Are the Quality of Organizational Changes Associated with Expected Retirement-Age Among Senior Employees?

OBJECTIVE: Major organizational changes may be associated with both positive and negative uncertainty in working life. This study described the prevalence of organizational changes (reorganizations or round of layoffs) within different job functions in Denmark and investigated whether quality of the implementation process (measured as "information", "involvement" and "consent") was associated with employees' expectations regarding retirement age. METHODS: A representative sample of older Danish employees ≥ 50 years (n = 12,269) replied to a questionnaire survey in 2020. In cross-sectional analyses, we compared employee's expected retirement age being either not exposed to organizational changes or exposed to implementation processes of high, moderate or low-quality, respectively. Analyses were further stratified for job function: office work, work with people and work in the field of production. RESULTS: More than half (56%) of the employees had experienced organizational changes within the past 2 years, and 23% of those effected reported that the changes had led to considerations of earlier retirement. Organizational changes were most prevalent within office work, and least prevalent within the job function working with people. The analyses showed significantly lower expected retirement age when the implementation process had been of moderate (mean reduction of 0.45 years) or low quality (mean reduction of 0.71 years) compared to high quality implemented changes. CONCLUSIONS: Experiences of organizational change processes of moderate or poor quality were associated with expectations of earlier retirement, while well implemented changes were not. This study underscores the importance of good implementation when changes at the organizational level are needed.

Expected reasons for leaving the labour market and loss of paid employment among older workers: prospective cohort study.

BACKGROUND: Surveying expected reasons for retirement may be a useful strategy to maintain labor market affiliation. The aim was to investigate the prospective association between self-reported expected reasons for leaving the labour market and subsequent loss of paid employment before the state pension age among older workers. METHODS: The prospective risk of loss of paid employment before the official state pension age was estimated from expected reasons for leaving the labour market among 10,320 currently employed older workers (50-63 years) from the SeniorWorkingLife study. In 2018, participants replied to 15 randomly ordered questions about expected reasons for leaving the labour market and were in 2020 followed in a national register containing information on labour market participation. RESULTS: Loss of paid employment before state pension age was predicted by expected reasons related to 'Health, work demands and occupational well-being': 'Poor physical health' (RR 1.47, 95% CI 1.45-1.49), 'Poor mental health' (RR 1.36, 95% CI 1.32-1.40), 'Not being capable of doing the job' (RR 1.20, 95% CI 1.18-1.22), and 'Not thriving at the workplace' (RR 1.14, 95% CI 1.11-1.17). Expected reasons related to the possibility of receiving voluntary early retirement benefits also increased this risk. Expected reasons related to 'Leisure' ('Wish for more self-determination'; 'Wish for more time for hobbies'), 'Economy' ('Economic considerations'; 'Possibility of receiving pension'), and 'Norms' ('Retirement norms'; 'To make space for younger employees') decreased the risk of loss of paid employment before state pension age. Age-stratified analyses revealed that expected reasons related to the domain of 'Health, work demands and occupational well-being' predicted risk of loss of paid employment to a greater extent among workers aged 50-55 compared to those aged 56-63. CONCLUSIONS: Expected reasons for leaving the labour market predicted actual labour market participation among older workers in Denmark. Expected reasons related to poor physical and mental health, and not being capable of doing the job seem to be stronger PUSH-factors among workers aged 50-55 compared to those aged 56-63. Preventing early labour market detachment should take the worker's expected reasons for leaving into account.

Long working hours and stroke among employees in the general workforce of Denmark.

AIMS: A systematic review and meta-analysis have found that long working hours were prospectively associated with an increased risk of overall stroke. The primary aim of the present study was to test if this finding could be reproduced in a sample that has been randomly selected from the general workforce of Denmark. A secondary aim was to estimate the association for haemorrhagic and ischaemic stroke separately. METHODS: Individual participant data on 20- to 64-year-old employees were drawn from the Danish Labour Force Survey, 1999-2013, and linked to data on socio-economic status (SES), migrations, hospitalisations and deaths from national registers. The participants were followed from the time of the interview until the end of 2014. Poisson regression was used to estimate age-, sex- and SES-adjusted rate ratios for stroke as a function of weekly working hours. RESULTS: With 35-40 working hours per week as reference, the estimated rate ratios for overall stroke were 0.97 (95% confidence interval (CI) 0.83-1.13) for 41-48 working hours, 1.10 (95% CI 0.86-1.39) for 49-54 working hours and 0.89 (95% CI 0.69-1.16) for ≥55 working hours. The estimated rate ratios per one category increase in working hours were 0.99 (95% CI 0.93-1.06) for overall stroke, 0.96 (95% CI 0.88-1.05) for ischaemic stroke and 1.15 (95% CI 1.02-1.31) for haemorrhagic stroke. CONCLUSIONS: Our analysis does not support the hypothesis that long working hours are associated with increased rates of overall stroke. It suggests, however, that long working hours might be associated with increased rates of haemorrhagic stroke.

