Effectiveness of workplace interventions with digital elements to reduce sedentary behaviours in office employees: a systematic review and meta-analysis.

BACKGROUND: Digital interventions are potential tools for reducing and limiting occupational sedentary behaviour (SB) in sedentary desk-based jobs. Given the harmful effects of sitting too much and sitting for too long while working, the aim of this systematic review and meta-analysis was to examine the effectiveness of workplace interventions, that incorporated digital elements, to reduce the time spent in SB in office workers. METHODS: Randomised control trials that evaluated the implementation of workplace interventions that incorporated digital elements for breaking and limiting SB among desk-based jobs were identified by literature searches in six electronic databases (PubMed, Web of Science, Scopus, CINAHL, PsycINFO and PEDro) published up to 2023. Studies were included if total and/or occupational SB were assessed. Only studies that reported pre- and postintervention mean differences and standard deviations or standard errors for both intervention arms were used for the meta-analysis. The meta-analysis was conducted using Review Manager 5 (RevMan 5; Cochrane Collaboration, Oxford, UK). Risk of bias was assessed using the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields QUALSYST tool. RESULTS: Nineteen studies were included in the systematic review. The most employed digital elements were information delivery and mediated organisational support and social influences. Multicomponent, information, and counselling interventions measuring total and/or occupational/nonoccupational SB time by self-report or via device-based measures were reported. Multicomponent interventions were the most represented. Eleven studies were included in the meta-analysis, which presented a reduction of 29.9 (95% CI: -45.2, -14.5) min/8 h workday in SB (overall effect: Z = 3.81). CONCLUSIONS: Multicomponent interventions, using a wide range of digital features, have demonstrated effectiveness in reducing time spent in SB at the workplace among desk-based employees. However, due to hybrid work (i.e., work in the office and home) being a customary mode of work for many employees, it is important for future studies to assess the feasibility and effectiveness of these interventions in the evolving work landscape. TRIAL REGISTRATION: The review protocol was registered in the Prospero database (CRD42022377366).

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 longitudinal association between working from home and musculoskeletal pain during the COVID-19 pandemic.

OBJECTIVE: This study investigates the associations between working from home and the presence of MSP during the COVID-19 pandemic. Working from home often involves a lot of sedentary computer screen work and the home working environment might not be optimally equipped, which can lead to health problems, including musculoskeletal pain (MSP). METHODS: Longitudinal data from 16 questionnaire rounds of the Lifelines COVID-19 cohort during the first year of the COVID-19 pandemic (March 2020-February 2021) were used. In total, 40,702 Dutch workers were included. In every round, participants reported whether they worked on location, from home, or hybrid. Logistic Generalized Estimating Equations were used to study the association of work situation with the presence of MSP and the presence of severe MSP. RESULTS: Working from home was associated with higher risks of having MSP in the lower back (OR: 1.05, 95% CI 1.02-1.08), in the upper back (OR: 1.24, 95% CI 1.18-1.31), and in the neck, shoulder(s) and/or arm(s) (OR: 1.18, 95% CI 1.13-1.22). Hybrid working was associated with higher risks of having pain in the upper back (OR: 1.09, 95% CI 1.02-1.17) and in the neck, shoulder(s) and/or arm(s) (OR: 1.14, 95% CI 1.09-1.20). Both home and hybrid workers had higher risks of severe MSP in the different body areas. CONCLUSION: Home workers, and to a smaller extent hybrid workers, had higher risks of having MSP than location workers during the first year of the COVID-19 pandemic. The results indicate the importance of measures to prevent MSP in future policies involving working from home.

Barriers and facilitators for participation in workplace health promotion programs: results from peer-to-peer interviews among employees.

