Extended Working Hours and Health

Statistical analyses of the relation between the amount of working hours and impairments to health, based on data from a European survey on working conditions in 2000, clearly reveal that there is a substantial correlation between the number of working hours per week and the frequencies of health complaints. This applies to both musculo‐skeletal disorders as well as to psycho‐vegetative complaints. The relationship of the duration of the exposure to working conditions to health impairments is moderated by a great number of individual (e.g., age) and situational (e.g., shift‐work) variables, showing additive or interactive effects for which selected examples have been presented. In general, however, there is a consistent functional relationship between the number or working hours and their effects on the workers that holds over a great variety of conditions. It is argued that requests for extending working hours should thus be handled with care.     

The interference of flexible working times with the circadian temperature rhythm--a predictor of impairment to health and well-being?

In order to analyze whether impairments to health and well-being under flexible working hours can be predicted from specific characteristics of the work schedules, periodic components in flexible working hours and their interference with the circadian temperature rhythm were analyzed applying univariate and bivariate spectrum analyses to both time series. The resulting indicators of spectral power and phase shift of these components were then related to reported health impairments using regression analysis. The results show that a suppression of both the 24 and the 168 h components in the work schedules (i.e., a lack of periodicity) can be used to predict reported health impairments, and that if there are relatively strong 24 and 168 h components left in the work schedules, their phase difference with the temperature rhythm (as an indicator of the interference between working time and the circadian rhythm) further predicts impairment. The results indicate that the periodicity of working hours and the amount of (circadian) desynchronization induced by flexible work schedules can be used for predicting the impairing effects of flexible work schedules on health and well-being. The results can thus be used for evaluating and designing flexible shift rosters.     

The Interference of Flexible Working Times with the Circadian Temperature Rhythm—a Predictor of Impairment to Health and Well‐Being?

In order to analyze whether impairments to health and well‐being under flexible working hours can be predicted from specific characteristics of the work schedules, periodic components in flexible working hours and their interference with the circadian temperature rhythm were analyzed applying univariate and bivariate spectrum analyses to both time series. The resulting indicators of spectral power and phase shift of these components were then related to reported health impairments using regression analysis. The results show that a suppression of both the 24 and the 168 h components in the work schedules (i.e., a lack of periodicity) can be used to predict reported health impairments, and that if there are relatively strong 24 and 168 h components left in the work schedules, their phase difference with the temperature rhythm (as an indicator of the interference between working time and the circadian rhythm) further predicts impairment. The results indicate that the periodicity of working hours and the amount of (circadian) desynchronization induced by flexible work schedules can be used for predicting the impairing effects of flexible work schedules on health and well‐being. The results can thus be used for evaluating and designing flexible shift rosters.     

Flexible Working Hours,Health, and Well-Being in Europe: Some Considerations from a SALTSA Project

The project brought together researchers from 9 EU-Countries and resulted in a number of actions, in particular the following: (a) There is an urgent need of defining the concept of flexible working hours, since it has been used in many different and even counterintuitive ways; the most obvious distinction is where the influence over the working hours lies, that is between the “company-based flexibility” and the “individual-oriented flexibility”; (b) The review of the Legislation in force in the 15 European countries shows that the regulation of working times is quite extensive and covers (Council Directive 93/104/EC) almost all the various arrangements of working hours (i.e., part-time, overtime, shift, and night work), but fails to provide for flexibility; (c) According to the data of the Third EU Survey on Working Conditions, longer and “irregular” working hours are in general linked to lower levels of health and well-being; moreover, low (individual) flexibility and high variability of working hours (i.e., company-based flexibility) were consistently associated with poor health and well-being, while low variability combined with high autonomy showed positive effects; (d) Six substudies from different countries demonstrated that flexible working hours vary according to country, economic sector, social status, and gender; overtime is the most frequent form of company-based flexibility but has negative effects on stress, sleep, and social and mental health; individual flexibility alleviates the negative effects of the company-based flexibility on subjective health, safety, and social well-being; (e) The literature review was able to list more than 1,000 references, but it was striking that most of these documents were mainly argumentative with very little empirical data. Thus, one may conclude that there is a large-scale intervention ongoing in our society with almost completely unknown and uncontrolled effects. Consequently, there is a strong need for systematic research and well-controlled actions in order to examine in detail what flexible working hours are considered, what and where are their positive effects, in particular, as concerns autonomy, and what regulation seem most reasonable.     

