Working hours and health - key research topics in the past and future

OBJECTIVE

This paper discusses the past and present highlights of working hours and health research and identifies key research needs for the future.

METHOD

We analyzed over 220 original articles and reviews on working hours and health in the Scandinavian Journal of Work, Environment & Health published during the last 50 years. Key publications from other journals were also included.

RESULTS

The majority of identified articles focussed on the effects of shift and night work, with fewer studying long and reduced working hours and work time control. We observed a transition from small-scale experimental and intensive field studies to large-scale epidemiological studies utilizing precise exposure assessment, reflecting the recent emergence of register-based datasets and the development of analytic methods and alternative study designs for randomized controlled designs. The cumulative findings provide convincing evidence that shift work and long working hours, which are often associated with night work and insufficient recovery, increase the risk of poor sleep and fatigue, sickness absence, occupational injuries, and several chronic health conditions such as cardiovascular diseases and cancer. The observed risks are strongly modified by individual and work-related factors.

CONCLUSIONS

Although the observed health risks of shift work and long working hours are mostly low or moderate, the widespread prevalence of exposure and the hazardousness of the many associated potential outcomes makes such working time arrangements major occupational health risks. Further research is needed to identify exposure-response associations, especially in relation to the chronic health effects, and to elucidate underlying pathways and effective personalized intervention strategies.

Prospective effects of work-time control on overtime, work-life interference and exhaustion in female and male knowledge workers

AIMS

Employee-based flexible working hours are increasing, particularly among knowledge workers. Research indicates that women and men use work-time control (WTC; control over time off and daily hours) differently: while men work longer paid hours, women use WTC to counteract work-life interference. In a knowledge-worker sample, we examined associations between WTC and overtime, work-life interference and exhaustion and tested whether gender moderates the mediating role of overtime.

METHODS

The sample contained 2248 Swedish knowledge workers. Employing hierarchical regression modelling, we examined effects of control over time off/daily hours on subsequent overtime hours, work-life interference and exhaustion in general and in gender-stratified samples. Using conditional process analysis, we tested moderated mediation models.

RESULTS

Control over time off was related to less work-life interference (βmen= -0.117; 95% confidence interval (CI): -0.237 to 0.003; βwomen= -0.253; 95% CI: -0.386 to -0.120) and lower exhaustion (βmen= -0.199; 95% CI: -0.347 to -0.051; βwomen= -0.271; 95% CI: -0.443 to -0.100). For control over daily hours, estimates were close to zero. While men worked more overtime (42 min/week), we could not confirm gender moderating the indirect effect of control over time off/daily hours on work-life interference/exhaustion via overtime. Independent of gender, effects of control over time off on work-life interference were partly explained by working fewer overtime hours.

CONCLUSIONS

Control over time off was related to lower exhaustion and better work-life balance (in particular for women). We found no evidence for men's work-life interference increasing with higher WTC owing to working more overtime. Knowledge workers' control over time off may help prevent work-life interference and burnout.

Pros and cons of quick returns-a cross-sectional survey among Swedish nurses and nurse assistants

Short rest (<11h) between evening and day shifts-known as quick returns (QRs)-impede recovery and may impair health. Nevertheless, QRs remain popular among some shift workers. This study explores nurses' and nurse assistants' perceptions of the merits and demerits of QRs from individual and organizational perspectives. Participants were recruited from eleven wards at two Swedish hospitals as part of a larger quasi-experimental intervention study. The majority (79%) had influence over their work schedules. Frequency distributions of responses are presented. Ninety six undertook a baseline survey regarding recovery, tolerance and work performance in relation to QRs. A majority experienced difficulties unwinding before bedtime (76%), insufficient sleep (80%), and daytime fatigue (72%). A third experienced an increased risk of errors and mistakes. However, QRs appeared to facilitate taking reports from patients and planning work, as this task was more often rated as 'very easy' following a QR compared to other shift combinations. Tolerance of QRs varied substantially. In conclusion, QRs seem to benefit continuity in work processes, but may do so at the expense of recovery and safety. Wards planning to reduce QRs-through participatory or fixed schedule models-should consider impacts on work processes.

Randomised control trial of a proactive intervention supporting recovery in relation to stress and irregular work hours: effects on sleep, burn-out, fatigue and somatic symptoms

Objectives

To examine if a proactive recovery intervention for newly graduated registered nurses (RNs) could prevent the development of sleep problems, burn-out, fatigue or somatic symptoms.

Methods

The study was a randomised control trial with parallel design. Newly graduated RNs with less than 12 months’ work experience were eligible to participate. 461 RNs from 8 hospitals in Sweden were invited, of which 207 signed up. These were randomised to either intervention or control groups. After adjustments, 99 RNs were included in the intervention group (mean age 27.5 years, 84.7% women) and 108 in the control group (mean age 27.0 years, 90.7% women). 82 RNs in the intervention group attended a group-administered recovery programme, involving three group sessions with 2 weeks between each session, focusing on proactive strategies for sleep and recovery in relation to work stress and shift work. Effects on sleep, burn-out, fatigue and somatic symptoms were measured by questionnaires at baseline, postintervention and at 6 months follow-up.

