Criteria For Fatigue Research Articles

A review of multiaxial low-cycle fatigue criteria for life prediction of metals

Most of real-world structural components that undergo cyclic loading feature multiaxial fatigue. When the cyclic loading involves also significant plastic deformation, multiaxial low-cycle fatigue takes place. Applications where multiaxial low-cycle fatigue can be observed very often involve metal components. To predict their lives multiple criteria and models have been proposed, but their development has not followed a regular path. Multiple reviews are available in literature. However, many of them are outdated, they often employ different classification methods to categorize available criteria, many focus on specific families of criteria, and others do not include sufficient theoretical background. Moreover, none of the available reviews is based on a systematic literature search method. As a result, approaching the topic can result arduous and chaotic, especially for first timers. This work aims at providing a clear, comprehensive, and definitive review of available criteria for multiaxial low-cycle fatigue. First, the basic theoretical background is explained. Secondly, a systematic approach is described and employed to identify all major currently available criteria. Then, they are classified and commentary about different classification styles that can be found in literature is added. Eventually they are described, together with their latest proposed variations. In this way this review can be employed as a guiding reference, especially for engineers approaching the topic for the first time.

An NEA/OECD benchmark-experiment for the validation of CFD for mixing and thermal fatigue in T-junction dead leg flows

The current screening criteria for thermal fatigue used in isolated branch lines at nuclear power plants are based on simplified approaches, which, on one hand, tend to be overly conservative, and on the other hand, appear to miss important physics. This is demonstrated by the fact that a number of affected pipes were missed by the current screening methods.The purpose of the present work is to produce novel and accurate experimental data, which can be used for a benchmark of Computational Fluid Dynamics (CFD) in order to advance the prediction capabilities of thermal mixing and fatigue in dead leg T-junctions and improve the accuracy of the screening criteria. The ultimate value creation is increased safety and availability at nuclear power plants. This is of great interest and utmost importance to the nuclear reactor safety community.A new pressurized experimental setup of a T-junction has been designed and constructed for the purpose. The experimental setup, with a temperature difference of 120 °C, more closely resembles plant conditions than in earlier experiments. The boundary conditions in terms of the flowrates and temperatures are controlled and stable within their measurement uncertainty – a prerequisite for CFD-grade experiments.The novelty of the present work is measurements of the temperature fluctuations both in the near wall fluid mixing region and throughout the solid pipe wall material.It has been shown that the interaction between the swirl penetration of hot water and the stratified layer in the cold dead leg has an intermittent character and that random clusters of bursts of hot water penetrate into the stratification and the stagnant cold water below. The average time scale of this process is of the order of hundreds of seconds.The stratification between the hot and the cold water in the dead leg has also shown to have a low frequency oscillation of the order of 0.1 Hz, which wiggles in the circumferential direction. After hot water has penetrated downward and excited the instability, the temperature falls back to the initial one in a manner similar to a damped oscillation.The vertical temperature profiles have shown to be self-similar, for moderate temperatures, when scaled with the temperature difference between the hot and the cold water and with the penetration length.The penetration length increases with the velocity in the hot leg confirming earlier reported correlations.A small (less than 0.1 % of the hot main flow) cold leakage flow into the T-junction is sufficient to suppress the swirl penetration and substantially reduces the penetration length. However, the temperature fluctuations have a larger amplitude and range across the whole mixing zone. The fluid temperature fluctuations are shifted towards a more high frequency content, however, the low frequency nature of the swirl penetration is still present.The obtained novel dataset will be provided for a blind CFD benchmark exercise as part of an OECD/NEA project in 2023 and 2024.

