Assessing workplace civility: Validity and 1-year test-retest reliability of a Japanese version of the CREW Civility Scale.

OBJECTIVES: This study aimed to examine the reliability and validity of the Japanese version of the eight-item CREW Civility Scale which measures workplace civility norms and compare the civility scores among various occupations. METHODS: A longitudinal study included all employees in a social care organization (N = 658) and a cross-sectional study included all civil servants in one city (N = 3242) in Japan. Structural validity was tested through confirmatory factor analyses (CFA). Construct validity was assessed through Pearson's correlations of civility with other variables. Internal consistency was assessed by Cronbach's alpha and 1-year test-retest reliability was assessed by the Intraclass Correlation Coefficient (ICC). RESULTS: The results of CFA showed an acceptable level of model fit (TLI =0.929; CFI =0.949; and SRMR =0.034). CREW Civility Scale scores were significantly positively correlated with supervisor support, co-worker support, and work engagement, while significantly negatively correlated with incivility, workplace bullying, intention to leave, and psychological distress, which were consistent with our hypotheses. Cronbach's alpha coefficient was 0.93 and ICC was 0.52. Younger, high-educated, and managerial employees and, childminder/nursery staff reported higher civility. High school graduates and respondents who did not graduate from high school, part-time employees, nurses, paramedical staff, and care workers reported lower civility. CONCLUSIONS: The Japanese version of the CREW Civility scale is a reliable, valid measure of civility, appropriate for Japanese workplaces as well as for use in multi-national studies alongside other existing versions of this scale in English, Portuguese and Farsi.

[Association of self-rated health with inflammatory markers among nursing home employees].

OBJECTIVES: Although self-rated health (SRH), the self-evaluation of one's own health status, has been reported to be associated with the immune status, the relationship between three different SRH measures (global, self-comparative, and age-comparative) with inflammatory markers as well as the relative strength of these associations by age are not well understood. The current study investigated the associations between SRH measures and inflammatory markers among nursing home employees. METHODS: A sample of 120 Japanese employees at a nursing home (90 women and 30 men), aged 21-68 years (mean, 40.9 years), underwent a blood test for the measurement of inflammatory markers (interferon-γ, interleukin [IL]-4, IL-6, and tumor necrosis factor [TNF]-α, white blood cell count) and SRH during the annual health checkup. Multiple regression analysis adjusted for covariates was performed to analyze the relationship between inflammatory markers and SRH measures stratified by age, that is, aged < 40 years (younger age group) and 40 years and over (older age group). RESULTS: Among the participants aged 40 years and over, poor global SRH was significantly associated with an increase in IL-6, while poor age-comparative SRH was significantly associated with an increase in TNF-α among participants aged < 40 years in the fully adjusted model controlling for potential confounders. Age-comparative SRH was also significantly associated with an increase in IL-6 among all participants. Self-comparative SRH was not significantly associated with inflammatory markers. CONCLUSIONS: Our results suggest that three SRH measures are not equivalently associated with inflammatory markers, especially when the analyses were performed separately for the younger and older populations. This implies that not only differences in forms of SRH but also in age modify the relationship between SRH and inflammatory markers.

Workplace social capital and refraining from seeking medical care in Japanese employees: a 1-year prospective cohort study.

