Validation of the National Aeronautics and Space Administration Task Load Index (NASA-TLX) adapted for the whole day repeated measures context

The interplay of brain neurotransmission and mental fatigue: A research protocol

INTRODUCTION

Mental fatigue (MF) significantly affects both cognitive and physical performance. However, the precise mechanisms, particularly concerning neurotransmission, require further investigation. An implication of the role of dopamine (DA) and noradrenaline (NA) is stated, but empirical evidence for this theory still needs to be provided. To address this gap, we aim to investigate the role of brain neurotransmission in elucidating if, and how prolonged cognitive activity induces MF and its subsequent impact on cognitive performance.

METHODS

This study (registration number: G095422N) will adopt a randomized cross-over design with sixteen healthy participants aged 18-35 years. The sessions include a familiarization, two experimental (DA: 20mg Methylphenidate; NA: 8mg Reboxetine) conditions, and one placebo (lactose tablet: 10mg) condition. A 60-minute individualized Stroop task will be used to investigate whether, and how the onset of MF changes under the influence of reuptake inhibitors. Attention and response inhibition will be assessed before and after the MF-inducing task using a Go/NoGo task. The integration of physiological (electroencephalography, heart rate), behavioral (attention, response inhibition), and subjective indicators (scales and questionnaires) will be used to detect the underlying mechanisms holistically. Data analysis will involve linear mixed models with significance at p<0.05.

DISCUSSION

The integration of diverse techniques and analyses offers a comprehensive perspective on the onset and impact of MF, introducing a novel approach. Future research plans involve extending this protocol to explore the connection between brain neurotransmission and physical fatigue. This protocol will further advance our understanding of the complex interplay between the brain and fatigue.

Whole Day Workload: Evaluation of a New Outcome Measure in Occupational Therapy for Adults With Type 1 Diabetes

IMPORTANCE

Typical whole day workload is a metric with potential relevance to the occupational balance and well-being of individuals with chronic conditions.

OBJECTIVE

To examine the reliability and validity of using multiple daily NASA Task Load Index measures (whole day TLX) as an indicator of typical whole day workload experienced by adults with Type 1 diabetes (T1D).

DESIGN

Participants with T1D completed cross-sectional measures and 2 wk of ecological momentary assessments (EMA) and daily diaries. Reliability was assessed across subgroups (e.g., workers vs. nonworkers); validity was evaluated with multilevel confirmatory factor analysis and with tests of convergent and divergent validity with patient-reported outcomes and blood glucose measures.

SETTING

Three outpatient endocrinology clinics in the United States.

PARTICIPANTS

Data from 164 U.S. adults with T1D (42% Latino, 30% White).

OUTCOMES AND MEASURES

Measures used included the whole day TLX (assessed via 2 wk of daily diaries), time in target blood glucose range (assessed with a continuous glucose monitor), illness intrusiveness (measured cross-sectionally), and stress (measured cross-sectionally and with EMA).

RESULTS

Number of days required for at least 0.70 reliability of the average whole day TLX ranged between 2 and 6 days depending on the subgroup. Results supported convergent and divergent validity of the average of the whole day TLX, including associations with average stress (r = .63, p < .001) and time in target blood glucose range (r = -.25, p = .002).

CONCLUSIONS AND RELEVANCE

The whole day TLX was a reliable and valid indicator of typical whole day workload. Plain-Language Summary: The health management responsibilities for Type 1 diabetes can be extremely burdensome. When these responsibilities are experienced, in addition to duties such as work and caregiving, the totality of demands experienced (i.e., whole day workload) can create further issues, such as unhealthy physiological changes and interference with self-care. We tested the psychometric properties of a measurement tool that assesses the typical level of workload people experience. This measure, referred to as the NASA Task Load Index (whole day TLX), was found to be a reliable and valid indicator of typical whole day workload. Occupational therapists may use the whole day TLX to track progress in interventions focused on reducing clients' whole day workload exposure to promote their health and well-being. Occupational therapists' expertise in areas such as activity analysis, task adaptation, and energy conservation makes them especially well-suited to intervene on whole day workload.

