Working hours and mental and physical fatigue in Japanese workers

BACKGROUND: Establishing a threshold number of working hours is very important when making recommendations to protect people from the potentially harmful health effects caused by long working hours. AIM: To clarify the influence of working hours on both mental and physical symptoms of fatigue and use the data obtained to determine permissible working hours. METHODS: Cross-sectional survey of male day-shift workers using the Self-Rating Depression Scale (SDS) and the Cumulative Fatigue Symptoms Index (CFSI). Working hours were subdivided into six groups and odds ratios were calculated for positive outcomes on the SDS and CFSI using logistic regression analysis. RESULTS: A total of 715 workers participated. In the group working 260-279 h/month, the odds ratios for SDS and 'irritability', 'anxiety' and 'chronic tiredness' of the CFSI were significantly increased. In the group working >or=280 h/month, the odds ratios on CFSI for 'general fatigue', 'physical disorders', 'anxiety' and 'chronic tiredness' were likewise significantly increased. CONCLUSIONS: The present results clarified that working hours should be <260 h/month in order to minimize fatigue symptoms in male day workers.     

Designing and managing healthy work for older workers

Throughout many countries in the developed world, largely because of increasing life expectancy, the population is ageing. One of the economic implications of this demographic change is that workers may need to work longer and retire later than they have done in recent years. Much needs to be done to ensure that work remains a positive experience for workers throughout their career trajectories, and that it does not damage their health. The major contemporary challenges to health at work are those associated with the way work and work organizations are designed and managed. This is especially true for older workers. This paper focuses on the relationships between age and work performance, between age and work-related health, and between age and work-related stress. It concludes that there remains considerable scope for designing optimal work systems to harness the potential and protect the health of older workers. This important initiative will require a co-ordinated and multidisciplinary occupational health strategy.     

Lifestyle and work predictors of fatigue in Japanese manufacturing workers

BACKGROUND: Fatigue is one of the most common symptoms encountered in medical practice. However, little is known about the causal relationship between change in lifestyle and fatigue. AIM: To help prevent fatigue-related disorders, we investigated the association between changes in lifestyle and fatigue among employees. METHODS: We studied data sets from the High-risk and Population Strategy for Occupational Health Promotion study for employees at 10 workplaces in Japan. The baseline survey was done in 1999 and the follow-up survey in 2003 via a questionnaire which examined lifestyle and fatigue variables using the vitality domain scale of the SF-36 Health Survey. The lifestyle factors focused on were diet, smoking and alcohol habits and working conditions. Four-year changes in lifestyle that predicted the vitality domain score in the follow-up survey were examined by analysis of covariance RESULTS: Of the 6284 participants in the baseline survey, 4507 replied to the follow-up survey, of whom 3498, with a mean age of 37 (SD 18) years, returned valid responses. A low vitality score at follow-up was predicted by a change in lifestyle factors such as an increase in overtime work, change to non-sedentary work and increased frequency of eating between meals (P < 0.01, P < 0.01 and P = 0.02, respectively). CONCLUSION: Fatigue in salaried workers as measured by the vitality domain of the SF-36 is predicted by an increase in overtime work, change to non-sedentary work and an increase in the frequency of eating between meals.     

A follow-up study on the association of working conditions and lifestyles with the development of (perceived) mental symptoms in workers of a telecommunication enterprise

