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.

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.

Mothers' nonstandard work schedules and adolescent obesity: a population-based cross-sectional study in the Tokyo metropolitan area.

BACKGROUND: Many wage earners in developed countries have irregular shift patterns and work evenings, nights, and weekends. Some studies have demonstrated that the nonstandard work schedules of parents have adverse effects on their children's weight, specifically leading to or worsening obesity. However, no such study has been conducted in adolescents of high school age. This study examined the association between mothers' nonstandard work schedules and adolescent obesity. METHODS: A cross-sectional study of adolescents aged 16-17 years (n = 1743) used paired matches of self-administered questionnaires for adolescents and their mothers from Tokyo, Japan. Obesity was defined by International Obesity Task Force cut-offs. Nonstandard work schedules were defined as working early mornings, nights, overnights, or weekends. Chi-square tests were conducted to examine the association between the mothers' work schedules and their adolescent children's poor lifestyles, overall and stratified by income levels. Then, logistic regression analyses were conducted to examine the association between mothers' work schedules and obesity of their adolescent children, overall and stratified by income levels. RESULTS: Overall, 6.5% of adolescents had obesity. The prevalence of obesity was higher among adolescents from low-middle income groups (8.2%) than that among those from high-income groups (5.9%). No clear patterns were found between mothers' work schedules and adolescents' poor lifestyles when stratified by income levels. Mothers' nonstandard work schedules were significantly associated with adolescent obesity (odds ratio [OR]: 1.56, 95% confidence interval [CI]: 1.02-2.40). However, this association was not significant after adjustment for confounders. After stratification by income levels, mothers' nonstandard work schedules significantly associated with their children's obesity (OR: 2.93, 95% CI: 1.45-5.92) only in high-income groups. This association remained after adjustment of the adolescents' lifestyles and their mothers' working hours. CONCLUSIONS: Our results suggest that mothers' nonstandard work schedules have adverse effects on adolescent obesity only in high-income families. Low-middle income families experienced higher levels of adolescent obesity, regardless of the mothers' work schedules. Policy makers should consider mothers' work schedules as a factor in preventing adolescent obesity.

Associations between work-related stressors and QALY in a general working population in Japan: a cross-sectional study.

OBJECTIVE: To investigate an association between quality-adjusted life years (QALY) and work-related stressors (job strain, effort/reward imbalance, and poor support from supervisor and coworkers), and estimate loss in QALY caused by these stressors. METHODS: A cross-sectional study investigated data from a third-wave survey (in December 2017) of a 2-year prospective cohort study of Japanese workers. At baseline (first-wave survey), 5000 participants were recruited from workers who registered with an internet survey company. A total of 2530 participants responded to the second-wave survey 1 year later. Participants were then further recruited to the third-wave survey. An online questionnaire collected information regarding health-related quality of life (measured by EQ-5D-5L), job strain, supervisor and coworker support (Brief Job Stress Questionnaire), effort/reward imbalance (Effort/reward Imbalance Questionnaire), and demographic variables (age, sex, education, occupation, work contract, smoking, and alcohol drinking). Multiple linear regression analysis of the QALY score calculated from responses to EQ-5D-5L was employed on standardized scores of the work-related stressors and adjusted for demographic variables (SPSS version 26). RESULTS: Data of 1986 participants were analyzed. Job strain (unstandardized coefficient, b = - 0.013, p < 0.01) and effort/reward imbalance (b = - 0.011, p < 0.01) and coworker support (b = 0017, p < 0.01) were significantly associated with QALY score in the fully adjusted model. CONCLUSION: Job strain, effort/reward imbalance, and poor coworker support may be associated with a reduced QALY score among workers. A substantial impairment in QALY associated with the work-related stressors indicates that workplace interventions targeting work-related stressors may be cost-effective.

Factors Related to Oncologists' Use of the Disease Treatment and Employment Support Guidance Fee.

