095 Steering Wheel Angle Excursions as a Measure of Fatigue-Related Driver Performance Impairment

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A39-A40
Author(s):  
Rachael Muck ◽  
Hans Van Dongen
Keyword(s):  
Effect Size ◽  
Fixed Effects ◽  
Night Shift ◽  
Driving Performance ◽  
Steering Wheel ◽  
Adaptation Period ◽  
Shift Schedule ◽  
Performance Impairment ◽  
Time Awake ◽  
Night Shifts

Abstract Introduction Fatigue from sleep loss and circadian misalignment causes automobile driving performance impairment. Metrics based on steering wheel angle, which is straightforward to measure, could be used to quantify this impairment. As the tail of the distribution of steering wheel angles (absolute magnitude of deviation from center) increases with fatigue, we investigated whether driving performance impairment could be quantified based on the prevalence of steering wheel excursions beyond a given angle threshold. We used data from two published laboratory studies of simulated shift work, in which fatigue remained low during day shifts but increased across time awake during night shifts. Methods N=37 healthy adults (ages 26.8±5.2y; 25 men) were assigned to a simulated night shift schedule (awake 20:00-10:00) or day shift schedule (awake 08:00-22:00; study 1 only). After an adaptation period, participants underwent two 5-day shift cycles with an intervening rest period. Driving performance was measured on a high-fidelity simulator during adaptation (data not used) and four times at 3h intervals during each shift day. Every drive involved 30min driving at 55mph, including ten 0.5mi uneventful straightaways being considered here. Steering wheel angle was measured at 72Hz (study 1) or 60Hz (study 2). A total of 1,471 drives (31,394,498 angle measurements) were available for analysis. Results We investigated angle thresholds across 0.01-0.25rad in 0.01rad intervals and counted the corresponding number of threshold excursions in each drive for each participant. For study 1, we applied mixed-effects ANOVA with fixed effects for condition and time awake, and their interaction, and determined the local effect size for interaction. A 0.03rad (1.7°) threshold yielded the greatest effect size, f²=0.031 (small). For this threshold, we repeated the analysis using the data from both studies, controlling for study. The interaction was significant (F[3,1428]=13.23, p<0.001), showing low driving impairment across time awake during day shifts but increasing impairment across time awake during night shifts. Conclusion The prevalence of steering wheel excursions beyond a 1.7° angle threshold yielded sensitivity to fatigue-related driving performance impairment during simulated night shifts. Further research will extend our results to driving through curves and with greater fatigue levels. Support (if any) FMCSA DTMC75-07-D-00006

Night work and sick leave during pregnancy: a national register-based within-worker cohort study

2019 ◽  
Vol 76 (3) ◽  
pp. 163-168 ◽  
Author(s):  
Paula Edeusa Cristina Hammer ◽  
Anne Helene Garde ◽  
Luise Moelenberg Begtrup ◽  
Esben Meulengracht Flachs ◽  
Johnni Hansen ◽  
...  
Keyword(s):  
Sick Leave ◽  
Fixed Effects ◽  
Public Hospital ◽  
Night Shift ◽  
Acute Effect ◽  
Night Work ◽  
Personal Factors ◽  
Hospital Employees ◽  
Time Invariant ◽  
Night Shifts

ObjectiveThe aim of our study was to investigate the acute effect of night work during pregnancy on the risk of calling in sick the following day using register-based information and the workers as their own controls.MethodsUsing the payroll-based national Danish Working Hour Database, including all public hospital employees in Denmark, we identified 9799 pregnant women with ≥1 day shift and ≥1 night shift and ≥1 day of sick leave during the first 32 pregnancy weeks from January 2007 to December 2013. We performed fixed effects logistic regression, that is, within-worker comparisons, of the risk of sick leave of any duration starting within 24 hours after night shifts of different length versus day shifts.ResultsMost of the participants were nurses (64%) or physicians (16%). We found an increased relative risk of sick leave following night shifts compared with day shifts during all pregnancy trimesters. The risk was highest for night shifts lasting >12 hours (OR 1.37, 95% CI 1.15 to 1.63 for nurses; OR 1.87, 95% CI 1.69 to 2.08 for physicians) and among women aged >35 years (OR 1.42, 95% CI 1.24 to 1.63).ConclusionAmong Danish public hospital employees night shifts during pregnancy, especially shifts longer than 12 hours, increased the risk of calling in sick the following day independent of personal factors and time-invariant confounders in all pregnancy trimesters.

