[Show abstract][Hide abstract] ABSTRACT: Bullying in the workplace is an increasingly recognized threat to employee health. We sought to test three hypotheses related to the determinants of workplace bullying: power distance at work; safety climate; and frustration related to perceived social inequality. A questionnaire survey was administered to a nationally representative community-based sample of 5,000 residents in Japan aged 20-60 years. The questionnaire included questions about employment, occupation, company size, education, household income, and subjective social status (SSS). We inquired about both the witnessing and personal experience of workplace bullying during the past 30 days. Among 2,384 respondents, data were analyzed from 1,546 workers. Multiple logistic regression analyses were used to examine the social determinants of workplace bullying. Six percent and 15 percent of the total sample reported experiencing or witnessing workplace bullying, respectively. After adjusting for gender and age, temporary employees (Odds Ratio [OR]: 2.45 [95% Confidence Interval (CI) = 1.03-5.85]), junior high school graduates (OR: 2.62 [95%CI: 1.01-6.79]), workers with lowest household income (OR: 4.13 [95%CI:1.58-10.8]), and workers in the lowest SSS stratum (OR: 4.21 [95%CI:1.66-10.7]) were at increased risk of experiencing workplace bullying. When all variables were entered simultaneously in the model, a significant inverse association was observed between higher SSS and experiencing bullying (p = 0.002). Similarly in terms of witnessing bullying; SSS was significantly inversely associated (p = 0.017) while temporary employees reported a significantly higher risk of witnessing bullying compared to permanent workers (OR: 2.25 [95%CI:1.04 to 4.87]). The significant association between SSS and experiencing/witnessing workplace bullying supports the frustration hypothesis. The power distance hypothesis was also partly supported by the finding that temporary employees experienced a higher prevalence of workplace bullying.
PLoS ONE 03/2015; 10(3):e0119435. DOI:10.1371/journal.pone.0119435 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study was aimed to investigate the test-retest reliability and validity of a short version of the New Brief Job Stress Questionnaire (New BJSQ) whose scales have one item selected from a standard version. Based on the results from an anonymous web-based questionnaire of occupational health staffs and personnel/labor staffs, we selected higher-priority scales from the standard version. After selecting one item with highest item-total correlation coefficient from each scale, a 23-item questionnaire was developed. A nationally representative survey was administered to Japanese employees (n=1,633) to examine test-retest reliability and validity. Most scales (or items) showed modest but adequate levels of test-retest reliability (r>0.50). Furthermore, job demands and job resources scales (or items) were associated with mental and physical stress reactions while job resources scales (or items) were also associated with positive outcomes. These findings provided a piece of evidence that the short version of the New BJSQ is reliable and valid.
Industrial Health 06/2014; 52(6). DOI:10.2486/indhealth.2014-0114 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed to investigate the reliability and construct validity of a new version of the Brief Job Stress Questionnaire (New BJSQ), which measures an extended set of psychosocial factors at work by adding new scales/items to the current version of the BJSQ. Additional scales/items were extensively collected from theoretical job stress models and similar questionnaires in several countries. Scales/items were field-tested and refined through a pilot internet survey. Finally, an 84-item questionnaire (141 items in total when combined with the current BJSQ) was developed. A nationally representative survey was administered to employees in Japan (n=1,633) to examine the reliability and construct validity. Most scales showed acceptable levels of internal consistency and test-retest reliability. Principal component analyses showed that the first factor explained 50% or greater proportion of the variance in most scales. A scale factor analysis and a correlation analysis showed that these scales fit the theoretical expectations. These findings provided a piece of evidence that the New BJSQ scales are reliable and valid. Although more detailed content and construct validity should be examined in future study, the New BJSQ is a useful instrument to evaluate psychosocial work environment and positive mental health outcomes in the current workplace.
