Twenty-four-hour shift work, depressive symptoms, and job dissatisfaction among Japanese firefighters

Inappropriate timing of salt intake increases the risk of heat-related illness: An observational study

The importance of salt intake in preventing heat-related illness (HRI) is well established, however, the specific method of ingestion has not been sufficiently studied. This study, therefore, aimed to investigate the optimal timing of salt intake to prevent HRI during hot outdoor work. We recruited 28 healthy male firefighters working at a fire department in Japan. They were provided a questionnaire to complete before and after receiving training in the summer season. We assessed their salt intake as before, during, and after training or none. In addition, they completed a brief self-administered diet history questionnaire to evaluate their daily salt and alcohol intake. HRI was determined through subjective and objective symptoms listed in the questionnaire, and environmental data were obtained from a national database. Subsequently, factors related to HRI were determined using a logistic regression model. The mean age of the participants was 31.0 ± 7.7 years. The study was performed within 250 working days, and we detected 28 HRI symptoms (11.2%). The median alcohol intake was 25.6 g/day when calculated according to the actual work system. Logistic mixed effect model analysis revealed that salt intake before training (OR: 5.893, 95% CI: 1.407-24.675), and salt intake before and during training (OR: 22.889, 95% CI: 4.276-122.516) were positively associated with HRI symptoms. The results indicate that inappropriate timing of salt intake increases the risks of HRI. Thus, a timely intake of salt in adequate amounts may be important in preventing these risks.

Non-cancer health risks in firefighters: a systematic review

osFirefighters are occupationally exposed to hazardous factors that may increase their risk of disease. However, non-cancer disease risk in firefighters has not been systematically examined. This systematic review aimed to identify non-cancer disease risk in firefighters and determine whether the risk differs according to job characteristics. We searched the Cochrane Library, Embase, PubMed, and KoreaMed databases using relevant keywords from their inception to April 30, 2021. The Risk of Bias Assessment Tool for Non-randomized Studies version 2.0 was used to assess the quality of evidence. Due to study heterogeneity, a narrative synthesis was presented. The systematic literature search yielded 2,491 studies, of which 66 met the selection and quality criteria. We confirmed that the healthy worker effect is strong in firefighters as compared to the general population. We also identified a significant increase in the incidence of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and post-traumatic stress disorder (PTSD) in firefighters compared to other occupational groups. Contradictory results for the risk of PTSD and anxiety disorders related to rank were reported. Sufficient evidence for increased risk of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and PTSD was available. The risk of non-cancer diseases varied depending on job type, years of service, and rank. However, caution should be exercised when interpreting the results because the classification criteria for firefighters' jobs and ranks differ by country.

Shifted Firefighter Health Investigation by Personal Health Insurance Record in Taiwan

INTRODUCTION

Taiwan's firefighters use a shift rotation system with 2 days of work and 1 day of rest. Numerous papers have already explored the risks of shift work to the body. However, little data concern the impact of shift work on health as reflected in medical visits. This study used individuals' medical visit record in Taiwan's health insurance system. The locally called "health bank" contains individuals' medical visit record, health insurance payment points and the medicine used.

METHODS

Consent was obtained from 150 firefighters who were serving under the shift rotation system to obtain their 2015 individual "My Health Bank" medical data. Comparisons were made between national health insurance data norm.

RESULTS

Firefighters make significantly more visits for Western medicine than the annual average (firefighters 6.27 vs norm 5.24, P = 0.04142), more total number of medical visits (9.57 vs 7.75, P = 0.0102), more annual average payment points for Western medicine (4079 vs 2741, P = 0.003151), and a greater average number of total annual medical visit points (7003 vs 4940, p = 0.0003157). Firefighters had significantly higher incidents of respiratory diseases, urogenital diseases, skin and subcutaneous tissue diseases, musculoskeletal system and connective tissue diseases, injuries, and illness from poisoning than did the norm (P<0.05).

CONCLUSION

A persuasive health-survey-based method for workers in high occupational hazard industries was proposed in this study, and the result was highly correlated with risk factors of fireworkers. The proposed study method is potential to investigate risk factors of other working.

Health outcomes of psychosocial stress within firefighters: A systematic review of the research landscape

BACKGROUND AND OBJECTIVES

Much of the research surrounding firefighter health has concerned the hazards intuitively associated with the occupation, such as physical, thermal, and chemical risks. However, an additional aspect of their work environment, psychosocial stressors, has begun to attract a growing level of attention. Work-related psychosocial stress may best be described as mental and emotional strain caused by a combination of workplace events and characteristics, and the objective of our review was to identify the health outcomes associated with these stressors in firefighters.

METHODS

A systematic review was performed of studies reporting on the psychosocial stressors and the associated health outcomes experienced by firefighters. Data sources included the MEDLINE, PsychInfo, and CINAHL databases.