Vortex-Induced Vibration and Fatigue Damage Assessment for a Submarine Pipeline on a Sand Wave Seabed

Sand waves are commonly formed on the sandy seabed of the continental shelf and characterized by their regular wave-like shape. When a submarine pipeline is laid on this type of seabed, it often experiences free spans due to the unevenness of the seabed. These free spans are particularly vulnerable to vortex-induced vibration (VIV) and the resulting fatigue damage, which have been identified as the primary causes of pipeline failures in offshore oil and gas exploration. This study examines the VIV and fatigue damage of free spans in a submarine pipeline in the Lufeng oilfield, which is located in a large area of sand waves. The assessment conditions encompass the as-laid empty state, the flooded state, and the operational state. Additionally, both the minimum and maximum lay tension are taken into account during the evaluation of VIV and fatigue. The VIV onset screening conducted revealed a considerable number of pipeline free spans exceeding the VIV onset span lengths under both temporary and operating conditions for the non-trench seabed. Furthermore, the analyses indicate that the pipeline does not meet the criteria for VIV fatigue on a non-trenched seabed. Consequently, a proposed solution of implementing a 1 m trench rectification measure for the seabed is recommended. The results demonstrate that this measure effectively mitigates the occurrence of VIV and subsequently reduces fatigue damage across all conditions.

Comparison between subjective and objective fatigue in patients with lung cancer and cancer-free participants: Evaluation of diagnostic criteria for cancer-related fatigue.

440 Background: Cancer-related fatigue is one of the most distressing symptoms of cancer patients. Finding a patient's fatigue often requires the use of a subjective assessment scale, such as the Brief Fatigue Inventory (BFI). There are few objective ways to measure fatigue. The aim of this study was to evaluate whether objective cancer-related fatigue (CRF) diagnostic criteria can differentiate cancer from cancer-free participants and to explore the relationship between subjective and objective fatigue. Methods: In this study, we used a photoplethysmography (PPG) smartband device to collect the PPG information from the patients. During PPG measurements, the heart rate variability (HRV) signal was included in the data collection process for subsequent calculation of the LF/HF ratio. Participants completed a self-report measure to assess demographics, fatigue levels, and brief sleep diaries for the next 7 days. At the same time, the participants wore a wristband to collect HRV signals, which triggered HRV every hour over a 24-hour period for 7 consecutive days. Results: Cancer patients (n = 71) and cancer-free controls (n = 75) were studied. Study participants completed CRF questionnaires and heart rate variability (HRV) records. The smartband can be worn continuously for 120 hours as an objective measure of activity phase, sleep phase and HRV. Compared with controls, cancer patients were more fatigued and were more likely to be disturbed by fatigue (t = -3.73, p < 0.001), especially general activity (t = -2.93, p < 0.001), walking ability (t = -3.6, p < 0.001) and normal work (t = -2.18, p = 0.03). Wearing the bracelet can get the LF/HF value of HRV in the time domain. The LF to HF and LF/HF disorder ratios were further divided into active and sleep phases. During sleep phase, the LF/HF disorder ratio was higher in the cancer group than in the control group regardless of whether fatigue was mild or moderate (t = -2.5, p = 0.01; t = -2.8, p = 0.01, respectively). The LF/HF disorder ratios was higher in cancer patients with mild fatigue than in cancer-free participants during sleep phase (40% vs 20%, respectively). Cancer patients with moderate fatigue had higher incidence of LF/HF disorder ratios than cancer-free participants (50% vs 20%, respectively). Conclusions: It can be concluded that the diagnostic criteria of subjective and objective CRF can distinguish cancer and cancer-free cases. Using this objective fatigue device could provide an indicator for further clinical monitoring. Clinical trial information: NCT04300842.

PATIENT-RELATED OUTCOMES AND BIOLOGIC MEDIATORS OF SARCOIDOSIS

PATIENT-RELATED OUTCOMES AND BIOLOGIC MEDIATORS OF SARCOIDOSIS

Validation of new diagnostic criteria for fatigue in patients with Parkinson disease.