OBJECTIVE: Workplace health promotion programs (WHPPs) have shown to be effective in improving lifestyle behaviors of employees. Despite potential benefits for employees, participation rates are generally low. The aim of this study was to gain deeper insight into barriers and facilitators for participation in WHPPs prior to implementation according to employees. METHODS: Peer-to-peer interviewing, a method derived from citizen science, was used to actively involve employees in the data collection. Employees working in the cleaning-, ICT- and facility-sector were trained to interview their co-workers. Interviews were recorded and transcribed verbatim. Thematic analysis was performed using the Consolidated Framework for Implementation Research (CFIR), complemented with the constructs 'interpersonal factors' and 'intrapersonal factors' from the social ecological model. Data were coded deductively and inductively, and rated by two researchers independently. RESULTS: Fourteen peer-interviewers conducted 62 peer-to-peer interviews. Main barriers for participation in WHPPs were an unsupportive organizational culture where lifestyle is not a common topic and programs that are not tailored to their needs. Support from peers and supervisors were facilitators. The availability of organizational resources, such as facilities and financial compensation, support participation. CONCLUSIONS: To enhance participation of employees in WHPPs it is recommended to take into account the barriers and facilitators identified in this study. For instance, employees should be involved in the development and implementation of WHPPS by the employer and their needs and available resources should be taken into account. This may lead to more successful implementation and higher participation rates in future WHPPs.

A study protocol of the adaptation and evaluation by means of a cluster-RCT of an integrated workplace health promotion program based on a European good practice.

BACKGROUND: An integrated workplace health promotion program (WHPP) which targets multiple lifestyle factors at different levels (individual and organizational) is potentially more effective than a single component WHPP. The aim of this study is to describe the protocol of a study to tailor a European good practice of such an integral approach to the Dutch context and to evaluate its effectiveness and implementation. METHODS: This study consists of two components. First, the five steps of the Map of Adaptation Process (MAP) will be followed to tailor the Lombardy WHP to the Dutch context. Both the employers and employees will be actively involved in this process. Second, the effectiveness of the integrated Dutch WHPP will be evaluated in a clustered randomized controlled trial (C-RCT) with measurements at baseline, 6 months and 12 months. Clusters will be composed based on working locations or units - dependent on the organization's structure and randomization within each organization takes place after baseline measurements. Primary outcome will be a combined lifestyle score. Secondary outcomes will be the separate lifestyle behaviors targeted, stress, work-life balance, need for recovery, general health, and well-being. Simultaneously, a process evaluation will be conducted. The study population will consist of employees from multiple organizations in different industry sectors. Organizations in the intervention condition will receive the integrated Dutch WHPP during 12 months, consisting of an implementation plan and a catalogue with activities for multiple lifestyle themes on various domains: 1) screening and support; 2) information and education; 3) adjustments in the social, digital or physical environment; and 4) policy. DISCUSSION: The MAP approach provides an appropriate framework to systematically adapt an existing WHPP to the Dutch context, involving both employers and employees and retaining the core elements, i.e. the catalogue with evidence-based activities on multiple lifestyle themes and domains enabling an integrated approach. The following process and effect evaluation will contribute to further insight in the actual implementation and effectiveness of the integrated WHP approach. TRIAL REGISTRATION: NTR (trialregister.nl ), NL9526. Registered on 3 June 2021.

The process evaluation of a citizen science approach to design and implement workplace health promotion programs.

BACKGROUND: Many workplace health promotion programs (WHPPs) do not reach blue-collar workers. To enhance the fit and reach, a Citizen Science (CS) approach was applied to co-create and implement WHPPs. This study aims to evaluate i) the process of this CS approach and ii) the resulting WHPPs. METHODS: The study was performed in two companies: a construction company and a container terminal company. Data were collected by questionnaires, interviews and logbooks. Using the framework of Nielsen and Randall, process measures were categorized in the intervention, context and mental models. Interviews were transcribed and thematically coded using MaxQDA software. RESULTS: The involvement in the CS approach and co-creating the WHPPs was positively experienced. Information provision, sustained engagement over time and alignment with the workplace's culture resulted in barriers in the CS process. As to the resulting WHPPs, involvement and interaction during the intervention sessions were particularly experienced in small groups. The reach was affected by the unfavorable planning off the WHPPs and external events of re-originations and the covid-19 pandemic. DISCUSSION: Continuous information provision and engagement over time, better alignment with the workplace's culture and favorable planning are considered to be important factors for facilitating involvement, reach and satisfaction of the workers in a Citizen science approach to design and implement a WHPP. Further studies continuously monitoring the process of WHPPs using the CS approach could be helpful to anticipate on external factors and increase the adaptability. CONCLUSIONS: Workers were satisfied with the involvement in WHPPs. Organizational and social cultural factors were barriers for the CS approach and its reach. Involvement and interaction in WHPPs were particularly experienced in small grouped sessions. Consequently, contextual and personal factors need be considered in the design and implementation of WHPPs with CS approach among blue-collar workers.