Collaboration among eldercare workers: barriers, facilitators and supporting processes.

To retain qualified care workers and to ensure high-quality care for residents in eldercare homes, well-functioning collaboration among care workers is pivotal. This study aims to identify barriers and facilitators of collaboration among eldercare workers and to describe the processes leading to well-functioning collaboration. We collected focus group data from 33 eldercare workers from seven Danish eldercare homes. We found that collaboration was hampered by a number of formal and informal divisions among care workers. To ensure well-functioning collaboration, social and professional relations among care workers needed to be dealt with actively by care workers and by managers. The analysis showed that managers are essential for creating a well-functioning framework around the collaboration between care workers by providing guidelines and procedures for working across various divisions, by being attentive to care workers and taking decisive action when needed and by dealing with conflicts in the workgroups.

Work-life balance among shift workers: results from an intervention study about self-rostering.

PURPOSE: The aims of the study were to explore the effects of the implementation of IT-based tools for planning of rosters among shift workers on work-family-related outcomes and to interpret the results in light of the different implementation processes. METHODS: A quasi-experimental intervention study was conducted with 12-month follow-up at 14 intervention and 14 reference worksites in Denmark. Workplaces planning to introduce IT-supported self-rostering were recruited, and three different kinds of interventions were implemented. Intervention A and B aimed at increasing workers satisfaction and well-being, while intervention C was designed to optimize the personnel resources. Questionnaire data were collected from 840 employees at baseline and 784 at follow-up. Process evaluation encompassed interviews with about 25 employees and 15 managers at baseline and follow-up. Work-family-related outcomes were work-life conflicts, work-life facilitation, marital conflicts and time with children. RESULTS: An overall decline in work-family conflicts and increase in work-family facilitation were found in the total intervention group. More specifically, in group B, work-family conflicts and marital conflicts decreased while work-family facilitation increased. In group C, work-family conflicts increased while work-family facilitation and time spend with children decreased, and no significant changes were observed in the reference group and in group A. CONCLUSION: An overall positive effect of the implementation of self-rostering was found on the balance between work and private life. However, results from the process evaluation suggested that the organizational aim with the intervention was crucial for the effect.

How do employees prioritise when they schedule their own shifts?

We investigated how employees prioritised when they scheduled their own shifts and whether priorities depended on age, gender, educational level, cohabitation and health status. We used cross-sectional questionnaire data from the follow-up survey of an intervention study investigating the effect of self-scheduling (n = 317). Intervention group participants were asked about their priorities when scheduling their own shifts succeeded by 17 items covering family/private life, economy, job content, health and sleep. At least half of the participants reported that they were giving high priority to their family life, having consecutive time off, leisure-time activities, rest between shifts, sleep, regularity of their everyday life, health and that the work schedule balanced. Thus, employees consider both their own and the workplace's needs when they have the opportunity to schedule their own shifts. Age, gender, cohabitation and health status were all significantly associated with at least one of these priorities. PRACTITIONER SUMMARY: Intervention studies report limited health effects of self-scheduling. Therefore, we investigated to what extent employees prioritise their health and recuperation when scheduling their own shifts. We found that employees not only consider both their health and family but also the workplace's needs when they schedule their own shifts.

Deadlines at work and sleep quality. Cross-sectional and longitudinal findings among Danish knowledge workers.

