Development and Validity of the Rating-of-Fatigue Scale

Objective: The purpose of these experiments was to develop a rating-of-fatigue (ROF) scale capable of tracking the intensity of perceived fatigue in a variety of contexts. Methods: Four experiments were carried out. The first provided the evidential basis for the construction of the ROF scale. The second tested the face validity of the ROF, and the third tested the convergent and divergent validity of the ROF scale during ramped cycling to exhaustion and 30 min of resting recovery. The final experiment tested the convergent validity of the ROF scale with time of day and physical activity (accelerometer counts) across a whole week. Results: Modal selections of descriptions and diagrams at different levels of exertion and recovery were found during Experiment 1 upon which the ROF scale was constructed and finalised. In Experiment 2, a high level of face validity was indicated, in that ROF was reported to represent fatigue rather than exertion. Descriptor and diagrammatic elements of ROF reportedly added to the coherence and ease of use of the scale. In Experiment 3, high convergence between ROF and various physiological measures were found during exercise and recovery (heart rate, blood lactate concentration, oxygen uptake, carbon dioxide production, respiratory exchange ratio and ventilation rate were all P < 0.001). During ramped cycling to exhaustion ROF and RPE did correspond (P < 0.0001) but not during recovery, demonstrating discriminant validity. Experiment 4 found ROF to correspond with waking time during each day (Mon–Sun all P < 0.0001) and with physical activity (accelerometer count) (Mon–Sun all P < 0.001). Conclusions: The ROF scale has good face validity and high levels of convergent validity during ramped cycling to exhaustion, resting recovery and daily living activities. The ROF scale has both theoretical and applied potential in understanding changes in fatigue in a variety of contexts

Upplevd trötthet efter mentalt arbete En fältstudie

The aim of this study was to investigate the validity of a multidimensional questionnaire for assessment of fatigue (Swedish Occupational Fatigue Inventory, SOFI ) after non simulated mental work. Two groups participated, 178 students and 90 operators in control rooms. Perceived fatigue was assessed by the SOFI and the CR10-scales, after a written examination and after a working day in a control room. As expected, both work tasks primarily influenced the scores on Lack of energy, Lack of motivation and Sleepiness as compared to Physical exertion and Physical discomfort. Among the students, the women reported a higher level of Physical discomfort than the men. The operators reported consistent, but low ratings of fatigue. In sum, the results showed that non simulated mental work primarily affected the ratings of Lack of energy. However, the discriminative power of SOFI concerning different fatigue states after mental work needs futher clarification.Syftet var att studera validiteten i ett flerdimensionellt instrument för mätning av trötthet (Swedish Occupational Fatigue Inventory, SOFI) efter mentalt arbete i realistiska miljöer. I studien deltog 178 studenter och 90 kontrollrumsoperatörer. Tröttheten mättes med SOFI och den endimensionella CR10-skalan efter en avslutad examination, och efter en arbetsdag i kontrollrum. Som väntat var skalvärdena i faktorerna Brist på energi, Brist på motivation och Sömnighet högre jämfört med Fysisk ansträngning och Fysiskt obehag. De kvinnliga studenterna rapporterade en högre upplevelse av Fysiskt obehag än männen. Kontrollrumsoperatörerna rapporterade konsistenta, men överlag låga skattningar av trötthet. Sammantaget visade resultatet att det främst var skalvärdena i faktorn Brist på energi som påverkades av mentalt arbete i realistiska miljöer. Det finns dock ett behov av att ytterligare klargöra SOFIs diskrimineringsförmåga mellan olika trötthetstillstånd efter mentalt arbete

