Personalized sleep and nutritional strategies to combat adverse effects of night shift work: a controlled intervention protocol.

BACKGROUND: Working during the night interferes with the timing of normal daily activities and is associated with an increased risk of chronic diseases. Under controlled experimental conditions, interventions focusing on sleep and nutrition can mitigate the short-term adverse effects of shift work. However, it is unclear how these results translate to real-life, how they can be targeted to individual conditions, and how they relate to long-term health. Therefore, the current study aims to implement a personalized sleep and nutritional intervention among night shift workers in the field. METHODS: A non-blinded controlled intervention study is used, consisting of a run-in period, an intervention of 3 months, post-intervention measurements, and a follow-up after 12 months. Three study arms are included: sleep intervention, nutritional intervention, and control group (n = 25 each). Participants are healthy 18-60-year male night shift workers, with at least one year of experience in night shift work. Information from the run-in period will be used to personalize the interventions. The main outcomes are sleep measurements and continuous interstitial glucose levels. Furthermore, general health biomarkers and parameters will be determined to further evaluate effects on long-term health. DISCUSSION: This study aims to mitigate negative health consequences associated with night shift work by introducing two personalized preventive interventions. If proven effective, the personalized interventions may serve as practical solutions that can have a meaningful impact on the sustainable health and employability of night shift workers. This study will thereby contribute to the current need for high-quality data on preventative strategies for night shift work in a real-life context. TRIAL REGISTRATION: This trial has been registered under ClinicalTrials.gov Identifier NCT06147089. Registered 27 November 2023.

Effects and implementation of an intervention to improve sleep, fatigue and recovery among healthcare workers with night shifts: A pre- and post-test study.

BACKGROUND: Previous intervention studies among night workers mainly focused on single interventions and found inconclusive evidence for effectiveness. A comprehensive intervention approach that includes individual and environmental components has been argued as important. Gaining insight into contributing factors for the implementation of interventions for night workers and effectiveness is important to distinguish between theory and programme failure. OBJECTIVES: To evaluate the effects and implementation of the PerfectFit@Night intervention to improve sleep, fatigue and recovery of night workers in healthcare, using the RE-AIM framework, which assesses reach, effectiveness, adoption, implementation and maintenance of interventions. DESIGN: A prospective pre-post study design, with two measurements before and three and six months after the intervention. SETTING: Twelve different departments of a university hospital in the Netherlands. PARTICIPANTS: Healthcare workers working night shifts (n = 210). METHODS: PerfectFit@Night consisted of environmental (provision of a powernap bed and healthy food, and workshop healthy rostering) and individual elements (e-learning and sleep coaching) and was implemented for three months in a phased manner. Questionnaires, logbooks and interview data were used. Effects of the intervention on sleep, fatigue and recovery were evaluated with mixed-effects models, and implementation factors of reach, adoption, implementation and maintenance were evaluated. RESULTS: Night shift-related insomnia (-11 %-points, 95 % CI: -19 %, -4 % at three months), need for recovery (ß: -2.45, 95 % CI: -4.86, -0.03 at six months) and fatigue (OR: 0.46, 95 % CI: 0.25, 0.86 at six months) decreased significantly after the intervention. No changes were found for subjective sleep quality and sleep duration. Barriers and facilitators for implementation were identified for each intervention element at individual (e.g., dietary preferences), organisational (e.g., responsibilities at work) and workplace levels (e.g., location of power nap bed), and for the intervention itself (e.g., useful information in e-learning). Although satisfaction was high and continuation was preferred, embedding of the intervention in the daily routine was limited. Facilitators for future implementation include a positive attitude towards the intervention, clear guidelines regarding intervention elements, appointment of night workers as ambassadors, and suitable conditions in terms of work demands and for the intervention elements. CONCLUSIONS: The multi-faceted PerfectFit@Night intervention reduced insomnia, fatigue and need for recovery in night workers in healthcare. The most important facilitators to improve the implementation of PerfectFit@Night exist at the organisational level (e.g., positive attitude within the culture and suitable work demands). Combining effect and implementation evaluation is crucial to identify barriers and facilitators that hamper or enhance intervention effects. TRIAL REGISTRATION: The study was registered in the Netherlands Trial Register on 17 January 2021 (trial number NL9224).