Background and purposeAlthough disabling fatigue is common in Parkinson disease (PD), available consensus‐based diagnostic criteria have not yet been empirically validated. The aim of this study was to evaluate the clinimetric properties of the criteria.MethodsA sample of outpatients with PD was evaluated for demographic, clinical, behavioral, and cognitive features. Fatigue was diagnosed according to the new diagnostic criteria and was rated by means of the Parkinson Fatigue Scale (PFS) and Fatigue Severity Scale (FSS). Acceptability, concurrent and discriminant validity, and interrater reliability were evaluated with binary logistic regression analyses and Cohen kappa (κ).ResultsOf 241 included patients, 17 (7.1%) met the diagnostic criteria for PD‐related fatigue. Eight of nine symptoms described in Section A of the diagnostic criteria occurred in >50% of patients with fatigue. Acceptability (missing data = 0.8%) of the criteria was good, as was their concurrent validity with the PFS (odds ratio = 3.65) and FSS (odds ratio = 3.63). The discriminant validity of fatigue criteria with other PD‐related behavioral and cognitive features was good (odds ratio < 1.68). The interrater reliability was excellent (κ = 0.92).ConclusionsThis is the first study to test the clinimetric properties of case definition diagnostic criteria for PD‐related fatigue. Our results suggest that current diagnostic criteria may be useful in both clinical practice and research. Future longitudinal studies should examine their long‐term stability.

Abstract TP66: Sex Differences In Neuromuscular Fatigability During Submaximal Isometric Knee Extension Exercise Post Stroke

Introduction: Annually, 55,000 more females than males are affected by stroke in the United States. Females also tend to experience more severe strokes with worse functional outcomes, which result in poorer health-related quality of life. Despite the marked differences in long-term recovery between males and females with stroke, little is known about the sex differences in motor performance that may contribute to the differences in recovery and what therapies could be used to optimize recovery, especially for female stroke survivors. In this study, we aimed to determine if sex-related differences in neuromuscular fatigability exist post stroke. Methods: Sixteen chronic stroke survivors (at least 6 months post stroke, 9 females, 58 +/- 14 years) and thirteen neurologically intact controls (7 females, 59 +/- 12 years) performed a submaximal isometric fatiguing knee extension contraction with either the paretic (stroke) or the dominant (control) leg. The submaximal fatiguing contraction torque was equivalent to 30% of the maximal voluntary isometric contraction (MVIC) of the knee extensors. The participants were asked to sustain at the target torque until one of the two criteria for fatigue was met: (1) if the participant’s torque cannot maintain within a 10% window of error for more than 5 seconds; or (2) if there are more than 5 deviations from the 10% error window in a consecutive 10-second time period. Time to task failure (TTF) was measured. Results: Overall, both male and female stroke survivors tended to have lower MVIC than their healthy counterparts (male: 151 +/- 60 Nm vs. 206 +/- 39 Nm; female: 58 +/- 17 Nm vs. 121 +/- 27 Nm). On average, males tended to fatigue similarly between stroke and control groups (259 +/- 164 s vs. 249 +/- 96 s, respectively); while female stroke survivors tended to have a briefer TTF compared to female controls (207 +/- 69 s vs. 311 +/- 129 s). Conclusions: During submaximal isometric knee extension exercise, female stroke survivors had a shorter task duration than female controls, while this stroke-related difference was not observed in males. Our results indicate that, although stroke impairs muscle strength in both sexes, fatigability may be exacerbated to a greater extent in females than in males post stroke.