BACKGROUND: Exposure to deadlines at work is increasing in several countries and may affect health. We aimed to investigate cross-sectional and longitudinal associations between frequency of difficult deadlines at work and sleep quality. METHODS: Study participants were knowledge workers, drawn from a representative sample of Danish employees who responded to a baseline questionnaire in 2006 (n = 363) and a follow-up questionnaire in 2007 (n = 302). Frequency of difficult deadlines was measured by self-report and categorized into low, intermediate, and high. Sleep quality was measured with a Total Sleep Quality Score and two indexes (Awakening Index and Disturbed Sleep Index) derived from the Karolinska Sleep Questionnaire. Analyses on the association between frequency of deadlines and sleep quality scores were conducted with multiple linear regression models, adjusted for potential confounders. In addition, we used multiple logistic regression models to analyze whether frequency of deadlines at baseline predicted caseness of sleep problems at follow-up among participants free of sleep problems at baseline. RESULTS: Frequent deadlines were cross-sectionally and longitudinally associated with poorer sleep quality on all three sleep quality measures. Associations in the longitudinal analyses were greatly attenuated when we adjusted for baseline sleep quality. The logistic regression analyses showed that frequent deadlines at baseline were associated with elevated odds ratios for caseness of sleep problems at follow-up, however, confidence intervals were wide in these analyses. CONCLUSIONS: Frequent deadlines at work were associated with poorer sleep quality among Danish knowledge workers. We recommend investigating the relation between deadlines and health endpoints in large-scale epidemiologic studies.

The relationship between performance-based self-esteem and self-reported work and health behaviors among Danish knowledge workers.

Since knowledge intensive work often requires self-management, one might fear that persons who are dependent on work success for self-esteem will have difficulties in finding a healthful and sustainable balance between internal needs and external demands. Accordingly, we examined to what degree work-related performance-based self-esteem (PBS) was linked to work and health behaviors in 392 knowledge workers (226 women, 166 men). In the women group, multiple binary logistic regression analyses with repeated measurements showed that the PBS score was associated with 10 of the 17 examined work and health behaviors. For men the corresponding figure was 3 of 17. In both men and women, higher PBS scores were positively associated with reports of efforts and strivings for work as well as attending work while ill. In conclusion, statistically significant relationships between PBS and work and health behaviors were more clearly visible among women than men. Whether this gender difference is dependent on the study design, or on true inherent differences between women and men, cannot be concluded with any certainty. However, persons who described themselves as being relatively more dependent on work accomplishments for a high self-esteem, as expressed by the PBS score, seem to display work behaviors that may lessen their restitution time. In addition, they also seem to be more prone to work while sick.

Mediating the effects of work-life conflict between transformational leadership and health-care workers' job satisfaction and psychological wellbeing.

AIM: To explore the mediating effects of work-life conflict between transformational leadership and job satisfaction and psychological wellbeing. BACKGROUND: The importance of work-life balance for job satisfaction and wellbeing among health-care employees is well-recognized. Evidence shows that transformational leadership style is linked to psychological wellbeing. It is possible that transformational leadership is also associated with employees' perceptions of work-life conflict, thereby influencing their job satisfaction and wellbeing. METHODS: A longitudinal design was used where staff working within Danish elderly care completed a questionnaire at baseline and 18-month follow-up (N=188). RESULTS: Regression analyses showed that transformational leadership style was directly associated with perceptions of work-life conflict, job satisfaction and psychological wellbeing. Work-life conflict mediated between transformational leadership and wellbeing, but not job satisfaction. CONCLUSION: The findings suggest transformational leadership style may improve perceptions of work-life balance and employee wellbeing. IMPLICATIONS FOR NURSING MANAGEMENT: Managers should adopt transformational leadership styles to reduce work-life conflict and enhance the wellbeing of their staff.

Night-shift work and psychiatric treatment. A follow-up study among employees in Denmark.

OBJECTIVES: We aimed to test the hypotheses that night-shift work is associated with an increased incidence of (i) redeemed prescriptions for psychotropic medicine and (ii) psychiatric hospital treatment due to mood, anxiety or stress-related disease. Moreover, we aimed to assess whether (iii) the effect of night-shift work on the rates of antidepressants differs from the effects on the rates of anxiolytics and (iv) the association between night-shift work and psychotropic medicine is affected by long working hours. METHODS: Full-time employees who participated in the Danish Labor Force Survey sometime in the period 2000-2013 (N=131 321) were followed for up to five years in national registers for redeemed prescriptions and psychiatric hospital treatment. The analyses were controlled for sex, age, weekly working hours, calendar time of the interview and socioeconomic status. RESULTS: We detected 15 826 cases of psychotropic drug use in 521 976 person-years at risk and 1480 cases of hospitalization in 636 673 person-years at risk. The rate ratio (RR) for psychotropic drugs was estimated to be 1.09 [99% confidence interval (CI) 1.02-1.16] for night-shift versus no night-shift work. The corresponding RR for psychiatric hospital treatment was 1.11 (95% CI 0.95-1.29). The odds of redeeming a prescription for antidepressants rather than anxiolytics was independent of night-shift work: 1.09 (95% CI 0.96-1.24), and we found no interaction effect between night-shift work and working hours (P=0.26). CONCLUSION: As it appears in the general working population in Denmark, night-shift work is not an important predictor of mental ill health.