AIM: This study investigated the association of working conditions and lifestyle with mental health in Japanese workers. METHODS: A follow-up study was carried out in the Kanto district of Japan of workers in a telecommunications enterprise who received their first annual health check-up between 1992 and 1996 and were between 20 and 54 years old. Workers who reported mental symptoms, had a past history of disease, or current illness at their first check-up were excluded from the analysis. In total, the study included 23 837 workers. The association between working conditions and lifestyle and the development of mental symptoms was investigated by pooled logistic regression analyses. RESULTS: Working long hours and part-time work, as opposed to normal daytime hours of work, were factors associated with the development of mental symptoms in males, as were smoking, short sleeping hours, little physical exercise, rarely taking three meals a day, frequently eating within 1 h before sleep, much preference for salty meals and little preference for vegetables. Consumption of alcohol was negatively associated with the development of mental symptoms in males. Overall, the results suggested that the lower the Healthy Work and Lifestyle Score, the higher the risk of developing mental symptoms. CONCLUSIONS: Working conditions and lifestyle, especially food preferences, have an apparent influence on the mental health of Japanese workers. Moreover, the Healthy Work and Lifestyle Score indicates that working conditions and lifestyle appear to have a cumulative influence upon the mental health of Japanese workers.     

A longitudinal study of the influence of shift work on serum uric acid levels in workers at a telecommunications company

BACKGROUND: Hyperuricemia is a lifestyle-related disease. Although there have been many previous reports about the association of serum uric acid (UA) levels with lifestyle, including eating habits and alcohol intake, there has been no report of a longitudinal study of the relationship between serum UA levels and shift work. AIMS: To clarify the influence of shift work on serum UA levels in Japanese workers. METHODS: This was a 4-year cohort study of 15 871 workers at a telecommunications company. Pooled logistic regression analyses by sex were performed, with job schedule type, age, body mass index (BMI), lifestyle and the results of blood chemistries as covariates. RESULTS: In males, shift work, part-time work, BMI, consumption of alcohol (less than twice per week, two to five times per week or more than five times per week) and little preference for vegetables were positively associated with the development of increased serum UA (>or=8 mg/dl in males, >or=6 mg/dl in females). In females, age, BMI and a history of smoking were positively associated with the development of increased serum UA. CONCLUSION: This study revealed that shift work is independently related to increased serum UA in males.     

Job stress and dissatisfaction in association with non-fatal injuries on the job in a cross-sectional sample of petrochemical workers

This cross-sectional study analysed the frequency and severity of work stressors and job satisfaction at workplaces in relation to work-related non-fatal injuries amongst a sample of petrochemical workers in Taiwan. The study participants consisted of 568 cases injured on the job between 1991 and 1997, and 954 injury-free controls matched to cases on frequencies of age, sex and work site. After adjusting for potential confounders, we found that cases were more likely than controls to report stressors with a higher frequency [odds ratio (OR) = 1.4, 95% confidence interval (CI) = 0.9-2.0] and a more severe reaction (OR = 1.3, 95% CI = 0.9-1.8). The dose-response analyses further indicated that the OR of injury was monotonically associated with stress reaction only (P for test for trend of ORs = 0.02). Job satisfaction, though, was unrelated to non-fatal injury. Although the cross-sectional nature of our study precludes a causal inference between stress reaction to stressors and risk of developing non-fatal injuries, our results tend to suggest that the severity of stress reaction is more associated with occupational non-fatal injury than is the frequency of stress or job dissatisfaction.     

Fatigue in industrial workers under thermal stress on extended shift lengths.

A field investigation to examine the fatigue levels in industrial workers working extended (10, 12 and 12.5 h) shifts under significant levels of thermal stress was conducted on 45 male underground miners. Studies were conducted both before and after a major change to the working-in-heat protocol used at the operation. Prior to the change, shortened (6 h) shifts had been used when thermal conditions exceeded certain values. This reduced shift length was removed and replaced with other protocols. Heart rates were continuously monitored, and a cycle ergometer was also used to assess cardiovascular fatigue over the shift. Average heart rates, as well as highest 10 and 30 min averages, and heart rate durations within various bands were analysed. No worker reported heat illness during the study. Results showed that removing the shortened shift did not increase the fatigue levels. Workers did experience fatigue, but this occurred in the first half of the shift. Evidence was found that these workers practised self-pacing.     

