Effects Of Shift Work Research Articles

The Effects of Shift Work on Cardio-Metabolic Diseases and Eating Patterns.

Energy metabolism is tightly linked with circadian rhythms, exposure to ambient light, sleep/wake, fasting/eating, and rest/activity cycles. External factors, such as shift work, lead to a disruption of these rhythms, often called circadian misalignment. Circadian misalignment has an impact on some physiological markers. However, these proxy measurements do not immediately translate into major clinical health outcomes, as shown by later detrimental health effects of shift work and cardio-metabolic disorders. This review focuses on the effects of shift work on circadian rhythms and its implications in cardio-metabolic disorders and eating patterns. Shift work appears to be a risk factor of overweight, obesity, type 2 diabetes, elevated blood pressure, and the metabolic syndrome. However, past studies showed discordant findings regarding the changes of lipid profile and eating patterns. Most studies were either small and short lab studies, or bigger and longer cohort studies, which could not measure health outcomes in a detailed manner. These two designs explain the heterogeneity of shift schedules, occupations, sample size, and methods across studies. Given the burden of non-communicable diseases and the growing concerns about shift workers’ health, novel approaches to study shift work in real contexts are needed and would allow a better understanding of the interlocked risk factors and potential mechanisms involved in the onset of metabolic disorders.

US research needs related to fatigue, sleep, and working hours among oil and gas extraction workers.

During 2003-2013, 1189 US oil and gas extraction (OGE) workers died while working, resulting in an average annual workplace fatality rate seven times that for all US workers. OGE work commonly involves long hours, shiftwork, irregular schedules, and long commutes, but effects of these factors on fatigue, occupational injury, and illness in OGE are largely unknown. A scoping review of relevant OGE research during 2000-2019 was completed and supplemented by input from a NIOSH-sponsored Forum. Seventy-eight papers were identified; 76% reported only offshore research. Five themes for research needs emerged: build knowledge about the impacts of fatigue; explore interactions between on- and off-the-job risk factors; identify and evaluate interventions; assess effectiveness of technology; and increase the diffusion of fatigue risk management information. Further collaboration between researchers and OGE operators and contractors can lead to action-oriented recommendations to mitigate the effects of fatigue, inadequate sleep, and shiftwork.

Daily stress and sleep associations vary by work schedule: A between- and within-person analysis in nurses.

Nurses experience poor sleep and high stress due to demanding work environments. Night shift work is common among nurses and may exacerbate stress-sleep associations. We examined bidirectional associations between daily stress and sleep, and moderation by recent shift worker status and daily work schedule among nurses. Participants were 392 nurses (92% female; 78% White, mean age=39.54, SD=11.15) who completed 14days of electronic sleep diaries and actigraphy. They simultaneously completed assessments of daily stress and work schedule upon awakening (day shift vs. night shift [work between 9p.m.-6a.m.] vs. off work). Participants were classified as recent night shift workers if they worked at least one night shift during the past 14days (n=101; 26%). In the entire sample, greater daily stress predicted shorter self-reported total sleep time and lower self-reported sleep efficiency that night. Shorter self-reported and actigraphy total sleep time and lower self-reported sleep efficiency predicted higher next-day stress. Compared with recent night shift workers, day workers reported higher stress after nights with shorter total sleep time. Stress-sleep associations mostly did not vary by nurses' daily work schedule. Sleep disturbances and stress may unfold in a toxic cycle and are prime targets for tailored interventions among nurses. Night shift workers may be less susceptible to the effects of short sleep on next-day stress. Research is needed to understand the short- and long-term effects of shift work and address the unique sleep challenges nurses face.

The Effect of Using Participatory Working Time Scheduling Software on Employee Well-Being and Workability: A Cohort Study Analysed as a Pseudo-Experiment.