New Technology and Loss of Paid Employment among Older Workers: Prospective Cohort Study.

BACKGROUND: This study investigates the association between the implementation of new technology in the workplace and the subsequent loss of paid employment among older workers. METHODS: We estimated the prospective risk of loss of paid employment (register-based) from questions on new technology among 10,320 older workers (≥50 years). To investigate potential differences between work types, analyses were stratified by job function: (1) work with symbols (office, administration, analysis, IT), (2) work with people (people, service, care), (3) work in the field of production (processing, producing or moving things). RESULTS: The introduction of new technology at the workplace reduced the risk of losing paid employment among older workers working with symbols (risk ratio [RR] 0.74, 95% CI 0.72-0.76) and in the field of production (RR 0.83, 95% CI 0.80-0.85), whereas new technology increased this risk among those working with people (RR 1.22, 95% CI 1.19-1.26). Being involved in the introduction of new technology and receiving adequate training in its use decreased the risk of loss of paid employment. CONCLUSIONS: Depending on the context, the introduction of new technology at work associates positively as well as negatively with future labour market participation among older workers. Worker involvement and adequate training in the use of new technology seem to be important for retaining workers in the labour market.

Do lifestyle factors and general health predict dropout among recently qualified eldercare workers? A two-year follow-up study.

BACKGROUND: The eldercare sector in Denmark as in many industrialised countries is characterised by difficulties in retaining labour. Research suggests a possible imbalance between lifestyle and health among eldercare trainees and the demanding work encountered as eldercare employees. The aim of the present study was to determine the predictive effect of lifestyle and self-rated health on dropout from the Danish eldercare sector two years after qualification. METHODS: We included 4,526 female eldercare trainees in the analyses of lifestyle parameters and 5,023 in the analyses of self-rated health. The participants in this prospective study were recruited from 27 of the 28 Danish colleges for eldercare. We linked survey data with national register data to obtain information about labour market attachment two years after qualification. RESULTS: The results of the present study showed that the poorer self-rated health, the higher the risk for dropout from the labour market (p < 0.0001). However, the results were less consistent regarding the predictive effect of a detrimental lifestyle. We found that overweight/obesity (p = 0.0021 and p = 0.0012) as well as smoking (p = 0.0017) decreased the risk of dropout from eldercare into education. We found no support for increased likelihood of dropout among physically inactive. CONCLUSIONS: The results of the present study show that a poorer self-rated health is a predictor for dropout, not only from the eldercare two years after qualification, but from the labour market as a whole. However, the results were less consistent regarding the predictive effect of a detrimental lifestyle on dropout.

The moderating effect of work-time influence on the effect of shift work: a prospective cohort study.

OBJECTIVES: To investigate whether work-time influence moderated the effect of shift work on psychological well-being measured as vitality, mental health, somatic stress symptoms, and disturbed sleep. METHODS: We used questionnaire data from 2,148 health care workers who finished their education in 2004 and were followed during their first 2 years of employment in the eldercare and health care sectors. We analyzed the effect of shift work, work-time influence, and the combination of these two variables adjusted for differences in baseline psychological well-being, background factors, and psychosocial work environment. RESULTS: Surprisingly, in this cohort, shift workers had higher vitality and better mental health than day workers. The combination of shift work and moderate or low work-time influence was associated with lower vitality, worse mental health, and more somatic stress symptoms than would have been expected when adding the separate effects of working hours and work-time influence. Work-time influence did not have any effect among day workers. CONCLUSION: Shift workers appear to be especially vulnerable to the negative effect of moderate or low work-time influence.

Bi-directional associations between psychological arousal, cortisol, and sleep.

The aim was to elucidate the possible bi-directional relation between daytime psychological arousal, cortisol, and self-reported sleep in a group of healthy employees in active employment. Logbook ratings of sleep (Karolinska Sleep Questionnaire), stress, and energy, as well as positive and negative experiences in work and private life, were collected together with salivary cortisol over 3 days (n = 265). Higher bedtime ratings of stress and problems during the day were associated with morning ratings of poor sleep. Poorer morning ratings of sleep were associated with higher ratings of stress and problems during the day. The results underpin the possibility that arousal and poor sleep might create a self-reinforcing vicious circle that negatively affects a person's well-being.