The purpose of this study is to examine the factors related to oncologists' use of the disease treatment and employment support guidance fee in Japan. A cross-sectional online survey was conducted in January 2021 among all the diplomates of the subspecialty board of medical oncology in the Japanese Society of Medical Oncology (n = 1,452), using the official mailing list. Logistic regression analysis was used to investigate the association between demographic and other factors and use of the disease treatment and employment support guidance fee. In total, 146 individuals participated in the study (response rate 10.0%). Experience of using the fee was associated with medical specialty and knowledge of the Guideline for Workplace Patient Coordination and Disease Treatment. It may be possible to increase the use of the disease treatment and employment support guidance fee among oncologists by raising awareness of the Guideline for Workplace Patient Coordination and Disease Treatment.

Psychosocial Work Environment Explains the Association of Job Dissatisfaction With Long-term Sickness Absence: A One-Year Prospect Study of Japanese Employees.

BACKGROUND: Using a 1-year prospective design, we examined the association of job dissatisfaction with long-term sickness absence lasting 1 month or more, before and after adjusting for psychosocial work environment (ie, quantitative job overload, job control, and workplace social support) in Japanese employees. METHODS: We surveyed 14,687 employees (7,343 men and 7,344 women) aged 20-66 years, who had not taken long-term sickness absence in the past 3 years, from a financial service company in Japan. The Brief Job Stress Questionnaire, including scales on job satisfaction and psychosocial work environment, was administered, and information on demographic and occupational characteristics (ie, age, gender, length of service, job type, and employment position) was obtained from the personnel records of the surveyed company at baseline (July-August 2015). Subsequently, information on the start dates of long-term sickness absences was obtained during the follow-up period (until July 2016) from the personnel records. Cox's proportional hazard regression analysis was conducted. RESULTS: After adjusting for demographic and occupational characteristics, those who perceived job dissatisfaction had a significantly higher hazard ratio of long-term sickness absence than those who perceived job satisfaction (hazard ratio 2.91; 95% confidence interval, 1.74-4.87). After additionally adjusting for psychosocial work environment, this association was weakened and no longer significant (hazard ratio 1.55; 95% confidence interval, 0.86-2.80). CONCLUSIONS: Our findings suggest that the association of job dissatisfaction with long-term sickness absence is spurious and explained mainly via psychosocial work environment.

Occupational stress and the risk of turnover: a large prospective cohort study of employees in Japan.

BACKGROUND: Although several studies have examined the association between occupational stress and turnover, these studies relied on cross-sectional designs, subjects' self-report, healthcare workforce, or small sample sizes. This study aimed to confirm whether occupational stress increases the risk of turnover in a large-scale prospective cohort study using actual turnover data from company records. METHODS: The participants were 3892 male and 5765 female employees aged 20-49 years in a financial service company. We followed them from October 2012 until April 1, 2016 and used company records to identify employees who resigned. We identified employees with high and low stress using the Brief Job Stress Questionnaire. Hazard ratios for turnover in high-stress employees were estimated using Cox proportional hazards models, and population attributable risks were calculated separately for men and women. RESULTS: During 11,475,862 person-days, 122 men and 760 women resigned. After adjustment for age, length of service, job type, and position, the hazard ratios (95% confidence intervals) for turnover in high-stress employees were 2.86 (1.74-4.68) for men and 1.52 (1.29-1.78) for women. The corresponding population attributable risks for high stress were 8.2% for men and 8.3% for women. The component scores, i.e., job stressors, psychological/physical stress response, workplace social support, and job strain (the combination of high job demands and low job control) were also significantly associated with turnover (p < 0.05). CONCLUSIONS: Occupational stress increases the risk of actual turnover. Measures to prevent occupational stress may be useful to prevent employee turnover.

Long working hours and depressive symptoms: moderating effects of gender, socioeconomic status, and job resources.

