Implementation of an internet-based stress management program in micro- and small-sized enterprises: a study protocol for a pre-post feasibility study of the effectiveness-implementation hybrid type 2 trial.

BACKGROUND: Although internet-based stress management programs are proven effective in improving mental health among workers, micro- and small-sized enterprises (MSEs), lacking in occupational healthcare services, face challenges implementing them. To address this gap, this study will develop the program with stakeholders at MSEs to aim for real-world implementation. OBJECTIVES: This paper describes a study protocol for a pre-post feasibility study of an effectiveness-implementation hybrid type 2 trial of text-based internet-based programs ("WellBe-LINE") in MSEs with less than 50 employees. This feasibility study primarily aims to evaluate trial methods for future effectiveness-implementation hybrid type 2 trials. METHODS: For this study protocol, an internet- and text-based self-care intervention program using the LINE app (a popular message tool in Japan) will be prepared according to evidence-based psychoeducational topics. Based on our online survey findings, personalized algorithms will be implemented according to employees' gender, age, and psychological distress levels. A personalized program using a popular pre-existing text app is expected to reduce employees' burdens and be attractive to them, resulting in successful implementation outcomes and mental health benefits. A pre-post design feasibility study will be conducted on ten companies to evaluate trial methods (e.g., recruitment and procedures). The primary outcome will involve individual-level penetration, defined as the proportion of the number of employees who register for the program divided by the total number of invited employees at the company. The progression criterion to go next trial specifies that more than 50% of the recruited companies obtain 60% individual penetration, which is set based on the findings of the prior survey of employees at MSEs and of interviews of stakeholders involved in this study, and will be measured by LINE system. Finally, acceptability, appropriateness, and feasibility will be measured using internet-based questionnaires and interviews. DISCUSSION: This pre-post feasibility study for future effectiveness-implementation hybrid type 2 trials will provide in-depth knowledge about the successful implementation of text-based, semi-personalized, self-care mental health interventions in real-world settings using both quantitative and qualitative data. CONCLUSIONS: This feasibility study will help validate the effectiveness of text-based interventions using a widely used social networking service (SNS) tool for employees in MSEs. TRIAL REGISTRATION: UMIN clinical trial registration, UMIN000046960. Registered on February 21, 2022. https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000053570.

Multifaceted ORganizational InterventiONs (M-ORION) project for prevention of depression and anxiety among workers: study protocol for a five-arm cluster randomized controlled trial.

BACKGROUND: Depression and anxiety are the most common mental health issues experienced by workers. Although organizational intervention has been extensively evaluated as a primary prevention of depression and anxiety, the corresponding scientific evidence remains limited because of the lack of cluster randomized controlled trials (cRCT) and failure to detect organizational-level effects. Therefore, the present study aims to assess the preventive effects of four types of interventions on depression and anxiety among workers in an open, five-arm, parallel-group cRCT. METHODS: Overall, 140 worksites and 18,200 nested employees will be recruited from September 2023. The eligible worksites will be randomly assigned to each of the five arms, and programs will be offered for 6-12 months. The five arms are 1) psychoeducation for workers, 2) psychoeducation for supervisors, 3) work environment improvement, 4) physical activity promotion, and 5) active control. The primary outcomes of interest are depression and anxiety. We will also assess psychosocial factors at work, work engagement, health-related quality of life, well-being, economic outcomes, physiological outcomes of health checkups, cortisol levels extracted from fingernails, and indices representing the process and implementation outcomes, including program completion rates. Follow-up surveys will be conducted at 6, 12, and 18 months from baseline, and the primary endpoint is set at the 6-month follow-up. Repeated-measures multi-level mixed modeling will be used to evaluate the effect of each intervention compared with the control. ETHICS AND DISSEMINATION: The study protocol was approved by the Research Ethics Committee of the Kitasato University Medical Ethics Organization (C22-082). The results and findings of this study will be published in a scientific journal and disseminated to companies that participate in the study. TRIAL REGISTRATION NUMBER: UMIN000050949.

mHealth Intervention to Promote Physical Activity Among Employees Using a Deep Learning Model for Passive Monitoring of Depression and Anxiety: Single-Arm Feasibility Trial.