Results

Preventive effect was seen on somatic symptoms for the intervention group. Also, the intervention group showed less burn-out and fatigue symptoms at postintervention. However, these latter effects did not persist at follow-up. Participants used many of the strategies from the programme.

Conclusions

A proactive, group-administered recovery programme could be helpful in strengthening recovery and preventing negative health consequences for newly graduated RNs.

Trial registration number

NCT04246736.

Psychosocial working conditions of shiftworking nurses: A long-term latent transition analysis

AIM

This study aimed to identify profiles of working conditions to which nurses were exposed to over time and investigate how changes in working conditions relate to shiftworking and health.

BACKGROUND

Previous studies rarely addressed the issue of working conditions development over long periods and the effects of such development on nurses' health.

METHODS

Data from a national cohort of nurses in Sweden (N = 2936) were analysed using a person-centred analytical approach-latent profile and latent transition analysis.

RESULTS

Nurses report better psychosocial working conditions as they progress into mid-career. Shiftworking nurses experience poorer working conditions than their dayworking counterparts and tend to move from shiftwork to daywork as they progress into mid-career. In mid-career, nurses in work environments characterized by low autonomy and support tend to report poorer health outcomes.

CONCLUSION

Current analyses suggest that shiftworking nurses are particularly in need of interventions that address poor work environments. Not only do they experience more negative psychosocial working conditions than their dayworking counterparts, but they do so while having to contend with demanding schedules.

IMPLICATIONS FOR NURSING MANAGEMENT

The findings highlight that organisational interventions should target different aspects of the work environment for nurses in diverse stages of their careers.

Comparing the acute effects of shiftwork on mothers and fathers

Background

Shift 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.

Aims

To 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.

Methods

Using 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.

Results

In 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.

Conclusions

Having 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.

Association of rotating shift work schedules and the use of prescribed sleep medication: A prospective cohort study

We examined whether working rotating shifts, with or without night work, is associated with the purchase of prescribed sleep medication, and whether the association is dependent on age. Data were obtained from a longitudinal cohort study of Finnish public sector employees who responded to questions on work schedule and background characteristics in 2000, 2004 and 2008. The data were linked to national register data on redeemed prescriptions of hypnotic and sedative medications, with up to 11 years of follow-up. Age stratified Cox proportional hazard regression models were computed to examine incident use of medication comparing two groups of rotating shift workers (those working shifts that included night shifts and those whose schedules did not include night shifts) with day workers who worked in a similar range of occupations. Shift work with night shifts was associated with increased use of sleep medication in all age groups, after adjustments for sex, occupational status, marital status, alcohol consumption, smoking and physical activity levels (hazard ratio [HR], [95% confidence interval, CI] 1.14 [1.01-1.28] for age group ≤39 years; 1.33 [1.19-1.48] for age group 40-49 years; 1.28 [1.13-1.44] for age group ≥50 years). Shift work without nights was associated with medication use in the two older age groups (HR [95% CI] 1.14 [1.01-1.29] and 1.17 [1.05-1.31] for age groups 40-49 years and >50 years, respectively). These findings suggest that circadian disruption and older age puts rotating shift workers, and especially those who work nights, at increased risk of developing clinically significant levels of sleep problems.

475 DEVELOPING A VIRTUAL CARE HOME SUPPORT FORUM DURING THE COVID-19 PANDEMIC

Introduction

COVID-19 has had a devastating effect on care homes, increasing both morbidity and mortality of residents and staff. Between 2 March and 12 June 2020, COVID-19 was the main cause of death in male care home residents (33.5%) and second for female (26.6%).1 By 1 May 2020, the death rate from all causes in care homes exceeded that in hospital (6,409 versus 6,397).2 Thus, care homes had to rapidly adapt to facilitate safe care of patients and staff.

Method

An expert outreach team visited a number of care homes in Surrey and Sussex to explore COVID-19 issues in care homes. Key themes were identified that informed topics for the Virtual Care Home Forum, where a series of virtual teaching, training and peer support sessions were hosted either live or on-demand, accessible for all care home staff.

Results

12 sessions were held with an average attendance of 25 people, predominantly care home managers and community healthcare professionals. Real time qualitative feedback was collected and an electronic survey was completed at the end of the series which showed 100% felt the sessions had improved their understanding of the topic, 100% felt the knowledge and skills obtained from the sessions would be useful in their job, 87.5% agreed the sessions would impact or change their practise and 100% felt more supported during the pandemic.

Conclusion

It has been an unprecedented year for the NHS, and the care home sector has suffered significantly. In order to provide the best level of care for patients and support for our community colleagues, we must work collaboratively, including provision of education and training. To ensure equal access for all, maintaining user-safety and compliance with government legislation, virtual webinars proved to be an excellent modality. We plan to continue providing training, teaching and support through this means in the future.