OBJECTIVES: We examined the association of workplace social capital (WSC), including structural and cognitive dimensions, with refraining from seeking medical care (RSMC) among Japanese employees. DESIGN: One-year prospective cohort study. SETTING AND PARTICIPANTS: We surveyed 8770 employees (6881 men and 1889 women) aged 18-70 years from 12 firms in Japan using a self-administered questionnaire comprising the WSC scale and the items on potential confounders (ie, age, educational attainment and equivalent annual household income) at baseline (from April 2011 to March 2013). OUTCOME MEASURES: At a 1-year follow-up, we measured RSMC using a single-item question 'In the past year, have you ever refrained from visiting a hospital, clinic, acupuncturist or dentist despite your sickness (including a slight cold or cavity) or injury?' RESULTS: The results of Cox regression with robust variance showed that, after adjusting for potential confounders, the low WSC group (ie, the lowest tertile group) had a significantly higher relative risk (RR) of RSMC compared with the high WSC group (ie, the highest tertile group) among both men and women (overall WSC: RR 1.09 (95% CI 1.01 to 1.17) and 1.20 (95% CI 1.06 to 1.37); structural dimension: RR 1.13 (95% CI 1.04 to 1.22) and 1.25 (95% CI 1.07 to 1.45); and cognitive dimension: RR 1.11 (95% CI 1.03 to 1.20) and 1.21 (95% CI 1.06 to 1.38), respectively). Trend analysis using a continuous score of the WSC scale also showed a significant association of low WSC with a higher risk of RSMC among both men and women. CONCLUSIONS: Our findings suggest that the lack of social capital in the workplace is associated with RSMC among Japanese employees.

The Association Between Unit-Level Workplace Social Capital and Intention to Leave Among Employees in Health Care Settings: A Cross-Sectional Multilevel Study.

OBJECTIVE: The aim of this study was to investigate the multilevel association between workplace social capital and intention to leave among employees in health care settings in Japan. METHODS: This study was a secondary data analysis of the cross-sectional data. A sample of 658 Japanese employees in health care settings with 17 facilities were recruited using a self-administered questionnaire. Multilevel linear regression analysis of intention to leave on unit-level workplace social capital (average score for each unit) was conducted. RESULTS: Among 317 respondents from 49 units, after adjusting for demographic and work-related variables, both unit-level and individual-level workplace social capital were significantly negatively associated with intention to leave (P < 0.001). CONCLUSIONS: The current study found that there was a significant negative association between unit-level workplace social capital and intention to leave in the health care field.

The Association of Workplace Social Capital With Work Engagement of Employees in Health Care Settings: A Multilevel Cross-Sectional Analysis.

OBJECTIVE: The aim of the study was to examine the cross-sectional multilevel association between unit-level workplace social capital and individual-level work engagement among employees in health care settings. METHODS: The data were collected from employees of a Japanese health care corporation using a questionnaire. The analyses were limited to 440 respondents from 35 units comprising five or more respondents per unit. Unit-level workplace social capital was calculated as an average score of the Workplace Social Capital Scale for each unit. Multilevel regression analysis with a random intercept model was conducted. RESULTS: After adjusting for demographic variables, unit-level workplace social capital was significantly and positively associated with respondents' work engagement (P < 0.001). The association remained significant after additionally adjusting for individual-level perceptions of workplace social capital (P < 0.001). CONCLUSIONS: Workplace social capital might exert a positive contextual effect on work engagement of employees in health care settings.

Relationship between sickness presenteeism (WHO-HPQ) with depression and sickness absence due to mental disease in a cohort of Japanese workers.

BACKGROUND: Absence due to mental disease in the workplace has become a global public health problem. We aimed to evaluate the influence of presenteeism on depression and absence due to mental disease. METHODS: A prospective study of 1831 Japanese employees from all areas of Japan was conducted. Presenteeism and depression were measured by the validated Japanese version of the World Health Organization Health and Work Performance Questionnaire (WHO-HPQ) and the K6 scale, respectively. Absence due to mental disease across a 2-year follow up was surveyed through medical certificates obtained for work absence. RESULTS: After adjusting for age and gender, participants with higher rates of sickness absolute and relative presenteeism (the lowest tertile of the scores) were significantly more likely to be absent due to mental disease (OR=4.40, 95% CI: 1.65-11.73, and OR=3.31, 95% CI: 1.50-7.27). Subsequently, higher rates of sickness absolute or relative presenteeism were significantly associated with higher rates of depression (K6≥13) one year later (OR=3.79, 95% CI: 2.48-5.81, and OR=2.89, 95% CI: 1.98-4.22). LIMITATIONS: The number of females in the sample was relatively small. However, the rates of absence for females with and without mental illness did not significantly differ from those of men. CONCLUSIONS: More sickness presenteeism scores were found to be related to higher rates of depression and absence due to mental disease in this large-scale cohort of Japanese workers. Measurement of presenteeism could be used to evaluate the risk for depression and absenteeism. Furthermore, our findings suggest that intervention to improve presenteeism would be effective in preventing depression and absence due to mental illness.