BACKGROUND: Physical activity effectively prevents depression and anxiety. Although mobile health (mHealth) technologies offer promising results in promoting physical activity and improving mental health, conflicting evidence exists on their effectiveness, and employees face barriers to using mHealth services. To address these problems, we recently developed a smartphone app named ASHARE to prevent depression and anxiety in the working population; it uses a deep learning model for passive monitoring of depression and anxiety from information about physical activity. OBJECTIVE: This study aimed to preliminarily investigate (1) the effectiveness of the developed app in improving physical activity and reducing depression and anxiety and (2) the app's implementation outcomes (ie, its acceptability, appropriateness, feasibility, satisfaction, and potential harm). METHODS: We conducted a single-arm interventional study. From March to April 2023, employees aged ≥18 years who were not absent were recruited. The participants were asked to install and use the app for 1 month. The ideal usage of the app was for the participants to take about 5 minutes every day to open the app, check the physical activity patterns and results of an estimated score of psychological distress, and increase their physical activity. Self-reported physical activity (using the Global Physical Activity Questionnaire, version 2) and psychological distress (using the 6-item Kessler Psychological Distress Scale) were measured at baseline and after 1 month. The duration of physical activity was also recorded digitally. Paired t tests (two-tailed) and chi-square tests were performed to evaluate changes in these variables. Implementation Outcome Scales for Digital Mental Health were also measured for acceptability, appropriateness, feasibility, satisfaction, and harm. These average scores were assessed by comparing them with those reported in previous studies. RESULTS: This study included 24 employees. On average, the app was used for 12.54 days (44.8% of this study's period). After using the app, no significant change was observed in physical activity (-12.59 metabolic equivalent hours per week, P=.31) or psychological distress (-0.43 metabolic equivalent hours per week, P=.93). However, the number of participants with severe psychological distress decreased significantly (P=.01). The digitally recorded duration of physical activity increased during the intervention period (+0.60 minutes per day, P=.08). The scores for acceptability, appropriateness, and satisfaction were lower than those in previous mHealth studies, whereas those for feasibility and harm were better. CONCLUSIONS: The ASHARE app was insufficient in promoting physical activity or improving psychological distress. At this stage, the app has many issues that are to be addressed in terms of both implementation and effectiveness. The main reason for this low effectiveness might be the poor evaluation of the implementation outcomes by app users. Improving acceptability, appropriateness, and satisfaction are identified as key issues to be addressed in future implementation. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry UMIN000050430; https://tinyurl.com/mrx5ntcmrecptno=R000057438.

The quantity and quality of scientific evidence about the health of working women in occupational health of Japan: A scoping review.

OBJECTIVE: We aim to investigate the quantity and quality of scientific evidence dealing with comprehensive health issues of working women in occupational health. METHODS: This scoping review of original articles that investigated comprehensive health issues of working women aged 19-64 years in Japan was published in PubMed (1967-2022) and Igaku Chuo Zasshi (or Ichu-shi, 1982-2022). Using identical broad search terms, we first identified 17 122 English and 6154 Japanese articles. We excluded those with clinically relevant topics, or ethnicity other than Japanese and included 853 English and 855 Japanese articles for review and classified them into nine research areas considered to be critical factors for women in the workforce and five study design groups to investigate the quality of the evidence accumulated. RESULTS: Among 853 English-language articles in PubMed, "Mental health" was the most frequent area studied, followed by "Work-related disease" and "Lifestyle-related disease." Among 855 Japanese-language articles from Ichu-shi, "Mental health" was the most frequently studied area followed by "Work and balance," and "Work-related disease." "Infertility, pregnancy, and childbirth" and "Menstruation, menopause, and genital disease" were well studied in Ichu-shi but scarcely published in PubMed. "Harassment and discrimination" were sparsely reported in both databases. As for research designs, many articles in both PubMed and Ichu-shi employed descriptive or cross-sectional study designs. However, a few studies employed cohort/longitudinal or interventional studies. CONCLUSION: The results underscored the need for higher-quality study designs with more scientific evidence on working women's health in the field of occupational health.

Corrigendum: What kind of intervention is effective for improving subjective well-being among workers? A systematic review and meta-analysis of randomized controlled trials.

[This corrects the article DOI: 10.3389/fpsyg.2020.528656.].

Work-related psychosocial factors and inflammatory markers: A systematic review and meta-analysis.