RESULTS

Twenty-nine studies met the inclusion criteria. Upon analysis, we found that firefighters experienced a range of psychosocial stressors (including interpersonal conflict and concerns over organizational fairness) and observed that these stressors were associated with a number of health-related outcomes that could be arranged into six areas: depression-suicidality, non-depressive mental health problems, burnout, alcohol use disorders, sleep quality, and physiological parameters and somatic disorders.

CONCLUSION

Our findings strongly suggest that work-related psychosocial stressors can affect the health and well-being of those in the fire service, and highlight that interventions meant to address these psychosocial risk factors should focus upon promoting self-esteem, enhancing self-efficacy, and strengthening social support.

Influence of organizational stress on reported depressive symptoms among police

BACKGROUND

There is a growing body of research on operational stress injuries (OSIs) among police officers and first responders. Most studies focus on operational stressors' contribution to OSI and the development of post-traumatic stress disorder. However, preliminary research shows that organizational stressors may uniquely contribute to OSI and depression, and thus should be examined more closely.

AIMS

This study explored the influence of organizational stress on symptoms of depression in a sample of police officers from a large urban region.

METHODS

Front-line (n = 109) police officers completed questionnaires measuring police organizational and operational stress, depression, anxiety, hostility, rumination, perceived social support and social desirability. Using negative binomial regression (NBR), a best subset model of self-reported depression symptoms was derived from the full model (a function of gender, age, police experience (years), organizational stress, operational stress, anxiety, anger, rumination and social support), based on Akaike Information Criterion (AIC) goodness of fit.

RESULTS

Organizational stress and anxiety were positively associated with self-reported depression symptoms. A paired t-test revealed no significant difference between reported organizational and operational stress levels.

CONCLUSIONS

Organizational stress may uniquely contribute to OSI and depressive symptoms and should be examined in future research. Findings support prior literature suggesting that initiatives to treat OSI among police should address workplace environment and organizational stressors. Addressing organizational issues in police culture and developing long-lasting initiatives is key in the future of OSI prevention and treatment for police officers.

Canadian Public Safety Personnel and Occupational Stressors: How PSP Interpret Stressors on Duty

Canadian public safety personnel (e.g., correctional workers, firefighters) experience potential stressors as a function of their occupation. Occupational stressors can include organizational (e.g., job context) and operational (e.g., job content) elements. Operational stressors (e.g., exposures to potentially psychologically traumatic events) may be inevitable, but opportunities may exist to mitigate other occupational stressors for public safety personnel. Research exploring the diverse forms of stress among public safety personnel remains sparse. In our current qualitative study we provide insights into how public safety personnel interpret occupational stressors. We use a semi-grounded thematic approach to analyze what public safety personnel reported when asked to further comment on occupational stress or their work experiences in two open-ended comment fields of an online survey. We provide a more comprehensive understanding of how public safety personnel experience occupational stress and the stressors that are unique to their occupations. Beyond known operational stressors, our respondents (n = 1238; n = 828) reported substantial difficulties with organizational (interpersonal work relationship dynamics; workload distribution, resources, and administrative obligations) and operational (vigilance, work location, interacting with the public) stressors. Some operational stressors are inevitable, but other occupational stressors can be mitigated to better support our public safety personnel.

Association between Shift Work and Neurocognitive Function among Firefighters in South Korea: A Prospective Before-After Study

Background: Recent research indicates that shift work is associated with neurocognitive function. However, studies that examine the association between shift work and neurocognitive function in firefighters have not yet been performed. We examined the effect of shift work on neurocognitive function in firefighters by measuring and comparing neurocognitive function before and after night shift. Methods: 352 firefighters from eight fire stations in South Korea were included in this study. We performed neurocognitive function test using central nervous system vital signs (CNSVS) during daytime work and on the next day after night work. We performed paired t-tests to assess differences between neurocognitive function before and after night work. We also compared neurocognitive function in insomnia and depression. We used a general linear model to analyze the associations between shiftwork schedule and the changes in neurocognitive function. Results: The neurocognitive function significantly decreased in six domains (composite memory, verbal memory, visual memory, complex attention, psychomotor speed, and motor speed) as did the neurocognitive index on the next day after night work compared with during day work. These decreased domains were the same following night work regardless of the type of shift work. Conclusion: Night work in firefighters may cause neurocognitive decline.

Mental health and quality of life in firefighters working on the scene in South Korea: Focused on the capital area and the ground pro-motion area

INTRODUCTION

Today, firefighters' work areas are expanding into various fields. The aim of the study was to investigate the effect of mental health on quality of life between firefighters in the capital area and in the growth promotion area.

METHOD

A survey was conducted with 206 firefighters including 110 firefighters in the capital area and 96 firefighters in the growth promotion area through a questionnaire.