The mediating role of lifestyle in the relationship between shift work, obesity and diabetes.

PURPOSE: Shift work has been related to obesity and diabetes, but the potential mediating role of lifestyle is yet unknown. Our aim was to investigate this mediating role of physical activity, diet, smoking, and sleep quality in the relationships between shift work, and obesity and diabetes. METHODS: In this cross-sectional study, 3188 shift workers and 6395 non-shift workers participated between 2013 and 2018 in periodical occupational health checks. Weight and height were objectively measured to calculate obesity (BMI ≥ 30 kg/m2). Diabetes status, physical activity, diet, smoking, and sleep quality were assessed using standardized questionnaires. Structural equation models adjusted for relevant confounders were used to analyze the mediating role of lifestyle in the relationships between shift work, and obesity and diabetes. RESULTS: Shift workers were more often obese (OR: 1.37, 95% CI 1.16-1.61) and reported more often to have diabetes (OR:1.35, 95% CI 1.003-1.11) than non-shift workers. Shift workers had lower physical activity levels, ate fruit and vegetables less often, smoked more often, and had poorer sleep quality (p < 0.05). Mediation analysis revealed that shift workers had a higher odds of obesity (OR: 1.07, 95% CI 1.01-1.15) and diabetes (OR: 1.13, 95% CI 1.02-1.27) mediated by poorer sleep quality. Lower physical activity levels (OR: 1.11, 95% CI 1.05-1.19) and lower intake of fruit and vegetables (OR: 1.04, 95% CI 1.01-1.15) were also mediators in the relationship between shift work and obesity, but not in the relationship between shift work and diabetes (p ≥ 0.05). CONCLUSION: These results imply that interventions targeting diet, physical activity and in particular sleep problems specifically developed for shift workers could potentially reduce the adverse health effects of shift work.

The mediating role of unhealthy behavior in the relationship between shift work and perceived health.

BACKGROUND: Little is known about the relationship between shift work and perceived health, including potential underlying mechanisms such as unhealthy behaviors. The aim of this study was to investigate whether unhealthy behaviors mediate the relationship between shift work and perceived mental and physical health, taking into account potential differences by level of education. METHODS: Data from 1633 workers participating in the Doetinchem Cohort Study during 1995-2016 were used. Being engaged in shift work was determined at 1 year preceding the assessment of health behaviors. Mental and physical health were assessed after 5 years of follow-up by the 5-item Mental Health Inventory and the physical functioning scale of the 36-item Short Form Health Survey. Smoking, physical inactivity, alcohol consumption, and overweight were considered as potential mediators and education was treated as moderator. Moderated mediation analyses using generalized estimated equations were performed. RESULTS: Shift work was not statistically significantly related to either mental or physical health. Despite this, statistically significant mediation effects of smoking (Beta - 0.09; 95% Confidence Interval - 0.20 - -0.01, respectively B -0.09; 95%CI -0.21 - -0.01) and physical inactivity (B 0.11; 95%CI 0.03-0.23, respectively B 0.08; 95%CI 0.01-0.18) were found in the relationship between shift work and mental or physical health. Direct and indirect effects outweighed each other in the relationship between shift work and mental health, since the direction of these effects was opposite. The relationship between shift work, unhealthy behavior, and health was not different by educational level. CONCLUSION: Shift workers did not report lower mental or physical health than non-shift workers. Though mediation effects of unhealthy behavior were observed in the relationship between shift work and perceived health, these small effects had minor public health relevance.

Shift work, and burnout and distress among 7798 blue-collar workers.