OBJECTIVE: We conducted a systematic review and meta-analysis to evaluate the prospective effect of adverse work-related psychosocial factors on increases in inflammatory markers. METHODS: A systematic literature search was conducted in PubMed, Embase, PsycINFO, PsycARTICLES, and the Japan Medical Abstracts Society database. Studies were eligible for inclusion if they examined associations between work-related psychosocial factors and inflammatory markers (interleukin-6, tumor necrosis factor-alpha, and C-reactive protein), used longitudinal or prospective cohort designs, were conducted among workers, were original articles written in English or Japanese, and were published up to 2017 for the first search, October 2020 for the second, and November 2022 for the third. A meta-analysis was conducted using a random-effects model to assess the pooled effect size for the associations. A meta-regression analysis was used to estimate the association between length of follow-up and effect size. The ROBINS-I tool was used to assess risk of bias. RESULTS: Of the 11,121 studies identified in the first search, 29,135 studies from the second, and 9448 studies from the third, eleven were eligible for this review and meta-analysis. The pooled coefficient between adverse work-related psychosocial factors and inflammatory markers was significant and positive (ß = 0.014, 95% confidence interval: 0.005-0.023). However, a clear association was only observed for interleukin-6, and all the studies included had serious risks of bias. Meta-regression showed the effect size decreased depending on the follow-up period. CONCLUSION: This study revealed a weak positive association between adverse work-related psychosocial factors and increases in inflammatory markers. TRIAL REGISTRATION: PROSPERO CRD42018081553 (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=81553).

Perceived psychosocial safety climate, psychological distress, and work engagement in Japanese employees: A cross-sectional mediation analysis of job demands and job resources.

OBJECTIVES: We examined the associations of perceived psychosocial safety climate (PSC) with psychological distress and work engagement in Japanese employees. We also examined the mediation effects of job demands (i.e., psychological demands) and job resources (i.e., job control, worksite support, and extrinsic reward) in these associations. METHODS: A total of 2200 employees (1100 men and 1100 women) registered with a Japanese online survey company were surveyed using a self-administered web-based questionnaire containing the scales on PSC (12-item PSC scale), job demands and job resources (Job Content Questionnaire and Effort-Reward Imbalance Questionnaire), psychological distress (K6 scale), and work engagement (9-item Utrecht Work Engagement Scale), and items on demographic and occupational characteristics (i.e., age, sex, education, occupation, work form, and working hours per week). A multiple mediation analysis with a bootstrap method was conducted. RESULTS: After adjusting for demographic and occupational characteristics, significant negative and positive total effects of perceived PSC were observed on psychological distress and work engagement, respectively (c = -0.258 [95% confidence interval (CI): -0.298 to -0.219] and 0.383 [95% CI: 0.344-0.421], respectively). When we included job demands and job resources as mediators in the model, significant total mediation effects in these associations were observed (c - c' = -0.181 [95% CI: -0.221 to -0.143] and 0.269 [95% CI: 0.234-0.304], respectively). CONCLUSIONS: Our findings suggest that perceived PSC is negatively associated with psychological distress and positively associated with work engagement, and that these associations are partially mediated (or explained) by job demands and job resources.

A proposed definition of participatory organizational interventions.

Participatory organizational interventions offer an effective way to promote occupational safety and health. Despite an increasing number of studies, a common definition of participatory organizational interventions has yet to be established. Therefore, we aimed to form a definition using the following process. First, we developed a tentative draft definition of organizational interventions and participatory elements, based on the relevant literature. The tentative definition was revised in several rounds of an extensive discussion by the authors. This resulted in the draft definition. We asked 15 selected international experts in occupational safety and health to review and comment on the draft definition. We carefully reviewed their comments, and formulated our final proposed definition. To summarize the key points of the final version of the definition, organizational interventions are planned actions that primarily directly target working conditions with the aim of promoting and maintaining of the highest degree of physical, mental, and social well-being of workers in all occupations. In addition, as participatory elements of organizational interventions in the final definition, ideally, all workers participate in every step of the intervention, while participating in part of the steps of the intervention in some cases. Furthermore, in principle, all workers participate in each step of intervention, while it is also acceptable that only elected representatives among workers participate in the intervention.

Usage of the Brief Job Stress Questionnaire: A Systematic Review of a Comprehensive Job Stress Questionnaire in Japan from 2003 to 2021.