Intensive longitudinal study of newly graduated nurses' quick returns and self-rated stress

Objective:

Little is known about the relationship between quick returns (QR) – shift combinations that result in inter-shift rest periods <11 hours) and stress. The current study examined whether variations in the frequency of QR, both between and within individuals, were associated with changes in self-rated stress.

Methods:

A questionnaire was sent weekly to newly graduated nurses during the first 12 weeks of work. Stress was measured with four items from the Stress-Energy Questionnaire on a scale from 1 “not at all” to 5 “very much” [mean 2.65, standard deviation (SD) 1.08]. Shifts worked in the past week were reported and QR were identified by evening-morning shift combinations (mean 0.98, SD 0.90 per week). In total, 350 persons were included in the analysis (3556 observations). Data were analyzed with a multilevel residual dynamic structural equation model (RDSEM) using Bayesian estimation procedures.

Results:

There was no between-person effect of QR on stress averaged across measurement occasions (0.181, 95% CI -0.060–0.415). However, there was a small within-person effect of QR (0.031, 95% CI 0.001–0.062), meaning that more QR during a given week, compared to that person’s average, was associated with an increase in their level of stress during that week.

Conclusions:

Nurses were likely to report increased stress during weeks in which they worked more QR. Intervention studies are needed to determine whether the relationship is causal.

Sleep and fatigue in newly graduated nurses-Experiences and strategies for handling shiftwork

AIMS AND OBJECTIVES

To explore newly graduated nurses' strategies for, and experiences of, sleep problems and fatigue when starting shiftwork. A more comprehensive insight into nurses' strategies, sleep problems, fatigue experiences and contributing factors is needed to understand what support should be provided.

BACKGROUND

For graduate nurses, the first years of practice are often stressful, with many reporting high levels of burnout symptoms. Usually, starting working as a nurse also means an introduction to shiftwork, which is related to sleep problems. Sleep problems may impair stress management and, at the same time, stress may cause sleep problems. Previously, sleep problems and fatigue have been associated with burnout, poor health and increased accident risk.

DESIGN AND METHODS

Semi-structured interviews were conducted with nurses (N = 11) from four different Swedish hospitals, and qualitative inductive content analysis was used. The study was approved by the Regional Ethical Review Board in Stockholm. The COREQ checklist was followed.

RESULTS

Many nurses lacked effective strategies for managing sleep and fatigue in relation to shiftwork. Various strategies were used, of which some might interfere with factors regulating and promoting sleep such as the homeostatic drive. Sleep problems were common during quick returns, often due to difficulties unwinding before sleep, and high workloads exacerbated the problems. The described consequences of fatigue in a clinical work context indicated impaired executive and nonexecutive cognitive function.

CONCLUSION

The findings indicate that supporting strategies and behaviours for sleep and fatigue in an intervention for newly graduated nurses starting shiftwork may be of importance to improve well-being among nurses and increase patient safety.

RELEVANCE TO CLINICAL PRACTICE

This study highlights the importance of addressing sleep and fatigue issues in nursing education and work introduction programmes to increase patient safety and improve well-being among nurses.

Assessing the effectiveness of a naturally occurring population-level physical activity intervention for children

OBJECTIVES

The aim of the study was to assess the impact of a recreation access pass on grade 5 children's physical activity (PA) levels.

STUDY DESIGN

This is a pre-post evaluation of a population-level community-based intervention.

METHODS

All grade 5 students in (London, Ontario, Canada) were invited to participate in the [ACT-i-Pass] program (G5AP) in May 2014. A total of 643 children completed surveys, that included Physical Activity Questionnaire for Children (PAQ-C), at baseline (October 2014) and 6-month follow-up (April 2015). Difference in the means t-test compared PAQ-C scores between baseline and follow-up for the sample and subgroups. Multiple regression analysis tested associations between change in PAQ-C scores and intrapersonal-, interpersonal-, and physical environment-level variables.

RESULTS

PA increased significantly from baseline to 6-month follow-up. Girls, visible minorities, immigrants, and children with low parental support experienced significant increases in PA. Regression found girls benefitted from the G5AP significantly more than boys, and lower parental support is related to increases in PA.

CONCLUSION

The findings indicate that collaboratively developed, community-based interventions can significantly increase children's PA levels, particularly among subgroups with traditionally lower PA. The pre-post evaluation of this community-based intervention provides useful evidence for developing policies and programs aimed at making population-level improvements in children's PA levels.