Severe, Intolerable Fatigue Associated with Hyperresponse to Clopidogrel

Clopidogrel is a commonly used antiplatelet agent for the prevention of thromboembolic complications following neuroendovascular procedures, but anecdotal data have raised concern for the possibility that clopidogrel may induce severe, intolerable fatigue. The purpose of this study is to systematically investigate this phenomenon. We performed a dual-institution, 9-year, retrospective study of patients undergoing clopidogrel therapy for neuroendovascular procedures. Patients were included only if their response to clopidogrel was assessed by platelet function testing using the VerifyNow P2Y12 (VNP) assay. Hyperresponse to clopidogrel was defined as P2Y12 reaction units ≤60. Patients were considered to have had clopidogrel-induced severe fatigue if the onset of symptoms followed the initiation of clopidogrel therapy; symptoms improved following a reduction in the dose of clopidogrel; and symptoms could not be attributed to any other medical explanation. Data were collected on 349 patients. Five patients (1.4%) met criteria for clopidogrel-induced severe fatigue. All 5 patients were female, ages 39-68. VNP assessments obtained while patients were symptomatic revealed hyperresponse to clopidogrel (0-22 P2Y12 reaction units). Symptoms improved in all 5 patients when the dose of clopidogrel was reduced by half. Notably, 30% of patients (n= 103) demonstrated a hyperresponse to clopidogrel on at least 1 VNP assessment, but 98 of these patients did not suffer from severe fatigue. A syndrome of severe fatigue and other constitutional symptoms is a rare but clinically significant side effect of hyperresponse to clopidogrel in patients undergoing neuroendovasular intervention.

"I'm So Tired": Fatigue as a Persistent Physical Symptom among Working People Experiencing Exhaustion Disorder.

Fatigue is widespread in the population, particularly among working people. Exhaustion disorder (ED), a clinical manifestation of burnout, is common, but, after treatment, about one-third still experience fatigue and other physical symptoms. We propose that in some instances, fatigue as a persistent physical symptom (PPS) might be a more appropriate formulation of ED patients’ fatigue problems, and we suggest that ED patients who meet fatigue PPS criteria will differ from other ED patients in terms of psychological distress, non-fatigue PPSs and functional impairment. Questionnaires were sent to 10,956 members of a trade union of which 2479 (22.6%) responded. Of 1090 participants who met criteria for ED, 106 (9.7%) met criteria for fatigue as a PPS. Participants who met fatigue PPS criteria scored on average higher on measures of depression, anxiety and functional impairment and were more likely to have clinically significant scores. Moreover, they had 27 times higher odds of meeting other PPS subtypes and reported more non-fatigue PPS subtypes, suggesting a more complex health problem. Specific evidence-based interventions are available for both ED and PPSs, and therefore, it is crucial to accurately formulate the fatigue problem reported by patients to provide appropriate treatment.

FEM assessment of the local side compression technique efficiency as applicable for notched prismatic specimens

A crack front straightness is one of the test result validity criteria for fatigue precracked static fracture toughness specimens. Actually, the ideally straight crack front cannot be reached due to the presence of residual stress. This is particularly actual for specimens cut out of welded joints containing the residual welding stress (RWS). One of the techniques allowing to lower the RWS effect is a local side compression of specimens. Its efficiency has been proved in physical testing however no quantitative assessments are known in the literature. This work comprises FEM simulation of welding, sampling and side compression processes. The effect of local compression on base metal containing no residual stress is also investigated.It has been found that in the course of local side compression the initial residual stress field caused by welding and specimen making is replaced by another field showing stress gradients more favourable for getting the fatigue crack shape meeting the validity criteria of test results as per approved test methods. The calculation results show that the complete removal of residual stress as in base metal as in welded specimens is not feasible in the range of actual practicable degrees of compression.

Неопределенности в оценке усталости конструкций при проектировании и эксплуатации

Неопределенности в оценке усталости конструкций при проектировании и эксплуатации

Policy Planning for the Post-Pandemic World: The Chronic Illness and Mental Health Needs of Tens of Millions of COVID-19 Survivors