The Brief Job Stress Questionnaire (BJSQ) is used widely in occupational health studies and practice. Summarizing scientific production based on measurement is crucial. This study aimed to systematically review observational studies that used the BJSQ and the New BJSQ to show their usability. A systematic search was conducted for studies investigating relationships between the BJSQ or the New BJSQ subscales and other validated measurements on 13 September 2021, in various literature databases. The BJSQ subscales, scoring methods, and other validated measurements in the studies were qualitatively summarized. In total, 145 published reports between 2003 and 2021 were included. Among the BJSQ subscales, job stressors (n = 95) such as quantitative job overload (n = 65) and job control (n = 64) were most often used. The subscales were utilized to investigate the relationships with several other measurements. Five reports used subscales from the New BJSQ. In the last two decades, the BJSQ and the New BJSQ help measure psychosocial factors (PF) at work and contribute to the publication of scientific papers in the occupational health field. This study would encourage the utilization of the questionnaires for future research and practice.

The Passive Monitoring of Depression and Anxiety Among Workers Using Digital Biomarkers Based on Their Physical Activity and Working Conditions: 2-Week Longitudinal Study.

BACKGROUND: Digital data on physical activity are useful for self-monitoring and preventing depression and anxiety. Although previous studies have reported machine or deep learning models that use physical activity for passive monitoring of depression and anxiety, there are no models for workers. The working population has different physical activity patterns from other populations, which is based on commuting, holiday patterns, physical demands, occupations, and industries. These working conditions are useful in optimizing the model used in predicting depression and anxiety. Further, recurrent neural networks increase predictive accuracy by using previous inputs on physical activity, depression, and anxiety. OBJECTIVE: This study evaluated the performance of a deep learning model optimized for predicting depression and anxiety in workers. Psychological distress was considered a depression and anxiety indicator. METHODS: A 2-week longitudinal study was conducted with workers in urban areas in Japan. Absent workers were excluded. In a daily survey, psychological distress was measured using a self-reported questionnaire. As features, activity time by intensity was determined using the Google Fit application. Additionally, we measured age, gender, occupations, employment status, work shift types, working hours, and whether the response date was a working or nonworking day. A deep learning model, using long short-term memory, was developed and validated to predict psychological distress the next day, using features of the previous day. Further, a 5-fold cross-validation method was used to evaluate the performance of the aforementioned model. As the primary indicator of performance, classification accuracy for the severity of the psychological distress (light, subthreshold, and severe) was considered. RESULTS: A total of 1661 days of supervised data were obtained from 236 workers, who were aged between 20 and 69 years. The overall classification accuracy for psychological distress was 76.3% (SD 0.04%). The classification accuracy for severe-, subthreshold-, and light-level psychological distress was 51.1% (SD 0.05%), 60.6% (SD 0.05%), and 81.6% (SD 0.04%), respectively. The model predicted a light-level psychological distress the next day after the participants had been involved in 3 peaks of activity (in the morning, noon, and evening) on the previous day. Lower activity levels were predicted as subthreshold- and severe-level psychological distress. Different predictive results were observed on the basis of occupations and whether the previous day was a working or nonworking day. CONCLUSIONS: The developed deep learning model showed a similar performance as in previous studies and, in particular, high accuracy for light-level psychological distress. Working conditions and long short-term memory were useful in maintaining the model performance for monitoring depression and anxiety, using digitally recorded physical activity in workers. The developed model can be implemented in mobile apps and may further be practically used by workers to self-monitor and maintain their mental health state.

The effects of pregnancy discrimination on postpartum depressive symptoms: a follow-up study.