Associations between shift work and use of prescribed medications for the treatment of hypertension, diabetes, and dyslipidemia: a prospective cohort study

Objective This study examined the associations between shift work and use of antihypertensive, lipid-lowering, and antidiabetic medications. Methods Survey data from two cohorts of Finnish men (N=11 998) and women (N=49 944) working in multiple occupations where shift work was used were linked to national Drug Prescription Register data, with up to 11 years of follow-up. In each cohort, age-stratified Cox proportional hazard regression models were computed to examine any incident use of prescription medication for each of the three medical conditions, separately comparing each of two groups of rotating shift workers (those whose schedules included night shifts, and those whose schedules did not include night shifts) with day workers who worked in a similar range of occupations. Results In the larger cohort, among participants aged 40-49 at baseline, shift work without night shifts was associated with increased use of type-2 diabetes medication after adjustments for sex, occupational status, marital status, alcohol consumption, smoking, and physical activity [hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.01-1.62], while shift work with night shifts was associated with increased use of dyslipidemia medication after adjustments (HR 1.33, 95% CI 1.12-1.57). There were no such associations among younger and older shift workers. Also in the larger cohort, among those aged <50 years at baseline, both types of shift work were associated with increased use of hypertension medication after adjustments [up to HR 1.20 (95% CI 1.05-1.37)]. There were no positive associations in the smaller cohort. Conclusions There was mixed evidence regarding the use of medications for cardiovascular risk factors by shift workers. Selection effects may have affected the associations.

Effect of work schedule on prospective antidepressant prescriptions in Sweden: a 2-year sex-stratified analysis using national drug registry data

INTRODUCTION

Depression-related mood disorders affect millions of people worldwide and contribute to substantial morbidity and disability, yet little is known about the effects of work scheduling on depression. This study used a large Swedish survey to prospectively examine the effects of work schedule on registry-based antidepressant prescriptions in females and males over a 2-year period.

METHODS

The study was based on an approximately representative sample (n=3980 males, 4663 females) of gainfully employed participants in the Swedish Longitudinal Occupational Survey of Health. Sex-stratified analyses were conducted using logistic regression. For exposure, eight categories described work schedule in 2008: 'regular days' (three categories of night work history: none, ≤3 years, 4+ years), 'night shift work', 'regular shift work (no nights)', 'rostered work (no nights)', 'flexible/non-regulated hours' and 'other'. For the primary outcome measure, all prescriptions coded N06A according to the Anatomical Therapeutic Chemical System were obtained from the Swedish National Prescribed Drug Register and dichotomised into 'any' or 'no' prescriptions between 2008 and 2010. Estimates were adjusted for potential sociodemographic, health and work confounders, and for prior depressive symptoms.

RESULTS

In 2008, 22% of females versus 19% of males worked outside of regular daytime schedule. Registered antidepressant prescription rates in the postsurvey period were 11.4% for females versus 5.8% for males. In fully adjusted models, females in 'flexible/non-regulated' schedules showed an increased OR for prospective antidepressant prescriptions (OR=2.01, 95% CI=1.08 to 3.76). In males, odds ratios were most increased in those working 'other' schedules (OR=1.72, 95% CI=0.75 to 3.94) and 'Regular days with four or more years' history of night work' (OR=1.54, 95% CI=0.93 to 2.56).

CONCLUSIONS

This study's findings support a relationship between work schedule and prospective antidepressant prescriptions in the Swedish workforce. Future research should continue to assess sex-stratified relationships, using detailed shift work exposure categories and objective registry data where possible.

Investigating the factorial structure and availability of work time control in a representative sample of the Swedish working population

AIMS

Past research has often neglected the sub-dimensions of work time control (WTC). Moreover, differences in levels of WTC with respect to work and demographic characteristics have not yet been examined in a representative sample. We investigated these matters in a recent sample of the Swedish working population.

METHODS

The study was based on the 2014 data collection of the Swedish Longitudinal Occupational Survey of Health. We assessed the structure of the WTC measure using exploratory and confirmatory factor analysis. Differences in WTC by work and demographic characteristics were examined with independent samplet-tests, one-way ANOVAs and gender-stratified logistic regressions.

RESULTS

Best model fit was found for a two-factor structure that distinguished between control over daily hours and control over time off (root mean square error of approximation = 0.06; 95% CI 0.04 to 0.09; Comparative Fit Index (CFI) = 0.99). Women, shift and public-sector workers reported lower control in relation to both factors. Age showed small associations with WTC, while a stronger link was suggested for civil status and family situation. Night, roster and rotating shift work seemed to be the most influential factors on reporting low control over daily hours and time off.

CONCLUSIONS

Our data confirm the two-dimensional structure underlying WTC, namely the components 'control over daily hours' and 'control over time off'. Women, public-sector and shift workers reported lower levels of control. Future research should examine the public health implications of WTC, in particular whether increased control over daily hours and time off can reduce health problems associated with difficult working-time arrangements.

Systematic review of the relationship between quick returns in rotating shift work and health-related outcomes

A systematic literature search was carried out to investigate the relationship between quick returns (i.e., 11.0 hours or less between two consecutive shifts) and outcome measures of health, sleep, functional ability and work-life balance. A total of 22 studies published in 21 articles were included. Three types of quick returns were differentiated (from evening to morning/day, night to evening, morning/day to night shifts) where sleep duration and sleepiness appeared to be differently affected depending on which shifts the quick returns occurred between. There were some indications of detrimental effects of quick returns on proximate problems (e.g., sleep, sleepiness and fatigue), although the evidence of associations with more chronic outcome measures (physical and mental health and work-life balance) was inconclusive.