Workload of home care nurses: Italian adaptation, validity, and reliability of the National Aeronautics and Space Administration Task Load Index questionnaire

The aim of this study was to adapt the National Aeronautics and Space Administration Task Load Index (NASA-TLX) to the home care setting and translate and validate it in Italian. An online questionnaire containing the Italian version of the NASA-TLX adapted to the home care setting was administered to home care nurses to measure workload. Content Validity Index, Exploratory, and Confirmatory Factor Analyses were used to measure the psychometric characteristics of the modified NASA-TLX. The modified Italian version of NASA-TLX_HC-IT showed good psychometric characteristics in measuring the workload of home care nurses, with excellent fit indices. The reliability, calculated with Cronbach's alpha, was 0.73, indicating adequate reliability. A negative correlation between workload and job satisfaction among home care nurses, as well as a positive association between high workload and intention to leave the workplace, was verified. The modified Italian version of the NASA-TLX_HC-IT was confirmed to be a valid and reliable instrument to measure workload in home care nursing. Furthermore, the correlation between workload and the intention to leave the workplace among home care nurses was an important result that community nursing managers should consider preventing the shortage of home care nurses.

Translation, cultural adaptation and assessment of psychometrics properties of the Extended Version of the Nordic Musculoskeletal Questionnaire (NMQ-E) in Persian language speaking people

BACKGROUND

To translate and cross-culturally adapt the Extended Version of the Nordic Musculoskeletal Questionnaire (NMQ-E) into Persian (NMQ-E-P) and evaluate the psychometric properties in a general population with different occupational tasks across nine body regions.

METHODS

This cross-sectional study was designed according to the standard guidelines and the COSMIN checklist. The NMQ-E-P was achieved through forward and backward translation methods and consensus to produce the final draft. A Persian-speaking population (n = 571, age 38.24 ± 7.65 years, female = 46.2%) was recruited from industries and office workers with three occupational task inclusion criteria: assembly, office, and lifting. Psychometric properties included validity for face (from confirmed clarity, simplicity, and readability), content (via the content validity index); and construct (through known group validity); additionally, the properties of internal consistency (Cronbach's α); and test-retest reliability (Kappa coefficient of agreement) were considered.

RESULTS

No significant issues during the translation process were found. The NMQ-E-P showed adequate internal consistency for all regions (α ≥ 0.87). The test-retest reliability was examined with Kappa agreement correlation coefficient and all items, except ankle regions, showed very good agreements (Kappa coefficient = 0.87-1.0). Excellent ICC values were obtained for quantitative variables (ICC > 0.88) and good construct validity was revealed (p < 0.001).

CONCLUSION

The Persian version of the NMQ-E has very good validity and reliability and can be used by researchers and professionals to evaluate the prevalence of MSDs in nine body regions simultaneously.

Structured Multidisciplinary work Evaluation Tool (SMET) questionnaire: Translation, cultural adaptation and psychometric evaluation of the Persian version

BACKGROUND

To assess relevant environmental conditions in any work-setting requires a multidisciplinary perspective that is practical, valid, and reliable. This includes the physical, environmental, and psychosocial risk-factors. The Structured Multidisciplinary work Evaluation Tool (SMET) questionnaire simultaneously considers multiple work-related demands.

OBJECTIVE

This study translated and culturally adapted the SMET into Persian and evaluated its psychometric properties in Persian industrial workers.

METHODS

Cross-sectional translation and cross-cultural adaptation in five standardized phases. A convenience sample (n = 211) recruited from an industrial-occupation setting completed: the SMET; and the Rapid Upper Limb Assessment (RULA), and National Aeronautics and Space Administration Task Load Index (NASA-TLX) criteria; plus light and noise levels were concurrently assessed. Psychometric properties included: validity, with face (from confirmed language clarity, simplicity, and readability), content (via the content validity index, CVI, for equivalency and relevancy), criterion (through Pearson's r correlation with relevant criteria), and construct (through known group validity between participants with/without work-related musculoskeletal disorders, WMSDs); internal consistency (Cronbach's α); and test-retest reliability (intraclass correlation coefficient, ICC2.1).