BACKGROUND: Pregnancy discrimination in the workplace is prevalent worldwide. However, few studies have examined the effects of pregnancy discrimination on mothers' perinatal mental health. We aimed to investigate the association between pregnancy discrimination and postpartum depressive symptoms, and the mediation effects of prenatal depressive symptoms on this association. METHODS: Our sample consisted of 285 Japanese women employed during pregnancy who completed a baseline online survey in May 2020 and a follow-up mail survey two months postpartum. Pregnancy discrimination was defined as exposure to any of 16 forms of disadvantageous treatment or harassment related to pregnancy, prohibited by national guidelines. Prenatal (assessed at baseline) and postpartum (assessed at follow-up) depressive symptoms were measured using the Edinburgh Postnatal Depression Scale. Multiple linear regression and mediation analyses were performed overall and stratified by regular (permanent) and non-regular (precarious) employees. RESULTS: Overall, 23.9% of participants experienced pregnancy discrimination during pregnancy. After adjusting for potential confounders, pregnancy discrimination was significantly associated with postpartum depressive symptoms (coefficient 1.76, 95% confidence interval [CI] 0.65-2.88). When stratified by employment type, these effects were observable among non-regular employees (coefficient 2.51, 95% CI 0.45-4.57) but not regular employees. Mediation analysis showed that prenatal depressive symptoms mediated 57.1% (95% CI 20.1-94.1%) of the association between pregnancy discrimination and postpartum depressive symptoms among all participants, with a greater effect among non-regular employees (64.1% [95% CI 18.5-109.8%]). CONCLUSIONS: Pregnancy discrimination has adverse effects on postpartum depressive symptoms, partially through prenatal depressive symptoms, especially among non-regular employees. To prevent perinatal depression in female workers, employers should comply with legislation and take preventive measures against pregnancy discrimination, while considering vulnerable employees.

Victimization and witnessing of workplace bullying and physician-diagnosed physical and mental health and organizational outcomes: A cross-sectional study.

BACKGROUND: Compared to the numerous reports on mental health outcomes of workplace bullying victims, research on organizational outcomes of witnesses and physical health outcomes of victims and witnesses is scarce. Therefore, the purpose of this study was to investigate the relationship between bullying victimization and witnessing and various physical and mental health outcomes and organizational outcomes such as sickness absence, work performance, and job satisfaction. METHODS: This study used cross-sectional data from a nationally representative, community-based sample of 5,000 Japanese residents aged 20-60. We analyzed data from 1,496 respondents after excluding those not working at the time of the survey and those with missing values. Workplace bullying, psychological distress, physical complaints, and job satisfaction were assessed with the New Brief Job Stress Questionnaire and work performance with the World Health Organization's Health and Work Performance Questionnaire. In addition, subjective health status, physician-diagnosed mental or physical illness, and sickness absence were asked as one item. Hierarchical multiple regression analysis or Poisson regression analysis was conducted to assess the association between victimization/witnessing workplace bullying and health and organizational outcomes. RESULTS: Both victimization and witnessing workplace bullying were significantly associated with psychological distress, physical complaints, subjective poor health, physician-diagnosed mental disorders, and job dissatisfaction. Victimization of workplace bullying was further associated with physician-diagnosed respiratory diseases, sickness absence (≥7 days), and poor work performance. Victims were absent from work for 4.5 more sick days and had 11.2% lower work performance than non-victims. CONCLUSIONS: The results showed that both victimization and witnessing workplace bullying were significantly associated with physical and mental outcomes and various organizational outcomes. Organizations should implement further measures to prevent personal and organizational losses due to workplace bullying.

The impact of workplace psychosocial factors on menstrual disorders and infertility: a protocol for a systematic review and meta-analysis.

INTRODUCTION: Workplace environment, especially psychosocial factors at work such as job strain, workplace social support, and shift work, may affect the menstrual abnormalities and fertility of female workers. However, the association between psychosocial factors at work and menstrual abnormalities or fertility is not well understood. To address this relationship, we will conduct a systematic review and a meta-analysis of the literature that has utilized a longitudinal or prospective cohort design. METHODS AND ANALYSIS: The inclusion criteria for this systematic review and meta-analysis are defined as follows: (P) adult female workers (over 18 years old), (E) the presence of adverse psychosocial factors at work, (C) the absence of adverse psychosocial factors at work, and (O) any menstrual cycle disorders, menstrual-related symptoms, or fertility. The MEDLINE, Embase, PsycINFO, PsycArticles, and Japan Medical Abstracts Society electronic databases will be used to search for published studies. The statistical synthesis of the studies included in the meta-analysis will be conducted to estimate pooled coefficients and 95% CIs. For the main analysis, we will synthesize measures of association between psychosocial factors at work and menstrual-related disorders/symptoms. At least three eligible studies will have to be gathered to conduct a meta-analysis; otherwise (i.e., if only one or two studies will be eligible and included), the results will be presented in a narrative table. We will use the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) to determine the quality of selected studies. To assess meta-bias, Egger's test, along with a funnel plot, will be used to check for publication bias. Lastly, we will examine heterogeneity using the χ2 test with Cochran's Q statistic and I2. ETHICS AND DISSEMINATION: The results and findings will be submitted and published in a scientific peer-reviewed journal and will be disseminated broadly to researchers and policymakers interested in the translatability of scientific evidence into good practices. SYSTEMATIC REVIEW REGISTRATION: The study protocol was registered at the UMIN registry (registration number: UMIN000039488). The registration date is on 14 Feb 2020. URL: https://upload.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000044704.

