Published papers

Psychological detachment from work, an off-job experience of "switching off" mentally, seems to be crucial for promoting employee's well-being. Previous studies on predictors of psychological detachment mainly focused on job-related factors, and only a few studies focused on family-related and personal factors. This study focuses not only on job-related factors (job demands, job control, workplace support) but also on family-related (family/friend support) and personal factors (workaholism), and examines the relation of these three factors with psychological detachment. Data of 2,520 Japanese employees was randomly split into two groups and then analyzed using cross-validation. Hierarchical multiple regression analyses revealed that family/friend support had a positive association with psychological detachment, whereas a subscale of workaholism (i.e. working compulsively) had negative associations with it across the two groups. Results suggest that family/friend support would facilitate psychological detachment whereas workaholism would inhibit it. © 2014 National Institute of Occupational Safety and Health.

© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. Introduction Chronic inflammation may be a mediator for the development of cardiovascular disease (CVD), metabolic diseases and psychotic and neurodegenerative disorders. Meta-analytic associations between work-related psychosocial factors and inflammatory markers have shown that work-related psychosocial factors could affect the flexibility and balance of the immune system. However, few systematic reviews or meta-analyses have investigated the association between work-related psychosocial factors and inflammatory markers. Based on prospective studies, the present investigation will conduct a comprehensive systematic review and meta-analysis of the association between work-related psychosocial factors and inflammatory markers. Methods and analysis The systematic review and meta-analysis will include published studies identified from electronic databases (PubMed, EMBASE, PsycINFO, PsycARTICLES, Web of Science and Japan Medical Abstracts Society) according to recommendations of the Meta-analysis of Observational Studies in Epidemiology guideline. Inclusion criteria are studies that: Examined associations between work-related psychosocial factors and increased inflammatory markers; used longitudinal or prospective cohort designs; were conducted among workers; provided sufficient data for calculating ORs or relative risk with 95% CIs; were published as original articles in English or Japanese; and were published up to the end of 2017. Study selection, data extraction, quality assessment and statistical syntheses will be conducted by 14 investigators. Any inconsistencies or disagreements will be resolved through discussion. The quality of studies will be evaluated using the Risk of Bias Assessment Tool for Non-randomized Studies. Ethics and dissemination The investigation study will be based on published studies, so ethics approval is not required. The results of this study will be submitted for publication in a scientific peer-reviewed journal. The findings may be useful for assessing risk factors for increased inflammatory markers in the workplace and determining future approaches for preventing CVD, metabolic diseases and psychotic and neurodegenerative disorders. PROSPERO registration number CRD42018081553.

Recent epidemiologic research has shown that people with higher socioeconomic status (SES) (e.g., educational attainment) have better psychological health than those with lower SES. However, the psychosocial mechanisms of underlying this relationship remain unclear. To fill this gap, the current study examines the mediating effects of job demands and job resources in the relationship between educational attainment and psychological distress. The hypothesized model was tested using large data sets from two different studies: a cross-sectional study of 9,652 Japanese employees from 12 workplaces (Study 1), and a longitudinal study of 1,957 Japanese employees (Study 2). Structural equation modeling revealed that (1) educational attainment was positively related to psychological distress through job demands, (2) educational attainment was negatively related to psychological distress through job resources, and (3) educational attainment was not directly related to psychological distress. These results suggest that educational attainment has an indirect effect, rather than a direct one, on psychological distress among workers; educational attainment had both a positive and a negative relationship to psychological distress through job demands and job resources, respectively. © 2013 National Institute of Occupational Safety and Health.

© 2018 Japan Society for Occupational Health. Objectives: This retrospective cohort study evaluated the impact of the Stress Check Program, a recently introduced national policy and program aimed at reducing psychological distress among Japanese workers. Methods: A baseline survey was conducted from November 2015 to February 2016, the period when Japan began enforcing the Stress Check Program. A oneyear follow-up survey was conducted in December 2016. In the follow-up survey, two exposure variables were collected: having taken the annual stress survey, and experiencing an improvement in the psychosocial work environment. Psychological distress was assessed using the Brief Job Stress Questionnaire (BJSQ) at baseline and 1-year follow-up. The two exposure variables were used to define four groups: "Neither", "Stress survey (SS) only ", " Psychosocial work environment improvement (WI) only", and "Both". BJSQ results were analyzed using repeated measures general linear modeling (GLM). Results: The study included 2,492 participants: 1,342 in the "Neither" group, 1,009 in the "SS only" group, 76 in the "WI only" group, and 65 in the "Both" group. Overall time-group interaction effects were not significant. The "Both" group showed significantly greater improvements in psychological distress than the "Neither" group (p = 0.02) at the 1-year follow-up, although the effect size was small (d = -0.14). Conclusions: Combination of the annual stress survey and improvement in psychosocial work environment may have been effective in reducing psychological distress in workers, although the effect size was small.