Industrial Health 02/2014; 52(3). DOI:10.2486/indhealth.2013-0185 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To clarify the correlation between kitchen work-related burns and cuts and job stress, a self-administered questionnaire survey was conducted involving 991 kitchen workers among 126 kitchen facilities. The demographics, condition of burns and cuts, job stress with the Brief Job Stress Questionnaire (BJSQ), health condition, and work-related and environmental factors were surveyed. Multiple logistic regression models and trend tests were used according to quartiles (Q1, Q2, Q3, and Q4) of each sub-scale BJSQ. After adjustment for potential confounding variables, burns/cuts were associated with a higher score category (Q4) of job demands (OR: 2.56, 95% CI: 1.10-6.02/OR: 2.72, 95% CI: 1.30-5.69), psychological stress (OR: 4.49, 95% CI: 2.05-9.81/OR: 3.52, 95% CI: 1.84-6.72), and physical stress (OR: 2.41, 95% CI: 1.20-4.98/OR 2.16, 95% CI: 1.16-4.01). The ORs of the burn/cut injures increased from Q1 to Q4 with job demands (p for trend=0.045/0.003), psychological stress (p for trend<0.001/0.001), and physical stress (p for trend=0.006/0.005), respectively. These findings suggest that kitchen work-related burns and cuts are more likely to be correlated with job stress, and the higher the job stress score, the higher the frequency of burns and cuts among kitchen workers.
Industrial Health 01/2014; 52(2). DOI:10.2486/indhealth.2013-0143 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study investigated risk factors for frequent work-related burn and cut injuries and low back pain (LBP) among kitchen workers including personal, work-related and environmental factors. Subjects were 991 kitchen workers in 103 schools, 17 hospitals and nursing homes, and 6 restaurants in central Japan. A cross-sectional survey was carried out using a structured self-administered questionnaire. Logistic regression models were used to examine associations between frequent injuries/LBP and risk factors. The effective response rate was 75.1% (n=744), the mean age was 40.7 (SD 11.7) and 77.2% were female. Burn injury was associated with a smaller kitchen (OR 1.94; 95%CI, 1.13-3.33), and gas kitchens rather than electric kitchens (OR 2.30; 95%CI, 1.17-4.52). LBP was associated with female gender (OR 2.46; 95%CI, 1.37-4.43), high body height (>160 cm) (OR 2.03; 95%CI, 1.22-3.36), and large number of meals produced per person (≥150 meals) (OR 1.83; 95%CI, 1.12-3.00). The results of this study suggest that securing adequate work space and introducing electric kitchen systems may reduce the risk to kitchen workers, as well as the importance of adequate height of cooking equipment and selecting an appropriate volume of meals to produce per person to prevent LBP in kitchen workers.
Industrial Health 02/2013; DOI:10.2486/indhealth.2012-0134 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To elucidate the subjective thermal strain of workers in kitchen working environments, we performed a cross-sectional study involving 991 workers in 126 kitchen facilities in Japan, using a self-reporting questionnaire survey and subjective judgment scales (SJS). The ambient temperature, mean radiant temperature (MRT), and wet-bulb globe temperature (WBGT) index were measured in 10 kitchen facilities of the 126 kitchens. The association of SJS with the types of kitchen was estimated by multiple logistic regression models. Of the 991 kitchen workers, 809 (81%) responded to the questionnaire survey. Compared with the electric kitchens, the proportion of workers who perceived the room temperature as hot to very hot was significantly higher, and the ambient temperature, MRT, and WBGT were significantly higher in the gas kitchens. Compared with the electric kitchens, workers in gas kitchens had a more than fivefold (males) and tenfold (females) higher SJS adjusted for confounding factors (male odds ratio (OR), 5.13; 95% confidence interval (CI), 1.65-15.9; and female OR, 10.9; 95%CI, 3.89-30.5). Although SJS was affected by some confounding factors, our results suggest that workers in gas kitchens might be exposed to a higher heat strains than those in electric kitchens.
Industrial Health 01/2010; 48(2):135-44. DOI:10.2486/indhealth.48.135 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Research on the association between job strain or other job stressors and depressive disorders is still limited. The purpose of the present study was to investigate the prospective association of job strain, role stressors and job insecurity with long-term sick leave due to depressive disorders.
A prospective study was conducted of a total of 15 256 men aged 18-67 years with no previous history of mental disorders employed in six manufacturing factories located in several regions of Japan. At baseline, they were surveyed using a self-administered questionnaire, including self-reported measures of job strain, as well as its components (job overload and job control), role stressors (role ambiguity and role conflict), social support at work, job insecurity and other demographic and psychological covariates. During the follow-up, a long-term sick leave of 30 days or more due to depressive disorders was recorded.
During 5.14 years of follow-up on average, 47 incident cases of sick leave of 30 days or more due to depressive disorders were observed. High job control at baseline was associated with a lower risk of long-term sick leave due to depressive disorders, after adjusting for demographic variables, depressive symptoms and neuroticism at baseline (hazard ratio 0.28, 95% CI 0.11 to 0.71); high role ambiguity was associated with the higher risk (hazard ratio 3.49, 95% CI 1.43 to 8.49).