Precarious work and methodological challenges to study hard-to-reach populations.

OBJECTIVE: To describe the methodological challenges and strategies of a web survey on the working conditions and health among delivery workers. METHODS: The study population consisted of Brazilian delivery workers operating in the national territory. Procedures include building solid and ongoing collaboration with worker representatives and conducting a four-month data collection from February to May 2022, sharing the link to the online questionnaire on social media such as social networks (Facebook, Instagram) and messaging apps (WhatsApp, Telegram). RESULTS: The recruitment of 41 leaders or influencers of delivery workers increased the dissemination of the study, some of whom participated in the consensual validation of the questionnaire; the production of content for social media for the dissemination of the questionnaire link on social networks and applications, and the in-person dissemination of the study at the delivery workers' meeting points during the workday played a fundamental role, totaling around 132 hours in 45 shifts. The strategies adopted for data collection with a hybrid approach to dissemination made it possible to carry out the web survey. After four months of the web survey, 564 delivery workers, 543 men and 18 women, responded to the online questionnaire. CONCLUSION: The web survey presented methodological strategies to overcome the challenge of reaching workers, including hybrid work, to increase the participation of workers, on whom epidemiological research is still scarce.

Physical and psychosocial work-related exposures and the occurrence of disorders of the shoulder: A systematic review update.

This review is an update of a previous systematic review and assesses the evidence for the association of work-related physical and psychosocial risk factors and specific disorders of the shoulders. Medline, Embase, Web of Science Core Collection, Cochrane Central and PsycINFO were searched and study eligibility and risk of bias assessment was performed by two independent reviewers. A total of 14 new articles were added with the majority focusing on rotator cuff syndrome (RCS) with seven studies. Nine articles reported psychosocial exposures in addition to physical exposures. The strongest evidence was found for the association between elevation, repetition, force and vibration and the occurrence of SIS and tendinosis/tendonitis. Evidence also suggests that psychosocial exposures are associated with the occurrence of RCS and tendinosis/tendonitis. Other findings were inconsistent which prevents drawing strong conclusions.

Changing smoking habits and the occurrence of lung cancer in Sweden-a population analysis.

BACKGROUND: The objective is to estimate the importance of the decrease of smoking habits in Sweden for the occurrence of lung cancer. METHODS: The change in smoking habits in the general population was retrieved from surveys and on taxation of sale of cigarettes. We used data from the Swedish Cancer Register on incidence of lung cancer between 1970 and 2021, stratified for sex, age and cell type, and compared the occurrence overtime in ages between 40 and 84 years. RESULTS: The sale of cigarettes peaked in 1980 to 1800 cigarettes per person and decreased to 600 per person in 2021. The change in incidence rates of squamous cell cancer and other cell types varied over time, sex, and age in a pattern that partly seems to be explained by change in the prevalence of daily smokers. The incidence of adenocarcinoma was similar in men and women 1970-2021 and increased, e.g. for women and men 75-79 years of age from around 20 cases in early 1970s to around 120 cases per 100 000 person-years in the 2020s. CONCLUSIONS: Our data indicate that the risk of lung cancer several years after smoking cessation is less favourable than previously studies have indicated. There is a similar increase in the incidence of adenocarcinoma in men and women which is hard to explain only with changing smoking habits. The change from non-filter to filter cigarettes in the 1960s-1970s may be a contributing factor.

Asbestos and disease - a public health success story?

OBJECTIVE: This paper discusses the failure and success of society to decrease the adverse health effects of asbestos exposure on workers' health in relation to scientific knowledge. METHODS: The findings are based on a narrative literature review. RESULTS: Early warnings of the adverse health effects of workplace exposure to asbestos were published already in the 1930s. Serious health effects, such as malignancies and fibrosis due to occupational asbestos exposure, were highlighted in major medical journals and textbooks in late 1960s. New technologies could detect also asbestos fibers in the lung of non-occupational exposed persons in the 1970s. The first bans for using asbestos came in the early 1970s, and more general bans by authorities came in the 1980s and continue until today. CONCLUSIONS: The rather late recognition of adverse effects of asbestos exposure in the general population and measures to decrease the exposure through more general bans came rather late. However, the very strong measures such as general bans in many countries have been a success. A Swedish study showed that the general ban and other measures have decreased the risk of malignancies due to occupational exposure. The effect of the bans on adverse effects in the general population has yet to be studied. Analysis of fibers in the lungs of persons born after the bans could be an efficient method.