RESULTS

Validity was confirmed with: face through the adaptation; content from suitable CVI values for items (CVI range = 0.78-1.0) and scale-total (CVI = 0.86); criterion from SMET associations with levels for light (r = - 0.42) and noise (r = 0.21), plus RULA (r = 0.42) and NASA-TLX (r = 0.39); and construct through participants with WMSD having significantly higher SMET total-scores (p = 0.01). Internal consistency (α= 0.89) and reliability (ICC2.1 = 0.87) were acceptable and strong.

CONCLUSION

This study indicated that the SMET Persian version had acceptable psychometric properties in an industrial occupational setting. Further investigation in longitudinal populations is recommended.

Effect of brain endurance training on maximal oxygen uptake, time-to-exhaustion, and inhibitory control in runners

We aimed to analyze the effect of brain endurance training on maximum oxygen consumption (VO2máx ), time-to-exhaustion, and inhibitory control in amateur trained runners. We employed a mixed experimental design, with the group as the between-participant factor and time as the within-participant factor. 45 participants attended 36 training sessions over 12 weeks. The cognitive training group (CT) performed the Stroop word-color task [trials of each type (congruent, incongruent, and neutral) were randomly presented during each training session], the endurance training group (ET) participated in a running training program (intensity was 60%Δ of maximal aerobic velocity and performed on a motor-driven treadmill), and the brain endurance training group (BET) make cognitive and endurance training simultaneously over 12 weeks. The total time of each session (i.e., 20-40 min) was identical in the experimental groups. VO2máx , time-to-exhaustion, and inhibitory control tests were measured before (baseline) and after (post-experiment) the 12-week intervention. A significant effect of interaction (group × time) for VO2máx (p < 0.05) was found. A post-hoc test showed an increase in VO2máx from baseline to post-experiment only for ET (Δ% = 2.98) and BET (Δ% = 3.78) groups (p < 0.05). Also, the analyses showed a significant interaction (group × time) for time-to-exhaustion (p < 0.05), and a post-hoc test revealed an improvement in time-to-exhaustion for ET (Δ% = 8.81) and BET (Δ% = 11.01) (p < 0.05). No group × time interaction was found for accuracy and response time in the inhibitory control task (p > 0.05). The results conclude that BET was not superior to ET for improving VO2máx and time-to-exhaustion. Also, the findings conclude that BET improved inhibitory control similar to CT.

Workload assessment: cross-cultural adaptation, content validity and instrument reliability

OBJECTIVES

to adapt, validate the content and assess the reliability of the instrument National Aeronautics and Space Administration - Task Load Index, translated into Brazilian Portuguese.

METHODS

a methodological study, divided into five steps: translation; synthesis; back-translation; assessment of the Portuguese version by an expert committee; pre-test and content validity of the final version by health professionals working in inpatient units. The Content Validity Index (CVI) (minimum 0.80) and Cronbach's alpha (minimum 0.70) were calculated.

RESULTS

in the first round, in the agreement analysis of the translated version, three items did not reach the minimum CVI value. It was decided to remove the statement. The instrument title and items "performance" and "effort" were changed. There was consensus and approval of the final version in the pre-test step.

CONCLUSIONS

the NASA Task Load Index instrument, adapted to Brazilian Portuguese, presents reliability and content validity evidence.

Impact of Overnight Glucose on Next-Day Functioning in Adults With Type 1 Diabetes: An Exploratory Intensive Longitudinal Study

OBJECTIVE

While there is evidence that functioning, or ability to perform daily life activities, can be adversely influenced by type 1 diabetes, the impact of acute fluctuations in glucose levels on functioning is poorly understood.