Aim and Background The purpose of this study was to examine the effects of web-based assertion training programmes for Japanese hospital nurses based on their assertion knowledge, attitude and behaviour, job stress and depression. Job stress has been reported to be high among Japanese hospital nurses, and it is thought that assertion, one type of communication skill, could help nurses to better manage their job stress. Method Twenty-five nurses from an urban tertiary hospital in western Japan completed the 70-minute assertion programme during 3 weeks. The changes between pretraining and post-training and between pretraining and 1 month after the training were tested. Result Results showed that assertion knowledge and voluntary behaviour in assertive behaviour had increased at post-training and remained higher a month later. With regard to job stress, mental workload decreased. Conclusion The results show the effects of web-based assertion training on assertion skills and stress management for Japanese hospital nurses. © 2007 The Authors. Journal compilation 2007 Blackwell Publishing Ltd.

Objectives: To examine the effects of single-session, small-group stress management program on knowledge about stress, coping skills, and psychological and physical distress. Methods: A total of 300 employees from a company in western Japan were invited to participate in the study. Those who consented to enter the study were assigned to an intervention (n = 149) or waiting list control group (n = 151). Participants in the intervention group received a small-group stress management program. The program was primarily aimed at increasing knowledge about stress and improving coping skills. To investigate the intervention effect, change scores in outcome variables were calculated by subtracting the scores at pre-intervention from those at post-intervention (8 weeks after the pre-intervention survey). Next, the difference in the scores between groups was examined using analyses of covariance (ANCOVA) with the pre-intervention score as the covariate. Results: Favorable intervention effects were found on knowledge about stress and on coping skills (P<0.001 and P = 0.012, respectively) and adverse effects on psychological distress (P = 0.022). However, this adverse effect on psychological distress did not exist among those who initially perceived higher levels of job control. Conclusion: The single-session stress management program was effective on improving knowledge about stress, and coping skills, where job control moderated the effect of the program on psychological distress. © Springer-Verlag 2006.

© 2016 The Author(s). Background: Job crafting, an employee-initiated job design/redesign, has become important for employees' well-being such as work engagement. This study examined the effectiveness of a newly developed job crafting intervention program on work engagement (as primary outcome), as well as job crafting and psychological distress (as secondary outcomes), using a pretest-posttest study design among Japanese employees. Methods: Participants were managers of a private company and a private psychiatric hospital in Japan. The job crafting intervention program consisted of two 120-min sessions with a two-week interval between them. Outcomes were assessed at baseline (Time 1), post-intervention (Time 2), and a one-month follow-up (Time 3). The mixed growth model analyses were conducted using time (Time 1, Time 2, and Time 3) as an indicator of intervention effect. Effect sizes were calculated using Cohen's d. Results: The program showed a significant positive effect on work engagement (t = 2.20, p = 0.03) in the mixed growth model analyses, but with only small effect sizes (Cohen's d = 0.33 at Time 2 and 0.26 at Time 3). The program also significantly improved job crafting (t = 2.36, p = 0.02: Cohen's d = 0.36 at Time 2 and 0.47 at Time 3) and reduced psychological distress (t = -2.06, p = 0.04: Cohen's d = -0.15 at Time 2 and -0.31 at Time 3). Conclusions: The study indicated that the newly developed job crafting intervention program was effective in increasing work engagement, as well as in improving job crafting and decreasing psychological distress, among Japanese managers. Trial registration: UMIN Clinical Trials Registry UMIN000024062. Retrospectively registered 15 September 2016.