PRACTITIONER SUMMARY

Modern societies are dependent on people working shifts. This study systematically reviews literature on the consequences of quick returns (11.0 hours or less between two shifts). Quick returns have detrimental effects on acute health problems. However, the evidence regarding effects on chronic health is inconclusive.

The impact of work time control on physicians' sleep and well-being

Physicians' work schedules are an important determinant of their own wellbeing and that of their patients. This study considers whether allowing physicians control over their work hours ameliorates the effects of demanding work schedules. A questionnaire was completed by hospital physicians regarding their work hours (exposure to long shifts, short inter-shift intervals, weekend duties, night duties, unpaid overtime; and work time control), sleep (quantity and disturbance) and wellbeing (burnout, stress and fatigue). Work time control moderated the negative impact that frequent night working had upon sleep quantity and sleep disturbance. For participants who never worked long shifts, work time control was associated with fewer short sleeps, but this was not the case for those who did work long shifts. Optimizing the balance between schedule flexibility and patient needs could enhance physicians' sleep when working the night shift, thereby reducing their levels of fatigue and enhancing patient care.

Work time control and sleep disturbances: prospective cohort study of Finnish public sector employees

OBJECTIVES

Employee control over work times has been associated with favorable psychosocial and health-related outcomes, but the evidence regarding sleep quality remains inconclusive. We examined cross-sectional and prospective associations between work time control and sleep disturbances in a large working population, taking into account total hours worked.

METHODS

The data were from a full-panel longitudinal cohort study of Finnish public sector employees who responded to questions on work time control and sleep disturbances in years 2000-2001, 2004-2005, 2008-2009, and 2012. The analysis of cross-sectional associations was based on 129,286 person measurements from 68,089 participants (77% women) aged 17-73 years (mean 43.1). Data from 16,503 participants were used in the longitudinal analysis. Log-binomial regression analysis with the generalized estimating equations method was used.

RESULTS

Consistently in both cross-sectional and longitudinal models, less control over work time was associated with greater sleep disturbances in the total population and among those working normal 40-hour weeks. Among participants working more than 40 hours a week, work time that was both very high (cross-sectional prevalence ratio compared to intermediate work time control [PR] 1.32, 95% confidence interval [CI] 1.05-1.65) and very low (PR 1.23, 95% CI 1.08-1.39) was associated with sleep disturbances, after adjustment for potential confounding factors.

CONCLUSIONS

These data suggest that having few opportunities to influence the duration and positioning of work time may increase the risk of sleep disturbances among employees. For persons working long hours, very high levels of control over working times were also associated with increased risk of sleep disturbances.

CITATION

Salo P, Ala-Mursula L, Rod NH, Tucker P, Pentti J, Kivimäki M, Vahtera J. Work time control and sleep disturbances: prospective cohort study of Finnish public sector employees.

Shiftwork and metabolic dysfunction

Many of the health problems that are more prevalent among shiftworkers are thought to be linked to their heightened susceptibility to metabolic syndrome, i.e., the association of even moderate degrees of visceral obesity, dyslipidemia, abnormal blood pressure, and serum glucose levels in the same individual. Although previous studies have identified associations between shiftwork and metabolic syndrome, there is relatively little evidence to date of how the risk of developing it varies as a function of exposure to shiftwork. The current study seeks to confirm earlier findings of an association between shiftwork exposure and metabolic dysfunction, and to examine the impact of exposure duration, while adjusting for a number of covariates in the analyses. The analyses were based on data from VISAT, a study involving the measurement of physiological, behavioral, and subjective outcomes from 1757 participants, 989 being current or former shiftworkers. The sample comprised employed and retired wage earners, male and female, who were 32, 42, 52, and 62 yrs old. The first analysis sought to confirm previous findings of an association between exposure to shiftwork and the risk of developing metabolic syndrome. It indicated that participants who were or who had previously been shiftworkers (i.e., working schedules that involved rotating shifts; not being able to go to bed before midnight; having to get up before 05:00 h; or being prevented from sleeping during the night) were more likely to exhibit symptoms of metabolic syndrome, after adjusting for age, sex, socioeconomic status, smoking, alcohol intake, perceived stress, and sleep difficulty (odds ratio [OR] 1.78; 95% confidence interval [CI] 1.03-3.08). The results suggest the association between shiftwork and metabolic syndrome cannot be fully accounted for by either higher levels of strain or increased sleep difficulty among shiftworkers, although it remains a possibility that either one or both of these factors may have played a contributing role. The second analysis addressed the issue of duration of exposure to shiftwork. Participants with >10 yrs' experience of working rotating shifts were more likely to exhibit symptoms of metabolic syndrome than participants without exposure to shiftwork, i.e., dayworkers, even after adjusting for age and sex (OR 1.96; 95% CI 1.03-3.75). Thus, the current study confirms the association between shiftwork exposure and metabolic syndrome. It also provides new information regarding the time course of the development of the illness as function of exposure duration, although this was only examined in relation to rotating shiftwork. It is concluded that those responsible for monitoring workers' health should pay particular attention to indices of metabolic dysfunction in workers who have been exposed to shiftwork for >10 yrs.