OBJECTIVE: This study aimed to investigate the association between shift work, and burnout and distress, and differences by degree of satisfaction with shift schedule and its impact on private life. METHODS: Population 4275 non-shift factory workers and 3523 rotating 5-shift workers. Workers participated between 2009 and 2016 one to three times in the companies' periodical occupational health checks. Burnout was measured using the distance, exhaustion and competence subscales of the Dutch Maslach Burnout Inventory and distress by the subscale of the Four-Dimensional Symptom Questionnaire (scale: 0-100). Multiple-adjusted linear mixed models were used to assess between- and within-subject associations between shift work and outcomes, and differences by age, years of shift work, and satisfaction with and impact of shift schedule. RESULTS: Shift work was significantly associated with lower scores on burnout distance (B - 1.0, 95% - 1.8 to 0.3), and among those aged < 48 years with burnout exhaustion (range B - 1.3 to - 1.6). However, the effect sizes were small. Compared to non-shift workers, shift workers dissatisfied with their schedule and those experiencing a high impact on private life had significantly higher burnout (range B 1.7-6.3) and distress levels (range B 4.9-6.1). In contrast, satisfied shift workers and those experiencing a low impact of shift schedule had lower burnout (range B - 0.2 to - 2.2) and no difference in distress levels (P ≥ 0.05). No clear pattern by years of shift work was observed. CONCLUSIONS: Shift work was associated with burnout and distress in those who were dissatisfied with or who had perceived high impact on the private life of their shift schedule.

The moderating role of lifestyle, age, and years working in shifts in the relationship between shift work and being overweight.

PURPOSE: This study aimed to investigate the relationship between the moderating role of lifestyle, age, and years working in shifts and, shift work and being overweight. METHODS: Cross-sectional data were used of 2569 shift and 4848 non-shift production workers who participated between 2013 and 2018 in an occupational health check. Overweight (BMI ≥ 25 kg/m2) was calculated using measured weight and height; lifestyle was assessed by questionnaires. Multiple-adjusted logistic regression with interaction terms between shift work and potential moderators assessed multiplicative interaction; the relative excess risk due to interaction assessed additive interaction (synergism). RESULTS: Shift work was significantly related to being overweight (OR 1.53, 95% CI 1.33 1.76). The strength of this association did not differ by level of sleep quality, fruit and vegetable intake, and physical activity (p ≥ 0.05). Additive and multiplicative interaction by smoking status was present (p < 0.01), with a stronger relationship between shift work and being overweight among non-smokers compared to smokers. Older age as well as more years of exposure to shift work were, independently from each other, related to a stronger relationship between shift work and being overweight (multiplicative interaction p < 0.05). CONCLUSION: Shift work was to a similar extent related to being overweight among those with a healthy and unhealthy lifestyle. This does, however, not imply that shift workers can behave unhealthy without any harm. Based on the evident health benefits of a healthy lifestyle, it is still recommended to get sufficient quality of sleep and to meet the recommended level of daily physical activity and, fruit and vegetable intake.

Shift Work and Respiratory Infections in Health-Care Workers.

Recently, there has been interest in whether shift work may enhance susceptibility to infection. Our aim was to determine whether shift workers in the health-care field have a higher incidence, duration, and/or severity of influenza-like illness (ILI) and acute respiratory infection (ARI) than non-shift workers. From September 2016 to June 2017, 501 rotating and/or night-shift workers and 88 non-shift workers from the Klokwerk+ Study (the Netherlands, 2016-2017) registered the occurrence of ILI/ARI symptoms daily using a smartphone application. The incidence rate of ILI/ARI (defined as ≥2 symptoms on the same day/≥1 symptom on 2 consecutive days), the mean duration of each episode, and the incidence rate of severe episodes were compared between shift workers and non-shift workers using negative binomial regression and linear mixed-model analysis. In total, participants completed 110,347 diaries. Shift workers' incidence rate of ILI/ARI was 1.20 (95% confidence interval (CI): 1.01, 1.43) times higher than that of non-shift workers, and for severe ILI/ARI episodes, shift workers' incidence rate was 1.22 (95% CI: 1.01, 1.49) times higher. The mean duration of an ILI/ARI episode did not differ (ratio between means = 1.02, 95% CI: 0.87, 1.19). In conclusion, shift workers in health care had more ILI/ARI episodes and more severe ILI/ARI episodes than non-shift workers, but with a similar duration. Insight into underlying mechanisms connecting shift work and infection susceptibility will contribute to the design of preventive initiatives.

Shift work, sleep disturbances and social jetlag in healthcare workers.

