological theories and the study of psychopathology, a series of studies was conducted to (a) empirically identify the major dimensions of sensory gating-like perceptual and attentional phenomenology in healthy young adults and (b) develop a psychometrically sound self-report rating scale to capture these dimensions, the Sensory Gating Inventory (SGI). Factor analyses of Likert items measuring a broad range of sensory gating-like subjective experiences revealed 1 primary factor that encompassed anomalies of perceptual modulation (eg, perceptions of heightened stimulus sensitivity and sensory inundation) and 3 other factors measuring disturbances in the processes of focal and radial attention as well as exacerbation of sensory gating-like anomalies by fatigue and stress. Psychometrically, the SGI demonstrated strong reliability and validity. An empirically based conceptual demarcation of the sensory gating construct is offered, and directions for future research are described.

Data mining: comparing the empiric CFS to the Canadian ME/CFS case definition

This article contrasts two case definitions for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We compared the empiric CFS case definition (Reeves et al., 2005) and the Canadian ME/CFS clinical case definition (Carruthers et al., 2003) with a sample of individuals with CFS versus those without. Data mining with decision trees was used to identify the best items to identify patients with CFS. Data mining is a statistical technique that was used to help determine which of the survey questions were most effective for accurately classifying cases. The empiric criteria identified about 79% of patients with CFS and the Canadian criteria identified 87% of patients. Items identified by the Canadian criteria had more construct validity. The implications of these findings are discussed.

Mild traumatic brain injury and fatigue: a prospective longitudinal study

PRIMARY OBJECTIVE

To examine fatigue prevalence, severity, predictors and co-variates over 6 months post-mild traumatic brain injury (MTBI).

RESEARCH DESIGN

Longitudinal prospective study including 263 adults with MTBI.

PROCEDURES

Participants completed the Fatigue Severity Scale (FSS), Rivermead Post-concussion Symptoms Questionnaire (RPSQ), Hospital Anxiety and Depression Scale (HADS) and the Short Form 36 Health Survey-Version 2 (SF-36v2). Complete data were available for 159 participants. Key measures; prevalence--RPSQ Item 6: severity--FSS. The effect of time on fatigue prevalence and severity was examined using ANOVA. Multiple regression analysis identified statistically significant covariates.

MAIN OUTCOMES AND RESULTS

Post-MTBI fatigue prevalence was 68%, 38% and 34% at 1 week, 3 and 6 months, respectively. There was a strong effect for time over the first 3 months and moderate-to-high correlations between fatigue prevalence and severity. Early fatigue strongly predicted later fatigue; depression, but not anxiety was a predictor. Fatigue was seen as laziness by family or friends in 30% of cases.

CONCLUSIONS

Post-MTBI fatigue is a persistent post-concussion symptom, exacerbated by depression but not anxiety. It diminishes in the first 3 months and then becomes relatively stable, suggesting the optimum intervention placement is at 3 months or more post-MTBI.

CFS prevalence and risk factors over time

The present natural history study examined the course of CFS from 1995-97 (Wave 1) to approximately 10 years later (Wave 2) from a random, community-based, multi-ethnic population. The rate of CFS remained approximately the same over the period of time from Wave 1 to Wave 2, although a high level of mortality was found (18% of those with medical or psychiatric exclusions group, 12.5% for the CFS group). Physical measures of disability and fatigue, along with measures of specific somatic symptoms, better differentiate individuals who later are diagnosed with CFS than more psychosocial measures such as stress and coping.

A natural history study of chronic fatigue syndrome

OBJECTIVE

There is a need for natural history chronic fatigue syndrome (CFS) studies from random, community-based, multi-ethnic populations.

DESIGN

The present study examined the course of CFS from Wave 1 to Wave 2, which spanned over a ten year period of time, and, assessed whether socio-environmental and symptomatology factors were associated with CFS status over the ten year period.