scholarly journals 0308 DRD2 C957T Genotype Influences Vigilant Attention Performance Impairment During Total Sleep Deprivation

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A116-A116
Author(s):  
R A Muck ◽  
L Skeiky ◽  
M A Schmidt ◽  
B C Satterfield ◽  
J P Wisor ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Analysis Of Covariance ◽  
Genotype Distribution ◽  
Total Sleep Deprivation ◽  
Psychomotor Vigilance Test ◽  
Time In Bed ◽  
Dat1 Gene ◽  
Performance Impairment ◽  
Attention Performance ◽  
Time Awake

Abstract Introduction There are substantial, phenotypical individual differences in the adverse impact of total sleep deprivation (TSD) on vigilant attention performance. Dopaminergic genotypes have been found to contribute to these phenotypical differences. Here we investigated the association between a single nucleotide polymorphism (SNP) of the dopamine receptor D2 (DRD2) gene, C957T (rs6277), on vigilant attention performance measured with the psychomotor vigilance test (PVT) in a laboratory TSD study. Methods N=46 healthy adults (ages 26.0±5.3y; 25 females) completed a 4-day in-laboratory study with a baseline day (10h time in bed: 22:00-08:00), a 38h TSD period, and a recovery day (10h time in bed: 22:00-08:00). DNA isolated from whole blood was assayed for DRD2 C957T genotype using real-time polymerase chain reaction. PVT performance was measured during TSD at 2-4h intervals, and analyzed for genotype using mixed-effects analysis of covariance of lapses of attention (RTs>500ms). Results The genotype distribution in this sample - 28.3% C/C, 50.0% C/T, 21.7% T/T - was found to be in Hardy-Weinberg Equilibrium (X21=0.0008, p=0.98). As expected, there was a significant effect of time awake on PVT performance (F14,602=26.67, p<0.001). There was a significant main effect of DRD2 genotype (F2,602=3.24, p=0.040) and a significant interaction of time awake by DRD2 genotype (F28,602=1.96, p=0.003). Subjects homozygous for the T allele showed greater impairment during extended wakefulness than carriers of the C allele. Genotype explained 7.6% of the variance in the PVT data observed during the 38h TSD period. Conclusion Subjects homozygous for the T allele of DRD2 C957T were considerably more vulnerable to TSD-induced PVT performance impairment than carriers of the C allele. A recent study showed that DRD2 C957T influences PVT performance in interaction with a SNP of the DAT1 gene. Here, DRD2 genotype was by itself also associated with PVT performance impairment during TSD. Support CDMRP awards W81XWH-16-1-0319 and W81XWH-18-1-0100.

scholarly journals Chronotype-specific Sleep in Two Versus Four Consecutive Shifts

2021 ◽  
pp. 074873042110060
Author(s):  
Dorothee Fischer ◽  
Till Roenneberg ◽  
Céline Vetter
Keyword(s):  
Night Shift ◽  
Sleep Diary ◽  
Sequence Length ◽  
Consecutive Night ◽  
Shift Workers ◽  
Subject Field ◽  
Sleep Diaries ◽  
Social Jetlag ◽  
Sleep Debt ◽  
Night Shifts