Shift workers are at increased risk of health problems. Effective preventive measures are needed to reduce the unfavourable effects of shift work. In this study we explored whether use of digital participatory working time scheduling software improves employee well-being and perceived workability by analysing an observational cohort study as a pseudo-experiment. Participants of the Finnish Public Sector cohort study with payroll records available between 2015 and 2019 were included (N = 2427). After estimating the propensity score of using the participatory working time scheduling software on the baseline characteristics using multilevel mixed-effects logistic regression and assigning inverse probability of treatment weights for each participant, we used generalised linear model to estimate the effect of using the participatory working time scheduling software on employees’ control over scheduling of shifts, perceived workability, self-rated health, work-life conflict, psychological distress and short sleep (≤ 6 h). During a 2-year follow-up, using the participatory working time scheduling software reduced the risk of employees’ low control over scheduling of shifts (risk ratio [RR] 0.34; 95% CI 0.25–0.46), short sleep (RR 0.70; 95% CI 0.52–0.95) and poor workability (RR 0.74; 95% CI 0.55–0.99). The use of the software was not associated with changes in psychological distress, self-rated health and work-life conflict. In this observational study, we analysed as a pseudo-experiment, the use of participatory working time scheduling software was associated with increased employees’ perceived control over scheduling of shifts and improved sleep and self-rated workability.

Factors that Affecting Female Nurse Performance with Work Stress as an Intervening Variable in the Hospital of Dr. Tadjuddin Chalid Makassar

Background: Professional nurse job, long term rhythm of life that is irregular, and pressure of many aspects of live cause multiple role conflicts, sleep problem, affect the efficiency and quality of nurses performance. 12 hours shift rotation are very common in the world, but there is worries that develop about the effect of quality and safety of nurses and patient.
 Aim : To find out the direct and indirect effect of work family conflict, shift work, nutrition status, sleep quality on nurse performance through work stress as an intervening variable on female nurses at Hospital of Dr Tadjuddin Chalid Makassar.
 Methods : The type of this research used observational analytic with cross-sectional design to see the effect of work family conflict, shift work, nutrition status, and quality of sleep on nurse performance through work stress as an intervening variable on female nurses in the Hospital of Dr MTadjuddin Chalid Makassar. This research was conducted in February – June 2021 at Dr. Hospital. Tadjuddin Chalid Makassar. The sample of this research was female nurses who were married as many as 73 respondents, Data collection used questionnare, scale, microtoice, and secondary data. Data analysis used univariate analysis with SPSS program version 24 and multivariate analysis to find out the effect of two or more variables and to see the direct and indirect effect with handle the anther variable with used Path Analysis that was conducted with used SmartPLS program.
 Results : There is no direct effect of work family conflict on performance with a score p (0,462)>0,05 There is an indirect effect of work family conflict on performance through work stress with a score p (0,001) < 0,05. There is direct effect of work stress on performance with p-value (0,003) < 0,05. There is no direct and indirect effect of shift work on performance although it through work stress as intervening variable on nurse with p-value > 0,05. There is no direct and indirect effect of nutrition status on performance athought it through work stress as an intervening variable on nurse with p-value > 0,05. There is direct effect of sleep quality on performance with p-value (0,007) < 0,05. However, there is no indirect offect of sleep quality on performance through work stress as intervening variable on female nurses in the Hospital of Dr Tadjuddin Chalid Makassar with p-value (0,983) > 0,05.
 Conclusion:There is no direct effect of work family conflict on performance, but there is an indirect effect of work family conflict on performance through work stress as variable intervening. There is no direct and indirect effect of nutrition status on performance athought it through work stress as intervening variable and there is direct effect of quality of life on performance but there is no indirect effect of quality of sleep on performance through work stress as intervenig variable on nurses in Hoospital of Dr Tadjuddin Chalid Makassar. Suggested on female nurses could manage their quality of sleep with rest first before doing the activity, so that when they work, they can work as optimal

Shift work and health outcomes: an umbrella review of systematic reviews and meta-analyses of epidemiological studies.

Shift work is commonly increasing, and some physiological changes occur as workers sleep less and their circadian rhythms are disrupted. This umbrella review not only summarizes the evidence but also evaluates the validity of the associations of shift work with different health outcomes. We searched the MEDLINE, Web of Science, and Embase databases from their inception to April 25, 2020. For each systematic review and/or meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Eight eligible systematic reviews and meta-analyses were identified, providing data on 16 associations. We observed highly suggestive evidence for associations between shift work and myocardial infarction (having ever vs having never done shift work) and diabetes mellitus incidence (per 5-year increment in shift work). Furthermore, we observed suggestive evidence for an association between shift work and diabetes mellitus incidence (having ever vs having never done shift work). Two health outcomes, including prostate cancer incidence (having ever vs having never done shift work and rotating night shift work vs daytime work) and colorectal cancer incidence (longest vs shortest shift work time), were only supported by weak evidence. This umbrella review found that shift work was associated with several health outcomes with different levels of evidence. Associations for myocardial infarction and diabetes mellitus incidence were supported by highly suggestive evidence. Registry: PROSPERO; Identifier: CRD42020188537. Wu Q-J, Sun H, Wen Z-Y, etal. Shift work and health outcomes: an umbrella review of systematic reviews and meta-analyses of epidemiological studies. J Clin Sleep Med. 2022;18(2):653-662.