Job control and role ambiguity may be important predictors of long-term sick leave due to depressive disorders among male employees, independent of depressive symptoms and neuroticism.
Journal of epidemiology and community health 09/2009; 64(3):229-35. DOI:10.1136/jech.2008.085548 · 3.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although the relationship between job stress and depressive symptoms has been well documented among workers in large scale enterprises, the situation in small- and medium-scale enterprises (SMEs) is not fully understood.
To clarify the factors associated with depressive symptoms in SMEs in Japan.
1,516 male and 738 female Japanese workers at SMEs were surveyed using a self-administered questionnaire. We applied hierarchical multiple linear regression with depressive symptoms (Center for Epidemiologic Studies Depressive Symptoms Scale) as the dependent variable, and (1) Individual, (2) Lifestyle, (3) Job stressors, and (4) SME unique factors as independent variables entered in 4 steps. Analyses were stratified by sex due to large differences in stress scores and demographic variables.
Perceived lack of understanding from others with regard to health was the strongest factor associated with increased depressive symptoms (BETA=0.29 in males and 0.28 in females). Higher intragroup conflict (BETA=0.15 in males and 0.09 in females), perceived job future ambiguity (BETA=0.09 in males and 0.11 in females), higher quantitative workload (BETA=0.06 in males and 0.10 in females), and being an employer or a member of the employer's family (BETA=0.06 in males and 0.10 in females) were additional factors associated with high depressive symptoms. Economic concern, being single, cigarette smoking, shorter sleep duration, and skill underutilization were male specific, while younger age and lower social support at work were female specific factors significantly associated with increased depressive symptoms.
These data suggest that poor mental health may be prevented by creating a workplace climate which focuses on the high value of the health of fellow workers.
Journal of Occupational Health 01/2009; 51(1):26-37. DOI:10.1539/joh.L7012 · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study was to assess the association between job strain and smoking cessation among Japanese male employees. In 1997, a baseline questionnaire was given to 2,625 (2,113 males and 512 females) employees of an electronics firm in Gifu Prefecture, Japan. The self-administered questionnaire was a set of questions on smoking habits and consisted of items on socio-demographic variables and smoking habits, including the Japanese version of the Job Content Questionnaire (JCQ). The JCQ consists of scales of job control, job demand, supervisory support, coworker support, job insecurity, physical demands, and isometric load. A total of 733 male smokers were then followed for 2 years, with 446 completing a follow-up questionnaire in 1999 (follow-up rate, 61%). Logistic regression analyses were performed to examine associations between job strain and smoking cessation. Among the 446 participants, 38 had quit smoking. After adjusting for age ((odds ratio: OR) = 0.38, 95% (contidence interval: CI) = 0.15-0.94), men with a high level of physical demands at baseline showed a lower smoking cessation rate at follow-up than did those with a low level. However, when adjustments were made for age and other socio-demographic variables, the odds ratio of smoking cessation showed marginal significance (OR = 0.45, 95% CI = 0.16-1.29). There was no significant association between other job strain variables and smoking cessation at the 2-year follow-up. No significant association was found between job strain and change in the number of smoked cigarettes per day. The present study did not support the hypothesis that higher levels of job stressors are associated with a lower rate of smoking cessation among men.
[Show abstract][Hide abstract] ABSTRACT: The relationship between passive smoking and sleep is uncertain.
To examine the association of passive/active smoking with sleep disturbances.
732 women and 1,896 men, working in a suburb of Tokyo, were surveyed using a self-administered questionnaire. Information on smoking, passive smoking exposure, and sleep was elicited. Exposure levels to passive smoking were assessed separately at work and at home as no, occasional, or regular exposure. Risk of sleep disturbances according to smoking status was estimated using logistic regression with odds ratios (OR) and 95% confidence intervals (CIs) as measures of association.
Compared to never smokers, odds of difficulty awakening in the morning (DAM) in current smokers were significantly higher for women (OR 1.95) and men (OR 1.50), while increased difficulty initiating sleep (OR 1.88) and decreased early morning awakening (OR 0.31) were found only in women. Never smoking men occasionally exposed to passive smoking at work but not at home had increased odds (OR 1.81) of short sleep duration (SSD, < 6 h) than unexposed counterparts.
The analyses suggest that exposure to passive smoking at work is associated with SSD in men, while current smoking relates to various subtypes of sleep disturbances in both sexes.