Physical and psychosocial work-related exposures and the incidence of carpal tunnel syndrome: A systematic review of prospective studies.

This systematic review summarizes the evidence on associations between physical and psychosocial work-related exposures and the development of carpal tunnel syndrome (CTS). Relevant databases were searched up to January 2020 for cohort studies reporting associations between work-related physical or psychosocial risk factors and the incidence of CTS. Two independent reviewers selected eligible studies, extracted relevant data, and assessed risk of bias (RoB). We identified fourteen articles for inclusion which reported data from nine cohort studies. Eight reported associations between physical exposure and the incidence of CTS and five reported associations between psychosocial exposures and the incidence of CTS. Quality items were generally rated as unclear or low RoB. Work-related physical exposure factors including high levels of repetition, velocity, and a combination of multiple physical exposures were associated with an increased risk of developing CTS. No other consistent associations were observed for physical or psychosocial exposures at work and CTS incidence.

Air pollution and childhood respiratory consultations in primary care: a systematic review.

BACKGROUND: Outdoor air pollution is a known risk factor for respiratory morbidity worldwide. Compared with the adult population, there are fewer studies that analyse the association between short-term exposure to air pollution and respiratory morbidity in children in primary care. OBJECTIVE: To evaluate whether children in a primary care setting exposed to outdoor air pollutants during short-term intervals are at increased risk of respiratory diagnoses. METHODS: A search in Medline, the Cochrane Library, Web of Science and Embase databases throughout March 2023. Percentage change or risk ratios with corresponding 95% CI for the association between air pollutants and respiratory diseases were retrieved from individual studies. Risk of bias assessment was conducted with the Newcastle-Ottawa Scale (NOS) for cohort or case-control studies and an adjusted NOS for time series studies. RESULTS: From 1366 studies, 14 were identified as meeting the inclusion criteria. Most studies had intermediate or high quality. A meta-analysis was not conducted due to heterogeneity in exposure and health outcome. Overall, studies on short-term exposure to air pollutants (carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter ≤10 µm (PM10)) were associated with increased childhood respiratory consultations in primary care. In general, exposure to ozone was associated with a reduction in respiratory consultations. CONCLUSIONS: The evidence suggests CO, SO2, NO2, PM10 and PM2.5 are risk factors for respiratory diseases in children in primary care in the short term. However, given the heterogeneity of the studies, interpretation of these findings must be done with caution. PROSPERO REGISTRATION NUMBER: CRD42022259279.

Fifty years of research in the Scandinavian Journal of Work, Environment & Health.

OBJECTIVE: The Scandinavian Journal of Work, Environment & Health was launched 50 years ago. In this paper we describe how research topics have changed over time. METHODS: A complete list of all 2899 articles in the past 50 years was compiled. Each article was coded for type of exposure, type of health outcome, research design, first author, and country of correspondence address. Count of citations was based on the Scopus database. RESULTS: Overall, the attention for chemical exposure in the first 30 years has shifted towards the psychosocial work environment, shift work, and physical work load. These shifts in exposure are mirrored by increased attention over time for mental disorders and musculoskeletal disorders. Cardiovascular disorders and cancer have been studied consistently over the past 50 years. Researchers from Scandinavian countries have been responsible for about 50% of the Journal's content, while authorship has broadened to about 30 countries in recent years. CONCLUSION: During the past 50 years, some research topics have consistently remained highly visible in the Journal, whereas other topics have gained or lost interest. In terms of authors' contribution, the Journal has its roots in research from the Nordic countries, but has evolved over time as a truly international periodical with a well-recognized position in research on occupational health.