Effects of Shift Work in a Sample of Italian Nurses: Analysis of Rest-Activity Circadian Rhythm.

Shift work can lead to circadian desynchronization due to temporary misalignment between working hours and physiological and behavioral functioning, resulting in compromised health, insomnia, worsening of sleep quality, reduced ability to work during waking hours, and increased cardiovascular risk. We evaluated the effects of shift work on the rest-activity circadian rhythm (RAR) and health status of Italian orthopaedic nurses. The study population was 59 nurses: 44 worked the night shift and 15 worked the day shift. All carried out continuous 5-day actigraphic monitoring to assess RAR, including both the working and the rest period. The rhythmometric analysis showed that, during the working period, the night shift nurses had a significantly lower amplitude than the day shift nurses (p < 0.001), and the acrophase was significantly different between the two groups (p < 0.01). When we stratified the two groups by median body mass index (<25 kg/m2 normal weight and ≥25 kg/m2 overweight), during the working period, we noted a significantly lower amplitude for both the normal weight and the overweight nurses who worked the night shift (p < 0.01 and p < 0.001, normal weight and overweight respectively). The current findings suggest the need for further study of the relationship between activity levels and shift work.

Age-specific Effects of Shift Work and Age Structure Analysis on Psychological Well-being

As the global workforce ages, it has become more important to understand how the effects of seemingly age-neutral practices change across working lives. Shift work has been shown to have stronger negative effects on the physical health of older workers, however the age-specific effects of shift work on psychological well-being is poorly understood despite the changes to cognitive, social, and emotional resources associated with age. Moreover, the role of the organization in setting human resource practices and policies may also in part determine the strength of the age-specific effects of shift work on psychological well-being. Using mixed effects and marginal effects analyses in a large linked dataset of German employees and employers, the present study draws on selection, optimization, and compensation theory to examine the relationship between shift work and psychological well-being at each year of age between 18 and 67 in establishments that do and do not conduct an age structure analysis of their employees. Results show that in establishments that do not conduct an age structure analysis, shift work is associated with increasingly lower psychological well-being with age. In establishments that do conduct such an analysis, effects of shift work on psychological well-being are more consistent across age.

Effects of Shift Work and Mental Workload on Fatigue of Intensive Care Unit Nurses

Effects of Shift Work and Mental Workload on Fatigue of Intensive Care Unit Nurses

Field Monitoring the Effects of Overnight Shift Work on Specialist Tactical Police Training with Heart Rate Variability Analysis

Police work exposes officers to high levels of stress. Special emergency response team (SERT) service exposes personnel to additional demands. Specifically, the circadian cycles of SERT operators are subject to disruption, resulting in decreased capacity to compensate in response to changing demands. Adaptive regulation loss can be measured through heart rate variability (HRV) analysis. While HRV Trends with health and performance indicators, few studies have assessed the effect of overnight shift work on HRV in specialist police. Therefore, this study aimed to determine the effects overnight shift work on HRV in specialist police. HRV was analysed in 11 SERT officers and a significant (p = 0.037) difference was found in pRR50 levels across the training day (percentage of R-R intervals varying by &gt;50 ms) between those who were off-duty and those who were on duty the night prior. HRV may be a valuable metric for quantifying load holistically and can be incorporated into health and fitness monitoring and personnel allocation decision making.

A Longitudinal Study of the Relationship between Shift Work and Prostate-Specific Antigen in Healthy Male Workers.