RESULTS

There was relative stability over time on critical measures of disability, fatigue, support, optimism and coping over time. One cardinal symptoms of CFS, post-exertional malaise, best differentiated the CFS group from the others. By Wave 2, of the original group of 32 individuals diagnosed with CFS, 4 had died, and 24 were found and agreed to be re-evaluated, and of this group, 16 continued to have CFS, 5 developed exclusionary illnesses, 2 were classified as Idiopathic chronic fatigue, and one had remitted.

CONCLUSIONS

The current study found that over time in a community-based sample, unbiased by help seeking behavior the CFS group remained rather ill with a variety of different conditions over time.

What is fatigue? Pathological and nonpathological fatigue

Aid in understanding issues surrounding the construct validity of fatigue including the distinction between pathological versus nonpathological fatigue. Fatigue is a universal symptom reported by individuals in the general population as well as by those suffering from different medical and psychological illnesses, including cancer, multiple sclerosis, chronic fatigue syndrome, depression, and anxiety. Chronic fatigue is a significant problem in many primary care settings, and the debilitating and prolonged nature of fatigue can pose significant economic consequences for society. Researchers have struggled to better assess and understand the etiology and classification of fatigue within different illness groups.

Aetiology of fatigue in Sri Lanka and its overlap with depression

BACKGROUND

Fatigue is a common symptom in Western high-income countries but is often medically unexplained and little is known about its presentation in other populations.

AIMS

To explore the epidemiology and aetiology of fatigue in Sri Lanka, and of its overlap with depression.

METHOD

A total of 4024 randomly selected twins from a population-based register in Sri Lanka (Colombo district) completed home interviews including the Chalder Fatigue Questionnaire.

RESULTS

The prevalence of fatigue was similar to that in other countries, although prolonged fatigue may be less common. There was substantial comorbidity with a screen for lifetime depression. Non-shared environmental factors made the largest contributions, although genetic/family factors also contributed. The aetiology appeared consistent across the spectrum of severity.

CONCLUSIONS

The aetiology of fatigue is broadly similar in Sri Lanka and Western high-income countries. Abnormal experiences of fatigue appear to be the extreme form of more common fatigue, rather than representing independent entities with different genetic or environmental risk factors.

A systematic review of chronic fatigue, its syndromes and ethnicity: prevalence, severity, co-morbidity and coping

BACKGROUND

Chronic Fatigue Syndrome (CFS) is characterized by unexplained fatigue that lasts for at least 6 months alongside a constellation of other symptoms. CFS was historically thought to be most common among White women of higher socio-economic status. However, some recent studies in the USA suggest that the prevalence is actually higher in some minority ethnic groups. If there are convincing differences in prevalence and risk factors across all or some ethnic groups, investigating the causes of these can help unravel the pathophysiology of CFS.

METHODS

A systematic review was conducted to explore the relationship between fatigue, chronic fatigue (CF--fatigue lasting for 6 months), CFS and ethnicity. Studies were population-based and health service-based. Meta-analysis was also conducted to examine the population prevalence of CF and CFS across ethnic groups.

RESULTS

Meta-analysis showed that compared with the White American majority, African Americans and Native Americans have a higher risk of CFS [Odds Ratio (OR) 2.95, 95% confidence interval (CI): 0.69-10.4; OR = 11.5, CI: 1.1-56.4, respectively] and CF (OR = 1.56, CI: 1.03-2.24; OR = 3.28, CI: 1.63-5.88, respectively). Minority ethnic groups with CF and CFS experience more severe symptoms and may be more likely to use religion, denial and behavioural disengagement to cope with their condition compared with the White majority.

CONCLUSIONS

Although available studies and data are limited, it does appear that some ethnic minority groups are more likely to suffer from CF and CFS compared with White people. Ethnic minority status alone is insufficient to explain ethnic variation of prevalence. Psychosocial risk factors found in high-risk groups and ethnicity warrant further investigation to improve our understanding of aetiology and the management of this complex condition.

Sleep problems and associated daytime fatigue in community-dwelling older individuals

BACKGROUND

Reported fatigue has been identified as a component of frailty. The contribution of nighttime sleep quality (duration and complaints) to fatigue symptoms in community-dwelling older adults has not been evaluated.