International Journal of Behavioral Medicine 02/2008; 15(2):81-91. DOI:10.1080/10705500801929577 · 2.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous studies have found that smoking is a strong factor that increases peripheral blood CD4+ T lymphocytes. However, most studies did not assess the cumulative long-life exposure of smoking on differential lymphocyte populations. In this study, to clarify the association of smoking habits and circulating lymphocytes, we conducted a cross-sectional study of 60 male current smokers. Smoking status was estimated by number of cigarettes smoked per day, smoking years, and Brinkman Index (BI) as calculated by multiplying the number of cigarettes smoked per day by the smoking years. Counts of CD4+CD45RO+CD69+ T and CD4+CD45RO+ T lymphocytes were strongly and positively correlated with BI and remained highly significant after controlling for alcohol drinking, leisure-time physical activity, and caffeine intake (r(p)>.465, p<.001). These lymphocytes were also significantly correlated with the number of cigarettes smoked per day and smoking years, but the association was weaker than the BI. The findings suggest that the CD4+CD45RO+CD69+ T and CD4+CD45RO+ T lymphocytes are sensitive to cumulative effect of smoking, and may serve as a potential immuno-biomarker for active smoking.
[Show abstract][Hide abstract] ABSTRACT: To examine the association of job stress with sleep-related breathing disturbance (SBD), a cross-sectional sample of 1940 males aged 17-83 (mean 45) years in 292 small and medium-sized enterprises in Japan were surveyed by means of a self-administered questionnaire. Perceived job stress was evaluated by the Japanese version of the Generic Job Stress Questionnaire developed by the US National Institute for Occupational Safety and Health, which included 13 job stress variables. Participants were divided into thirds according to their job stress scores. SBD was assessed by the question "Have you ever felt difficulty breathing during sleep or has anyone in your family told you that you have such difficulty?" SBD was defined as presence of symptoms more than once a month. Risk of SBD through job stress was estimated using logistic regression with odds ratios (ORs) and 95% confidence intervals (CIs) as measures of association. Prevalence of study-defined SBD was 6.7%. Participants who perceived the lowest level of social support from supervisors, and highest levels of job future ambiguity, interpersonal conflict at the workplace, job dissatisfaction, variance in workload, and quantitative workload had significantly increased risk of SBD after adjusting for potential confounders. High depressive symptoms, as measured by Center for Epidemiologic Studies Depression scale scores of 16 or higher, were also significantly associated with increased SDB. Although the results should be considered preliminary because of the self-reporting and cross-sectional design, data suggest that exposure to high job stress could be a possible risk factor for developing or aggravating SBD. Results also indicate that job stress should be considered when evaluating SBD in occupational and clinical settings.
Social Science & Medicine 07/2007; 64(12):2520-32. DOI:10.1016/j.socscimed.2007.03.012 · 2.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Associations between psychosocial work factors and sickness absence were investigated in a cross-sectional study of 833 daytime workers. Participants completed a questionnaire regarding psychosocial work factors using the US National Institute for Occupational Safety and Health Generic Job Stress Questionnaire (job control, quantitative workload, cognitive demands, variance in workload, intragroup conflict, intergroup conflict, supervisor support, coworker support, family support, job satisfaction and depressive symptoms) and the number of days of sickness absence within the previous year. Multivariate analyses of covariance with age and occupation as covariates (MANCOVA) were used to test the relationships between psychosocial work factors and sickness absence stratified by sex. In men, the age-adjusted MANCOVA showed that, quantitative workload was highest in the 0.5-4.5 d of sickness absence group (p<0.001). However, the levels of stress reactions (job satisfaction and depressive symptoms) in this group were almost identical to the levels recorded in the no sickness absence group. In contrast, low levels of job control (p<0.01), supervisor support (p<0.05), and job satisfaction (p<0.01) and higher symptoms of depression (p<0.001) were associated with 5 d or more sickness absence. In women, only high job satisfaction was associated with 5 d or more sickness absence (p<0.10). This study suggests that appropriate use of sickness absence at times of being exposed to high quantitative workload may help male workers to recover from stressful situations.