Objectives: The purpose of this study was to evaluate the effectiveness of a multi-component worksite stress management training (SMT) program among employees belong to Japanese steel company. Methods: Five workplaces were assigned to an intervention group and two workplaces to a control group. SMT with monthly 30-min sessions were provided to the intervention group for 6 mo. Intention- to-treat analyses were conducted among respondents of the intervention (n=96) and control groups (n=53). Results: Significant favorable intervention effects were found on knowledge (p<0.001) and marginally significant ones on professional efficacy (p=0.074) at one-month after completing the program. No significant intervention effects were observed on psychological distress, physical complaints, or job performance (p>0.05). However, in per-protocol analyses of those who attended all sessions, significant favorable effects were observed on psychological distress and job performance, as well as knowledge and professional efficacy (p<0.05). In addition, subgroup analyses revealed that those with initial low job control showed a favorable intervention effect only on knowledge (p<0.001), whereas those with initial high job control showed favorable intervention effects on knowledge (p<0.001), professional efficacy (p=0.023) and anxiety (p=0.033). Conclusions: The results suggest that the multi-component SMT program is effective at improving knowledge and professional efficacy, although job control appeared to moderate the effect of the program on professional efficacy. The program may also be effective at reducing psychological distress and increasing job performance, if participants complete all sessions.

Objective: The purpose of this study was to develop a new Internet-based computerized cognitive behavior therapy (iCBT) program in Manga format, the Japanese cartoon, for workers and to examine the effects of the iCBT program on improving subthreshold depression using a randomized controlled trial (RCT) design among workers employed in private companies in Japan. Method: All workers in a company (n = 290) and all workers in three departments (n = 1,500) at the headquarters of another large company were recruited by an invitation e-mail. Participants who fulfilled the inclusion criteria were randomly allocated to intervention or control groups (N = 381 for each group). A six-week, six-lesson iCBT program using Manga (Japanese comic) story was developed. The program included several CBT skills: self-monitoring, cognitive restructuring, assertiveness, problem solving, and relaxation. The intervention group studied the iCBT program at a frequency of one lesson per week. Depression (Beck Depression Inventory II; BDI-II) was assessed as a primary outcome at baseline, and threeand six-month follow-ups for both intervention and control groups were performed. Results: The iCBT program showed a significant intervention effect on BDI-II (t = -1.99, p<0.05) with small effect sizes (Cohen's d: -0.16, 95% Confidence Interval: -0.32 to 0.00, at six-month follow-up). Conclusions: The present study first demonstrated that a computerized cognitive behavior therapy delivered via the Internet was effective in improving depression in the general working population. It seems critical to improve program involvement of participants in order to enhance the effect size of an iCBT program. Trial Registration: UMIN Clinical Trials Registry UMIN000006210. © 2014 Imamura et al.

Copyright © 2015 by American College of Occupational and Environmental Medicine. Objective: This study reported a randomized controlled trial of the effectiveness of an Internet-based cognitive behavioral therapy (iCBT) program on work engagement and secondary work-related outcomes. Methods: Participants who fulfilled the inclusion criteria were randomly allocated to an intervention or a control group (N = 381 for each). A 6-week, 6-lesson iCBT program using a Manga (Japanese comic) story was provided only to the intervention group.Work engagement was assessed at baseline and at 3- and 6-month follow-ups for both groups. Results: The iCBT program showed a significant intervention effect on work engagement (P = 0.04) with small effect sizes (Cohen's d = 0.16 at 6-month follow-up). Conclusions: The study showed computerized cognitive behavior therapy delivered via the Internet to be effective (with a small effect size) in increasing work engagement in the general working population. Trial Registration: UMIN Clinical Trials Registry (UMIN-CTR) UMIN000006210.

© 2015, BMJ Publishing Group. All rights reserved. Introduction: The aim of this study is to examine the effects of an internet-based cognitive behavioural therapy (iCBT) program on decreasing the risk of major depressive episodes (MDEs) among workers employed in a private corporate group in Japan, using a randomised controlled trial design. Methods and analysis: All of the workers in a corporate group (n=20 000) will be recruited through an invitation email. Participants who fulfil the inclusion criteria will be randomly allocated to intervention or control groups ( planned N=4050 for each group). They will be allowed to complete the six lessons of the iCBT program within 10 weeks after the baseline survey. Those in the control group will receive the same iCBT after 12 months. The program includes several CBT skills: self-monitoring, cognitive restructuring, assertiveness, problem-solving and relaxation. The primary outcome measure is no new onset of MDE (using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR)/DSM-5 criteria) during the 12-month follow-up. Assessment will use the web version of the WHO Composite International Diagnostic Interview V.3.0 depression section. Ethics and dissemination: The Research Ethics Review Board of Graduate School of Medicine, the University of Tokyo (No. 3083-(2)), approved the study procedures. Trial registration number: The study protocol is registered at the UMIN Clinical Trials Registry (UMIN-CTR; ID=UMIN000014146).