Effects of age, gender, and retirement on perceived sleep problems: results from the VISAT combined longitudinal and cross-sectional study

OBJECTIVES

This study examined the effects of age, gender, and retirement on the subjective frequency of various sleep problems in individuals on a normal work schedule.

DESIGN

Data were taken from the VISAT study (Aging, Health, - Work), which allowed both cross-sectional and longitudinal aspects of age-related changes to be examined.

SETTING

Various sorts of companies in southern France.

PARTICIPANTS

The cohorts comprised 623 male and female, employed and retired, wage earners who were 32, 42, 52, and 62 years old at the time of the first measurement (t1, 1996), and who were seen again 5 (t2) and 10 (t3) years later.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Subjective ratings of the frequency of sleep problems and hypnotic usage were recorded on all 3 occasions, as was the employment status of the individuals. After controlling for age and gender, an effect of decade was observed for difficulty falling asleep and difficulty maintaining sleep, indicating that the frequency of these sleep problems was rated higher in 2006 than in 1996 by people of the same age at both measurement occasions. The perceived frequency of difficulty maintaining sleep, difficulty getting back to sleep, and premature awakening was found to increase up to the mid-50s but to then remain relatively constant, or even in the case of premature awakening to reduce, up to the age of 72. There was also a significant improvement in premature awakening among those individuals who changed from being active to being retired during the study period (n = 111). In contrast, the rated frequency of difficulty falling asleep and hypnotic usage increased fairly linearly over the entire age range.

CONCLUSIONS

Sleep complaints were reported early in the workers' lives, and were more frequent with age, but some of them improved after retirement, especially the complaint of premature awakening.

Quiescence regulator Foxp1 restrains antigen-induced T cell activation and response by mechanisms including a novel negative feedback loop (121.17)

Previously we have shown that transcription factor Foxp1 is an essential regulator in maintaining the quiescence of naive T cells during homeostasis. In mice, Foxp1 has four isoforms. Now we find that whereas the full-length Foxp1A is constitutively expressed in mature T cells, T cell receptor (TCR) stimulation induces the expression of a short Foxp1 isoform, Foxp1D, which in turn dampens TCR signaling and T cell proliferation, constituting a negative feedback loop. In Foxp1D conditional transgenic mice, Foxp1D transgene in T cells reduces the generation of CD8+ and CD4+ T effectors to viral infections. On the contrary, Foxp1-deficient T cells (lacking all Foxp1 isoforms) elicit a faster and stronger effector response to antigen challenge. These results suggest that quiescence gene Foxp1 plays an important role in restraining antigen-induced T cell activation and response with a novel negative feedback loop by Foxp1D.

Structural and functional profiling of the human histone methyltransferase SMYD3

The SET and MYND Domain (SMYD) proteins comprise a unique family of multi-domain SET histone methyltransferases that are implicated in human cancer progression. Here we report an analysis of the crystal structure of the full length human SMYD3 in a complex with an analog of the S-adenosyl methionine (SAM) methyl donor cofactor. The structure revealed an overall compact architecture in which the "split-SET" domain adopts a canonical SET domain fold and closely assembles with a Zn-binding MYND domain and a C-terminal superhelical 9 α-helical bundle similar to that observed for the mouse SMYD1 structure. Together, these structurally interlocked domains impose a highly confined binding pocket for histone substrates, suggesting a regulated mechanism for its enzymatic activity. Our mutational and biochemical analyses confirm regulatory roles of the unique structural elements both inside and outside the core SET domain and establish a previously undetected preference for trimethylation of H4K20.

The impact of shift patterns on junior doctors' perceptions of fatigue, training, work/life balance and the role of social support

BACKGROUND

The organisation of junior doctors' work hours has been radically altered following the partial implementation of the European Working Time Directive. Poorly designed shift schedules cause excessive disruption to shift workers' circadian rhythms.

METHOD

Interviews and focus groups were used to explore perceptions among junior doctors and hospital managers regarding the impact of the European Working Time Directive on patient care and doctors' well-being.

RESULTS

Four main themes were identified. Under "Doctors shift rotas", doctors deliberated the merits and demerits of working seven nights in row. They also discussed the impact on fatigue of long sequences of day shifts. "Education and training" focused on concerns about reduced on-the-job learning opportunities under the new working time arrangements and also about the difficulties of finding time and energy to study. "Work/life balance" reflected the conflict between the positive aspects of working on-call or at night and the impact on life outside work. "Social support structures" focused on the role of morale and team spirit. Good support structures in the work place counteracted and compensated for the effects of negative role stressors, and arduous and unsocial work schedules.