Does collective efficacy moderate the associations between physical work load and intention to leave or sickness absence?

AIM: This paper is a report of a study, which examines the moderating effect of collective efficacy on the associations between physical workload, intention to leave and sickness absence. BACKGROUND: The positive association between physical workload and both intention to leave and sickness absence in the healthcare sector is well-established. However, knowledge is limited with respect to how social contextual factors such as collective efficacy moderate these associations. METHODS: A questionnaire was distributed over a 4-month period in 2006/2007 to all employees at elderly care centres in 35 Danish municipalities who were asked to rate their groups' collective efficacy. The final sample consisted of 6929 female employees from 290 work groups. Employees were predominantly healthcare helpers and assistants, but also nurses and other healthcare professionals participated in the study. Information on collective efficacy was aggregated to work group level. RESULTS: Collective efficacy moderated the association between physical workload and intention to leave, i.e. employees with high levels of physical workload had lower intention to leave if they worked in a group with high levels of collective efficacy and higher intention to leave if they worked in a group with low levels of collective efficacy. No moderating effect of collective efficacy on the association between physical workload and sickness absence was found. CONCLUSION: Our findings suggest that enhancing the sense of collective efficacy might be a mean for organizations and managers to reduce intention to leave, but further research is needed.

Long working hours and psychiatric treatment: A Danish follow-up study.

Objective This study aimed to estimate prospective associations between long working hours and (i) redeemed prescriptions for psychotropic drugs and (ii) psychiatric hospital treatment due to mood, anxiety or stress-related disease, among full-time employees in Denmark. Methods Full-time employees who participated in the Danish Labor Force Survey sometime in the period 2000-2013 (N=131 321] were followed for up to five years in national registers for redeemed prescriptions for psychotropic drugs and psychiatric hospital treatment due to mood, anxiety or stress-related disease. Rate ratios (RR) were estimated for 41-48 versus 32-40 and >48 versus 32-40 working hours a week. The analyses were controlled for sex, age, night shift work, calendar time of the interview and socioeconomic status (SES). Prevalent cases were excluded in primary analyses. Results The RR for psychotropic drugs were estimated at 0.94 [99% confidence interval (CI) 0.88-1.01] for 41-48 versus 32-40 working hours a week and 1.08 (99% CI 0.99-1.18) for >48 versus 32-40 working hours a week. The corresponding RR for psychiatric hospital treatments were estimated at 0.90 (95% CI 0.75-1.08) and 0.96 (95% CI 0.76-1.21). We did not find any statistically significant interaction between weekly working hours and age, sex, SES or night shift work. Conclusion Long working hours as they occur in in the general working population of Denmark are not an important predictor of mental ill health.

Do dimensions from the Copenhagen Psychosocial Questionnaire predict vitality and mental health over and above the job strain and effort-reward imbalance models?

AIMS: The Copenhagen Psychosocial Questionnaire (COPSOQ) comprises dimensions (emotional demands, demands of hiding emotions, meaning of work, quality of leadership, and predictability) that are not in the job strain or the effort-reward imbalance (ERI) models. The study aim was to investigate whether these dimensions explain changes in vitality and mental health over and above the job strain and ERI models. METHODS: A cohort of 3552 employees in 2000 were followed up in 2005 (cohort participation of 51%). Regression analyses were carried out with mental health and vitality as dependent variables. A significance level of 0.01 was applied when comparing regression models. RESULTS: Regarding mental health, both the full COPSOQ-ERI model (p = 0.005) and the full job strain-COPSOQ model (p = 0.01) were significantly better than the ERI and the job strain models. Regarding vitality, none of the full COPSOQ models (i.e. with new COPSOQ dimensions together with job strain or ERI respectively) was significantly better than the ERI (p = 0.03) or the job strain (p = 0.04) models. Emotional demands and low meaning of work predicted poor mental health and low vitality. CONCLUSIONS: In relation to mental health, new psychosocial risk factors have the potential to add to the predictive power of the job strain and ERI models. The current practice of including only items from the ERI and job strain models in public health studies should be reconsidered. Theories regarding the status of, for example, emotional demands and meaning of work should be developed and tested.

The effect of the work environment and performance-based self-esteem on cognitive stress symptoms among Danish knowledge workers.