PURPOSE: Systematic reviews and meta-analyses have found inconsistent associations between working hours and depressive symptoms. The purpose of this study was to investigate the possible moderators of this association, using data from a large-scale cross-sectional survey. METHODS: A total of 16,136 Japanese employees (men 83.5%; women 16.5%) responded to a self-administered questionnaire inquiring about overtime working hours during the previous month and depressive symptoms (Center for Epidemiologic Studies Depression scale), as well as moderating factors including gender, age, marital status, socioeconomic status, commuting time, sleeping hours per day, job control and worksite social support (Job Content Questionnaire), neuroticism (Eysenck's Personality Questionnaire Revised), and social desirability (Social Desirability Scale) (response rate, 85%). We conducted sequential regression analyses to investigate the main effects and interaction effects of all moderating variables. RESULTS: The association between overtime working hours and depressive symptoms was significantly moderated by gender (interaction effect: ß = 0.03), age (ß = - 0.02), manager (ß = 0.03), sleeping hours (ß = - 0.02), job control (ß = - 0.03), and neuroticism (ß = 0.02). Among workers engaged in 80 + hours of overtime, higher depressive symptoms were reported by women, younger employees, non-managers, employees with low job control, low worksite social support, and high neuroticism. A significant main effect of long overtime working hours on depressive symptoms was also observed even after controlling for all independent variables (ß = 0.02). CONCLUSIONS: Long overtime working hours is associated with depressive symptoms. We also found significant heterogeneity in the association according to employee characteristics, which may explain the inconsistent findings in previous literature.

Organizational Justice and Refraining from Seeking Medical Care Among Japanese Employees: A 1-Year Prospective Cohort Study.

BACKGROUND: Using a 1-year prospective design, we examined the association of organizational justice (i.e., procedural justice and interactional justice) with refraining from seeking medical care (RSMC) among Japanese employees. METHODS: We surveyed 2695 employees (1994 men and 701 women) from two factories of a manufacturing company in Japan. A self-administered questionnaire comprising scales for measuring organizational justice (Organizational Justice Questionnaire) and potential confounders (i.e., demographic and socioeconomic characteristics as well as health-related behaviors) was administered at baseline (from April to June 2011). At 1-year follow-up (from April to June 2012), a single-item question was used to measure RSMC during the follow-up period. Multiple logistic regression analysis was conducted by gender. RESULTS: After adjusting for potential confounders, low procedural justice and low interactional justice at baseline were found to be significantly associated with higher odds of RSMC during the 1-year follow-up for male employees (odds ratio = 1.33 [95% confidence interval = 1.16-1.52], p < 0.001 and 1.15 [95% confidence interval = 1.02-1.29], p = 0.019, respectively). Similar patterns were observed for female employees (odds ratio = 1.37 [95% confidence interval = 1.08-1.74], p = 0.009 and 1.23 [95% confidence interval = 1.02-1.50], p = 0.035 for low procedural justice and low interactional justice, respectively). CONCLUSIONS: The present study provided evidence that the lack of organizational justice is positively associated with RSMC among Japanese employees, independently of demographic and socioeconomic characteristics as well as of health-related behaviors.

Caregiver Burden and Work Productivity Among Japanese Working Family Caregivers of People with Dementia.

BACKGROUND: We examined the association between caregiver burden and work productivity (i.e., absenteeism, presenteeism, and overall work impairment) among working family caregivers of people with dementia and whether job characteristics (i.e., job demands, job control, supervisor and coworker support) moderate this association. METHODS: A cross-sectional correlational study design using a web-based questionnaire survey was conducted among 379 Japanese working family caregivers of people with dementia (105 female, age range 20-77) in May 2016, which measured caregiver burden, work productivity, care situation, job characteristics, and demographics. Caregiver burden was designated as an independent variable and each aspect of work productivity as a dependent variable in a hierarchical multiple regression analysis, adjusting for demographics. Interaction terms between caregiver burden and each job characteristic were also included in the model. RESULTS: Caregiver burden was significantly and positively associated with presenteeism (ß = 0.219, p < 0.001) and overall work impairment (ß = 0.181, p < 0.001), while the association of caregiver burden with absenteeism was not significant (ß = - 0.003, p = 0.953). Interaction effects of caregiver burden × coworker support on presenteeism (ß = - 0.189, p = 0.023) and overall work impairment (ß = - 0.172, p = 0.034) were significant. According to simple slope analyses, caregiver burden was greater at lower levels of coworker support compared to higher levels of coworker support for both presenteeism and overall work impairment. CONCLUSIONS: Our study suggests that higher caregiver burden is associated with a decrease in work productivity. Additionally, coworker support appears to buffer the association of caregiver burden with presenteeism and overall work impairment among working family caregivers of people with dementia.