Health Status, Type of Contract and Labour Force Participation.

BACKGROUND: Health status, type of contract, education and age might affect labour force participation (LFP). We investigated possible factors associated with LFP among European countries. METHODS: European Union Statistics on Income and Living Conditions (EU-SILC) data of 149,798 individuals were used and the odds ratios were calculated in logistic regression analyses. RESULTS: LFP rates were higher among those in good health. Self-perceived poor health frequencies were higher in people with temporary contracts than in those with permanent contracts in Bulgaria, Finland, and Hungary, while they were lower in Republic of Serbia. Multivariate analyses revealed that having temporary contract, poor health, oldest age group, and lower educational level were associated with lower probability of being in paid employment in the total study population. Poor health was stronger driver of lower LFP than temporary contracts in Austria, Hungary, Iceland, Netherlands. Temporary contracts were stronger driver of lower LFP than poor health in Greece, Spain, Finland, Portugal, Serbia, Slovenia and total study population. CONCLUSION: Both poor health and temporary contracts were associated with lower LFP. The magnitude of these associations varied among countries. Worker's health status differed by type of contract in Bulgaria, Hungary, Finland and Serbia.

Precarious work and methodological challenges to study hard-to-reach populations

ABSTRACT OBJECTIVE To describe the methodological challenges and strategies of a web survey on the working conditions and health among delivery workers. METHODS The study population consisted of Brazilian delivery workers operating in the national territory. Procedures include building solid and ongoing collaboration with worker representatives and conducting a four-month data collection from February to May 2022, sharing the link to the online questionnaire on social media such as social networks (Facebook, Instagram) and messaging apps (WhatsApp, Telegram). RESULTS The recruitment of 41 leaders or influencers of delivery workers increased the dissemination of the study, some of whom participated in the consensual validation of the questionnaire; the production of content for social media for the dissemination of the questionnaire link on social networks and applications, and the in-person dissemination of the study at the delivery workers' meeting points during the workday played a fundamental role, totaling around 132 hours in 45 shifts. The strategies adopted for data collection with a hybrid approach to dissemination made it possible to carry out the web survey. After four months of the web survey, 564 delivery workers, 543 men and 18 women, responded to the online questionnaire. CONCLUSION The web survey presented methodological strategies to overcome the challenge of reaching workers, including hybrid work, to increase the participation of workers, on whom epidemiological research is still scarce.

Sleep quality, sleep duration, and sleep disturbances among hospital night workers: a prospective cohort study.

PURPOSE: This study aimed to assess among hospital night workers (i) to what extent sleep quality, sleep duration and sleep disturbances overlap, and (ii) associations between sociodemographic factors, lifestyle factors and work characteristics and sleep components. METHODS: Data were used from 467 hospital night workers participating in the Klokwerk + study, a prospective cohort study with two measurements. Sleep quality was measured by the Pittsburgh Sleep Quality Index, sleep duration and sleep disturbances were measured by the Medical Outcomes Study Sleep Scale. The overlap between the three sleep measures was visualized with a Venn diagram and the proportions of overlap was calculated. Associations between independent variables (sociodemographic factors, lifestyle factors and work characteristics) and the three sleep outcomes were estimated using between-within Poisson regression models. RESULTS: About 50% of the hospital night workers had at least one poor sleep outcome. Overlap in poor sleep outcomes was apparent for 36.8% of these workers, while the majority had a poor outcome in one of the sleep components only (63.1%). Former smoking had a significant association with poor sleep quality. For most independent variables no associations with poor sleep outcomes were observed. CONCLUSION: Our findings suggest that sleep quality, sleep duration and sleep disturbances are separate entities and should be studied separately. Lifestyle factors and work characteristics were generally not associated with poor sleep. Since these factors can have an acute effect on sleep, future research should consider ecological momentary assessment to examine how exposure and outcomes (co)vary within-persons, over time, and across contexts. Trial registration Netherlands Trial Register trial number NL56022.041.16.

The relationship between having a job and the outcome of brief therapy in patients with common mental disorders.