Perceived fatigue related to work

Perceived fatigue at work is important because it may be unpleasant for the individual, it may interfere with productivity, and prolonged fatigue without recovery may lead to work-related disorders. This thesis presents a comprehensive approach towards assessment of work-related perceived fatigue. The thesis is based on the notion that perceived fatigue is a multidimen-sional construct, and the principal aim is to identify these dimensions. The aim is further to develop an instrument for measuring work-related perceived fatigue based on self-reports, and to validate the importance of these fatigue dimensions during different types of work. An instrument, the Swedish Occupational Fatigue Inventory (SOFI), was developed for measuring fatigue based on self-reports. In a questionnaire survey 705 employees from different occupations described their perceived fatigue by rating 95 verbal expressions. Factor analyses resulted in five dimensions of work-related perceived fatigue. These dimensions were called Lack of energy, Physical exertion, Physical discomfort, Lack of motivation, and Sleepiness. The SOFI consisted of 25 items, and each of the five dimensions were assessed by five items. The proposed five-dimensional model of perceived fatigue was evaluated in two laboratory experiments and one field study. The first experiment focused on fatigue after physical work, whereas the second experiment focused on fatigue after mental work. The field study was conducted among industrial three-shift workers, who answered a questionnaire after each shift. The results indicated a reasonably good validity of the instrument, in the sense that it showed an ability to reflect different fatigue dimensions in different types of work. That is, perceived fatigue due to physical work was primarily described by Lack of energy, Physical exertion and Physical discomfort, fatigue due to mental work primarily by Lack of energy, Lack of motivation and Sleepiness, and fatigue due to night work primarily by Sleepiness. The results also add to previous knowledge by showing that night work is not only associated with perceived Sleepiness, but also with Lack of energy and Lack of motivation. The proposed five-dimensional model of perceived fatigue was cross-validated in a new occupational population, using the SOFI to assess fatigue in different work situations. Linear structural equation analyses (LISREL) of the results suggested a slightly revised model for perceived fatigue, still comprising five dimensions, but with a reduced number of variables : 20 instead of 25. Lack of energy was defined as a latent factor directly related to all observed variables, indicating its general character. The results in this thesis also showed common gender differences of perceived fatigue in field settings: women reported more fatigue than men. However, gender did not differ in fatigue during simulated work in the laboratory, irrespective of whether the work consisted of similar mental workload or individually adjusted physical workload. This indicates that work-related perceived fatigue is influenced by factors other than the work task. In conclusion, work-related perceived fatigue can be described as being composed of five dimensions. An instrument, the SOFI, has been developed. The result indicated a reasonably good validity for the SOFI.Upplevd trötthet i arbetslivet är viktigt eftersom: den enskilde individen kan besväras av trötthet; trötthet kan minska produktiviteten; och trötthet över tid, utan möjlighet till återhämtning, kan leda till arbetsrelaterade besvär. Denna avhandling presenterar en övergripande ansats mot mätning av arbetsrelaterad trötthet. Avhandlingen utgår från upplevd trötthet som ett flerdimensionellt konstrukt, och det huvudsakliga syftet är att identifiera dessa dimensioner. Dessutom är syftet att utveckla ett mätinstrument för arbets-relaterad upplevd trötthet, och att pröva betydelsen av trötthetsdimensionerna vid olika arbeten. Ett mätinstrument, Swedish Occupational Fatigue Inventory (SOFI), konstruerades för att mäta tröttet med hjälp av självskattningar. I en frågeformulärsstudie beskrev 705 anställda, från olika yrken, sina trötthetsupplevelser genom att skatta 95 verbala uttryck. Via faktoranalyser erhölls en fem-dimensionell modell om arbetsrelaterad trötthet. Dessa dimensioner kallas Brist på energi, Fysisk ansträngning, Fysiskt obehag, Brist på motivation, och Sömnighet. SOFI bestod av 25 uttryck, varav var och en av de fem dimensionerna skattades med hjälp av fem uttryck. Validiteten i den förslagna fem-dimensionella modellen om upplevd trötthet prövades med två experiment och en fältstudie. Det första experimentet rörde trötthet efter fysiskt arbete, medan det andra experimentet rörde trötthet efter mentalt arbete. Fältstudien utfördes bland tre-skifts arbetande industriarbetare, vilka besvarade ett frågeformulär efter varje skiftpass. Resultaten indikerade en relativt god validitet av mätinstrumentet, så till vida att det kunde urskilja olika trötthetsdimensioner vid olika typer av arbetsuppgifter. Det vill säga: upplevd trötthet efter mentalt arbete beskrevs huvudsakligen som Brist på energi, Brist på motivation, och Sömnighet; trötthet efter fysiskt arbete beskrevs huvudsakligen som Brist på energi, Fysisk ansträngning och Fysiskt obehag; och trötthet efter nattarbete beskrevs huvudsakligen som Sömnighet. Resultaten visar också att nattarbete inte bara är förknippat med upplevelser av Sömnighet, utan också med Brist på energi och Brist på motivation. Den förslagna fem-dimensionella modellen om upplevd trötthet korsvaliderades med hjälp av en ny undersökningsgrupp. Resultaten tydde på att modellen borde revideras något, till en modell där de fem dimensionerna kvarstod, men där antalet variabler var färre : 20 istället för 25. Brist på energi definierades som en latent faktor direkt relaterad till samtliga observerade variabler, vilket talar för den generella karaktären av dimensionen Brist på energi. Resultaten i denna avhandling visar vanliga könsskillnader i fältstudier: kvinnor rapporterar en högre grad av trötthet jämför med män. Däremot kunde inga sådana könskillnader påvisas i experimenten, oavsett om kvinnor och män var utsatta för samma mentala arbetsbelastning, eller individuellt anpassad fysisk arbetsbelastning. Detta indikerar att arbetsrelaterade trötthetsupplevelser även påverkas av andra faktorer än enbart arbetsuppgiften. Sammanfattningsvis, arbetsrelaterad upplevd trötthet kan beskrivas med hjälp av fem dimensioner. Ett mätinstrument, SOFI, har utvecklats. Resultaten tyder på en relativt god validitet för SOFI