Severe Acute Respiratory Syndrome (SARS), which was caused by the SARS-associated coronavirus (SARS-CoV), originated in 2003 in Guangdong, China, infecting over 8000 people globally and killing 774.3 Middle East Respiratory Syndrome (MERS), which was caused by the Respiratory Syndrome Coronavirus (MERS-CoV), originated in 2012, infecting 2000 globally and killing 842.4 [End Page 119] Long-term effects of COVID-19 Among patients hospitalized with SARS and MERS, the most common long-term effects were new-onset psychiatric illness and fatigue.5 Some studies found many post-SARS and post-MERS patients met diagnostic criteria for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME).6 These effects can be debilitating and prevent usual functioning at work. The CFS/ME diagnostic criteria include a substantial reduction in usual activities for at least six months, exhaustion after exertion, non-refreshing sleep, and either cognitive impairment (“brain fog”) or feeling light-headed while standing.10 Historical research has found that similar symptoms were noted among survivors of the 1918 influenza pandemic.11 CFS/ME has been noted one year12 and three years13 after SARS infection and one year after MERS.14 A large study of middle-aged SARS survivors in Hong Kong four years after infection found 27% met chronic fatigue syndrome criteria.15 Initial reports of post-COVID-19 illness include symptoms such as extreme fatigue, concentration difficulties, memory lapses, and muscle weakness that are consistent with CFS/ME,16,17 as well as short-term reduced cognitive ability.18 Damage to organs throughout the body COVID-19 also damages organs throughout the body, creating potentially life-long physical health impacts, even for low-risk populations that were not hospitalized.19 COVID-19 symptoms, especially fatigue and difficulty breathing, have been shown to persist for months after infection.20 Lung damage may be life-long for some. While this cardiomyopathy is often reversible, some patients who have otherwise recovered from COVID-19 appear to have long-term myocarditis (inflammation of the heart tissue), which can lead to arrhythmias, heart attacks, and irreversible heart failure.23,24 Studies on patients with viral myocarditis have also shown an increase in five-year mortality.25 As the body’s immune system fights the virus, scientists believe the immune system overreacts, leading to many of the acute lung complications seen in the severe form of COVID-19, including acute respiratory distress syndrome (ARDS).26 ARDS is an illness of acute respiratory failure in which both lungs fill with fluid, often leading to intensive care unit (ICU) admission and intubation with mechanical ventilation. During acute disease, many viruses, including SARS, MERS, and COVID-19 cause coagulation disorders, leading to an increase in blood clotting (thrombosis) throughout the body, which can ultimately cause multi-organ failure.31 An observational study in the Netherlands found rates of thrombosis as high as 31% in COVID-19 patients.32 In the lungs, a clot can cause a pulmonary embolism leading to reduced oxygenation;in the kidneys, a clot can cause kidney failure;and in the brain, a clot can cause a stroke.

Effects of a light therapy intervention on diurnal salivary cortisol in fatigued cancer survivors: A secondary analysis of a randomized controlled trial

ObjectiveAltered diurnal cortisol rhythms are a potential mechanism through which symptoms of fatigue are maintained in post-treatment cancer survivors. Exposure to early morning bright light may target this underlying dysregulation, resulting in improved diurnal cortisol patterns, subsequently improving symptoms of fatigue. This research investigates the effects of a 4-week light therapy intervention on the diurnal cortisol slopes and output in fatigued cancer survivors. MethodsPost-treatment adult cancer survivors who met diagnostic criteria for cancer-related fatigue were randomly assigned to receive either a bright white light (BWL) or dim red light (DRL) device, used daily for 30 min over four consecutive weeks. Assessments of fatigue and salivary cortisol were collected at baseline and post-intervention. Cortisol was sampled four times per day (waking, noon, 5 pm, bedtime) for three days at each timepoint. Diurnal cortisol slopes and total cortisol output were calculated at baseline and post-intervention. Linear mixed models were used to analyze the data. ResultsSeventy-seven participants were included in this analysis (BWL n = 40; DRL n = 37). Participants in both groups displayed increased steepness in cortisol slope (B = -0.02, p = .01, Cohen's d = 0.57) and increased total cortisol output (B = 9.58, p = .03, Cohen's d = 0.49) from baseline to post-intervention, indicating only a moderate effect of time. Neither diurnal cortisol slopes nor total cortisol output mediated the relationship between the light therapy intervention and fatigue levels. ConclusionThough the results of this trial are promising for light therapy as an effective intervention to reduce fatigue in cancer survivors, this does not appear to be achieved through alterations in neuroendocrine function.ClinicalTrials.gov registration #: NCT01780623