Optimal cutoff values of WHO-HPQ presenteeism scores by ROC analysis for preventing mental sickness absence in Japanese prospective cohort.

OBJECTIVES: Sickness absence due to mental disease in the workplace has become a global public health problem. Previous studies report that sickness presenteeism is associated with sickness absence. We aimed to determine optimal cutoff scores for presenteeism in the screening of the future absences due to mental disease. METHODS: A prospective study of 2195 Japanese employees from all areas of Japan was conducted. Presenteeism and depression were measured by the validated Japanese version of the World Health Organization Health and Work Performance Questionnaire (WHO-HPQ) and K6 scale, respectively. Absence due to mental disease across a 2-year follow-up was surveyed using medical certificates obtained for work absence. Socioeconomic status was measured via a self-administered questionnaire. Receiver operating curve (ROC) analysis was used to determine optimal cutoff scores for absolute and relative presenteeism in relation to the area under the curve (AUC), sensitivity, and specificity. RESULTS: The AUC values for absolute and relative presenteeism were 0.708 (95% CI, 0.618-0.797) and 0.646 (95% CI, 0.546-0.746), respectively. Optimal cutoff scores of absolute and relative presenteeism were 40 and 0.8, respectively. With multivariate adjustment, cohort participants with our proposal cutoff scores for absolute and relative presenteeism were significantly more likely to be absent due to mental disease (OR = 4.85, 95% CI: 2.20-10.73 and OR = 5.37, 95% CI: 2.42-11.93, respectively). The inclusion or exclusion of depressive symptoms (K6≥13) at baseline in the multivariate adjustment did not influence the results. CONCLUSIONS: Our proposed optimal cutoff scores of absolute and relative presenteeism are 40 and 0.8, respectively. Participants who scored worse than the cutoff scores for presenteeism were significantly more likely to be absent in future because of mental disease. Our findings suggest that the utility of presenteeism in the screening of sickness absence due to mental disease would help prevent such an absence.

Altered DNA methylation status of human brain derived neurotrophis factor gene could be useful as biomarker of depression.

Brain-derived neurotrophic factor (BDNF) is involved in the survival, development, and synaptic plasticity of neurons. BDNF is believed to be associated with the pathophysiology of psychiatric disorders. Several studies have suggested the relevance of DNA methylation in its promoter region with depression. Here, we report different methylation statuses in groups with different depressive scores or undergoing different levels of job-stress. DNA samples were extracted from the saliva of 774 Japanese workers, and the methylation status was determined using the Illumina HumanMethylation 450 K Microarray. Depressive symptoms were measured using the Kessler's K6 questionnaire. Job-stress scales were assessed via a self-administered questionnaire. Independent DNA pools were formed based on K6 and job-strain scores, and the methylation levels were compared among these pools. The average DNA methylation rate was significantly decreased in the highest K6 score group compared to the lowest group (methylated signals, 14.2% vs. 16.5%, P = 2 · 16 × 10(-198)). This difference remained for the CpG island in the promoter region (10.4% vs. 5.8%, P = 3 · 67 × 10(-133)). Regarding the job-strain score, there was a slight increase in the methylation level of the whole gene in the group with the highest score compared to that with the lowest score; however, these groups showed no difference in the promoter region. Our results revealed significant changes in the DNA methylation status of the complete human BDNF gene in persons with depression compared to normal individuals, especially in the promoter region of exon 1. This indicates that DNA methylation in this gene is a promising biomarker for diagnosing depression.