RESULT

The differences in mental health based on working areas between firefighter groups have been identified. In addition, among the factors affecting the quality of life among firefighter, the factor most closely associated with quality of life was "sociopsychological health stress," followed by "occupational stress," "depression," and "working area."

CONCLUSION

There is a need for research into mental health interventions appropriate for regional characteristics of each region regarding the implementation of mental health management by working area.

Assessing the Relative Impact of Diverse Stressors among Public Safety Personnel

Public Safety Personnel (PSP; e.g., correctional workers and officers, firefighters, paramedics, police officers, and public safety communications officials (e.g., call center operators/dispatchers)) are regularly exposed to potentially psychologically traumatic events (PPTEs). PSP also experience other occupational stressors, including organizational (e.g., staff shortages, inconsistent leadership styles) and operational elements (e.g., shift work, public scrutiny). The current research quantified occupational stressors across PSP categories and assessed for relationships with PPTEs and mental health disorders (e.g., anxiety, depression). The participants were 4820 PSP (31.7% women) responding to established self-report measures for PPTEs, occupational stressors, and mental disorder symptoms. PPTEs and occupational stressors were associated with mental health disorder symptoms (ps < 0.001). PSP reported substantial difficulties with occupational stressors associated with mental health disorder symptoms, even after accounting for diverse PPTE exposures. PPTEs may be inevitable for PSP and are related to mental health; however, leadership style, organizational engagement, stigma, sleep, and social environment are modifiable variables that appear significantly related to mental health.

The Interaction Effects of Burnout and Job Support on Peptic Ulcer Disease (PUD) among Firefighters and Policemen

Policemen and firefighters encounter numerous emergency events that frequently lead to high burnout and low job support, resulting in adverse health effects. A number of studies reported the correlation between job characteristics and the risk of peptic ulcer diseases (PUD) across various industries. However, there is very little research on evaluating the interaction effects of burnout and job support on the prevalence of PUD among firefighters and policemen. The objective of this study was to assess the interactional effects between burnout and job support on the prevalence of PUD among firefighters and policemen. This was a cross-sectional quantitative study. Registered, full-time police officers and firefighters in Taiwan were anonymously interviewed by a mail-delivered questionnaire. All female workers were excluded due to different job characteristics and a limited sample size. A total of 9328 firefighters and 42,798 policemen completed the questionnaire, with a response rate of 78.7%. Overall, prevalence rates of self-reported and self-reports of physician-diagnosed PUD were 8.3% and 6.5% for policemen and 7.1% and 5.5% for firefighters, respectively. There was a 22% reduced odds ratio of PUD as diagnosed by physicians for the group with low burnout and high job support, but an increased odds ratio of 53% for the group with high burnout and low job support, after adjusting for lifestyle and demographic variables. There must be an increase of job support and reduction of burnout through the modification of work structure and setting up of counseling services to reduce workplace stress and the prevalence of PUD among policemen and firefighters.

Relationships between psychological contract violation, stress and well-being in firefighters

Purpose

Negative emotions resulting from the broken promises by the organisation or employers, as perceived by an employee are called psychological contract (PC) violation. The purpose of this paper is to examine the relationships between perceived feelings of violation, work-related stress, anxiety and depression. Fairness and self-efficacy are used as mediators to understand the underlying mechanism of associations.

Design/methodology/approach

In total, 97 firefighters completed an online-survey and structural equation modelling was used to examine the multiple mediation models.

Findings

PC violation was positively associated with occupational stress and job-related well-being. Together, fairness and self-efficacy mediated the relationship between feelings of violation and job-related depression. Therefore, the results partially supported the hypotheses.

Originality/value

As the first quantitative study of its kind, this study makes an important contribution to the firefighters literature by investigating the potential influence of PC violation on their work-related stress and well-being. Also, previous studies have failed to identify fairness and self-efficacy as potential mediators of the PC violation.

Military Veteran Status and Posttraumatic Stress Disorder Symptomatology Among Urban Firefighters: The Moderating Role of Emotion Regulation Difficulties

A significant portion of firefighters are military veterans, and both populations experience high rates of trauma and posttraumatic stress disorder (PTSD) symptomatology. We investigated main and interactive effects of military veteran status (MVS) and emotion regulation difficulties (ERD) with regard to PTSD symptom severity in firefighters. Covariates included trauma load, number of years in the fire department, and depressive symptom severity. The sample was composed of 839 (93.9% men; mean age = 38.4, SD = 8.5) trauma-exposed firefighters who completed a web-based questionnaire battery. Structural equation modeling was used. ERD were significantly, positively associated with PTSD symptom severity (β = 0.30, confidence interval [CI] = 0.20-0.41, p < 0.001). A significant interactive effect was noted (β = 0.07, CI = 0.01-0.14, p = 0.020); firefighters who endorsed MVS and greater ERD had the highest levels of PTSD symptom severity. It is vital that future work examine associations between MVS and relevant cognitive mechanisms for the purposes of informing effective screening, intervention, and prevention programs.