Creep and morphological evaluation of polypropylene waste modified asphalt for pavement applications

Synoptic findings by researchers have revealed tremendous physic-chemical improvements of polymer modified mixes over the conventional asphalt. Traditionally, laboratory mechanical properties were carried out for asphalt testing, but cannot calibrate simple performance test (SPTs) criteria for fatigue and field performance. Marshall test-sized specimens of polymer asphalt mixtures were engineered with arbitrary contents of 0 to 3.0% polypropylene waste admixed with 4.5 to 6.5% bitumen contents based on relevant literature. Creep deformation involves uniaxial static creep (USC) test using BS 598-111. Morphological examinations were test with Hitachi S-4700 field-emission scan-electron-microscope (FE-SEM). Thirdly, thermal degradation was determined using Shimadzu TGA-50 thermo-gravimetric analyzer. The results showed creep resistivity with fatigue recovery of 23.2% and 28.9% strain reduction at 10oC and 60oC respectively from the optimal 2.0% polypropylene and 6.0% bitumen compared to the control mix. Also, the same mix produced well dispersed and better enhanced pore packaging micro-structure capable of resisting ageing volatization under severe traffic and environmental loading conditions considered.&#x0D; Keywords: Asphalt pavement, polypropylene, creep deformation, age volatization and microstructure

Experimental and Field Investigation of Road Mesh Reinforcement in Flexible Pavements

The most acceptable combination of layer thickness and types of materials used in the different layers of pavement along with an estimated traffic to be carried, during the service life of the pavement, complete the flexible pavement design process. In addition to satisfying the tolerable criteria for fatigue and rutting mechanisms, the pavements are subjected to much higher load intensities than that of the estimated traffic during design. This increases the importance of maintaining the quality of base layer materials as base layer plays a major role in maintaining the performance of unpaved roads. Due to the absence of confinement in the lateral direction, there is a possibility of permanent deformation when a vertical load is applied. To restrict both resilient and permanent deformations, it is essential to consider geosynthetic reinforcement in pavement engineering. The use of road mesh manufactured from double twisted steel wire mesh is studied as a possible reinforcement material for carrying the increased traffic loads, and experiments are conducted in this direction. The primary objective of this study is to reduce the thickness of the base layer and to improve the performance of the base layer under heavy loading conditions. Static and repeated plate load tests were conducted on unreinforced as well as road mesh-reinforced base layer. The results of the experimental studies showed better performance of road mesh-reinforced base layer by reducing the permanent deformations. The improvement in the performance of reinforced sections was also measured in terms of resilient deformation and predicted resilient modulus from resilient deformations. The studies also include the role of reinforcement in improving the pressure distribution in the base layer and the pressure above the subgrade level in terms of stress distribution angle. The improved performance of reinforced sections was reflected in the field studies by conducting FWD tests and calculating LCR from those results.

Incorporating binder type into asphalt fatigue life characterisation of airport pavement surfaces

Most airport pavement design tools include a failure criterion for predicting bottom-up asphalt fatigue cracking. However, in practice bottom-up cracking is rarely observed in airport pavement surfaces and many designers question the efficacy of the common asphalt fatigue failure criteria. Where asphalt fatigue is considered, asphalt mixtures are characterised primarily by mixture stiffness and the volume of bituminous binder, while the type of binder (unmodified, acid modified, plastomeric or elastomeric) is not directly considered. By comparing the stiffness and fatigue lives of asphalt mixtures produced with four different aggregate sources and four different binder types, the importance of binder type on the relationship between mixture stiffness and laboratory fatigue life is clear. Further work is recommended to incorporate parameters representing the type of binder into mechanistic-empirical pavement design failure criteria for asphalt fatigue.