The aim of this study was to compare chronotype- and age-dependent sleep disturbances and social jetlag between rotating shift workers and non-shift workers, and between different types of shifts. In the Klokwerk+ cohort study, we included 120 rotating shift workers and 74 non-shift workers who were recruited from six Dutch hospitals. Participants wore Actigraph GT3X accelerometers for 24 hr for 7 days. From the Actigraph data, we predicted the sleep duration and social jetlag (measure of circadian misalignment). Mixed models and generalized estimation equations were used to compare the sleep parameters between shift and non-shift workers. Within shift workers, sleep on different shifts was compared with sleep on work-free days. Differences by chronotype and age were investigated using interaction terms. On workdays, shift workers had 3.5 times (95% confidence interval: 2.2-5.4) more often a short (< 7 hr per day) and 4.1 times (95% confidence interval: 2.5-6.8) more often a long (≥ 9 hr per day) sleep duration compared with non-shift workers. This increased odds ratio was present in morning chronotypes, but not in evening chronotypes (interaction p-value < .05). Older shift workers (≥ 50 years) had 7.3 times (95% confidence interval: 2.5-21.8) more often shorter sleep duration between night shifts compared with work-free days, while this was not the case in younger shift workers (< 50 years). Social jetlag due to night shifts increased with increasing age (interaction p-value < .05), but did not differ by chronotype (interaction p-value ≥ .05). In conclusion, shift workers, in particular older workers and morning chronotypes, experienced more sleep disturbances than non-shift workers. Future research should elucidate whether these sleep disturbances contribute to shift work-related health problems.

Physical workload and obesity have a synergistic effect on work ability among construction workers.

PURPOSE: Obesity and high physical workload are both associated with poor work ability, but the interaction between obesity and high physical workload on work ability is not yet fully understood. Obesity and high physical workload may share a common mechanical pathway, possibly leading to a synergistic negative effect on work ability. The purpose of this study was to investigate the effect of obesity on work ability in workers with high versus low physical work load. METHODS: A longitudinal study was conducted among 36,435 Dutch construction workers who participated in at least two periodic medical examinations during the years 2008-2015. Logistic regression analyses were used to investigate the effect of manual material handling and strenuous work postures in sports on the association between obesity and work ability. Work ability was measured using the self-reported Work Ability Index consisting of seven dimensions. Confounding effects were tested for age, educational level, smoking, vigorous physical activity, psychosocial work demands, and working hours. Additive interaction between obesity and physical workload on work ability was tested using the relative excess risk due to interaction (RERI). RESULTS: Construction workers with overweight (OR = 1.09; 95% CI 1.02-1.16) or obesity (OR = 1.27; 95% CI 1.17-1.38) had an increased risk of poor/moderate work ability. Exposure to manual material handling (OR = 1.58; 95% CI 1.49-1.68) or strenuous work postures (OR = 1.80; 95% CI 1.70-1.90) also increased the risk of poor/moderate work ability. The effect of the combination of obesity with high physical workload was greater than the sum of the individual effects (strenuous work postures: RERI = 0.39; 95% CI 0.10-0.67; manual material handling: RERI = 0.26; 95% CI 0.02-0.51). CONCLUSIONS: Obesity and high physical workload were associated with poor work ability and had a synergistic, negative effect on work ability. Interventions that prevent obesity and high physical workload might have a beneficial effect on work ability.

Shift work, chronotype and the risk of cardiometabolic risk factors.

Background: The relation between shift work and a large variety of cardiometabolic risk factors is unclear. Also, the role of chronotype is understudied. We examined relations between shift work and cardiometabolic risk factors, and explored these relations in different chronotypes. Methods: Cardiometabolic risk factors (anthropometry, blood pressure, lipids, diabetes, γ-glutamyltransferase, C-reactive protein, uric acid and estimated glomerular filtration rate) were assessed among 1334 adults in 1987-91, with repeated measurements every 5 years. Using shift work history data collected in 2013-15, we identified shift work status 1 year prior to all six waves. Linear mixed models and logistic generalized estimating equations were used to estimate the longitudinal relations between shift work and risk factors 1 year later. Results: Shift work was not significantly related with cardiometabolic risk factors (P ≥ 0.05), except for overweight/body mass index. Shift workers had more often overweight (OR: 1.44, 95% CI 1.06-1.95) and a higher body mass index (BMI) (ß: 0.56 kg m-2, 95% CI 0.10-1.03) than day workers. A significant difference in BMI between day and shift workers was observed among evening chronotypes (ß: 0.97 kg m-2, 95% CI 0.21-1.73), but not among morning chronotypes (ß: 0.04 kg m-2, 95% CI -0.85 to 0.93). No differences by frequency of night shifts and duration of shift work were observed. Conclusion: Shift workers did not have an increased risk of cardiometabolic risk factors compared with day workers, but, in particular shift working evening chronotypes, had an increased risk of overweight. More research is needed to verify our results, and establish whether tailored interventions by chronotype are wanted.