METHODS

We studied 2264 men and women, aged 75-84 years (mean 77.5 years; standard deviation [SD] 2.9), participating in the Year 5 (2001--2002) clinic visit of the Health, Aging, and Body Composition (Health ABC) study. Fatigue was determined using a subscale of the Modified Piper Fatigue Scale (0-50; higher score indicating higher fatigue). Hours of sleep per night, trouble falling asleep, waking up during the night, and waking up too early in the morning were assessed using interviewer-administered questionnaires.

RESULTS

The average fatigue score was 17.7 (SD 8.4). In multivariate models, women had a 3.8% higher fatigue score than men did. Individuals who slept < or = 6 hours/night had a 4.3% higher fatigue score than did those who slept 7 hours/night. Individuals with complaints of awakening too early in the morning had a 5.5% higher fatigue score than did those without these complaints. These associations remained significant after multivariate adjustment for multiple medical conditions.

CONCLUSION

The association between self-reported short sleep duration (< or = 6 hours), and waking up too early and fatigue symptoms suggests that better and more effective management of sleep behaviors may help reduce fatigue in older adults.

Fatigue among Spanish- and English-speaking Latinos

The present study investigated sociodemographic differences, fatigue severity, and the occurrence of prolonged or chronic fatigue reported by Spanish-speaking and English-speaking Latinos. The sample included 2,102 English-speaking Latinos and 1,348 Spanish-speaking Latinos interviewed as part of an epidemiological study of persons with chronic fatigue syndrome in the Chicago area. Results indicated that English-speaking Latinos scored higher on measure of fatigue than Spanish-speaking Latinos. Further, language status continued to be a predictor of fatigue level even when controlling for other sociodemographic differences found between the groups. Findings suggest that language spoken in Latino populations is important in predicting fatigue, and point to the potential importance of cultural factors such as acculturation or acculturative stresses.

Fatigue varies by social class in African Americans but not Caucasian Americans

Socioeconomic status explains many ethnic disparities in health; however, mechanisms are hard to identify. Fatigue-a frequent complaint in patients and normals-is associated with poorer quality of life. We wondered if ethnicity and social class interact to explain fatigue. A total of 40 African Americans (AAs) and 64 Caucasian Americans (CAs) completed short forms of the Profile of Mood States (POMS-SF) and Multidimensional Fatigue Symptom Inventory (MFSI-SF). Participants were divided into high-middle and low social class groups (as per Hollingshead, 1958a). After controlling for gender, body mass index, depressive symptoms, and response bias, ethnicity and social class interacted for POMS-SF fatigue. AAs in the high-middle classes reported more fatigue than AAs in the low classes and CAs in the high-middle classes. Fatigue did not differ by class for CAs nor by ethnicity in the lower classes. Similar findings emerged for MFSI-SF general fatigue. Social class is important for understanding fatigue in AAs but not CAs.

Chronic fatigue syndrome: the need for subtypes

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.

Sociodemographic and symptom correlates of fatigue in an adolescent primary care sample

PURPOSE

To describe the prevalence of prolonged fatigue, chronic fatigue syndrome (CFS)-like illness, and associated symptom patterns in adolescents attending primary care.

METHODS

The design was cross-sectional. A questionnaire designed by the authors assessing fatigue and associated symptoms was administered to 901 adolescents (aged 11-18 years) attending 12 primary care clinics in the Chicago area. Prevalence rates for prolonged fatigue and CFS-like illness were calculated. Univariate comparisons involving sociodemographic data and fatigue severity were made between adolescents with and without prolonged fatigue, and sociodemographic and symptom predictors of prolonged fatigue were identified using logistic regression analysis.

RESULTS

Prolonged fatigue (> or = 1 month) occurred at a rate of 8.0% and CFS-like illness occurred at a rate of 4.4%. Adolescents with prolonged fatigue were significantly older and also reported greater fatigue severity than those without fatigue. Findings from logistic regression indicated that, in addition to increasing age, headaches, muscle pains, fever, and fatigue made worse by exercise were significantly associated with prolonged fatigue.