Understanding mental health among military veterans in the fire service

Firefighters who have previously served in the military may be at potentially higher risk for worsened mental health outcomes. This investigation examined the mental health of military veterans, as compared to non-veterans, in the fire service. We hypothesized that firefighters who endorsed military veteran status would have higher rates of mental health symptoms, in comparison to firefighters who did not endorse prior service in the military. Age, gender, and race/ethnicity were used as covariates. The sample was comprised of 910 career firefighters, 209 (23.0%) of whom endorsed military veteran status. One-way analyses of covariance were employed. The military veteran subsample reported significantly higher levels of sleep disturbance, depression, and posttraumatic stress symptom severity in comparison to the non-veteran subsample; however, effect sizes were small indicating that between group differences are actually negligible. Results highlight the need to improve our understanding of risk and resilience factors for firefighters who have served in the military, as this line of inquiry has potentially important mental health intervention implications for this exceptionally understudied population.

Association between workplace discrimination and depressive symptoms among firefighters in South Korea

BACKGROUND

Workplace discrimination is associated with poor mental health. However, there is a lack of studies examining the effects of discrimination on depressive symptoms among firefighters.

METHODS

We analyzed a national cross-sectional survey of 6369 firefighters in South Korea. Workplace discrimination during the past year was measured and main reasons for the discriminatory experience (gender, birth region, age, education, field/office work, job division) were identified separately by gender and job division. Depressive symptoms during the previous week were measured by the CES-D11.

RESULTS

Overall, 30.3% of firefighters experienced workplace discrimination and the main reasons for discrimination differed by gender and job division. Firefighters who experienced workplace discrimination had a higher likelihood of depressive symptoms than those who did not after adjusting for potential confounders (PR: 1.73; 95%CI: 1.55, 1.92).

CONCLUSIONS

This finding suggests that experience of workplace discrimination could aggravate the mental health of firefighters who provide an important public service.

The mediation effect of PTSD, perceived job stress and resilience on the relationship between trauma exposure and the development of depression and alcohol use problems in Korean firefighters: A cross-sectional study

BACKGROUND

Firefighters constitute a high-risk group for depression and alcohol use disorders (AUDs) due to frequent exposure to trauma. Perceived job stress and resilience are powerful factors affecting the occurrence of depression and AUDs; however, research on this subject is scarce.

METHODS

We investigated the relationship of perceived job stress and resilience with depression or AUDs in firefighters. A total of 7151 Korean firefighters were included for analysis. Participants completed self-report scales, including a self-reported number of exposure to incident stressors, the Korean Occupational Stress Scale - Short Form, the Post-traumatic Stress Disorder (PTSD) Symptoms Checklist - Civilian version, the Patient Health Questionnaire 9, the Brief Resilience Scale, and the Alcohol Use Disorders Identification Test. Hierarchical multivariable linear regression analyses were performed to identify the relationship of perceived job stress and resilience with depression or AUDs. Path analyses were applied to investigate the mediation effects of PTSD, perceived job stress and resilience between trauma exposure and depression or AUDs.

RESULTS

There were significant associations of perceived job stress and resilience with depression and AUDs, respectively, even after adjusting for demographic factors, number of traumatic events, and PTSD symptoms. The relationship between trauma exposure and depression/AUDs was mediated by PTSD symptoms, which had both direct and indirect effects on depression and AUDs; indirect effect was mediated by job stress and resilience.

CONCLUSIONS

The findings in this study demonstrated that PTSD, perceived job stress and resilience can mediate the development of depression or AUDs following trauma exposure in firefighters. Efforts to prevent PTSD, reduce job stress and increase individual resilience could help prevent depression and AUDs.

LIMITATIONS

The cross-sectional study design and self-report nature of the assessment tools limit the current findings.