Working on Sundays–effects on safety, health, and work-life balance

Several attributes of the work schedule can increase the risk of occupational injuries and accidents, health impairments, and reduced social participation. Although previous studies mainly focused on the effects of shiftwork and long working hours on employee health and safety, there is little evidence of a potential negative impact of working Sundays on the incidence of occupational accidents, health impairments, and work-life balance. A representative sample of employed workers in 31 member and associated states of the European Union (n?=?23,934) served as the database for a cross-sectional analysis. The sample was collected via face-to-face interviews in the year 2005. The association of the risks of occupational accidents, health impairments, and decreases in work-life balance with working Sundays was calculated using logistic regression models, controlling for potential confounders, such as shiftwork, workload, and demographic characteristics. The results indicated that working one or more Sundays/month was associated with increase both in the risk of reporting one or more health impairments (odds ratio [OR]: 1.17, 95% confidence interval [CI]: 1.06-1.29) and poorer work-life balance (OR: 1.15, 95% CI: 1.02-1.28). These effects remained after controlling for potentially confounding factors, such as other work schedule attributes, intensity of physical and mental workload, and individual characteristics. Furthermore, working Sundays was also related to increased risk of occupational accidents within the last year (OR: 1.34, 95% CI: 1.03-1.73). Controlling again for individual, workload, and working-time characteristics, a significant association with accident risk, however, remained only in work sectors with low a priori risk of occupational accidents (OR: 1.40, 95% CI: 1.02-1.91), although the increased risk could be observed for both medium and high a priori risk sectors working Sundays (without controlling for additional confounders). The results thus indicate that the detrimental effects of working Sundays on safety, health, and social well-being should be taken into account when designing work schedules. The potential hazards to employees' safety, health, and work-life balance, in particular, should be considered in discussions concerning extending work on Sundays in certain sectors, e.g., retail.     

Flexible working hours, health, and well-being in Europe: some considerations from a SALTSA project

The project brought together researchers from 9 EU-Countries and resulted in a number of actions, in particular the following: (a) There is an urgent need of defining the concept of flexible working hours, since it has been used in many different and even counterintuitive ways; the most obvious distinction is where the influence over the working hours lies, that is between the “company-based flexibility” and the “individual-oriented flexibility”; (b) The review of the Legislation in force in the 15 European countries shows that the regulation of working times is quite extensive and covers (Council Directive 93/104/EC) almost all the various arrangements of working hours (i.e., part-time, overtime, shift, and night work), but fails to provide for flexibility; (c) According to the data of the Third EU Survey on Working Conditions, longer and “irregular” working hours are in general linked to lower levels of health and well-being; moreover, low (individual) flexibility and high variability of working hours (i.e., company-based flexibility) were consistently associated with poor health and well-being, while low variability combined with high autonomy showed positive effects; (d) Six substudies from different countries demonstrated that flexible working hours vary according to country, economic sector, social status, and gender; overtime is the most frequent form of company-based flexibility but has negative effects on stress, sleep, and social and mental health; individual flexibility alleviates the negative effects of the company-based flexibility on subjective health, safety, and social well-being; (e) The literature review was able to list more than 1,000 references, but it was striking that most of these documents were mainly argumentative with very little empirical data. Thus, one may conclude that there is a large-scale intervention ongoing in our society with almost completely unknown and uncontrolled effects. Consequently, there is a strong need for systematic research and well-controlled actions in order to examine in detail what flexible working hours are considered, what and where are their positive effects, in particular, as concerns autonomy, and what regulation seem most reasonable.     

