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.

Correction: Development of Risk Score for Predicting 3-Year Incidence of Type 2 Diabetes: Japan Epidemiology Collaboration on Occupational Health Study.

[This corrects the article DOI: 10.1371/journal.pone.0142779.].

Workplace social capital and the onset of major depressive episode among workers in Japan: a 3-year prospective cohort study.

BACKGROUND: This study examined the prospective association of workplace social capital (WSC) with major depressive episode (MDE) among Japanese employees. METHODS: A 3-year prospective cohort study was conducted among 1058 employees from a private think-tank company who participated in a baseline survey; after excluding those with MDE in the past 12 months, 929 were followed up. WSC at baseline was measured using a 3-item scale. MDE was assessed at baseline and at follow-up every year, by using a web-based, self-administered version of the WHO Composite International Diagnostic Interview (WHO-CIDI) 3.0 depression section, based on the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition: Text Revision (DSM-IV-TR)/DSM-5 criteria. Cox discrete-time hazards analyses were used to estimate HRs and 95% CIs, adjusting for covariates. RESULTS: A group with middle-level WSC scores had the lowest risk of MDE after being fully adjusted (HR 0.34, 95% CI 0.14 to 0.84, p=0.02). The relationship between WSC and MDE was U-shaped, although a non-linear model fit better than a linear model, with only marginally statistical significance (p=0.06). Dichotomised and continuous variables of WSC scores were significantly and negatively associated with MDE (p=0.03 and p<0.01, respectively). CONCLUSIONS: The current study replicated a previous finding from Finland that WSC was a protective factor of the onset of MDE in Japan. The slightly U-shaped relationship, that is, the group with high WSC having a small elevated risk of MDE, may reflect a dark side of WSC in a country with collectivity-oriented and hierarchy-oriented culture, such as Japan.

Correction: Work Engagement as a Predictor of Onset of Major Depressive Episode (MDE) among Workers, Independent of Psychological Distress: A 3-Year Prospective Cohort Study.

[This corrects the article DOI: 10.1371/journal.pone.0148157.].

Work Engagement as a Predictor of Onset of Major Depressive Episode (MDE) among Workers, Independent of Psychological Distress: A 3-Year Prospective Cohort Study.

OBJECTIVE: This study investigated work engagement as a baseline predictor of onset of major depressive episode (MDE). METHODS: The study used a prospective cohort design, conforming to the STROBE checklist. Participants were recruited from the employee population of a private think tank company (N = 4,270), and 1,058 (24.8%) of them completed a baseline survey, of whom 929 were included in this study. Work engagement and psychological distress at baseline were assessed as predictor variables. MDE was measured at baseline and at each of the follow-ups as the outcome, using the web-based, self-administered version of the Japanese WHO-CIDI 3.0 depression section based upon DSM-IV-TR/DSM-5 criteria. Cox discrete-time hazards analyses were conducted to estimate hazard ratios (95% confidence intervals CIs). RESULTS: Follow-up rates of participants (N = 929) were 78.4%, 67.2%, and 51.6% at 1-, 2-, and 3-year follow-ups, respectively. The association between work engagement at baseline and the onset of MDE was U-shaped. Compared with a group with low work engagement scores, groups with the middle and high scores showed significantly (HR = 0.19, 95% CI = 0.05 to 0.64; p = 0.007) and marginally significantly (HR = 0.48, 95% CI = 0.20 to 1.15, p = 0.099) lower risks of MDE, respectively, over the follow-ups, after adjusting for covariates. The pattern remained the same after additionally adjusting for psychological distress. CONCLUSIONS: The present study first demonstrated work engagement as an important predictor of the onset of MDE diagnosed according to an internationally standard diagnostic criteria of mental disorders.

Development of Risk Score for Predicting 3-Year Incidence of Type 2 Diabetes: Japan Epidemiology Collaboration on Occupational Health Study.