STRENGTH AND LIMITATIONS OF THIS STUDY: • This systematic review and a meta-analysis will investigate the associations between psychosocial factors at work and menstrual abnormalities or fertility. • This review will include only the literature that has utilized a longitudinal design. • Various outcomes related to reproductive health in female workers will be examined (e.g., fertility, premenstrual symptoms, cycle disorders, menopausal symptoms).

Low Adaptation to Management Philosophy and Refraining From Seeking Medical Care in Japanese Employees: A 1-Year Prospective Study.

OBJECTIVE: We examined the prospective association of low adaptation to management philosophy with refraining from seeking medical care (RSMC) among Japanese employees in a company with a management philosophy of "pursuing employees' well-being." METHODS: We surveyed 2791 employees (2059 men and 732 women) from 2 factories of a Japanese manufacturing company following the management philosophy of "pursuing employees' well-being." Using a self-administered questionnaire, we measured adaptation to management philosophy at baseline and RSMC at a 1-year follow-up. We conducted robust Poisson regression analysis. RESULTS: Low adaptation to management philosophy was significantly associated with RSMC (incidence rate ratio, 1.17; 95% confidence interval, 1.03-1.35). CONCLUSIONS: Adaptation to management philosophy may be an important factor associated with the decision of employees working at a company following the "pursuing employees' well-being" management philosophy to seek medical care for their perceived health issues.

Workplace Social Support and Reduced Psychological Distress: A 1-Year Occupational Cohort Study.

OBJECTIVE: There is little evidence that workplace social support can relieve workers' mental health problems. Therefore, we examined whether social support from coworkers and supervisors was associated with reduced serious psychological distress among employees. METHODS: We used two-wave panel data from 13 Japanese companies. The baseline survey was conducted in 2011, and the follow-up survey 1 year later. From 9889 respondents, we selected 759 who had psychological distress at baseline, defined as ≥13 on the Kessler Psychological Distress Scale (K6). RESULTS: Increased coworker support was significantly associated with employees' reduced psychological distress (odds ratio, 3.51; 95% confidence interval, 2.17 to 5.68). The association between increased supervisor support and reduced psychological distress was nonsignificant (odds ratio, 1.32, 95% confidence interval, 0.85 to 2.04). CONCLUSION: Encouraging coworker support may contribute to the secondary prevention of mental health problems among employees.

The Survey Measure of Psychological Safety and Its Association with Mental Health and Job Performance: A Validation Study and Cross-Sectional Analysis.

OBJECTIVES: This study validated the Japanese version of O'Donovan et al.'s (2020) composite measure of the psychological safety scale and examined the associations of psychological safety with mental health and job-related outcomes. METHODS: Online surveys were administered twice to Japanese employees in teams of more than three members. Internal consistency and test-retest reliability were tested using Cronbach's α and intra-class correlation coefficient (ICC), respectively. Structural validity was examined using confirmatory factor analysis (CFA) and exploratory factor analysis (EFA). Convergent validity was tested using Pearson's correlation coefficients. Multiple linear regression analyses were conducted to examine the relationship between psychological safety and psychological distress, work engagement, job performance, and job satisfaction. RESULTS: Two hundred healthcare workers and 200 non-healthcare workers were analyzed. Internal consistency, test-retest reliability, and convergent validity were acceptable. CFA demonstrated poor fit, and EFA yielded a two-factor structure, with team leader as one factor and peers and team forming the second factor. The total score showed significant and expected associations with all outcomes in the adjusted model for all workers. CONCLUSIONS: The Japanese version of the measure of the psychological safety scale presented good reliability and validity. Psychological safety is important for employees' mental health and performance.