Long working hours, job satisfaction, and depressive symptoms: a community-based cross-sectional study among Japanese employees in small- and medium-scale businesses

Although long working hours have been suspected to be a risk factor for depressive symptoms (DS), it is not well understood the conditions under which long working hours are associated with it. This study investigated the moderating effect of job satisfaction on the relationship between working hours and DS. A total of 2,375 full-time non-shift day workers (73% men), aged 18-79 (mean 45) years, in 296 small- and medium-scale businesses were surveyed using a self-administered questionnaire evaluating working hours, job satisfaction, DS and covariates. The Center for Epidemiologic Studies Depression scale (CES-D) was used to assess DS. Risk of DS (CES-D ≥ 16) by working hours, job satisfaction, and both combined was estimated by multivariable logistic regression analysis. Compared to participants working 6-8 hrs/day, those working 12+ hrs/day had significantly higher odds of DS (adjusted odds ratio [aOR] 1.49), while participants with low satisfaction, as opposed to high satisfaction, had increased odds of DS (aOR 1.81). Furthermore, compared to those working 6-8 hrs/day with high satisfaction (reference group), participants working 6-8 hrs/day, > 8 to 10 hrs/day, and > 10 hrs/day combined with low satisfaction had dose-response increase of DS (aOR 1.48, 2.21 and 2.31, respectively, p < 0.05), whereas those working > 8 to 10 hrs/day and > 10 hrs/day combined with high satisfaction had not (aOR 0.93 and 1.39, respectively, p > 0.10). The results suggest that long working hours are associated with increased risk of DS only under reduced job satisfaction condition, which highlights the importance of improving job satisfaction, particularly among those working excessive hours.

Effect of Sleep Quality on Psychiatric Symptoms and Life Quality in Newspaper Couriers

INTRODUCTION

Working at unusual hours has been found to be related to sleep problems, psychiatric symptoms, and low quality of life. This study aimed to investigate the effect of sleep quality on psychiatric symptoms and the quality of life in newspaper couriers who permanently wake up at early morning hours.

METHODS

Thirty-five newspaper couriers who worked for a media company in Ankara and 35 healthy individuals who worked at usual hours and who were matched according to age, gender, and work duration were included in the study. All individuals were evaluated using the demographic forms, Symptom Checklist (SCL)-90-R, Pittsburg Sleep Quality Index (PSQI), and Short Form-36 (SF-36).

RESULTS

The somatization subscale of SCL-90-R and the sleep duration sub-component scores of PSQI were significantly higher and the physical role functioning domain score of SF-36 was significantly lower in newspaper couriers compared with the scores in healthy individuals. There were significantly positive correlations between the PSQI total and sub-component scores and the SCL-90-R subscale and global symptom index scores. There were significantly negative correlations between the PSQI total and sub-component scores and the SF-36 domain scores.

CONCLUSION

This study demonstrates that waking up permanently at early morning hours may be related to sleep disturbances, psychiatric symptoms, and low quality of life. Measures to increase sleep quality in individuals working at unusual hours may improve their mental health and quality of life. Future studies should investigate the effects of interventions toward sleep disturbances on mental health and quality of life in different occupational groups.

Prevalência de depressão em bombeiros

A depressão apresenta alta carga de doença no mundo. Fatores socioeconômicos e exposição a situações extremas no trabalho podem estar associados à doença. O objetivo do trabalho é investigar a prevalência e fatores associados à depressão em bombeiros de Belo Horizonte, Minas Gerais, Brasil. Estudo transversal foi realizado em universo de bombeiros do sexo masculino em Belo Horizonte (n = 711). O Inventário Beck para Depressão (IBD) foi utilizado para avaliar a presença de depressão. Modelos de regressão logística (uni e multivariada) foram utilizados para estudar a associação entre características sociodemográficas, estressores ocupacionais, situação de saúde e depressão. A prevalência de depressão na amostra estudada foi 5,5%. A chance de depressão foi maior entre bombeiros que relataram sintomas de estresse pós-traumático (OR = 12,47; IC95%: 5,64-27,57) e uso abusivo de álcool (OR = 5,30; IC95%: 2,35-11,96). Os resultados são discutidos considerando as inter-relações entre transtornos mentais, o efeito do trabalhador sadio e o reconhecimento social do trabalho dos bombeiros.

Socioeconomic and gender inequalities in job dissatisfaction among Japanese civil servants: the roles of work, family and personality characteristics

This study examines (1) whether there are employment grade and gender differences in job dissatisfaction and (2) whether work, family, and personality characteristics explain grade and gender differences in job dissatisfaction. The participants were 3,812 civil servants, aged 20-65, working at a local government in Japan. In both males and females, low control, low social support, work-to-family conflict, type A behaviour pattern and negative affectivity were significantly associated with job dissatisfaction. In females, high demands, long work hours and being unmarried were also associated with job dissatisfaction. Among males, in comparison with the highest grade employees, the age-adjusted odds ratio (OR) for job dissatisfaction in the lowest grade employees was 1.90 (95% CI: 1.40-2.59). The grade differences reduced to 1.08 (0.76-1.54) after adjustment for work, family and personality characteristics. Among females, similar grade differences were observed, although the differences were not statistically significant. In comparison with males, the age-adjusted OR in females for job dissatisfaction was 1.32 (1.14-1.52). This gender difference was reduced to 0.95 (0.79-1.14) following adjustment for the other factors. The majority of employees belong to low to middle grades, and female employees have increased. Reducing grade and gender differences in work and family characteristics is needed.