© 2014 by National Institute of Occupational Safety and Health. This study evaluated the effectiveness of a computer-based stress management training (SMT) program in improving employees’ psychological well-being and work performance. A total of 12 work units (N=263) were randomly assigned to either an intervention group (8 work units, n=142) or to a wait-list control group (4 work units, n=121). All participants were requested to answer online questionnaires assessing psychological well-being as a primary outcome, and coping style, social support, and knowledge about stress management as secondary outcomes at baseline (T0), immediately after the intervention (T1), and 2 months after the intervention (T2). The group × time interaction was tested using a mixed-model repeated measures ANOVA. Results showed a group × time interaction for “knowledge about stress management” in the entire sample. Among participants who had more than 3 d of training, a significant group × time interaction was observed for “problem-solving” and “avoidance and suppression” as well as “knowledge about stress management.” Our computer-based stress management program was effective for improving knowledge about stress management. It was also effective for improving coping skills in instances where participants had enough time (at least 3 d) to complete all sessions.

© Springer International Publishing Switzerland 2016. Previous research has shown that cognitive behavioral therapy (CBT) is effective in reducing work-related stress, preventing the onset of major depressive episodes, and increasing positive mental health among workers. An innovative way to deliver CBT-based treatment widely is by using computerized CBT (CCBT) and CCBT via the internet (iCBT). In this part, we will review and introduce the recent iCBT studies, and discuss the possibility of utilization of iCBT program in workplace.

The aim of this study was to examine the effects of a stress management program for teachers on their stress responses, social support, and coping. Participants (n=24) were assigned to either an intervention or a waiting list control group. A five-session program, including psychoeducation, group discussion, role-playing and relaxation training, was conducted for the intervention group at two week intervals. Eight participants from each of the groups responded to pre- and post-intervention questionnaire surveys. The positive intervention effect was significant for social support from co-workers (p=0.035), whereas the negative intervention effect was significant for proactive coping (p=0.033). No significant effect was observed for stress responses (vigor, anger, fatigue, anxiety, depression, and somatic stress responses) (p>0.05). The positive intervention effect was marginally significant for social support from co-workers (p=0.085) and anger (p=0.057) among those who at first had high stress response scores in the pre-intervention survey (n=5 and n=4 for the intervention and waiting list control groups, respectively). Furthermore, the positive intervention effect was significant for social support from co-workers (p=0.021) and marginally significant for resignation coping (p=0.070) among those who at first had high job control scores (n=4 and n=5 for the intervention and waiting list control groups, respectively). Results showed that the stress management program conducted in this study contributed to increasing social support from co-workers. This study suggests that a program that focuses on a particular subgroup (e.g., those with high stress responses or high job control) might be effective in enhancing coping skills, increasing social support, and reducing stress responses.

The aim of this study was to examine the effects of a stress management program for teachers on their stress responses, social support, and coping. Participants (n=24) were assigned to either an intervention or a waiting list control group. A five-session program, including psychoeducation, group discussion, role-playing and relaxation training, was conducted for the intervention group at two week intervals. Eight participants from each of the groups responded to pre- and post-intervention questionnaire surveys. The positive intervention effect was significant for social support from co-workers (p=0.035), whereas the negative intervention effect was significant for proactive coping (p=0.033). No significant effect was observed for stress responses (vigor, anger, fatigue, anxiety, depression, and somatic stress responses) (p>0.05). The positive intervention effect was marginally significant for social support from co-workers (p=0.085) and anger (p=0.057) among those who at first had high stress response scores in the pre-intervention survey (n=5 and n=4 for the intervention and waiting list control groups, respectively). Furthermore, the positive intervention effect was significant for social support from co-workers (p=0.021) and marginally significant for resignation coping (p=0.070) among those who at first had high job control scores (n=4 and n=5 for the intervention and waiting list control groups, respectively). Results showed that the stress management program conducted in this study contributed to increasing social support from co-workers. This study suggests that a program that focuses on a particular subgroup (e.g., those with high stress responses or high job control) might be effective in enhancing coping skills, increasing social support, and reducing stress responses.