As shift work has become prevalent globally, it is important to evaluate the health effects of shift work on employees. Several studies have demonstrated a positive association between shift work and prostate cancer. Therefore, we aimed to further examine the relationship between shift work and elevated prostate-specific antigen (PSA). Our study collected data from 66,817 male participants at baseline and followed up for about 6 years. We categorized shift worker status and shift schedule types. To evaluate the risk of elevated PSA on shift workers, we estimated hazard ratios using the Cox proportional hazards regression analyses. During a median follow-up of 4.1 years, 1030 participants developed elevated PSA. The multivariable-adjusted hazard ratio (HR) of elevated PSA for shift workers compared with daytime workers was 1.37 (1.04–1.80). Among shift workers, rotating shift workers (HR = 1.47, 95% CI 1.06–2.03) showed a significantly increased risk of elevated PSA compared with daytime workers. Our longitudinal study provides evidence for an association between shift work, especially rotating shift work, and elevations of PSA.

Inflammatory Status and Cardio-metabolic Risk Stratification of Rotational Shift Work.

To investigate the physiological effects of rotational shift work on measures of cardio-metabolic function. Sedentary, healthy men (n = 87; age 37 ± 9 years; body mass index: 30.7 ± 5.1 kg m2) were recruited and categorized via occupation. SHIFT group: currently employed in rotational shift work defined by 8-12 h morning, afternoon, and night rotations; or NSHIFT: working fixed daytime hours. Testing procedures included baseline objective sleep assessment and laboratory testing, conducted between 0600 and 0900 h to assess body composition, cardiorespiratory fitness (VO2peak), inflammatory status [C-reactive protein, interleukin (IL)-6, and tumour necrosis factor-alpha (TNF-α)], glucose metabolism, heart rate variability (HRV), and self-reported leisure time physical activity (PA). SHIFT reported significantly less leisure time PA (P = 0.019), reduced VO2peak (P = 0.007), higher body fat percentage (BF%) (P = 0.021), increase response time to oral glucose tolerance test (P = 0.016), and higher IL-6 values (P = 0.008) compared with NSHIFT. A significant difference was observed in actigraphy measured total sleep time, with SHIFT recording reduced sleep following a night shift (P = 0.001). No group difference was observed in HRV or average sleep parameters (P > 0.05). Linear regression identified a significant association between occupation and inflammatory status (P = 0.006). Rotational shift work is associated with increased risk factors for cardio-metabolic disorders, despite no differences in sleep quality and quantity. The results suggest rotational shift work has a detrimental effect on the health and wellbeing of employees; with homeostatic desynchronization identified as potential pathogenic mechanisms.

Comparing the acute effects of shiftwork on mothers and fathers.

BackgroundShift work may impact women more negatively than men due to the increased burden of coping with demanding work schedules while also undertaking more of the domestic chores, including childcare.AimsTo examine whether the combination of shift working and caring for children affects the sleep, fatigue and work–family conflict experienced by women more than it affects men.MethodsUsing data from a survey of the Swedish working population, mixed linear regression models examined work schedule (daywork, shift work with nights, shift work without nights), gender and presence of children <13 years at home as predictors of sleep insufficiency, sleep disturbance, fatigue and work–family conflict, over up to three successive measurement occasions. Adjustments were made for age, education, full/part-time working and baseline year.ResultsIn fully adjusted models (N = 8938), shift work was associated with insufficient sleep (P < 0.01), disturbed sleep (P < 0.01), fatigue (P < 0.05) and work–family conflict (P < 0.001). Interactions in the analyses of sleep disturbance (P < 0.001) and work–family interference (P < 0.05) indicated that among participants with no children, females reported more disturbed sleep and more work–family conflict than their male counterparts, irrespective of schedule; while among participants with children, female dayworkers reported more disturbed sleep than their male counterparts, and females working shifts without nights reported more work–family interference.ConclusionsHaving young children did not exacerbate negative effects of shift work, in either men or women. This may reflect high levels of gender equality and childcare provision in Sweden.