Correction to: Caregiver Burden and Work Productivity Among Japanese Working Family Caregivers of People with Dementia.

The authors have noted that the number of participants in the final sample should be 377, rather than 379. In this correction, the two mistaken cases were removed and analyses were repeated with 377 cases.

Interaction effect of job insecurity and role ambiguity on psychological distress in Japanese employees: a cross-sectional study.

PURPOSE: We examined the interaction effect of job insecurity (JI) and role ambiguity (RA) on psychological distress in Japanese employees. METHODS: Overall, 2184 male and 805 female employees from two factories of a manufacturing company in Japan completed a self-administered questionnaire comprising the scales measuring JI (Job Content Questionnaire), RA (National Institute for Occupational Safety and Health Generic Job Stress Questionnaire), psychological distress (K6 scale), and potential confounders (i.e., age, education, family size, occupational class, and work shift). Taking psychological distress as a dependent variable, hierarchical multiple regression analyses were conducted by gender and employment status (i.e., permanent and non-permanent employees). An interaction term of JI × RA was included in the model. RESULTS: After adjusting for potential confounders, the main effects of JI and RA on psychological distress were significant regardless of gender or employment status. Furthermore, the significant interaction effect of JI × RA on psychological distress was observed among permanent male employees (ß = 0.053, p = 0.010). Post hoc simple slope analyses showed that the simple slope of JI was greater at higher levels of RA (i.e., one standard deviation [SD] above the mean) (ß = 0.300, p < 0.001) compared to lower levels of RA (i.e., one SD below the mean) (ß = 0.212, p < 0.001). On the other hand, the interaction effect of JI × RA was not significant among permanent or non-permanent female employees. CONCLUSIONS: The present study suggests that higher levels of RA strengthen the association of JI with psychological distress, at least among Japanese permanent male employees.

The validity and psychometric properties of the Japanese version of the Compulsive Internet Use Scale (CIUS).

BACKGROUND: Prolonged Internet use is often associated with reduced social involvement and comorbid psychopathologies, including depression, anxiety, attention-deficit/hyperactivity disorder, and obsessive-compulsive disorder. Asian countries where Internet access is widely available have high reported levels of Internet addiction. As Internet use has changed drastically since concerns about Internet addiction were first raised, the results of recent studies may be inaccurate because the scales they employed to measure Internet addiction were formulated for different Internet usage from the present. It is thus necessary to develop more-up-to-date scales to assess problematic private use of the Internet. METHODS: The Compulsive Internet Use Scale (CIUS) was translated into Japanese. An online sample whose ages and sexes reflected that of the national population of Internet users was recruited to test the scale's reliability and validity. Correlations between the scale and Internet-related parameters (such as time spent online, motivation for going online, and applications used) and psychosocial factors (such as psychological distress symptoms and loneliness) were examined. Psychometric properties were examined by the split-half method using both exploratory and confirmatory factor analysis. Model fits were compared across gender. RESULTS: CIUS was found to have a high reliability and good concurrent, correlation and construct validity. Both exploratory and confirmatory factors revealed that the one-factor solution yielded a satisfactory result across gender. However, the three-factor structural model in which compulsiveness was gauged by "excessive absorption", "difficulty in setting priorities", and "mood regulation" gave the best fit of the model for the general population as well as across gender. CONCLUSIONS: Compulsive Internet behavior in Japan can be assessed in terms of absorption, priorities, and mood. CIUS is a valid scale for screening compulsive Internet behavior in the general Japanese population regardless of age and gender.

Modifying effect of cigarette smoking on the association of organizational justice with serious psychological distress in Japanese employees: a cross-sectional study.