The study aimed to explore chronotype-specific effects of two versus four consecutive morning or night shifts on sleep-wake behavior. Sleep debt and social jetlag (a behavioral proxy of circadian misalignment) were estimated from sleep diary data collected for 5 weeks in a within-subject field study of 30 rotating night shift workers (29.9 ± 7.3 years, 60% female). Mixed models were used to examine whether effects of shift sequence length on sleep are dependent on chronotype, testing the interaction between sequence length (two vs. four) and chronotype (determined from sleep diaries). Analyses of two versus four morning shifts showed no significant interaction effects with chronotype. In contrast, increasing the number of night shifts from two to four increased sleep debt in early chronotypes, but decreased sleep debt in late types, with no change in intermediate ones. In early types, the higher sleep debt was due to accumulated sleep loss over four night shifts. In late types, sleep duration did not increase over the course of four night shifts, so that adaptation is unlikely to explain the observed lower sleep debt. Late types instead had increased sleep debt after two night shifts, which was carried over from two preceding morning shifts in this schedule. Including naps did not change the findings. Social jetlag was unaffected by the number of consecutive night shifts. Our results suggest that consecutive night shifts should be limited in early types. For other chronotypes, working four night shifts might be a beneficial alternative to working two morning and two night shifts. Studies should record shift sequences in rotating schedules.

Task-induced fatigue states and simulated driving performance

2002 ◽  
Vol 55 (2) ◽  
pp. 659-686 ◽  
Author(s):  
Gerald Matthews ◽  
Paula A. Desmond
Keyword(s):  
Motor Vehicle ◽  
Driving Performance ◽  
Task Demands ◽  
Vehicle Accidents ◽  
Stress Symptoms ◽  
Performance Impairment ◽  
Driving Task ◽  
Effort Regulation ◽  
Compensatory Effort

States of fatigue are implicated in driver impairment and motor vehicle accidents. This article reports two studies investigating two possible mechanisms for performance impairment: (1) loss of attentional resources; and (2) active regulation of matching effort to task demands. The first hypothesis predicts that fatigue effects will be accentuated by high task demands, but the second hypothesis predicts that fatigue effects will be strongest in “underload” conditions. In two studies, drivers performed a stimulated driving task, in which task demands were manipulated by varying road curvature. In a “fatigue induction” condition, the early part of the drive was occupied by performance of a demanding secondary task concurrently with driving, after which the concurrent task ceased. Post-induction driving performance was compared with a control condition in which drivers were not exposed to the induction. In both studies, the fatigue induction elicited various subjective fatigue and stress symptoms, and also raised reported workload. Fatigue effects on vehicle control and signal detection were assessed during and after the fatigue induction. The fatigue induction increased heading error, reduced steering activity, and, in the second study, reduced perceptual sensitivity on a secondary detection task. These effects were confined to driving on straight rather than on curved road sections, consistent with the effort regulation hypothesis. The second study showed that fatigue effects were moderated by a motivational manipulation. Results are interpreted within a control model, such that task-induced fatigue may reduce awareness of performance impairment, rather than reluctance or inability to mobilize compensatory effort following detection of impairment.

Abstract 3789: Nessun Dorma : Have the Risks of Rosiglitazone been Exaggerated?

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
George A Diamond ◽  
Sanjay Kaul
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Cardiovascular Death ◽  
Sensitivity Analyses ◽  
Odds Ratios ◽  
True Effect Size ◽  
Index Study ◽  
The Stability

Background A highly publicized meta-analysis of 42 clinical trials comprising 27,844 diabetics ignited a firestorm of controversy by charging that treatment with rosiglitazone was associated with a “…worrisome…” 43% greater risk of myocardial infarction ( p =0.03) and a 64% greater risk of cardiovascular death ( p =0.06). Objective The investigators excluded 4 trials from the infarction analysis and 19 trials from the mortality analysis in which no events were observed. We sought to determine if these exclusions biased the results. Methods We compared the index study to a Bayesian meta-analysis of the entire 42 trials (using odds ratio as the measure of effect size) and to fixed-effects and random-effects analyses with and without a continuity correction that adjusts for values of zero. Results The odds ratios and confidence intervals for the analyses are summarized in the Table . Odds ratios for infarction ranged from 1.43 to 1.22 and for death from 1.64 to 1.13. Corrected models resulted in substantially smaller odds ratios and narrower confidence intervals than did uncorrected models. Although corrected risks remain elevated, none are statistically significant (*p<0.05). Conclusions Given the fragility of the effect sizes and confidence intervals, the charge that roziglitazone increases the risk of adverse events is not supported by these additional analyses. The exaggerated values observed in the index study are likely the result of excluding the zero-event trials from analysis. Continuity adjustments mitigate this error and provide more consistent and reliable assessments of true effect size. Transparent sensitivity analyses should therefore be performed over a realistic range of the operative assumptions to verify the stability of such assessments especially when outcome events are rare. Given the relatively wide confidence intervals, additional data will be required to adjudicate these inconclusive results.