Effect of shift work on menopausal age and menstruation span of professional women

Objective: To explore the relationship between shift work and menopausal age and menstruation span of retired women. Methods: During July 2017 and October 2018, the research was performed by using cluster sampling in nine districts of Shenzhen City to select all permanent residents (3518 people) with Shenzhen household registration in which was equal to or over 60 years old from the Community Health Service Centers. The data of age, marital status, menopausal age, smoking, drinking, shift experience and shift years were collected. The relationship between shift work and menopausal age as well as menstruation span of professional women were analyzed by multivariate linear regression model. Results: There were 359 people (10.2%) in the shift experience group, the menopausal age was (49.71±3.63) years, and the menstrual period was (34.27±3.92) years. The non-shift experience group were 3159 people (89.8%) , the menopausal age was (50.20±3.60) years, and the menstrual period was (34.86±4.13) years. The differences of menopausal age and menstrual years between the two groups were statistically significant (P<0.05) . After adjusting for factors such as passive smoking and drinking, the results of the multiple linear regression model showed that menopausal age, menstrual years were negatively correlated with shift work (β=-0.493, -0.575, P<0.05) . Conclusion: Shifts are related to women's menopausal age and menstrual years, and attention should be paid to the impact of work intensity and circadian rhythm on the occupational health of female employees.

Exogenous melatonin decreases circadian misalignment and body weight among early types.

Shift workers experience chronic circadian misalignment, which can manifest itself in reduced melatonin production, and has been associated with metabolic disorders. In addition, chronotype modulates the effect of night shift work, with early types presenting greater circadian misalignment when working night shift as compared to late types. Melatonin supplementation has shown positive results reducing weight gain in animal models, but the effect of exogenous melatonin in humans on body weight in the context of shift work remains inconsistent. The aim of this study was thus to evaluate the effects of exogenous melatonin on circadian misalignment and body weight among overweight night shift workers, according to chronotype, under real-life conditions. We conducted a double-blind, randomized, placebo-controlled, crossover trial where melatonin (3mg) or placebo was administered on non-night shift nights for 12weeks in 27 female nurses (37.1 yo, ±5.9 yo; BMI 29.9kg/m2 , ±3.3kg/m2 ). Melatonin (or placebo) was only taken on nights when the participants did not work night shifts, that is, on nights when they slept (between night shifts and on days off). Composite Phase Deviations (CPD) of actigraphy-based mid-sleep timing were calculated to measure circadian misalignment. The analyses were performed for the whole group and by chronotype. We found approximately 20% reduction in circadian misalignment after exogenous melatonin administration considering all chronotypes. Moreover, melatonin supplementation in those who presented high circadian misalignment, as observed in early chronotypes, reduced body weight, BMI, waist circumference, and hip circumference, without any change in the participants' calorie intake or physical activity levels.

Association of Rotating Night Shift Work with Body Fat Percentage and Fat Mass Index among Female Steelworkers in North China.

The aim of this study was to evaluate the associations of rotating night shift work with body fat percentage (BF%) and fat mass index (FMI). A cross-sectional study was conducted among 435 female steelworkers, aged 26–57 years in Tangshan, China. BF% was assessed via bioelectrical impedance analysis and FMI was calculated. Different exposure metrics of night shift work were used to examine the effects of night shift work on BF% and FMI. The duration (years), cumulative number (nights), and cumulative length of night shifts (hours) were positively correlated with FMI and BF%, and these relationships were independent of body mass index (BMI). Compared with day workers, night shift workers with an average frequency of night shifts >7 nights/month (odds ratio (OR) 2.50, 95% confidence interval (CI) 1.17 to 5.35) and percentage of hours on night shifts >30% (OR 2.55, 95% CI 1.21 to 5.39) had elevated odds of obesity (BF% ≥ 35.0%). Nonobese night shift workers by the BMI criterion should also be alert to the risk of the excess accumulation of body fat, which is actually responsible for most obesity-associated adverse health consequences. Health interventions for related populations need to be improved, which is currently more focused on overall weight control.

The acute effects of working time patterns on fatigue and sleep quality using daily measurements of 6195 observations among 223 shift workers.