This study examined effects of web-based psychoeducation on self-efficacy, problem solving behavior, stress responses and job satisfaction. The program was based on social cognitive theory and was primarily aimed at increasing knowledge of stress, self-efficacy, and the use of problem solving behavior. A total of 225 employees were invited to participate in the study. Participants were assigned to an intervention (n=112) or waiting list control group (n=113). Those in the intervention group were asked to access the website and to complete learning within 1 month. To investigate the intervention effect, the change score in the outcome variable was calculated by subtracting the score at pre-intervention from that at post-intervention (1 week after completion of the learning period). Then, the difference in the scores between groups was examined using analyses of covariance (ANCOVA) with the pre-intervention score as the covariate. We detected a marginally significant difference between groups in changes in job satisfaction from pre- to post-intervention (p=0.081). Participants in the intervention group showed an increase in job satisfaction score, while those in the waiting list control group showed a decrease in it. No significant differences were detected between groups in the other indicators (p>.10). We detected significant or marginally significant intervention effects on self-efficacy, problem solving behavior, stress responses, and job satisfaction among males and younger individuals, and those who had initially higher job strain and higher interest in managing stress. Further research is required with longer time periods (controlled follow-up) and a broader sample to fully determine the intervention effect.

Objective: The purpose of this randomized, controlled trial was to examine the effects of a psychoeducational information website on improving work engagement among individual workers with low work engagement, where work engagement was measured as a secondary outcome. Methods: Participants were recruited from registered members of a web survey site in Japan. Participants who fulfilled the eligibility criteria were randomly allocated to intervention or control groups. Immediately after the baseline survey, the intervention group was invited to study a psychoeducational website called the "UTSMed," which provided general mental health literacy and cognitive behavioral skills. Work engagement was assessed by using the Utrecht Work Engagement Scale at baseline, 1-, and 4-month follow-ups for both intervention and control groups. An exploratory analysis was conducted for a subgroup with low (lower than the median scores) work engagement scores at baseline. Results: A total of 1,236 workers completed the baseline survey. In the low work engagement subgroup, a total of 313 and 300 participants were allocated to an intervention and control group, respectively. In the high work engagement subgroup, 305 and 318 participants were allocated to an intervention and control group, respectively. The program showed a significant effect on work engagement (t = 1.98, P = 0.048) at the 4-month follow-up in the low work engagement subgroup, with a small effect size (d = 0.17). Conclusion: A web-based psychoeducation resource of mental health literacy and cognitive behavioral skills may be effective for improving work engagement among individual workers with low work engagement.

Background: High levels of control over working time and low variability in working hours have been associated with improved health-related outcomes. The potential mechanisms for this association remain unclear. Aims: To examine how work-time control and variability of working times are associated with fatigue recovery, sleep quality, work-life balance, and 'near misses' at work. Methods: Manufacturing sector employees completed a questionnaire that assessed work-time control, worktime variability, fatigue recovery, sleep quality, work-life balance and the frequency of near misses in the past 6 months. Mixed model analysis of covariance and multiple logistic regression analysis tested the main effects of work-time control and variability and their interaction, while adjusting for age, sex, work schedules, and overtime work in the past month. Subscales of work-time control were also investigated (control over daily working hours and over days off). Results: One thousand three hundred and seventy-two completed questionnaires were returned, a response rate of 69%. A significantly higher quality of sleep and better work-life balance were found in the 'high control with low variability' reference group than in the other groups. Significantly better recovery of fatigue was also observed in the group having control over days off with low variability. While near misses were more frequent in the group with high control over daily working hours coupled with high variability compared with the reference group this was not significant. Conclusions: High work-time control and low variability were associated with favourable outcomes of health and work-life balance. This combined effect was not observed for the safety outcome addressed here. © The Author 2013 Published by Oxford University Press on behalf of the Society of Occupational Medicine.