BACKGROUND: Previous studies have shown that being employed is associated not only with patients' health but also with the outcome of their treatment for severe mental illness. This study examined what influence employment had on improvements in mental health and functioning among patients with common mental disorders who received brief treatment and how patients' diagnosis, environmental and individual factors moderated the association between being employed and treatment outcome. METHODS: The study used naturalistic data from a cohort of patients in a large mental health franchise in the Netherlands. The data were obtained from electronic registration systems, intake questionnaires and Routine Outcome Monitoring (ROM). The International Classification of Functioning, Disability and Health (ICF) framework was used to identify potential subgroups of patients. Logistic regression models were used to analyze the relationship between employment status and treatment outcome and to determine how the relationship differed among ICF subgroups of patients. RESULTS: A strong relationship was found between employment status and the outcome of brief therapy for patients with common mental disorders. After potential confounding variables had been controlled, patients who were employed were 54% more likely to recover compared to unemployed patients. Two significant interactions were identified. Among patients who were 60 years of age or younger, being employed was positively related to recovery, but this relationship disappeared in patients older than 60 years. Second, among patients in all living situations there was a positive effect of being employed on recovery, but this effect did not occur among children (18+) who were living with a single parent. CONCLUSIONS: Being employed was positively associated with treatment outcome among both people with a severe mental illness and those with a common mental disorder (CMD). The main strength of this study was its use of a large dataset from a nationwide franchised company. Attention to work is important not only for people with a severe mental illness, but also for people with a CMD. This means that in addition to re-integration methods that focus on people with a severe mental illness, more interventions are needed for people with a CMD.

Reach and effectiveness of a worksite health promotion program combining a preventive medical examination with motivational interviewing; a quasi-experimental study among workers in low socioeconomic position.

BACKGROUND: This study aimed to evaluate individual characteristics associated with participation and effectiveness of a worksite health promotion program with motivational interviewing targeting health and health behaviour among Dutch workers in low socioeconomic position. METHODS: In a production company and a hospital, 838 workers were invited for a Preventive Medical Examination and subsequent coaching with motivational interviewing up to 7 sessions within 6 months. Follow-up information was collected after 6 months. Characteristics associated with participation in coaching were assessed with logistic regression models. The effectiveness of coaching on body mass index (BMI), bodyweight, self-rated health, vigorous physical activity, smoking, alcohol intake, fruit- and vegetable consumption, work ability, and sickness absence was evaluated with linear regression models and on participation in health promotion activities with logistic regression analysis. The analyses on effectiveness were performed without and with propensity score adjustment. RESULTS: Of the 838 invited workers, 313 workers participated in the Preventive Medical Examination and follow-up data were available for 176 workers, of whom 100 workers with increased cardiovascular risk attended coaching. The majority of workers with obesity (73%), overweight (60%), and unhealthy behaviours (58%-69%) at baseline participated in motivational interviewing. Males, workers with overweight or obesity, workers at the production company, workers with insufficient vigorous physical activity, and workers with a low educational level were most likely to participate in coaching. Coaching with motivational interviewing after the Preventive Medical Examination was associated with a 4.74 times higher likelihood [95% confidence interval (CI): 1.99;11.32] to participate in health promotion activities and 10.9% (95%CI: 0.6;21.3) more persons who quit smoking compared to workers without coaching. No statistically significant effects were observed on BMI, bodyweight, health, health behaviour, work ability and sickness absence. CONCLUSIONS: The program combining a Preventive Medical Examination with follow-up coaching reached - as intended - workers with obesity or overweight, those with a low education and with unhealthy behaviours. Adding coaching with motivational interviewing to a Preventive Medical Examination contributed to higher participation in health promotion activities and an increase in smoking cessation after 6 months among workers with a lower socioeconomic position, but was not effective on other outcomes. TRIAL REGISTRATION: The study was registered retrospectively in the Netherlands Trial Register as NL8178 on 22/11/2019.

Work as a social determinant of health in high-income countries: past, present, and future.