Occupational and socioeconomic differences in actigraphically measured sleep.

Occupational conditions, together with socioeconomic status, may modulate sleep. This study examined the association of occupational conditions and socioeconomic status with actigraphic measures of sleep in workers. Fifty-five employees (40 ± 12 years) wore a wrist actigraph during sleep for seven consecutive nights. Sleep variables addressed included total sleep time, sleep efficiency, mean activity during sleep, sleep-onset latency, and wake after sleep onset. We also measured household income, occupational class, work schedule, weekly work hours, job demand, job control, worksite social support, effort-reward imbalance, organizational justice, and workplace social capital. Multiple linear regression models were used to determine the association of occupational indicators, socioeconomic status, as well as age and gender with each sleep variable. Higher workplace social capital was associated consistently with longer total sleep time (P < 0.001), higher sleep efficiency (P < 0.05) and lower mean activity during sleep (P < 0.07). Low occupational class (P < 0.01), higher job demand (P < 0.05) and lower job control (P < 0.05) were associated with longer total sleep time. No associations were significant for sleep-onset latency or wake after sleep onset. These preliminary results suggest that enhanced workplace social capital is closely associated with better quality and quantity of sleep.

Association of job demands with work engagement of Japanese employees: comparison of challenges with hindrances (J-HOPE).

OBJECTIVES: Recent epidemiological research in Europe has reported that two groups of job demands, i.e., challenges and hindrances, are differently associated with work engagement. The purpose of the present study was to replicate the cross-sectional association of workload and time pressure (as a challenge) and role ambiguity (as a hindrance) with work engagement among Japanese employees. METHODS: Between October 2010 and December 2011, a total of 9,134 employees (7,101 men and 1,673 women) from 12 companies in Japan were surveyed using a self-administered questionnaire comprising the Job Content Questionnaire, National Institute for Occupational Safety and Health Generic Job Stress Questionnaire, short 10-item version of the Effort-Reward Imbalance Questionnaire, short nine-item version of the Utrecht Work Engagement Scale, and demographic characteristics. Multilevel regression analyses with a random intercept model were conducted. RESULTS: After adjusting for demographic characteristics, workload and time pressure showed a positive association with work engagement with a small effect size (standardized coefficient [ß] = 0.102, Cohen's d [d] = 0.240) while role ambiguity showed a negative association with a large effect size (ß = -0.429, d = 1.011). After additionally adjusting for job resources (i.e., decision latitude, supervisor support, co-worker support, and extrinsic reward), the effect size of workload and time pressure was not attenuated (ß = 0.093, d = 0.234) while that of role ambiguity was attenuated but still medium (ß = -0.242, d = 0.609). CONCLUSIONS: Among Japanese employees, challenges such as having higher levels of workload and time pressure may enhance work engagement but hindrances, such as role ambiguity, may reduce it.

Risk of progression to hypertension in nonhypertensive Japanese workers aged 20-64 years.

OBJECTIVE: Prehypertension is a known risk factor for hypertension in individuals aged less than 20 or more than 35 years, but no large studies have investigated this risk in individuals aged 20-34 years. This study investigated progression to hypertension in nonhypertensive individuals aged 20-34 years and compared this group with individuals aged 35-64 years. METHODS: A total of 12,639 nonhypertensive individuals aged 20-64 years were followed from 1999 to 2008. Hazard ratios for progression to hypertension were calculated for men and women according to three blood pressure (BP) categories (optimal BP: <120/80 mmHg; normal BP: 120-129/80-84 mmHg; high-normal BP: 130-139/85-89 mmHg) and three age groups (20-34, 35-49 and 50-64 years). RESULTS: Progression to hypertension occurred in 4617 individuals (36.5%). The risk of progression to hypertension increased significantly with increasing baseline BP category in men and women in all age groups. The association between baseline BP and progression to hypertension was stronger in the group aged 20-34 years than in the older age groups, especially in men. CONCLUSION: The results of this study confirm that normal or high-normal BP increases the risk of progression to hypertension in individuals aged 20-34 years. In men, the association between baseline BP and progression to hypertension is stronger in this age group than in older age groups. Health providers should be aware that normal or high-normal BP is a risk factor for progression to hypertension even in individuals aged 20-34 years.