Objectives:This study aimed to estimate acute effects of roster characteristics on fatigue and sleep quality and investigated whether these effects differed by individual characteristics.Methods:Using an ecological measurement assessment survey, fatigue and sleep quality were daily measured among 223 shift workers for up to eight weeks. A questionnaire assessed baseline characteristics, and roster data were retrieved from the company registers to determine roster parameters. The effects between each shift parameter on fatigue and sleep quality were estimated with random- and fixed-effects models.Results:Compared to day shifts, night shifts were related to fatigue [β=0.22; 95% confidence interval (CI) 0.05–0.39] and poorer sleep quality (β =0.64; 95% CI 0.47–0.80), and more successive night shifts with more fatigue (up to β=0.68; 95% CI 0.49–0.87 for ≥2 nights). Fatigue was increased after a quick return (<11 hours) (β=1.94; 95% CI 1.57–2.31) or 11–16 hours (β=0.43; 95% CI 0.26–0.61) compared to >16 hours between shifts. Compared to forward rotation, stable (β=0.22; 95% CI 0.01–0.43) and backward rotation (β=0.49; 95% CI 0.23–0.74) were also associated with more fatigue. Workers with a morning or intermediate chronotype had poorer sleep quality after a night shift, while workers with poor health reported poor sleep quality as well as more fatigue after a night shift.Conclusions:To alleviate acute effects of shift work on fatigue, shift schedules should be optimized by ensuring more time to recover and rotate forwards.

Metabolomic Profiles of Shift Workers and Day Workers: A Cross-Sectional Study.

The purpose of this study was to characterize the metabolomic profiles of shift workers and day workers and to discover the effect of shift work on workers' metabolic health. A total of 824 participants aged 25 to 55 years were recruited, and 485 (275 shift workers and 210 day workers) completed the study. The mean age of the shift workers was 37.32 (5.53) years old, and that of day workers was 36.50 (7.83) years old. Serum and salivary samples were collected for the detection of key biochemical indicators (melatonin, cholesterol, and low-density lipoprotein cholesterol) and for metabolome profile analyses. Compared with female day workers, female shift workers had a higher BMI, waist circumference, and hip circumference. Correspondingly, we identified 76 significant metabolites (false discovery rate < 0.05) in shift workers, including L-tryptophan, acylcarnitines, and several fatty acids. Three pathways that presented significant differences were biosynthesis of unsaturated fatty acids, linoleic acid metabolism, and ubiquinone and other terpenoid-quinone biosynthesis. Compared with day workers, shift workers were more prone to weight gain and central obesity and were at a higher risk for impaired lipid metabolism with disrupted circadian rhythms.

Shift work and incidence of psychiatric disorders: The Danish Nurse Cohort study

BackgroundResearch on health effects of shift work has especially focused on somatic diseases, such as breast cancer and cardiometabolic disease, while less attention has been given to the association between shift work and mental health. MethodsWe used information on 19 964 female nurses (≥44 years) from the Danish Nurse Cohort, who reported current work schedule (day, evening, night, or rotating) at recruitment (1993/1999). In 5102 nurses who participated in both cohort waves, we defined persistent night shift work as working night shift in 1993 and 1999. We used Cox regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for relevant confounders.Through linkage of cohort participants to national registers, we defined incidence of mood and neurotic disorders as first hospital contact or redeemed prescription until November 2018. ResultsWe found association between night shift work with mood disorders (HR = 1.31; 95%CI = 1.17–1.47) and neurotic disorders (1.29; 1.17–1.42), compared to day work. Associations were enhanced in nurses with persistent night shift work (1.85; 1.43–2.39 and 1.62; 1.26–2.09 for mood and neurotic disorders, respectively) and in nurses with specialist confirmed mood (1.69; 1.24–2.29) and neurotic (1.72; 1.22–2.44) disorders. Nurses with preexisting psychiatric disorders and full-time work seemed most susceptible. ConclusionsNight shift work is associated with increased risk of major psychiatric disorders. The novel suggestive findings of vulnerable groups, including nurses with a history of psychiatric disorders and full-time workers, are based on a limited number of cases, and further research is needed to confirm the results.

The impact of shift work on the wellbeing and subjective levels of alertness and sleepiness in firefighters and rescue service workers

Shift work can be associated with health and sleep problems which may lead to cognitive impairment. This study investigated effects of shift work on sleep, health behaviours and cognitive functions of polish rescue service workers. We tested 18 paramedics working 12-hour shifts, 15 firefighters working 24-hours shifts, and 17 daytime workers. We measured general sleepiness, workload during shifts, an occurrence of health behaviours. Additionally we measured attention, executive functions and subjective alertness. Paramedics showed lower average sleep duration and quality, and fewer health behaviours than firefighters and control group. However, no differences in performance in cognitive tests between the groups and between the measures were found. The results indicate that the differences in job specificity may contribute to the effects of shift-work on sleep and health of the workers.