Working on Sundays–Effects on Safety,Health, and Work-life Balance

Several attributes of the work schedule can increase the risk of occupational injuries and accidents, health impairments, and reduced social participation. Although previous studies mainly focused on the effects of shiftwork and long working hours on employee health and safety, there is little evidence of a potential negative impact of working Sundays on the incidence of occupational accidents, health impairments, and work-life balance. A representative sample of employed workers in 31 member and associated states of the European Union (n?=?23,934) served as the database for a cross-sectional analysis. The sample was collected via face-to-face interviews in the year 2005. The association of the risks of occupational accidents, health impairments, and decreases in work-life balance with working Sundays was calculated using logistic regression models, controlling for potential confounders, such as shiftwork, workload, and demographic characteristics. The results indicated that working one or more Sundays/month was associated with increase both in the risk of reporting one or more health impairments (odds ratio [OR]: 1.17, 95% confidence interval [CI]: 1.06–1.29) and poorer work-life balance (OR: 1.15, 95% CI: 1.02–1.28). These effects remained after controlling for potentially confounding factors, such as other work schedule attributes, intensity of physical and mental workload, and individual characteristics. Furthermore, working Sundays was also related to increased risk of occupational accidents within the last year (OR: 1.34, 95% CI: 1.03–1.73). Controlling again for individual, workload, and working-time characteristics, a significant association with accident risk, however, remained only in work sectors with low a priori risk of occupational accidents (OR: 1.40, 95% CI: 1.02–1.91), although the increased risk could be observed for both medium and high a priori risk sectors working Sundays (without controlling for additional confounders). The results thus indicate that the detrimental effects of working Sundays on safety, health, and social well-being should be taken into account when designing work schedules. The potential hazards to employees' safety, health, and work-life balance, in particular, should be considered in discussions concerning extending work on Sundays in certain sectors, e.g., retail. (Author correspondence: awirtz@hsph.harvard.edu)     

A New Approach for Evaluating Flexible Working Hours

Recent studies on flexible working hours show at least some of these working time arrangements seem to be associated with impairing effects of health and well-being. According to available evidence, variability of working hours seems to play an important role. The question, however, is how this variability can be assessed and used to explain or predict impairments. Based on earlier methods used to assess shift-work effects, a time series analysis approach was applied to the matter of flexible working hours. Data on the working hours of 4 week's length of 137 respondents derived from a survey on flexible work hours involving 15 companies of different production and service sectors in Germany were converted to time series and analyzed by spectral analysis. A cluster analysis of the resulting power spectra yielded 5 clusters of flexible work hours. Analyzing these clusters for differences in reported impairments showed that workers who showed suppression of circadian and weekly rhythms experienced severest impairments, especially in circadian controlled functions like sleep and digestion. The results thus indicate that analyzing the periodicity of flexible working hours seems to be a promising approach for predicting impairments which should be investigated further in the future.     

Relative concerns and sleep behavior

We investigate the relationship between relative concerns with respect to income and the quantity and quality of sleep using a 6-year panel dataset on the sleep behavior of people in Germany. We find a substantial negative association between relative income and number of hours of sleep and satisfaction with sleep, i.e., sleep quality, whereas there is no particular association between absolute level of income and sleep quantity and quality. A 10-percent increase in the income of relevant others is associated with 6–8 min decrease in a person's weekly amount of sleep on average, yet this effect is particularly strong among the relatively deprived, i.e., upward comparers, as this group shows a corresponding decrease in sleeping time of 10–12 min/week. These findings are highly robust to several specification checks, including measures of relative concerns, reference group, income inequality, and local price differences. The heterogeneity analysis reveals that the relationship is mainly driven by people with relatively fewer working hours, a higher demand for household production and leisure activities, and lower physical health and well-being.     

A new approach for evaluating flexible working hours

Recent studies on flexible working hours show at least some of these working time arrangements seem to be associated with impairing effects of health and well-being. According to available evidence, variability of working hours seems to play an important role. The question, however, is how this variability can be assessed and used to explain or predict impairments. Based on earlier methods used to assess shift-work effects, a time series analysis approach was applied to the matter of flexible working hours. Data on the working hours of 4 week's length of 137 respondents derived from a survey on flexible work hours involving 15 companies of different production and service sectors in Germany were converted to time series and analyzed by spectral analysis. A cluster analysis of the resulting power spectra yielded 5 clusters of flexible work hours. Analyzing these clusters for differences in reported impairments showed that workers who showed suppression of circadian and weekly rhythms experienced severest impairments, especially in circadian controlled functions like sleep and digestion. The results thus indicate that analyzing the periodicity of flexible working hours seems to be a promising approach for predicting impairments which should be investigated further in the future.     