RESEARCH DESIGN AND METHODS

Using dynamic structural equation modeling, we examined whether overnight glucose (coefficient of variation[CV], percent time <70 mg/dL, percent time >250 mg/dL) predicted seven next-day functioning outcomes (mobile cognitive tasks, accelerometry-derived physical activity, self-reported activity participation) in adults with type 1 diabetes. We examined mediation, moderation, and whether short-term relationships were predictive of global patient-reported outcomes.

RESULTS

Overall next-day functioning was significantly predicted from overnight CV (P = 0.017) and percent time >250 mg/dL (P = 0.037). Pairwise tests indicate that higher CV is associated with poorer sustained attention (P = 0.028) and lower engagement in demanding activities (P = 0.028), time <70 mg/dL is associated with poorer sustained attention (P = 0.007), and time >250 mg/dL is associated with more sedentary time (P = 0.024). The impact of CV on sustained attention is partially mediated by sleep fragmentation. Individual differences in the effect of overnight time <70 mg/dL on sustained attention predict global illness intrusiveness (P = 0.016) and diabetes-related quality of life (P = 0.036).

CONCLUSIONS

Overnight glucose predicts problems with objective and self-reported next-day functioning and can adversely impact global patient-reported outcomes. These findings across diverse outcomes highlight the wide-ranging effects of glucose fluctuations on functioning in adults with type 1 diabetes.

Workers' whole day workload and next day cognitive performance

Workload experienced over the whole day, not just work periods, may impact worker cognitive performance. We hypothesized that experiencing greater than typical whole day workload would be associated with lower visual processing speed and lower sustained attention ability, on the next day. To test this, we used dynamic structural equation modeling to analyze data from 56 workers with type 1 diabetes. For a two-week period, on smartphones they answered questions about whole day workload at the end of each day, and completed cognitive tests 5 or 6 times throughout each day. Repeated smartphone cognitive tests were used, instead of traditional one- time cognitive assessment in the laboratory, to increase the ecological validity of the cognitive tests. Examples of reported occupations in our sample included housekeeper, teacher, physician, and cashier. On workdays, the mean number of work hours reported was 6.58 (SD 3.5). At the within-person level, greater whole day workload predicted decreased mean processing speed the next day (standardized estimate=-0.10, 95% CI -0.18 to -0.01) using a random intercept model; the relationship was not significant and only demonstrated a tendency toward the expected effect (standardized estimate= -0.07, 95% CI -0.15 to 0.01) in a model with a random intercept and a random regression slope. Whole day workload was not found to be associated with next-day mean sustained attention ability. Study results suggested that just one day of greater than average workload could impact next day processing speed, but future studies with larger sample sizes are needed to corroborate this finding.

Perception of Whole Day Workload as a Mediator Between Activity Engagement and Stress in Workers with Type 1 Diabetes

Associations between various forms of activity engagement (e.g. work, leisure) and the experience of stress in workers have been widely documented. The mechanisms underlying these effects, however, are not fully understood. Our goal was to investigate if perceived whole day workload accounted for the relationships between daily frequencies of activities (i.e. work hours and leisure/rest) and daily stress. We analyzed data from 56 workers with type 1 diabetes (T1D) who completed approximately two weeks of intensive longitudinal assessments. Daily whole day workload was measured with an adapted version of the National Aeronautics and Space Administration Task Load Index (NASA-TLX). A variety of occupations were reported including lawyer, housekeeper, and teacher. In multilevel path analyses, day-to-day changes in whole day workload mediated 67% (p<.001), 61% (p<.001), 38% (p<.001), and 55% (p<.001) of the within-person relationships between stress and work hours, rest frequency, active leisure frequency, and day of week, respectively. Our results provided evidence that whole day workload perception may contribute to the processes linking daily activities with daily stress in workers with T1D. Perceived whole day workload may deserve greater attention as a possible stress intervention target, ones that perhaps ergonomists would be especially suited to address.