Upplevd trötthet efter mentalt arbete En experimentell utvärdering av ett mätinstrument

Syftet var att studera trötthetsupplevelser efter mentalt arbete och pröva ett instrument för mätning av trötthet, SOFI (Swedish Occupational Fatigue Inventory). Tjugo kvinnor och 20 män arbetade med korrekturläsning (2x90 min) och en vigilansuppgift (2x60 min). Efter arbetsuppgifterna skattades tröttheten med SOFI och CR10-skalan. Dessutom registrerades dels fysiologiska reaktioner; blodtryck, hjärtfrekvens, hjärtfrekvensvariabilitet och muskelaktivitet i corrugator, dels prestationsmått; antal upptäckta korrekturfel, antal lästa sidor, antal upptäckta signaler, reaktionstid. De högsta skattningarna återfanns i Brist på energi, Brist på motivation och Sömnighet, särskilt efter vigilansuppgiften. Förhållandevis höga skattningar gjordes även på CR10-skalan, efter båda arbetsuppgifterna. Ingen könsskillnad avseende skattningar, eller någon entydig fysiologisk reaktion som samvarierade med trötthetsupplevelsen, kunde påvisas. Sammanfattningsvis har validiteten i den mentala dimensionen i SOFI belysts

Assessment of human fatigue: A comparison between machining and assembly tasks

© Springer International Publishing Switzerland 2014. All rights are reserved. Research on human fatigue in industrial environments is limited, especially in developing countries. Currently, with the inclusion of new and more complex technologies; levels of mental effort performed by workers have increased while levels of physical exertion have decreased. This research presents the comparison of fatigue scores of two processes including Advanced Manufacturing Technologies (AMT). The first one involves machining of steel pieces using Computerized Numerical Control (CNC) lathes and the second one involves Constant Velocity (CV) Joints assembly using hydraulic presses. For the assessment of fatigue, the Swedish Occupational Fatigue Inventory Spanish version (SOFI-S) was applied. The study was conducted in a manufacturing company of CV Joints located in Central Mexico. A sample of 75 operators of CNC lathes and 66 operators of hydraulic presses were surveyed. As results, Lack of energy was the fatigue dimension that obtained the highest score of (SOFI-S) in both processes analyzed. Nonparametric comparisons show no difference in scores of fatigue dimensions between both processes analyzed

Collaboration in compulsory schools´s scientific subjects : A qualitative study on some science teacher´s experiences of collaboration as a form of teaching

Denna kvalitativa studie undersöker lärares erfarenheter av och uppfattningar om grupparbete i skolans naturvetenskapliga ämnen. Lärare, undervisande i NO och verksamma i skolår 1-9, har intervjuats med förutbestämda frågor i öppen form. Genom en fenomenografisk metod har studien resulterat i fyra kategorier av uppfattningar hos lärarna. Grupparbete i NO för att avdramatisera ämnet Grupparbete i NO för att berika lärandeprocessen Grupparbete i NO för att läraren ”måste” Grupparbete i NO ur ekonomiska aspekter Vår studie visar att informanterna har olika uppfattningar om begreppet grupparbete och därigenom skiljer sig också formen för hur grupparbetet kan te sig. Dessa skillnader faller ut i våra kategorier.This qualitative study investigates teacher´s experiences with and opinions of using collaboration in science education. A selected group of science teachers tutoring in compulsory school were interviewed in an open form using a set of pre-defined questions. The study resulted in four categories of teacher responses using a phenomenographical method of category sorting Collaboration in Science to make it more approachable and understandable Collaboration in Science to enrich the learning process Collaboration in Science because the teacher “has to” Collaboration in Science due to economical limitations Our study shows that the respondents have different receptions about the term collaboration resulting in differences in the implementation of collaboration exercises. Our categories shed light on these differences

Fatigue dimensions in patients with advanced cancer in relation to time of survival and quality of life

To understand the relation between fatigue and patients emotional situation at the end of life, this cross-sectional study aimed to explore the association between multidimensional aspects of fatigue, emotional functioning and quality of life (QoL) in patients with advanced cancer at the end of life. Patients with advanced cancer answered fatigue related measurements (Borg Category Ratio-10 scale, Multidimensional Fatigue Inventory-20, Swedish Occupational Fatigue Inventory and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30), when admitted for specialised palliative care. A total of 228 patients with a median length of survival of 63 days were included. In relation to time of survival, fatigue increased closer to death, in both global and multidimensional aspects, as well as the patient’s experience of being sleepy. Marital status was found to affect the experience of fatigue in both global and multidimensional ratings of fatigue. The association between the experience of fatigue and feelings of being tense, worried, irritable or depressed and rated QoL decreased and was not evident closer to death. Fatigue in all dimensions increased, as patients got closer to death. The association between fatigue and both QoL and negative emotions faded away during the last days and weeks of life