PURPOSE: We examined the modifying effect of cigarette smoking (i.e., smokers vs. non-smokers) on the association of organizational justice (i.e., procedural justice and interactional justice) with serious psychological distress (SPD) in Japanese employees. METHODS: Overall, 2838 participants from two factories of a manufacturing company in Japan completed a self-administered questionnaire comprising the scales on organizational justice (Organizational Justice Questionnaire), smoking status, psychological distress (K6 scale), demographic and occupational characteristics (i.e., gender, age, education, family size, history of depression, chronic physical conditions, occupation, and work form), and other health-related behaviors (i.e., drinking habit and physical activity). Multiple logistic regression analyses were conducted. In a series of analyses, interaction term of procedural justice or interactional justice with smoking status was included in the model. RESULTS: After adjusting for demographic and occupational characteristics as well as other health-related behaviors, low procedural justice and low interactional justice were significantly associated with SPD (defined as K6 ≥ 13). Furthermore, marginally significant interaction effect of procedural justice with smoking status was observed. Specifically, the association of low procedural justice with SPD was greater among smokers [prevalence odds ratio 7.13 (95 % confidence interval 3.25-15.7) for low vs. high procedural justice subgroup] than among non-smokers [prevalence odds ratio 2.34 (95 % confidence interval 1.52-3.60) for low vs. high procedural justice subgroup]. On the other hand, interaction effect of interactional justice with smoking status was not significant. CONCLUSIONS: Cigarette smoking seems to have a harmful effect on the association of the lack of procedural justice with SPD in Japanese employees.

Interrelationships Between Job Resources, Vigor, Exercise Habit, and Serum Lipids in Japanese Employees: a Multiple Group Path Analysis Using Medical Checkup Data.

BACKGROUND: Physical inactivity is one of the major risk factors for dyslipidemia and coronary heart disease. Job resources have been identified as determinants of employees' vigor and physical activity habits. PURPOSE: Our first purpose was to comprehensively analyze the series of relationships of job resources, through vigor and exercise habit (i.e., one aspect of physical activity), to serum lipid levels in a sample of Japanese employees in a manufacturing company. Our second purpose was to investigate sex differences in these relationships using a multiple-group path analysis. METHODS: Data were collected from 4543 employees (men = 4018, women = 525) during a medical checkup conducted in February and March 2012. Job resources (job control, skill utilization, suitable jobs, and meaningfulness of work), vigor, exercise habit, triglyceride, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured cross-sectionally. RESULTS: Job resources and vigor were positively associated with exercise habit in both sexes. Exercise habit was inversely associated with triglyceride (-0.03 in men and -0.01 in women, ps < 0.05) and LDL-C (-0.07 in both sexes, ps < 0.05). HDL-C was positively associated with exercise habit (0.03 in both sexes, ps < 0.05). There was no significant difference by sex in path coefficients, except for the covariance between suitable jobs and meaningfulness of work. CONCLUSION: Higher levels of job resources were associated with greater vigor, leading to exercise habit, which in turn, improved serum lipid levels. Longitudinal studies are required to demonstrate causality.

Source-specific workplace social support and high-sensitivity C-reactive protein levels among Japanese workers: A 1-year prospective cohort study.

BACKGROUND: This study investigated the prospective association between source-specific workplace social support and high-sensitivity C-reactive protein (hs-CRP) levels in workers in Japan. METHODS: We conducted a 1-year prospective cohort study with 1,487 men and 533 women aged 18-65 years. Participants worked at two manufacturing worksites in Japan and were free of major illness. We used multivariable linear regression analyses to evaluate the prospective association between supervisor and coworker support at baseline, and hs-CRP levels at follow-up. We conducted the analyses separately for men and women. RESULTS: For women, high supervisor support at baseline was significantly associated with lower hs-CRP levels at follow-up (ß = -0.109, P < 0.01), whereas coworker support at baseline was not significantly associated with hs-CRP levels at follow-up. Associations between supervisor and coworker support and hs-CRP levels were not significant for men. CONCLUSIONS: Supervisor support may have beneficial effects on inflammatory markers in working women. Am. J. Ind. Med. 59:676-684, 2016. © 2016 Wiley Periodicals, Inc.

Work engagement and high-sensitivity C-reactive protein levels among Japanese workers: a 1-year prospective cohort study.