Very Long (> 48 hours) Shifts and Cardiovascular Strain in Firefighters: a Theoretical Framework

Shift work and overtime have been implicated as important work-related risk factors for cardiovascular disease (CVD). Many firefighters who contractually work on a 24-hr work schedule, often do overtime (additional 24-hr shifts) which can result in working multiple, consecutive 24-hr shifts. Very little research has been conducted on firefighters at work that examines the impact of performing consecutive 24-hr shifts on cardiovascular physiology. Also, there have been no standard field methods for assessing in firefighters the cardiovascular changes that result from 24-hr shifts, what we call “cardiovascular strain”. The objective of this study, as the first step toward elucidating the role of very long (> 48 hrs) shifts in the development of CVD in firefighters, is to develop and describe a theoretical framework for studying cardiovascular strain in firefighters on very long shifts (i.e., > 2 consecutive 24-hr shifts). The developed theoretical framework was built on an extensive literature review, our recently completed studies with firefighters in Southern California, e-mail and discussions with several firefighters on their experiences of consecutive shifts, and our recently conducted feasibility study in a small group of firefighters of several ambulatory cardiovascular strain biomarkers (heart rate, heart rate variability, blood pressure, salivary cortisol, and salivary C-reactive protein). The theoretical framework developed in this study will facilitate future field studies on consecutive 24-hr shifts and cardiovascular health in firefighters. Also it will increase our understanding of the mechanisms by which shift work or long work hours can affect CVD, particularly through CVD biological risk factors, and thereby inform policy about sustainable work and rest schedules for firefighters.

Work-related Stress, Caregiver Role, and Depressive Symptoms among Japanese Workers

Background

In Japan, more than 60% of employees are reported to suffer from anxiety and stress. Consequently, Japanese society has begun to address such important issues as psychogenic disability and job-related suicide. Furthermore, given the aging of society and the surge in the number of elderly people requiring care, it is necessary to adequately and proactively support employees who care for their elderly relatives. The purpose of the present study was to investigate caregiver burden in caring for elderly relatives and work-related stress factors associated with mental health among employees.

Methods

We studied 722 men and women aged 18–83 years in a cross-sectional study. The K10 questionnaire was used to examine mental health status.

Results

The proportion of participants with a high K10 score was 15% (n = 106). Having little conversation with their supervisor and/or coworkers significantly increased the risk of depression [odds ratio (OR) 1.8], as did high job overload (OR 2.7) and job dissatisfaction (OR 3.8), compared with employees who frequently conversed with their supervisor and/or coworkers. Caring for elderly relatives as a prominent characteristic of an employee was a significant risk factor for depression (OR 2.1).

Conclusion

The present study demonstrated that employees who were caring for elderly relatives were significantly associated with an increased risk of depression. To prevent depressive disorders, it may be important to focus on reducing the work-caregiving role conflict, as well as enhancing employees' job control and better rewarding their efforts in the workplace.

Using Bayesian networks to analyze occupational stress caused by work demands: preventing stress through social support

Occupational stress is a major health hazard and a serious challenge to the effective operation of any company and represents a major problem for both individuals and organizations. Previous researches have shown that high demands (e.g. workload, emotional) combined with low resources (e.g. support, control, rewards) are associated with adverse health (e.g. psychological, physical) and organizational impacts (e.g. reduced job satisfaction, sickness absence). The objective of the present work is to create a model to analyze how social support reduces the occupational stress caused by work demands. This study used existing Spanish national data on working conditions collected by the Spanish Ministry of Labour and Immigration in 2007, where 11,054 workers were interviewed by questionnaire. A probabilistic model was built using Bayesian networks to explain the relationships between work demands and occupational stress. The model also explains how social support contributes positively to reducing stress levels. The variables studied were intellectually demanding work, overwork, workday, stress, and social support. The results show the importance of social support and of receiving help from supervisors and co-workers in preventing occupational stress. The study provides a new methodology that explains and quantifies the effects of intellectually demanding work, overwork, and workday in occupational stress. Also, the study quantifies the importance of social support to reduce occupational stress.

[The influence of attitude of inhibiting spousal disclosure about stress on the mental health of firefighters]

The present study focused on attitudes related to inhibiting spousal disclosure about stress as an influential factor for the mental health of firefighters. In a pilot study using semi-structured interviews (N = 14), we found that some firefighters usually did not talk about their stresses with their spouses. Some reasons were that they were hiding their weakness, were feeling sure of controlling their stress, out of consideration for their spouse, were giving up on the possibility for improving the situation after spousal disclosure, or hoped to distract themselves. In a subsequent questionnaire survey (N = 554), the results showed that attitudes about inhibiting spousal disclosure of stress have an effect on spousal disclosure about stress and the mental health of firefighters. The findings of the present study imply that spousal disclosure about interpersonal stress can be regarded as an effective factor, along with the disclosure to colleagues, for relieving stress. It is necessary to consider the importance of attitudes about inhibiting disclosure for stress as part of stress management for firefighters.