Health effects of supplemental work from home in the European Union

Internationalization and technological developments have changed the work organization in developed and developing industrial economies. Information and communication technologies, such as computers and smartphones, are increasingly used, allowing more temporal and spatial flexibility of work. This may lead to an increase in supplemental work, i.e. constant availability or working in addition to contractually agreed work hours. This in turn extends work hours and leads to work hours in evenings and weekends, causing interferences of work hours with biological and social rhythms for sleep, recovery and social interaction. However, empirical findings on the effects of supplemental work and work hours on occupational health are rather scarce. Therefore, the aim of this study was to investigate the association between (1) work-related contacts outside of regular work hours and (2) working in the free time with self-reported work-related health impairments in the fourth and fifth European Working Conditions Surveys (EWCS 2005, EWCS 2010). Out of these cross-sectional, large-scale surveys, data on n?=?22?836 and n?=?34?399 employed workers were used for weighted logistic regression analyses. About half of the sample reported at least occasional supplemental work. The results showed an increased risk of reporting at least one health problem for employees who had been contacted by their employer (EWCS 2005), or worked in their free time to meet work demands (EWCS 2010) in the last 12 months, compared to those reporting no supplemental work or work-related contacts during free time. These results were controlled for demographic variables, physical and mental work load, worker autonomy, and several work hours characteristics (e.g. hours per week, unusual and variable hours). The risk of reporting health problems was increased by being contacted both sometimes (Odds Ratio [OR] 1.26, 95% Confidence Interval [CI] 1.14–1.39) and often (OR 1.13, 95% CI 1.02–1.25), whereas the frequency of working in the free time showed a clear dose-response effect (sometimes: OR 1.14, 95% CI 1.04–1.24; often: OR 1.60, 95% CI 1.47–1.75), both compared to the category “never”. The findings, thus, indicate that even a small amount of supplemental work beyond contractually agreed work hours may increase the risk of work-related health impairments. Working in the free time was associated with a substantial risk increase and might be a better indicator for actual work load than being contacted by the employer outside of contractually agreed work hours. Thus, in order to minimize negative health effects, availability requirements for employees outside their regular work hours should be minimized. While these effects definitely need further study, especially regarding a quantification of actual supplemental work and its temporal location, addressing the company culture and using incentives and policies might be options to reduce the amount of supplemental work and maintain the risks of health impairments in the working population at a lower level.     

THE EFFECTS OF EXTENDED WORKING HOURS ON HEALTH AND SOCIAL WELL-BEING—A COMPARATIVE ANALYSIS OF FOUR INDEPENDENT SAMPLES

Using structural equation modeling, it can be shown that long weekly working hours and work on weekends, nights, and in shifts have detrimental effects on psychovegetative health. Employees' reported subjective work-life balance also decreases with increasing number of hours worked/week, days worked on weekends, or at nights, and with working shifts. A decrease in work-life balance in turn increases the risk of psychovegetative impairments (PVIs). Thus, long and unusual working hours increase the risk of psychovegetative health impairments both directly and indirectly, moderated by the subjective work-life balance. In fact, the indirect effects of working time on PVIs via the work-life balance seem to be stronger than the direct effects. Results of a cross-validation study of four independent and representative samples from Germany and the European Union (N?>?50,000) indicate high structural stability of these results and thus an increased validity and range for generalization. (Author correspondence: anna.wirtz@gawo-ev.de)     

The “Long-arm” of chronic conditions in childhood: Evidence from Canada using linked survey-administrative data

The objective of this study was to investigate the relationship between health conditions in childhood (ages 4–11), and health and socioeconomic outcomes in adulthood (ages 21–33). This study takes advantage of a new linkage between the National Longitudinal Survey of Children and Youth (NLSCY) and administrative tax data from the T1 Family File (T1FF) from Statistics Canada. The NLSCY includes rich longitudinal information on child development, while the T1FF includes administrative tax information on each child in adulthood (e.g., income, social assistance). The primary measures of child health relate to the diagnosis of a chronic condition, affecting the child’s physical or mental/developmental health. The results suggest that mental/developmental health conditions in childhood more negatively influence adult health and socioeconomic conditions, compared to physical health conditions. Interaction models reveal modest heterogenous effects; for example, there is some evidence of a cushioning effect from higher household income in childhood, as well as an exacerbating negative effect from lower birth weight for mental/developmental health conditions. Using a covariate decomposition approach to explore underlying pathways, the results reveal that associations between health in early life and outcomes in adulthood are partially explained by differences in cognitive skills (i.e., mathematics test scores) in adolescence (ages 16–17). Results may encourage policy investments to mitigate the occurrence of health conditions in childhood and to ensure timely access to educational supports and health services for children with chronic conditions.     