AIMS: Interpersonal relations at work as well as individual factors seem to play prominent roles in the modern labour market, and arguably also for the change in stress symptoms. The aim was to examine whether exposures in the psychosocial work environment predicted symptoms of cognitive stress in a sample of Danish knowledge workers (i.e. employees working with sign, communication or exchange of knowledge) and whether performance-based self-esteem had a main effect, over and above the work environmental factors. METHODS: 349 knowledge workers, selected from a national, representative cohort study, were followed up with two data collections, 12 months apart. We used data on psychosocial work environment factors and cognitive stress symptoms measured with the Copenhagen Psychosocial Questionnaire (COPSOQ), and a measurement of performance-based self-esteem. Effects on cognitive stress symptoms were analyzed with a GLM procedure with and without adjustment for baseline level. RESULTS: Measures at baseline of quantitative demands, role conflicts, lack of role clarity, recognition, predictability, influence and social support from management were positively associated with cognitive stress symptoms 12 months later. After adjustment for baseline level of cognitive stress symptoms, follow-up level was only predicted by lack of predictability. Performance-based self-esteem was prospectively associated with cognitive stress symptoms and had an independent effect above the psychosocial work environment factors on the level of and changes in cognitive stress symptoms. CONCLUSIONS: The results suggest that both work environmental and individual characteristics should be taken into account in order to capture sources of stress in modern working life.

Shift work and use of psychotropic medicine: a follow-up study with register linkage.

Objective This study aimed to investigate a prospective association between shift work and use of psychotropic medicine. Methods Survey data from random samples of the general working population of Denmark (N=19 259) were linked to data from national registers. Poisson regression was used for analyses of prospective associations between shift work and redeemed prescriptions of psychotropic medicine. Prevalent cases were excluded at baseline. In secondary analyses, we tested differential effects on subsets of psychotropic medicine and, cross-sectionally, we studied correspondence between estimates based on psychotropic medicine and self-reported mental health. According to the protocol we interpret results from the secondary analyses following the principles for nested hypothesis testing, if the primary analyses reject the null-hypothesis, and otherwise we regard it as hypothesis generating exploratory analyses. Results In the primary analysis, the rate ratio for incidence of psychotropic medicine among shift workers was 1.09 (95% confidence interval 0.99-1.21). Results from the secondary analyses suggested increased incidence of use of hypnotics, sedatives and antidepressants and decreased incidence of use of anxiolytics. Cross-sectional analysis suggested increased risk for use of psychotropic medicine (all kinds), but not for poor self-rated mental health. Conclusions Results did not support that working in shifts to the extent that is currently practiced in Denmark is associated with an increased incidence of overall psychotropic medicine use. Future studies should test, whether there is a differential incidence for different drugs among shift workers as suggested by the secondary analyses and how psychotropic medicine use and mental health are related.

Prospective Associations Between Working Time Arrangements and Psychiatric Treatment in Denmark: Protocol for a Cohort Study.

BACKGROUND: The burden of mental ill health in working-age populations has prompted research on possible links between work-related factors and mental ill health. Long working hours and night shift work are some of the factors that have been studied in relation to the risk of developing mental ill health. Yet, previous studies have not generated conclusive evidence, and further studies of high quality are needed. OBJECTIVE: This study aims to investigate the prospective association between working time arrangements and mental health in terms of psychotropic drug usage or psychiatric hospital treatment in the general working population of Denmark. METHODS: Data on total weekly working hours in any job and night shift work from the Danish Labor Force Survey 2000-2013 will be linked to data from the Psychiatric Central Research Register (expected 2400 cases during 700,000 person years at risk) and National Prescription Registry (expected 17,400 cases during 600,000 person years at risk). Participants will be followed for up to 5 years. We will use Poisson regression to separately analyze incidence rates of redeemed prescriptions for psychotropic medicine and incidence rates of psychiatric hospital treatment due to mood disorders, anxiety disorders, or stress-related disorders as a function of weekly working hours and night shift work. The analyses will be controlled for sex, age, calendar time of the interview, and socioeconomic status. RESULTS: This is a study protocol. Power calculations indicate that the study has sufficient statistical power to detect relatively small differences in risks and minor interactions (eg, ~90% power to detect a rate ratio of 1.1 for psychoactive medication use). We expect the analyses to be completed by the end of 2020 and the results to be published in 2021. CONCLUSIONS: In this study protocol, all hypotheses and statistical models of the project have been completely defined before we link the exposure data to the outcome data. The results of the project will indicate to what extent and in what direction the national burden of mental ill health in Denmark has been influenced by long working hours and night shift work. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/18236.