Influence of obesity and physical workload on disability benefits among construction workers followed up for 37 years.

OBJECTIVES: The objectives of this study are to investigate the relation between obesity and labour force exit via diagnosis-specific disability benefits, and whether physical workload modifies this association. METHODS: A longitudinal analysis was performed among 3 28 743 Swedish construction workers in the age of 15-65 years. Body weight and height were measured at a health examination and enriched with register information on disability benefits up to 37 years later. Diagnoses of disability benefits were categorised into cardiovascular diseases (CVDs), musculoskeletal diseases (MSDs), mental disorders and others. A job exposure matrix, based on self-reported lifting of heavy loads and working in bent forward or twisted position, was applied as a measure of physical workload. Cox proportional hazards regression analyses were performed, and the relative excess risk due to interaction (RERI) between obesity and physical workload was calculated. RESULTS: Obese construction workers were at increased risk of receiving disability benefits (HR 1.70, 95% CI 1.65 to 2.76), mainly through CVD (HR 2.30) and MSD (HR 1.71). Construction workers with a high physical workload were also more likely to receive a disability benefit (HR 2.28, 95% CI 2.21 to 2.34), particularly via MSD (HR 3.02). Obesity in combination with a higher physical workload increased the risk of disability benefits (RERI 0.28) more than the sum of the risks of obesity and higher physical workload, particularly for MSD (RERI 0.44). CONCLUSIONS: Obesity and a high physical workload are risk factors for disability benefit. Furthermore, these factors are synergistic risk factors for labour force exit via disability benefit through MSD. Comprehensive programmes that target health promotion to prevent obesity and ergonomic interventions to reduce physical workload are important to facilitate sustained employment.

Non-occupational physical activity levels of shift workers compared with non-shift workers.

OBJECTIVES: Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure-response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. METHODS: Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. RESULTS: Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1-4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure-response relationships were found between years of shift work and PA levels. CONCLUSIONS: Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies.

Klokwerk + study protocol: An observational study to the effects of night-shift work on body weight and infection susceptibility and the mechanisms underlying these health effects.

BACKGROUND: Night-shift work may cause severe disturbances in the worker's circadian rhythm, which has been associated with the onset of health problems and diseases. As a substantial part of the workforce is exposed to night-shift work, harmful aspects of night-shift work should not be overlooked. The aim of the Klokwerk + study is to study the effects of night-shift work on body weight and infection susceptibility and the mechanisms underlying these health effects. First, we will study the relation between night-shift work exposure and body weight and between night-shift work exposure and infection susceptibility. Second, we will examine the mechanisms linking night-shift work exposure to body weight and infection susceptibility, with a specific focus on sleep, physical activity, diet, light exposure, vitamin D level, and immunological factors. Lastly, we will focus on the identification of biomarkers for chronic circadian disturbance associated with night-shift work. METHODS/DESIGN: The design of this study is a prospective observational cohort study consisting of 1,960 health care workers aged 18-65 years. The study population will consist of a group of night-shift workers and an equally sized group of non-night-shift workers. During the study, there will be two measurement periods. As one of the main outcomes of this study is infection susceptibility, the measurement periods will take place at approximately the first (September/October) (T0) and the last month (April/May) (T1, after 6 months) of the flu season. The measurements will consist of questionnaires, anthropometric measurements, a smartphone application to determine infection susceptibility, food diaries, actigraphy, light sensors, and blood sample analyses. DISCUSSION: The Klokwerk + study will contribute to the current need for high-quality data on the health effects of night-shift work and its underlying behavioral and physiological mechanisms. The findings can be the starting point for the development of interventions that prevent negative health effects caused by night-shift work. In addition, the identification of biomarkers indicative of loss of homeostasis due to circadian disturbance may be an important asset in monitoring the effects of such interventions.