Optimum cut-off point of the Japanese short version of the effort-reward imbalance questionnaire.

OBJECTIVES: The theoretical threshold (effort-reward ratio >1.0) may not be ideal for the Japanese short version of the effort-reward imbalance (ERI) questionnaire. We aimed to seek the optimum cut-off point. METHODS: We administered the original and short versions of the ERI questionnaire with a psychological distress scale to randomly selected workers (n=1,489) in a web-based survey. We evaluated kappa statistics and conducted receiver operating characteristics curve analyses. Cut-off values of the short version effort-reward ratios at 0.1 intervals in the range of 1.0-1.9 were tested using the criterion of an effort-reward ratio >1.0 for the original version. RESULTS: The short version questionnaire had acceptable reliabilities. When using the theoretical cut-off point, the prevalence of high-risk groups was 63.2% for the short version compared with 18.9% for the original version, and their agreement was slight. Kappa agreements and receiver operating characteristics curve analyses suggested that a short-version effort-reward ratio of around 1.3 and 1.4 was the most equivalent to the original criterion. Regression equation procedures supported the findings, and ERI defined by the cut-off values showed significant associations with an external criterion (psychological distress) with minimal estimation error. Because the highest but only moderate kappa agreements with the risk group defined by the original criterion were obtained when setting 1.4-1.6 as the cut-offs, we considered >1.4 as optimal. CONCLUSIONS: This empirical investigation suggests the cut-off value of >1.4 for the Japanese short version of the ERI questionnaire screens out the ERI group with the most compatibility with the original version.

Psychosocial mechanisms of psychological health disparity in Japanese workers.

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.

Japanese dietary pattern consistently relates to low depressive symptoms and it is modified by job strain and worksite supports.

BACKGROUND: This study examined the association between traditional Japanese dietary pattern and depressive symptoms in Japanese workers, employing large-scale samples, considering socioeconomic status (SES) and job stress factors. METHODS: A cross-sectional study of 2266 Japanese employees aged 21-65 years from all areas of Japan was conducted as part of the Japanese Study of Health, Occupation and Psychosocial factors related Equity (J-HOPE). Habitual diet was assessed by FFQ (BDHQ). The depression degree and job stress factors (job demand, job control, and worksite support) were measured by K6 and Job Content Questionnaire. RESULTS: Participants with high scores for the balanced Japanese dietary pattern were significantly less likely to show probable mood/anxiety disorders (K6≥9) with multivariate adjustment including SES and job stress factors (odds ratio=0.66 [0.51-0.86], trend P=0.002). Other dietary patterns were not associated with depressive symptoms. Even after stratification by job stress factors, the Japanese dietary pattern was consistently protective against depressive symptoms. Furthermore, a highly significant difference between the first and third tertiles of the dietary pattern was observed in participants with active strain (high demand and high control) with low worksite supports (8.5 vs. 5.2, P=0.011). LIMITATIONS: Female participant sample was relatively small. CONCLUSIONS: Japanese dietary pattern consistently related to low depressive symptoms in this large-scale cohort of Japanese workers, even after adjusting for SES and job stress factors. The protective impact is especially strong for workers with active strain and low support. Making better use of traditional dietary patterns may facilitate reducing social disparities in mental health.

Socioeconomic status is significantly associated with dietary salt intakes and blood pressure in Japanese workers (J-HOPE Study).