PURPOSE: Evidence on the association between psychological well-being and high-sensitivity C-reactive protein (hs-CRP) levels is limited. We carried out a prospective study to investigate the association between work engagement and hs-CRP levels in a group of Japanese workers. METHODS: Our cohort included 1,857 men and 657 women aged 65 and under, and free from major illness, working at two manufacturing worksites in Japan. Baseline examinations were conducted from April to June 2011 to determine the demographic and lifestyle characteristics and levels of work engagement. Blood samples were obtained from participants at baseline and after 1 year. Participants were classified into tertiles of low, moderate, and high work engagement at baseline. Hs-CRP levels were split into low (≤3.0 mg/L) and high (>3.0 mg/L). We used multiple logistic regression analyses to evaluate the association between work engagement at baseline and hs-CRP levels at follow-up, adjusting for hs-CRP at baseline and potential confounding factors. RESULTS: Participants reporting moderate and high levels of work engagement at baseline had significantly lower odds ratios (ORs) of having high hs-CRP levels at follow-up than those with low levels of work engagement at baseline [OR of moderate level 0.44, 95% confidence interval (CI) 0.24-0.81; OR of high level 0.57, 95% CI 0.33-0.99; p for trend <0.05]. CONCLUSION: Findings suggest that work engagement has beneficial effects on workers' cardiovascular health.

Buffering effects of job resources on the association of overtime work hours with psychological distress in Japanese white-collar workers.

PURPOSE: The purpose of the present study was to investigate the buffering effects of job resources, utilizing the job demands-control (or demand-control-support) and effort-reward imbalance models (i.e., job control, workplace social support, and extrinsic reward), on the association of overtime work hours with psychological distress in Japanese employees. METHODS: A total of 1,198 participants (valid response rate = 93.7 %) from five branches of a manufacturing company in Japan completed a self-administered questionnaire comprising the scales assessing job resources, psychological distress, and demographic characteristics. We obtained the information on working hours in the most recent month from the personnel records of the surveyed company. Multiple logistic regression analyses were conducted. In a series of analyses, interaction term of overtime work hours with each job resource was included in the model. RESULTS: Significant interaction effect of overtime work hours with job control was observed. Among the low job control group, the long overtime (80 h or more) subgroup had a significantly higher prevalence odds ratio of psychological distress compared to the short overtime (44 h or less) subgroup. No significant association of overtime work hours with psychological distress was found among the high job control group. On the other hand, there was no significant interaction effect of overtime work hours with workplace social support or extrinsic reward. CONCLUSIONS: The present findings suggest that high job control has an effect on reducing psychological distress in relation to overtime work hours in Japanese employees.

Organizational Justice and Physiological Coronary Heart Disease Risk Factors in Japanese Employees: a Cross-Sectional Study.

BACKGROUND: Growing evidence has shown that lack of organizational justice (i.e., procedural justice and interactional justice) is associated with coronary heart disease (CHD) while biological mechanisms underlying this association have not yet been fully clarified. PURPOSE: The purpose of the present study was to investigate the cross-sectional association of organizational justice with physiological CHD risk factors (i.e., blood pressure, high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol, and triglyceride) in Japanese employees. METHODS: Overall, 3598 male and 901 female employees from two manufacturing companies in Japan completed self-administered questionnaires measuring organizational justice, demographic characteristics, and lifestyle factors. They completed health checkup, which included blood pressure and serum lipid measurements. Multiple logistic regression analyses and trend tests were conducted. RESULTS: Among male employees, multiple logistic regression analyses and trend tests showed significant associations of low procedural justice and low interactional justice with high triglyceride (defined as 150 mg/dL or greater) after adjusting for demographic characteristics and lifestyle factors. Among female employees, trend tests showed significant dose-response relationship between low interactional justice and high LDL cholesterol (defined as 140 mg/dL or greater) while multiple logistic regression analysis showed only marginally significant or insignificant odds ratio of high LDL cholesterol among the low interactional justice group. Neither procedural justice nor interactional justice was associated with blood pressure or HDL cholesterol. CONCLUSION: Organizational justice may be an important psychosocial factor associated with increased triglyceride at least among Japanese male employees.