143 Effect of Supplementary Selenium Source on Dairy Cow Performance, Antioxidant Status, and Apparent Absorption and Retention

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 80-80
Author(s):  
Keira M Cruickshank ◽  
Bayissa Hatew ◽  
Amanda M Gehman ◽  
Karen M Koenig ◽  
Eduardo S Ribeiro ◽  
...  
Keyword(s):  
Dairy Cow ◽  
Fixed Effects ◽  
Antioxidant Status ◽  
Treatment Time ◽  
Rumen Fluid ◽  
Random Effect ◽  
Fecal Excretion ◽  
Adaptation Period ◽  
Apparent Absorption ◽  
Cow Performance

Abstract The objective of this experiment was to determine how source of selenium (Se) affects dairy cow performance, antioxidant status, and apparent absorption and retention. Multiparous Holstein cows (n = 24; 597 ± 49 kg BW) were blocked by days in milk (161 ± 18) and randomly assigned to receive 0.3 mg/kg of either: 1) organic Se (selenized yeast; ORG; Sel-Plex-Alltech); or, 2) inorganic Se (sodium selenite; INO) premix, top dressed and mixed into a ration daily. After an 11-week adaptation period (blood and milk sampled monthly), cows received an intraruminal dose of Se77 (either Se77 yeast or NaSe77O3) followed by a 4-day period of blood and rumen fluid sampling, and total collection of feces, urine, and milk. Data were analyzed using PROC GLIMMIX in SAS with fixed effects of treatment, time, and their interaction, and random effect of block. Daily DMI (23 ± 0.6 kg), milk yield (35 ± 1.2 kg), plasma glutathione peroxidase (64 ± 4.2 U), and serum Se (0.11 ± 0.003 µg/g) were not different between treatments during the adaptation period. Serum Se77 maximum concentration and area under the curve (AUC) were not different between treatments for 72 hours following infusion, but rumen fluid Se77 AUC was higher (P = 0.02) for ORG cows. Apparent absorption (64 ± 1.3%) and retention (44 ± 1.5%) of the Se77 dose did not differ between treatments. The ORG cows had lower urinary excretion (13 vs. 17 ± 0.6%; P &lt; 0.01), higher milk excretion (6 vs. 2 ± 0.3%; P &lt; 0.01), and similar fecal excretion (36 ± 1.3%; P = 0.9) of Se77 compared to INO cows. These results indicate that ORG Se increased Se content of milk and decreased Se excretion in urine, but did not alter performance, antioxidant status, and apparent absorption and retention of Se in mid-lactation cows.

scholarly journals Reducing potentially avoidable tasks in a hyperacute stroke unit

2021 ◽  
Vol 10 (3) ◽  
pp. e001482
Author(s):  
Derya Tireli ◽  
Michael Broksgaard Jensen
Keyword(s):  
Stroke Unit ◽  
Junior Doctor ◽  
Night Shift ◽  
Healthcare Providers ◽  
Junior Doctors ◽  
Patient Admissions ◽  
Work Routines ◽  
Routine Tasks ◽  
Very High ◽  
Night Shifts