Sleep improves memory: the effect of sleep on long term memory in early adolescence

Sleep plays an important role in the consolidation of memory. This has been most clearly shown in adults for procedural memory (i.e. skills and procedures) and declarative memory (e.g. recall of facts). The effects of sleep and memory are relatively unstudied in adolescents. Declarative memory is important in school performance and consequent social functioning in adolescents. This is the first study to specifically examine the effects of normal sleep on auditory declarative memory in an early adolescent sample. Given that the majority of adolescents do not obtain the recommended amount of sleep, it is critical to study the cognitive effects of normal sleep. Forty male and female normal, healthy adolescents between the ages of ten and fourteen years old were randomly assigned to sleep and no sleep conditions. Subjects were trained on a paired-associate declarative memory task and a control working memory task at 9am, and tested at night (12 hours later) without sleep. The same number of subjects was trained at 9pm and tested 9am following sleep. An increase of 20.6% in declarative memory, as measured by the number correct in a paired-associate test, following sleep was observed compared to the group which was tested at the same time interval without sleep (p<0.03). The performance on the control working memory task that involved encoding and memoranda manipulation was not affected by time of day or relationship to sleep. Declarative memory is significantly improved by sleep in a sample of normal adolescents.     

The relationship between quality of life, binge-eating disorder, and obesity status in an ethnically diverse sample

This study examined the relationship between obesity status, binge-eating disorder (BED), and quality of life (QOL) in a large, ethnically diverse community sample of adult men and women. Using data from the Collaborative Psychiatric Epidemiological Surveys (N = 20,013), individuals were categorized into four groups: nonobese with BED (n = 142), nonobese without BED (n = 14,301), obese with BED (n = 136), and obese without BED (n = 4,863). Results indicated obese individuals with BED consistently reported the poorest QOL. Findings suggested that obesity status was more strongly related to physical health-related QOL variables (e.g., number of physical conditions, mobility impairment) whereas diagnostic status was more predictive of mental health and social functioning QOL variables (e.g., cognitive impairment, social interaction impairment, time out of role). The degree to which lifetime BED diagnosis was associated with impairment in social interaction differed across ethnic groups. For black individuals, the number of physical health conditions was associated with BED presence moreso than weight status.     

Low-Arousal Speech Noise Improves Performance in N-Back Task: An ERP Study

The relationship between noise and human performance is a crucial topic in ergonomic research. However, the brain dynamics of the emotional arousal effects of background noises are still unclear. The current study employed meaningless speech noises in the n-back working memory task to explore the changes of event-related potentials (ERPs) elicited by the noises with low arousal level vs. high arousal level. We found that the memory performance in low arousal condition were improved compared with the silent and the high arousal conditions; participants responded more quickly and had larger P2 and P3 amplitudes in low arousal condition while the performance and ERP components showed no significant difference between high arousal and silent conditions. These findings suggested that the emotional arousal dimension of background noises had a significant influence on human working memory performance, and that this effect was independent of the acoustic characteristics of noises (e.g., intensity) and the meaning of speech materials. The current findings improve our understanding of background noise effects on human performance and lay the ground for the investigation of patients with attention deficits.     

The Interference of Flexible Working Times with the Utility of Time: A Predictor of Social Impairment?

Periodic components inherent in actual schedules of flexible working hours and their interference with social rhythms were measured using spectrum analysis. The resulting indicators of periodicity and interference were then related to the reported social impairments of workers. The results show that a suppression of the 24 and the 168 h (seven‐day) components (absence of periodicity) in the work schedules predicts reported social impairment. However, even if there are relatively strong 24 and 168 h components left in the work schedules, their interference with the social rhythm (using the phase difference between working hours and the utility of time) further predicts impairment. The results thus indicate that the periodicity of working hours and the amount of (social) desynchronization induced by flexible work schedules can be used both for predicting the impairing effects of the specific work schedules on social well‐being as well as for the design of socially acceptable flexible work hours.     

The interference of flexible working times with the utility of time: a predictor of social impairment?

Periodic components inherent in actual schedules of flexible working hours and their interference with social rhythms were measured using spectrum analysis. The resulting indicators of periodicity and interference were then related to the reported social impairments of workers. The results show that a suppression of the 24 and the 168 h (seven-day) components (absence of periodicity) in the work schedules predicts reported social impairment. However, even if there are relatively strong 24 and 168 h components left in the work schedules, their interference with the social rhythm (using the phase difference between working hours and the utility of time) further predicts impairment. The results thus indicate that the periodicity of working hours and the amount of (social) desynchronization induced by flexible work schedules can be used both for predicting the impairing effects of the specific work schedules on social well-being as well as for the design of socially acceptable flexible work hours.