CONCLUSIONS

The impact of junior doctors' work schedules is influenced by the nature of specific shift sequences, educational considerations, issues of work/life balance and by social support systems. Poorly designed shift rotas can have negative impacts on junior doctors' professional performance and educational training, with implications for clinical practice, patient care and the welfare of junior doctors.

Mass mortality and its environmental and evolutionary consequences

The latest Mesozoic and earliest Tertiary sediments at Deep Sea Drilling Project site 524 provide an amplified record of environmental and biostratographic changes at the end of Cretaceous. Closely spaced samples, representing time intervals as short as 10(2) or 10(3) years, were analyzed for their bulk carbonate and trace-metal compositions, and for oxygen and carbon isotopic compositions. The data indicate that at the end of Cretaceous, when a high proportion of the ocean's planktic organisms were eliminated, an associated reduction in productivity led to a partial transfer of dissolved carbon dioxide from the oceans to the atmosphere. This resulted in a large increase of the atmospheric carbon dioxide during the next 50,000 years, which is believed to have caused a temperature rise revealed by the oxygen-isotope data. The lowermost Tertiary sediments at site 524 include fossils with Cretaceous affinities, which may include both reworked individuals and some forms that survived for a while after the catastrophe. Our data indicate that many of the Cretaceous pelagic organisms became extinct over a period of a few tens of thousands of years, and do not contradict the scenario of cometary impact as a cause of mass mortality in the oceans, as suggested by an iridium anomaly at the Cretaceous-Tertiary boundary.

The impact of junior doctors' worktime arrangements on their fatigue and well-being

OBJECTIVE

Many doctors report working excessively demanding schedules that comply with the European Working Time Directive (EWTD). We compared groups of junior doctors working on different schedules in order to identify which features of schedule design most negatively affected their fatigue and well-being in recent weeks.

METHODS

Completed by 336 doctors, the questionnaires focused on the respondents' personal circumstances, work situation, work schedules, sleep, and perceptions of fatigue, work-life balance and psychological strain.

RESULTS

Working 7 consecutive nights was associated with greater accumulated fatigue and greater work-life interference, compared with working just 3 or 4 nights. Having only 1 rest day after working nights was associated with increased fatigue. Working a weekend on-call between 2 consecutive working weeks was associated with increased work-life interference. Working frequent on-calls (either on weekends or during the week) was associated with increased work-life interference and psychological strain. Inter-shift intervals of <10 hours were associated with shorter periods of sleep and increased fatigue. The number of hours worked per week was positively associated with work-life interference and fatigue on night shifts.

CONCLUSION

The current findings identify parameters, in addition to those specified in the EWTD, for designing schedules that limit their impact on doctors' fatigue and well-being.

Eating and shift work - effects on habits, metabolism and performance

Compared to individuals who work during the day, shift workers are at higher risk of a range of metabolic disorders and diseases (eg, obesity, cardiovascular disease, peptic ulcers, gastrointestinal problems, failure to control blood sugar levels, and metabolic syndrome). At least some of these complaints may be linked to the quality of the diet and irregular timing of eating, however other factors that affect metabolism are likely to play a part, including psychosocial stress, disrupted circadian rhythms, sleep debt, physical inactivity, and insufficient time for rest and revitalization. In this overview, we examine studies on food and nutrition among shift workers [ie, dietary assessment (designs, methods, variables) and the factors that might influence eating habits and metabolic parameters]. The discussion focuses on the quality of existing dietary assessment data, nutritional status parameters (particularly in obesity), the effect of circadian disruptions, and the possible implications for performance at work. We conclude with some dietary guidelines as a basis for managing the nutrition of shift workers.

Memory and attention problems in children with chronic fatigue syndrome or myalgic encephalopathy

OBJECTIVE

To understand more about the problems children with chronic fatigue syndrome (CFS) or myalgic encephalopathy (ME) experience with memory and attention, and to test the feasibility of quantitative measurement of both memory and attention.

DESIGN

Four-item semistructured questionnaire and neuropsychological test battery with 10 psychometric subtests.

SETTING

Family home of the child taking part.

PATIENTS

20 children with a diagnosis of CFS/ME experiencing memory and/or concentration problems were recruited between April and October 2007 from a regional CFS/ME clinical service (female 13; average age 13.5 years; range 8-16).

METHODS

Each child, parent and teacher was asked to describe the child's memory and attention problems. Responses were subject to thematic analysis by two independent researchers. In addition, each child completed a battery of 10 tests to measure: processing speed; attention; immediate and delayed memory; working memory; executive function. Raw scores were converted into age-scaled scores and the children's psychometric scores on the 10 tests taken were compared with normative data using t tests.