The workflow in a stroke unit can be very high, and this is especially noticeable during evening and night shifts, where staffing is reduced but the patient’s need for frequent and intensive care is not. The specialised and standardised settings in a stroke regime are constant and demanding for healthcare providers who, therefore, must work efficiently. Patient admissions, acute situations and routine tasks are major contributors to the burden of work during evening and night shifts for junior doctors on call. Thus, it is important to reduce the number of potentially avoidable tasks done by these junior doctors during night shifts so they have more time to perform tasks of high priority. The aim of this project was to reduce the potentially avoidable tasks occurring at night for the on-call junior doctor to only one per shift. We investigated the types of tasks that frequently occur for the on-call junior doctor during the night shift and improved our daily morning and evening rounds to reduce the number of tasks during the night shift. Using the plan–do–study–act method, we made improvements through education, knowledge sharing, checklists and feedback, and we reduced the number of potentially avoidable tasks for on-call junior doctors from a median of 11 to a median of 3 per week, demonstrating that the workload for the on-call junior doctor during the night shift can be reduced through a systematic approach to improving the work routines of doctors and nurses.

scholarly journals Disturbances of Autonomic Regulation of Cardiovascular System at Different Working Regimes with Night Shifts

Kardiologiia ◽  
2020 ◽  
Vol 60 (9) ◽  
pp. 62-67
Author(s):  
Yu. A. Merkulov ◽  
A. A. Pyatkov ◽  
S. G. Gorokhova ◽  
D. M. Merkulova ◽  
O. Yu. Atkov
Keyword(s):  
Shift Work ◽  
Spectral Characteristics ◽  
Night Shift ◽  
Autonomic Regulation ◽  
Total Power ◽  
Orthostatic Test ◽  
Heart Rhythm Variability ◽  
Shift Workers ◽  
Rotating Shift Work ◽  
Night Shifts

Aim        To study temporal and spectral characteristics of heart rhythm variability (HRV) in night shift workers.Materials and methods       Along with traditional risk factors, conditions of labor contribute to development of cardiovascular morbidity, including night shift work, which can be associated with disorders of the autonomic regulation detected by analysis of HRV. This study included 100 healthy men. 74 of them were engaged in shift work, including 53 men with rotating shift work, 21 men with fixed night shifts, and 26 men with day-time work. HRV was analyzed by data of 5-min electrocardiogram recording (background recording and orthostatic test).Results   Night-shift workers had decreases in total power of regulation (ТР, SDNN) and in the parasympathetic branch (HF, pNN50). Rotating night-shift workers displayed significant decreases in SDNN and pNN50 and pronounced changes in the VLF / LF / HF ratio in the orthostatic test.Conclusion            In work with night shifts, the type of autonomic regulation differs from the “standard” functioning of the autonomic nervous system (ANS). This study showed different effects of night work regimens on HRV indexes. With the rotating shift work, the ANS dysregulation was more profound and was evident by a significant decrease in the ANS total tone and parasympathetic activity (SDNN, pNN50) compared to night shifts with fixed working hours. The excessive weakening of the parasympathetic component in the passive orthostatic test can be considered as an early marker for ANS maladaptation. 

scholarly journals Perception of Fatigue Among Surgeons During Night Shifts

2013 ◽  
Vol 95 (7) ◽  
pp. 1-5 ◽  
Author(s):  
I Amirian ◽  
AK Danielsen ◽  
J Rosenberg
Keyword(s):  
Time Pressure ◽  
Night Shift ◽  
Sleep Time ◽  
Work Hours ◽  
Impaired Performance ◽  
Impaired Cognition ◽  
Long Work Hours ◽  
Call Night ◽  
Night Shifts ◽  
Increase In Risk

It is well known that sleep deprivation induces fatigue and that fatigue induces impaired cognition. Studies have demonstrated that long work hours, restricted sleep, time pressure and high demands may cause impaired performance in physicians. Some studies have shown through laparoscopic simulation that surgeons, when deprived of sleep, take longer to perform the procedure, make more unnecessary movements with their instruments and significantly more mistakes. Surgeons with an opportunity for sleep of less than 6 hours on the previous on-call night shift had an 83% increase in risk of postoperative complications when working the following day.

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