Sleep problems, depression, substance use, social bonding, and quality of life in professional firefighters

OBJECTIVE

Little attention has been given to factors contributing to firefighters' psychosomatic well-being. The purpose of this descriptive study was to examine such contributing factors in a sample of professional firefighters.

METHODS

Measures assessing sleep, depression, substance use, social bonding, and quality of life were examined in 112 firefighters.

RESULTS

Overall, many firefighters reported sleep deprivation (59%), binge drinking behavior (58%), poor mental well-being (21%), current nicotine use (20%), hazardous drinking behavior (14%), depression (11%), poor physical well-being (8%), caffeine overuse (5%), or poor social bonding (4%).

CONCLUSIONS

Small-to-medium correlations were identified between sleep deprivation, depression, physical/mental well-being, and drinking behaviors. High-risk behaviors that impact psychosomatic well-being are prevalent in professional firefighters, which require environmental and individual-based health promotion interventions. The inter-correlation relationships between such behaviors, therefore, need to be explored in further details.

Exploring occupational and behavioral risk factors for obesity in firefighters: a theoretical framework and study design

Firefighters and police officers have the third highest prevalence of obesity among 41 male occupational groups in the United States (US). However, few studies have examined the relationship of firefighter working conditions and health behaviors with obesity. This paper presents a theoretical framework describing the relationship between working conditions, health behaviors, and obesity in firefighters. In addition, the paper describes a detailed study plan for exploring the role of occupational and behavioral risk factors in the development of obesity in firefighters enrolled in the Orange County Fire Authority Wellness Fitness Program. The study plan will be described with emphasis on its methodological merits: adopting a participatory action research approach, developing a firefighter-specific work and health questionnaire, conducting both a cross-sectional epidemiological study using the questionnaire and a sub-study to assess the validity of the questionnaire with dietary intake and physical activity measures, and evaluating the strengths and weaknesses of the body mass index as an obesity measure in comparison to skinfold-based percent body fat. The study plan based on a theoretical framework can be an essential first step for establishing effective intervention programs for obesity among professional and voluntary firefighters.

Comparison of coronary microcirculation in female nurses after day-time versus night-time shifts

Nightshift work, which is known to cause mental stress and disrupt normal biological diurnal rhythms, leads to endothelial dysfunction resulting in increased risk for cardiovascular disease. This study aimed to investigate the acute effect of night-shift work on coronary microcirculation through assessment of coronary flow reserve (CFR) by transthoracic Doppler echocardiography. This study consisted of 36 women nurses who underwent transthoracic Doppler echocardiographic examinations after working a nightshift and on a regular day without previous nightshift work. Flow velocity in the distal portion of the left anterior descending coronary artery was measured at baseline and during adenosine infusion. CFR was calculated as the ratio of hyperemic to basal mean diastolic flow velocity. CFR after night work was lower than that on a regular workday (3.8 ± 0.6 vs 4.1 ± 0.6, p <0.001). Degree of decreases in CFR after night work was correlated to Framingham risk score (r = 0.35, p = 0.036). In conclusion, this study demonstrated that coronary microcirculation was impaired after nightshift work in women nurses.

Aromatherapy alleviates endothelial dysfunction of medical staff after night-shift work: preliminary observations

Night-shift work causes mental stress and lifestyle changes, and is recognized as a risk of cardiovascular diseases associated with impaired endothelial function. Aromatherapy is becoming popular as a complementary therapy that is beneficial for mental relaxation. The purpose of this study was to investigate the effect of aromatherapy on the endothelial function of medical staff after night-shift work. This study consisted of 19 healthy medical personnel (19 men, mean age 32 ± 7 years), including 11 physicians and 8 technicians. Aromatherapy was performed for 30 min by inhalation of the essential oil of lavender. Flow-mediated dilation (FMD) of the brachial artery was measured three times in each subject: on a regular workday, and after night-shift work before and immediately after aromatherapy. A control study was performed to assess the effect of a 30-min rest without aromatherapy. The mean value of sleep time during night-shift work was 3.3 ± 1.3 h. FMD after night-shift work was lower than on a regular workday (10.4 ± 1.8 vs. 12.5 ± 1.7%, P<0.001), which improved after aromatherapy (11.8 ± 2.5%, P=0.02 vs. before aromatherapy). FMD was stable in the control study (10.1 ± 1.9 vs. 10.1 ± 2.2%, P=0.9). This study demonstrated that night-shift work impaired endothelial function in medical staff, an effect that was alleviated by short-term aromatherapy.