This paper, the first in a three-part Series on work and health, provides a narrative review of research into work as a social determinant of health over the past 25 years, the key emerging challenges in this field, and the implications of these challenges for future research. By use of a conceptual framework for work as a social determinant of health, we identified six emerging challenges: (1) the influence of technology on the nature of work in high-income countries, culminating in the sudden shift to telework during the COVID-19 pandemic; (2) the intersectionality of work with gender, sexual orientation, age, race, ethnicity, migrant status, and socioeconomic status as codeterminants of health disparities; (3) the arrival in many Organisation for Economic Co-operation and Development countries of large migrant labour workforces, who are often subject to adverse working conditions and social exclusion; (4) the development of precarious employment as a feature of many national labour markets; (5) the phenomenon of working long and irregular hours with potential health consequences; and (6) the looming threat of climate change's effects on work. We conclude that profound changes in the nature and availability of work over the past few decades have led to widespread new psychosocial and physical exposures that are associated with adverse health outcomes and contribute to increasing disparities in health. These new exposures at work will require novel and creative methods of data collection for monitoring of their potential health impacts to protect the workforce, and for new research into better means of occupational health promotion and protection. There is also an urgent need for a better integration of occupational health within public health, medicine, the life sciences, and the social sciences, with the work environment explicitly conceptualised as a major social determinant of health.

Health and inclusive labour force participation.

The future of work is rapidly changing, with higher flexibility of the labour market and increasing informal employment in many countries worldwide. There is also an increased pressure to extend working careers until older age. We introduce the concept of working life expectancy as a useful metric, capturing the expected numer of years in paid employment across the working age individuals, in particular among different groups. We describe factors that determine working life expectancy. Macro-level factors focus on the socioeconomic and political context that influences labour force participation, primarily policies and legislation in specific countries. At the meso level, employment contracts and working conditions are important. The micro level shows that individual characteristics, such as education, gender, and age, influence working careers. There are three important groups with a disadvantaged position in the labour market-workers with chronic diseases, workers with impairing disabilities, and workers aged 50 years or more. Within each of these disadvantaged groups, macro-level, meso-level, and micro-level factors that influence entering and exiting paid employment are discussed. To assure that paid employment is available for everyone of working age and that work contributes to better health, specific challenges need to be addressed at the macro, meso, and micro levels. To reach inclusive labour force participation, national policies, company practices, and workplace improvements need to be aligned to ensure safe and healthy workplaces that contribute to the health and wellbeing of workers and their communities.

The effects of a national, voluntary agreement for a more inclusive working life on work participation following long-term sickness absence: a Norwegian cohort study.

OBJECTIVES: This study aimed to estimate the average individual effect of the company-level Norwegian Agreement on a More Inclusive Working Life (IA Agreement) on individuals' (i) sustained return to work after a sickness absence (SA) episode, and (ii) recurrent SA. METHODS: Using register data, 79 253 men and 94 914 women born in Norway 1967-1976 were followed for one year between 2005 and 2010 after returning to work from an SA episode (>16 days). Weighted Cox proportional hazard models analysed time to first exit from work by companies' IA status (IA/non-IA). Weighted cumulative incidence differences between IA and non-IA groups with 95% bootstrapped confidence intervals (CI) were calculated for the competing events of full SA, graded (<100%) SA, unemployment/economic inactivity, education, disability pension, and death/emigration. Stabilised inverse probability of treatment weights balanced IA/non-IA groups according to nine covariates. Analyses were stratified by gender, and separately for two initial SA diagnoses (musculoskeletal and psychological). RESULTS: Both men [adjusted hazard ratio (HR) 0.96, 95% CI 0.93-0.99] and women (adjusted HR 0.97, 95% CI 0.94-0.99) in IA companies were less likely to exit work in the year following SA. Similar findings were seen among individuals with musculoskeletal diagnoses and women with psychological diagnoses. Men with psychological diagnoses were more likely to exit work. Recurrent full and graded SA were more likely, and unemployment/economic inactivity less likely, in IA companies. However, the estimated effects were small and the CI often included the null. CONCLUSIONS: Individuals working in IA companies were more likely to remain in work. This was mainly due to reduced unemployment/economic inactivity, suggesting the IA Agreement may have influenced work participation through other means than reduced SA.