De la neurastenia a la enfermedad postesfuerzo: evolución de los criterios diagnósticos del síndrome de fatiga crónica/encefalomielitis miálgica

Changes in the terminology and diagnostic criteria for chronic fatigue syndrome/myalgic encephalomyelitis are explained in this paper.This syndrome is a complex and controversial entity of unknown origins. It appears in the medical literature in 1988, although clinical pictures of chronic idiopathic fatigue have been identified since the nineteenth century with different names, from neurasthenia, epidemic neuromyasthenia, and benign myalgic encephalomyelitis up to the current proposal of disease of intolerance to effort (post-effort). All of them allude to a chronic state of generalised fatigue of unknown origin, with limitations to physical and mental effort, accompanied by a set of symptoms that compromise diverse organic systems.The International Classification of Diseases (ICD-10) places this syndrome in the section on neurological disorders (G93.3), although histopathological findings have not yet been found to clarify it.Multiple organic alterations have been documented, but a common biology that clarifies the mechanisms underlying this disease has not been established. It is defined as a neuro-immune-endocrine dysfunction, with an exclusively clinical diagnosis and by exclusion.Several authors have proposed to include CFS/ME within central sensitivity syndromes, alluding to central sensitisation as the common pathophysiological substrate for this, and other syndromes.The role of the family doctor is a key figure in the disease, from the detection of those patients who present a fatigue of unknown nature that is continuous or intermittent for more than 6 months, in order to make an early diagnosis and establish a plan of action against a chronic disease with high levels of morbidity in the physical and mental sphere. ObjectiveTo carry out a bibliographic review of the terminology and diagnostic criteria of the chronic fatigue syndrome/myalgic encephalomyelitis, in order to clarify the pathology conceptually, as a usefulness in the diagnosis of Primary Care physicians.

Fatigue Measurements in Systemic Lupus Erythematosus.

Fatigue is a frequent, disabling issue in systemic lupus erythematosus (SLE). It is, however, difficult to quantify. The Ad Hoc Committee on SLE Response Criteria for Fatigue in 2007 recommended using the Krupp Fatigue Severity Scale (FSS). Since then, the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue Scale has also been validated in SLE. We performed a review of instruments used to measure fatigue in adult SLE patients from 2007 onward. We searched PubMed, Medline, and Embase (January 2008-October 2017), identifying clinical trials and observational studies in adult SLE, where fatigue was a specifically measured outcome. All English and French studies were reviewed to determine fatigue measures and results. Thirty-seven studies met inclusion criteria. Eight scales were used. The visual analog scale (VAS), FSS, and FACIT-Fatigue Scale were most frequent. FSS was the most often used instrument in both clinical trials and observational studies. Twenty-five of the 37 studies demonstrated a difference in fatigue that was statistically significant and clinically meaningful. Of the 12 studies that did not, 6 used FSS, 3 used VAS, 2 used the Multidimensional Assessment of Fatigue, and 1 used the Brief Fatigue Index. All 6 studies using the FACIT-Fatigue Scale detected clinically meaningful and statistically significant differences. VAS, FSS, and FACIT-Fatigue Scale were the most frequently used instruments in adult SLE studies from 2008 to 2017. Many studies detected clinically important changes in fatigue. Fatigue remains a key measure in both clinical trials and observational SLE studies.

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.

Fatigue in Parkinson's disease: concepts and clinical approach.

Parkinson's disease (PD) is a progressive neurological disorder characterized by a large number of motor and non-motor features. Fatigue is one of the most common and most disabling symptoms among patients with PD, and it has a significant impact on their quality of life. Although fatigue has been recognized for a long time, its pathophysiology remains poorly understood, and there is no evidence to support any therapeutic approach in PD patients. Expert consensus on case definition and diagnostic criteria for PD-related fatigue have been recently published, and although they still need to be adequately validated, they provide a great step forward in the study of fatigue. The goal of this article is to provide relevant information for the identification and management of patients with fatigue.