CONCLUSIONS

Abnormal fatigue is a disabling and prevalent condition in adolescents in primary care. It is associated with a number of additional symptoms, many of which may have viral origins.

Chronic fatigue and sociodemographic characteristics as predictors of psychiatric disorders in a community-based sample

OBJECTIVES

To explore the roles of chronic fatigue and sociodemographic characteristics (eg, parental status, work status, socioeconomic status, sex, age, marital status, and ethnicity) as predictors of psychiatric disorders.

METHODS

A stratified random sample of 18,675 adults residing in diverse neighborhoods in Chicago completed a telephone-screening questionnaire. A control group without chronic fatigue (N = 74) and a group of individuals with chronic fatigue (N = 227) were identified and administered a semi-structured psychiatric interview. Stepwise logistic regression analyses predicting occurrence of current and lifetime psychiatric disorders according to chronic fatigue status and sociodemographics were conducted on this overall sample of 301 participants.

RESULTS

Chronic fatigue, low socioeconomic status, and unemployment were among significant predictors of overall Axis I psychiatric disorders. Chronic fatigue functioned as a predictor for mood and anxiety disorders (including posttraumatic stress disorder), but did not function as a predictor for somatoform disorders, substance abuse/dependence, and eating disorders. Low socioeconomic status and unemployment were significantly associated with current psychiatric disorder, and low socioeconomic status was also significantly associated with mood and anxiety disorders. Women were significantly more likely to experience mood disorder, and minorities (eg, African Americans, Latinos, and individuals of other ethnicity) were significantly more likely to report posttraumatic stress disorder.

CONCLUSIONS

Results support prior findings for increased rates of psychiatric disorder among individuals with chronic fatigue and highlight the roles of low socioeconomic status, unemployment, being a woman, and being classified as a minority in their association with certain psychiatric disorders.

Chronic fatigue syndrome: symptom subtypes in a community based sample

Most studies of Chronic Fatigue Syndrome (CFS) have been based on patients recruited from primary or tertiary care settings. Patients from such settings might not be typical of patients in the general population. The present investigation involved examining individuals with CFS from a community-based study. A random sample of 18,675 respondents in Chicago were first interviewed by telephone. A group of individuals with chronic fatigue accompanied by at least four Fukuda et al. (1994) symptoms associated with CFS were given medical and psychiatric examinations. From this sample, a physician review group diagnosed individuals with CFS. Those diagnosed with CFS were subclassified based on frequency of symptoms. Important differences emerged on measures of sociodemographics and disability. The implications of these findings and others are discussed.

Prognosis of chronic fatigue in a community-based sample

OBJECTIVE

This study examined predictors of fatigue severity and predictors of continued chronic fatigue status at wave 2 follow-up within a random, community-based sample of individuals previously evaluated in a wave 1 prevalence study of chronic fatigue and chronic fatigue syndrome that originally took place between 1995 and 1997.

METHODS

Wave 1 data were from a larger community-based prevalence study of chronic fatigue syndrome. In the present study, a second wave of data were collected by randomly selecting a sample of participants from the wave 1 sample of 18,675 adults and readministering a telephone screening questionnaire designed to assess symptoms of chronic fatigue syndrome.

RESULTS

Findings revealed that wave 1 fatigue severity was a predictor of fatigue severity at wave 2 in the overall sample of individuals with and without chronic fatigue. In the smaller sample of individuals with chronic fatigue, wave 1 fatigue severity, worsening of fatigue with physical exertion, and feeling worse for 24 hours or more after exercise significantly predicted continued chronic fatigue status (vs. improvement) at wave 2 follow-up.

CONCLUSIONS

These findings underscore the prognostic validity of postexertional malaise in predicting long-term chronic fatigue and also highlight the importance of using population-based, representative random samples when attempting to identify long-term predictors of chronic fatigue at follow-up.