Industrial Health 05/2007; 45(2):224-31. DOI:10.2486/indhealth.45.224 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Active smoking is a risk factor for occupational injury, whereas its association with passive smoking is unknown. To evaluate the contribution of active and passive smoking to non-fatal occupational injury in manufacturing sectors, 2302 randomly selected workers aged 16-83 years working in 244 small- and medium-scale enterprises in Yashio city, Japan, were surveyed by means of a self-administered questionnaire. Smoking history, exposure to passive smoking, and occupational injury were evaluated by self-report. Exposure levels to passive smoking were assessed separately at work and at home as never, occasional, or regular exposure. Overall, 61.4% of men and 22.3% of women were current smokers. Among never smokers, 62.2% of men and 68.6% of women reported exposure to passive smoking either at work or home. Prevalence of occupational injuries was 36.2% for never, 43.3% for former, and 41.2% for current smokers among men and 19.7% for never, 22.2% for former, and 25.2% for current smokers among women. Among never smoking men, odds ratios (ORs) of occupational injury were 2.11 when regularly exposed to passive smoking at work or at home (p=0.025), 2.27 at work (p=0.015), and 3.08 at home (p=0.106), in comparison to never smoking men who were never exposed to passive smoking either at work or at home (referent group). These associations were attenuated to be non-significant, after controlling for potential confounders. Never smoking men with occasional exposure to passive smoking were not significant ORs (1.11-1.19). In contrast, current and former smoking men had significant increases in adjusted ORs (1.57-2.00). In women exposed to smoking there was a non-significant increase in occupational injury. The present study indicates an expected increase in the risk of, occupational injury for current and former smoking men and suggests that exposure to passive smoking is a possible risk factor for never smoking men.
Social Science & Medicine 12/2006; 63(9):2452-63. DOI:10.1016/j.socscimed.2006.06.009 · 2.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Workers involved in small-scale manufacturing businesses are known to comprise a high-risk population for occupational injury. The present study investigated the prevalence and correlates of occupational injury in this population. A self-administered questionnaire that solicited answers about occupational information including injury, demographic characteristics, health conditions and lifestyle factors was collected from a sample of 1,298 workers in 228 small-scale manufacturing enterprises (defined as fewer than 50 workers) aged 16-78 (mean 46) yr in Yashio city, Saitama, Japan (response rate 65.5%). The enterprises were randomly selected from the 2000 edition of the city commercial directory corresponding to the distribution of types of businesses in the city. Occupational injury was assessed by asking subjects, ;Have you ever been injured during your work, including minor scratches and cuts in the previous 1-yr period?' The possible response was either ;yes' or ;no.' The prevalence of study-defined occupational injury among the workers was 35.6% (male 43.0%, female 17.9%). Among job types, manufacturing (44.2%) and driving (43.5%) had high rates of occupational injuries. Similarly, occupational injuries were high in the papermaking (54.5%) and machinery (47.7%) industries. For males, younger age, current or former smoking, insomnia symptoms, and disease(s) currently under treatment were correlated with injury, whereas for females, being unmarried, higher educational status, and insomnia symptoms were the correlating factors. Occupational injury is common among small-scale manufacturing businesses, and is associated with multiple controllable factors. Countermeasures such as prohibiting smoking during work, sleep health education, job safety training for young/inexperienced workers are appropriate methods for eliminating or reducing injuries.
Journal of Occupational Health 10/2006; 48(5):366-76. DOI:10.1539/joh.48.366 · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Workers involved in manufacturing are known to comprise a high-risk population for occupational injury, and this risk is greater in small and medium-sized enterprises (SMEs). The purpose of this study was to examine the association between psychosocial job stress and occupational injuries among workers in SMEs.
One thousand forty-nine men and 721 women from 244 SMEs participated in this study. Perceived job stress was evaluated with the Japanese version of the generic job stress questionnaire, which covered 14 job stress variables. Occupational injury was assessed by self-report during the last 1-year period.
Workers with high quantitative workload (odds ratio [OR] = 1.55 for men, 1.62 for women), high cognitive demands (OR = 1.70 for men, 1.53 for women), and low job satisfaction (OR = 1.33 for men, 1.93 for women) had a significantly increased risk of occupational injury in the multivariate model. High variance in workload (OR = 1.70) and high job future ambiguity (OR = 1.35) in men, and low job control (OR = 2.04) and high intragroup conflict (OR = 1.66) in women were significantly associated with occupational injury. In manufacturing/production workers, high quantitative workload (OR = 1.91), high variance in workload (OR = 2.02), and high depressive symptoms (OR = 1.55) were significantly associated with injury in men, while low social support from colleagues (OR = 2.36) or family (OR = 2.51) was related to injury in women.
These data point to an independent relationship between psychosocial job stress and self-reported occupational injury in SMEs.
American Journal of Industrial Medicine 08/2006; 49(8):658-69. DOI:10.1002/ajim.20338 · 1.59 Impact Factor