Individual differences in tolerance to shift work--a systematic review

Shift work tolerance is a term describing the ability to adapt to shift work without adverse consequences. In this paper we systematically review literature published investigating the relation between individual differences such as age, gender, personality, morningness/eveningness as well as biological variables and different measures of shift work tolerance from 1998 till 2009. A total of 60 articles were included in this review, of which ten studies were classified as longitudinal, while the rest were classified as cross-sectional. Overall, the studies indicate that young age, male gender, low scores on morningness, high scores on flexibility and low scores on languidity, low scores on neuroticism, high scores on extraversion and internal locus of control and some genetic dispositions are related to higher shift work tolerance. More longitudinal studies, especially concerning personality, are needed to make conclusions about the predictive power of individual differences for shift work tolerance.

Validation of the Center for Epidemiologic Studies Depression Scale in screening for major depressive disorder among retired firefighters exposed to the World Trade Center disaster

BACKGROUND

We evaluated the performance of a modified Center of Epidemiologic Studies Depression Scale (CES-D-m), which captured symptoms in the past month, in comparison to the Diagnostic Interview Schedule (DIS) in identification of major depressive disorder (MDD) in World Trade Center (WTC)-exposed retired Fire Department, City of New York (FDNY) firefighters.

METHODS

From 12/2005 to 7/2007, FDNY enrolled retired firefighters in its Medical Monitoring and Treatment Program. All participants completed the CES-D-m and the DIS on the same day. Sensitivity, specificity, receiver operating characteristic (ROC) curves, and Youden's index were used to assess properties of the CES-D-m. Multivariate logistic regression analyses were also used.

RESULTS

7% of 1915 retired male firefighters were diagnosed with MDD using the DIS. Using the most common CES-D cutoff score of 16, the prevalence of elevated risk was 36%, which declined to 23% using a cutoff score of 22, as determined by Youden's index. At 22, CES-D-m sensitivity was 0.84, specificity was 0.82, and the area under the ROC curve was 0.89 relative to DIS MDD diagnosis.

LIMITATIONS

Participants were more likely than non-participants to live in the New York City area.

CONCLUSIONS

This is the first study of WTC rescue/recovery workers to assess the performance of a one-month version of the CES-D. The CES-D-m performed well in identifying those at elevated risk. Since diagnostic follow-up is time consuming and costly, it is important to correctly distinguish those at elevated risk using a screening tool that has been validated in the population under study.

Intragroup and intergroup conflict at work, psychological distress, and work engagement in a sample of employees in Japan

The possible associations of intragroup and intergroup conflict at work with psychological distress and work engagement were investigated in a cross-sectional study in a manufacturing factory in Japan. A self-administered questionnaire was sent to all employees, and 255 responses were returned (a response rate of 84%). Data from 247 workers (187 males and 60 females) with no missing values were analyzed. Intragroup and intergroup conflict at work, psychological distress, and work engagement were measured by the NIOSH-GJSQ, K6, and Utrecht Work Engagement Scale (UWES-9), respectively. An ANCOVA was conducted to compare K6 and UWES-9 scores among the tertiles on intragroup conflict or intergroup conflict scores, adjusting for demographic and occupational variables as well as worksite social support, separately for males and females. Intragroup conflict was associated with greater psychological distress for males (p for trend=0.009). Intergroup conflict was marginally significantly associated with psychological distress for both males and females (p for trend=0.050 and 0.051, respectively). Contrary to expectation, intergroup conflict was significantly associated with greater work engagement for females (p for trend=0.024). For males, intragroup and intergroup conflict at work may increase psychological distress; for females, intergroup conflict may increase both psychological distress and work engagement.

Circadian disruption, Per3, and human cytokine secretion

Circadian disruption has been linked with inflammation, an established cancer risk factor. Per3 clock gene polymorphisms have also been associated with circadian disruption and with increased cancer risk. Patients completed a questionnaire and provided a blood sample prior to undergoing a colonoscopy (n = 70). Adjusted mean serum cytokine concentrations (IL-6, TNF-alpha, gamma-INF, IL-1ra, IL-1-beta, VEGF) were compared among patients with high and low scores for fatigue (Multidimensional Fatigue Inventory), depressive symptoms (Beck Depression Inventory II), or sleep disruption (Pittsburgh Sleep Quality Index), or among patients with different Per3 clock gene variants. Poor sleep was associated with elevated VEGF, and fatigue-related reduced activity was associated with elevated TNF-alpha concentrations. Participants with the 4/5 or 5/5 Per3 variable tandem repeat sequence had elevated IL-6 concentrations compared to those with the 4/4 genotype. Biological processes linking circadian disruption with cancer remain to be elucidated. Increased inflammatory cytokine secretion may play a role.