RESULTS

Children with CFS/ME, their parents and teachers described problems with focussed attention, sustained attention, recall and stress. Scores for sustained attention (mean 8.1, 95% CI 6.3 to 9.9), switching attention (7.5, 5.5 to 9.4), divided attention (6.9, 5.5 to 8.2), auditory learning (8.2, 6.8 to 9.6) and immediate recall (8.7, 7.3 to 10.0) appeared lower than the normative mean of 10.

CONCLUSIONS

Children with CFS/ME appear to experience problems with attention, which may have adverse implications for verbal memory. These cognitive problems may explain some of the educational difficulties associated with CFS.

Decreasing disparity in cholesterol screening in minority communities--findings from the racial and ethnic approaches to community health 2010

BACKGROUND

Highly controlled research projects demonstrated success in preventing and controlling cardiovascular diseases. Community-based programs have yet to demonstrate significant influence. Data on large-scale community-level interventions targeting minority communities are limited. The aim of this study is to measure the impact of the Racial and Ethnic Approaches to Community Health (REACH 2010) project, a community-based intervention to eliminate racial/ethnic disparities in blood cholesterol screening in minority communities.

METHODS

Annual survey data from 2001 to 2006 were gathered in 22 communities. Trends in the prevalence of age-standardised blood cholesterol screening were examined for four racial/ethnic groups (black, Hispanic, Asian and American Indian/Alaska Native), stratified by education level, and compared with national data from the Behavioral Risk Factor Surveillance System.

RESULTS

The prevalence of cholesterol screening increased among persons in black, Hispanic and Asian REACH communities (p<0.001), whereas prevalence decreased in the total US and Hispanic populations (p<0.001) and remained similar among blacks and Asians nationwide. The relative disparity between the total US population and most REACH communities decreased (p<0.05). Relative disparity in cholesterol screening related to education level decreased (p<0.05) within REACH communities, whereas relative disparity related to education level nationwide remained similar in blacks and increased (p<0.001) in Hispanics.

CONCLUSION

The REACH project decreased racial and ethnic disparities in cholesterol screening between REACH communities and the total US population, as well as disparities related to education level within REACH communities.

Short‐term growth and bone turnover in children undergoing occlusive steroid (‘Wet‐Wrap’) dressings for treatment of atopic eczema

To assess the effects of steroid wet-wrap therapy on short-term growth and bone turnover, eight prepubertal (M:F,5:3) children with a median age of 5.1years (range 3.3-8.8) were studied over a 2-week period prior to therapy and at 2-week intervals during therapy. Short-term growth was assessed by measuring lower leg length velocity (LLLV) by knemometry and bone and collagen turnover was assessed by urinary deoxypyridinoline crosslink excretion corrected for creatinine excretion (DPD). Median duration of study during occlusive dressings was 12 weeks (range 2-18). Topical beclomethasone dipropionate diluted 1:10 or 1:4 in white soft paraffin was applied under tubular (Tubifast) bandages in 7/8 children. Median LLLV before and during therapy were 0.43 mm/week (10(th),90(th) centile; 0.0,0.7) and 0.42 mm/week (10(th),90(th) centile; -0.35,1.01), respectively (not significant). Median DPD before and during therapy were 25.9 nmol/l/creatinine (10(th),90(th) centile; 20.8, 33.0) and 26.3 nmol/l/creatinine (10(th),90(th) centile; 21.7, 34.1) respectively (not significant). Non-invasive assessment of the effects of steroid wet-wrap therapy can be performed in children with eczema. These preliminary results show no substantial growth promoting or adverse effects of therapy.

The Impact of Rest Breaks on Temporal Trends in Injury Risk

This study examined the impact of rest breaks on temporal trends in industrial accident risks in an attempt to replicate earlier findings of a linear increase in risk as a function of elapsed time on task. In two separate studies, the trend in work-related injuries were studied in relation to the timing of rest breaks. In study one, comparisons were made between on- and off-track workers on weekly rotating three-shift systems operating in a large engineering company. Records of on-duty injuries that occurred over 12 months were examined (N = 4645 incidents). Study two involved interviewing patients who had suffered work-related hand injuries in a variety of occupational settings (N = 407 patients). Hierarchical log linear analysis was used in both studies. In study one, risk increased from the first to the second half-hour of continuous work following a break, but then remained relatively constant in subsequent half-hour periods, although there was a fall in the third half-hour for on-track workers. In some of the data, there was also a decrease in risk in the period leading up to the end of a work period. There was a sharp decline in reported injuries toward the very end of a shift, but otherwise the observed trends did not differ between successive periods of continuous work or between morning, afternoon, and night shifts. In study two, risk increased from the first to the second half-hour of continuous work and then remained relatively constant in the third half-hour. The contrast between the current and previous findings may be due to the relatively unique work environment of the previous study. It is suggested that the current trends reflect the effects of working in a relatively unconstrained task environment, and that causes other than fatigue may underlie the trends observed in both the previous and current studies.