OBJECTIVE: Risk models and scores have been developed to predict incidence of type 2 diabetes in Western populations, but their performance may differ when applied to non-Western populations. We developed and validated a risk score for predicting 3-year incidence of type 2 diabetes in a Japanese population. METHODS: Participants were 37,416 men and women, aged 30 or older, who received periodic health checkup in 2008-2009 in eight companies. Diabetes was defined as fasting plasma glucose (FPG) ≥ 126 mg/dl, random plasma glucose ≥ 200 mg/dl, glycated hemoglobin (HbA1c) ≥ 6.5%, or receiving medical treatment for diabetes. Risk scores on non-invasive and invasive models including FPG and HbA1c were developed using logistic regression in a derivation cohort and validated in the remaining cohort. RESULTS: The area under the curve (AUC) for the non-invasive model including age, sex, body mass index, waist circumference, hypertension, and smoking status was 0.717 (95% CI, 0.703-0.731). In the invasive model in which both FPG and HbA1c were added to the non-invasive model, AUC was increased to 0.893 (95% CI, 0.883-0.902). When the risk scores were applied to the validation cohort, AUCs (95% CI) for the non-invasive and invasive model were 0.734 (0.715-0.753) and 0.882 (0.868-0.895), respectively. Participants with a non-invasive score of ≥ 15 and invasive score of ≥ 19 were projected to have >20% and >50% risk, respectively, of developing type 2 diabetes within 3 years. CONCLUSIONS: The simple risk score of the non-invasive model might be useful for predicting incident type 2 diabetes, and its predictive performance may be markedly improved by incorporating FPG and HbA1c.

Smoking, Smoking Cessation, and the Risk of Type 2 Diabetes among Japanese Adults: Japan Epidemiology Collaboration on Occupational Health Study.

AIMS: To examine the association of smoking status, smoking intensity, and smoking cessation with the risk of type 2 diabetes (T2D) using a large database. METHODS: The present study included 53,930 Japanese employees, aged 15 to 83 years, who received health check-up and did not have diabetes at baseline. Diabetes was defined as fasting plasma glucose ≥126 mg/dl, random plasma glucose ≥200 mg/dl, HbA1c ≥6.5% (≥48 mmol/mol), or receiving medication for diabetes. Cox proportional-hazards regression models were used to investigate the association between smoking and the risk of diabetes. RESULTS: During 3.9 years of median follow-up, 2,441 (4.5%) individuals developed T2D. The multivariable-adjusted hazard ratios (95% CI) for diabetes were 1 (reference), 1.16 (1.04 to 1.30) and 1.34 (1.22 to 1.48) for never smokers, former smokers, and current smokers, respectively. Diabetes risk increased with increasing numbers of cigarette consumption among current smokers (P for trend <0.001). Although the relative risk of diabetes was greater among subjects with lower BMIs (< 23 kg/m2), attributable risk was greater in subjects with higher BMIs (≥ 23 kg/m2). Compared with individuals who had never smoked, former smokers who quit less than 5 years, 5 to 9 years, and 10 years or more exhibited hazards ratios for diabetes of 1.36 (1.14 to 1.62), 1.23 (1.01 to 1.51), and 1.02 (0.85 to 1.23), respectively. CONCLUSIONS: Results suggest that cigarette smoking is associated with an increased risk of T2D, which may decrease to the level of a never smoker after 10 years of smoking cessation.

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.

Cross-sectional study on respiratory effect of toner exposure.

In this baseline study, part of a cohort study to clarify the effect of toner exposure on the respiratory system, we surveyed 803 male toner workers and 802 referents with regard to their subjective respiratory symptoms and chest X-ray results. We also examined individual exposure history, current working conditions, and personal exposure levels to toner. There was a significantly higher prevalence of "coughing and sputum" related complaints among toner-exposed workers in the 30 and 40-year age groups. The group with toner-exposure history showed a higher odds ratio, by logistic regression, in relation to all questions regarding coughing. Mild fibrotic changes were observed in the chest X-rays of four workers who had engaged in toner-exposure work for at least a decade or more, and all four had reported allergic disease. Although we observed a tendency of higher prevalence of "coughing and sputum" in toner-exposed workers, the possibility of information bias cannot be eliminated. It should also be noted that this tendency did not exceed that of the general public. Further analysis is required in this ongoing 10-year cohort study to clarify the effect of toner exposure on the respiratory system.