The association of socioeconomic status (SES) with nutrients intakes attracts public attention worldwide. In the current study, we examined the associations of SES with dietary salt intake and health outcomes in general Japanese workers (2,266) who participated in this Japanese occupational cohort. SES was assessed by a self-administered questionnaire. Dietary intakes were assessed with a validated, brief, self-administered diet history questionnaire (BDHQ). Multiple linear regression and stratified analysis were used to evaluate the associations of salt intake with the confounding factors. Education levels and household incomes were significantly associated with salt intake, as well as blood pressures (P < 0.05). After adjusting for age, sex and total energy intake, both years of education and household income significantly affect the salt intake (for education, ß = -0.031, P = 0.040; for household income, ß = -0.046, P = 0.003). SES factors also affect the risk of hypertension, those subjects with higher levels of education or income had lower risk to become hypertensive (ORs for education was 0.904, P < 0.001; ORs for income was 0.956, P = 0.032). Our results show that SES is an independent determinant of salt intake and blood pressure, in order to lower the risk of hypertension, the efforts to narrow the social status gaps should be considered by the health policy-makers.

Socioeconomic status is significantly associated with the dietary intakes of folate and depression scales in Japanese workers (J-HOPE Study).

The association of socioeconomic status (SES) with nutrient intake attracts public attention worldwide. In the current study, we examined the associations of SES with dietary intake of folate and health outcomes in general Japanese workers. This Japanese occupational cohort consisted off 2266 workers. SES was assessed by a self-administered questionnaire. Intakes of all nutrients were assessed with a validated, brief and self-administered diet history questionnaire (BDHQ). The degree of depressive symptoms was measured by the validated Japanese version of the K6 scale. Multiple linear regression and stratified analysis were used to evaluate the associations of intake with the confounding factors. Path analysis was conducted to describe the impacts of intake on health outcomes. Education levels and household incomes were significantly associated with intake of folate and depression scales (p < 0.05). After adjusting for age, sex and total energy intake, years of education significantly affect the folate intake (ß = 0.117, p < 0.001). The structural equation model (SEM) shows that the indirect effect of folate intake is statistically significant and strong (p < 0.05, 56% of direct effect) in the pathway of education level to depression scale. Our study shows both education and income are significantly associated with depression scales in Japanese workers, and the effort to increase the folate intake may alleviate the harms of social disparities on mental health.

Folate intake and depressive symptoms in Japanese workers considering SES and job stress factors: J-HOPE study.

BACKGROUND: Recently socioeconomic status (SES) and job stress index received more attention to affect mental health. Folate intake has been implicated to have negative association with depression. However, few studies were published for the evidence association together with the consideration of SES and job stress factors. The current study is a part of the Japanese study of Health, Occupation and Psychosocial factors related Equity (J-HOPE study) that focused on the association of social stratification and health and our objective was to clarify the association between folate intake and depressive symptoms in Japanese general workers. METHODS: Subjects were 2266 workers in a Japanese nationwide company. SES and job stress factors were assessed by self-administered questionnaire. Folate intake was estimated by a validated, brief, self-administered diet history questionnaire. Depressive symptoms were measured by Kessler's K6 questionnaire. "Individuals with depressive symptoms" was defined as K6≥9 (in K6 score of 0-24 scoring system). Multiple logistic regression and linear regression model were used to evaluate the association between folate and depressive symptoms. RESULTS: Several SES factors (proportion of management positions, years of continuous employment, and annual household income) and folate intake were found to be significantly lower in the subjects with depressive symptom (SES factors: p < 0.001; folate intake: P = 0.001). There was an inverse, independent linear association between K6 score and folate intake after adjusting for age, sex, job stress scores (job strains, worksite supports), and SES factors (p = 0.010). The impact of folate intake on the prevalence of depressive symptom by a multiple logistic model was (ORs[95% CI]: 0.813 [0.664-0.994]; P =0.044). CONCLUSIONS: Our cross-sectional study suggested an inverse, independent relation of energy-adjusted folate intake with depression score and prevalence of depressive symptoms in Japanese workers, together with the consideration of SES and job stress factors.