The prevalence of implementation of mental health measures in companies and its association with sickness absence.

OBJECTIVE: The main objective was to determine the prevalence of implementation of mental health measures aimed at the prevention of high workload (workload measures) and the promotion of work engagement (engagement measures) in companies and sectors. Additionally, its associations with sickness absence was explored. STUDY DESIGN: Cross-sectional survey. METHODS: An internet-based survey among 12,894 company representatives in the Netherlands. Descriptive analyses were performed to determine the prevalence, and differences between sectors were tested using Chi-squared tests. ANOVA was performed to examine the association between companies with or without mental health measures and sickness absence rates. RESULTS: 32.8% and 21.7% of the companies reported to have implemented 'continuously or often' workload measures and engagement measures, respectively. The sectors 'health care and welfare' and 'education' reported to have implemented measures most often. Having implemented engagement measures was significantly associated with lower sickness absence (4.1% vs 4.5%). CONCLUSIONS: Overall, workload measures were more often implemented than engagement measures. Future research is recommended to determine reasons for implementation as well as causality in the association between mental health measures and sickness absence.

Psychological distress as a determinant of changes in body mass index over a period of 10years.

OBJECTIVE: To examine the longitudinal relationship between psychological distress and body mass index (BMI) changes over a period of five and ten years. METHOD: Data were used from the Dutch, prospective, population based Doetinchem Cohort study over the period 1995/1999 until 2005/2009 (N=5504). Psychological distress was assessed using the Mental Health Inventory (MHI-5). BMI (kg/m(2)) was calculated from measured body height and body weight. GEE analyses were used to examine the relationship between psychological distress at baseline and BMI change, and the development of overweight over five years. Linear and logistic regression analyses were used to examine these relations over ten years. RESULTS: Psychological distress predicted an extra overall increase in BMI of 0.14kg/m(2) (95% CI 0.03-0.25) over five years and an increase of 0.18kg/m(2) (95% CI 0.01-0.35) over ten years, when comparing psychologically distressed participants to psychologically healthy participants. This was especially the case among persons with normal weight (five years; B=0.26kg/m(2), 95% CI=0.12-0.40/ten years; B=0.32kg/m(2) 95% CI=0.11-0.53) and moderate overweight (five years: B=0.18kg/m(2), 95% CI=0.02-0.35) at baseline. Psychological distress did not predict the development of overweight five and ten years later. CONCLUSION: The results in this study indicated that psychological distress predicted an increased risk in gaining weight, but did not result in an increased risk for developing overweight.

The effectiveness of interventions for ageing workers on (early) retirement, work ability and productivity: a systematic review.

PURPOSE: To systematically summarise the literature on the effects of interventions for ageing workers that address work-related measures of sustainable employability, i.e. (early) retirement, work ability and work productivity. METHODS: A systematic review was performed by searching five electronic databases for relevant studies published between January 1992 and February 2014. Randomised controlled trials (RCTs) and quasi-experimental intervention studies were included. The study population included workers aged ≥40 years, and the measured outcomes were positive indicators of labour force participation, i.e. (early) retirement, work ability and work productivity. The methodological quality of each included study was assessed, and best-evidence synthesis was applied to draw conclusions about the evidence for the effectiveness of each outcome. RESULTS: Four studies met the inclusion criteria. The interventions were diverse and ranged from individual (e.g. exercise) programmes to workplace programmes. Limited evidence for a favourable effect on early retirement was found. Insufficient evidence was found for the remaining outcomes, i.e. work ability and productivity, due to a lack of high-quality studies and consistent findings. CONCLUSIONS: Insufficient and limited evidence is available for a favourable effect of interventions to promote work-related components of sustainable employability in ageing workers. This is due to a scarcity of RCTs and inconsistent findings between the limited number of studies. Additional intervention studies are needed to support evidence-based decision making to prolong a healthy and productive working life for ageing workers.