Effects of overtime work on blood pressure and body mass index in Japanese male workers

BACKGROUND: Effects of overtime work on health is a controversial issue. AIMS: To determine the effects of overtime work on blood pressure and body mass index (BMI) for male workers in Japan. METHODS: Participants were 323 male participants of three companies. Data were collected by occupational physicians at periodic physical examinations and additional examinations. The time courses for the development of definite hypertension and an increase in BMI were recorded. The Kaplan-Meier method was used to estimate the cumulative incidence rates of developing definite hypertension and increasing BMI, and the Cox proportional hazard model was used to determine the adjusted relative hazard of overtime work. RESULTS: The age-adjusted incidence rates of developing definite hypertension and increasing BMI were significantly lower among the participants whose mean overtime was > or =50 h than among those whose mean overtime was <50 h/month (log-rank P < 0.05). The Cox proportional hazard model indicated that those who worked a mean overtime of > or =50 h/month had lower risks of developing definite hypertension (hazard ratio, 0.36; 95% CI, 0.15-0.88; P < 0.05) and increasing their BMI (hazard ratio, 0.44; 95% CI, 0.31-0.63; P < 0.01) after adjusting for age. CONCLUSIONS: The results of this study indicate that workers whose mean overtime was > or =50 h have lower risks of developing definite hypertension and increasing their BMI.     

Occupational mental health: a brief history

This paper describes the development of occupational mental health in the United Kingdom. It looks at the increasing involvement of occupational health staff in this aspect of the workplace and the role played by organizational psychologists in exploring the relationship between work and mental well-being. It provides a background for the reviews of current knowledge described in the other papers in this issue of Occupational Medicine.     

Burnout as a clinical entity--its importance in health care workers

Burnout, viewed as the exhaustion of physical or emotional strengthas a result of prolonged stress or frustration, was added tothe mental health lexicon in the 1970s, and has been detectedin a wide variety of health care providers. A study of 600 Americanworkers indicated that burnout resulted in lowered production,and increases in absenteeism, health care costs, and personnelturnover. Many employees are vulnerable, particularly as theAmerican job scene changes through industrial downsizing, corporatebuyouts and mergers, and lengthened work time, Burnout producesboth physical and behavioural changes, in some instances leadingto chemical abuse. The health professionals at risk includephysicians, nurses, social workers, dentists, care providersin oncology and AIDS-patient care personnel, emergency servicestaff members, mental health workers, and speech and languagepathologists, among others. Early identification of this emotionalslippage is needed to prevent the depersonalization of the provider-patientrelationship. Prevention and treatment are essentially parallelefforts, including greater job control by the individual worker,group meetings, better up-and-down communication, more recognitionof individual worth, job redesign, flexible work hours, fullorientation to job requirements, available employee assistanceprogrammes, and adjuvant activity. Burnout is a health careprofessional's occupational disease which must be recognizedearly and treated.     

Bullying in Turkish white-collar workers

OBJECTIVES: To determine the prevalence of reported workplace bullying among a group of white-collar workers, to evaluate the association between reported bullying and its effect on health and to assess the effects of support at work for bullied workers. METHODS: A cross-sectional questionnaire survey among full-time government employees in the health, education and security sectors. Bullying was assessed using a 20-item inventory. The potential effects of reported bullying were assessed using the Job Induced Stress Scale, the Hospital Anxiety and Depression Scale, Job Satisfaction Scale and the Propensity to Leave Scale. RESULTS: The response rate was 79% (944/1,200) and 877 questionnaires were analysed after exclusion of non-complete data. Of respondents, 55% (483) reported experiencing one or more types of bullying in the previous year and 47% (416) had witnessed the bullying of others. The bully was most likely to be a superior. Sixty per cent of victims had tried to take action against bullying, but most were dissatisfied with the outcome. There were significant differences in anxiety, depression, job-induced stress and support at work scores between those reporting bullying and those not reporting bullying at work. Those who reported bullying with low support at work had the poorest scores on the mental health scales. CONCLUSIONS: Bullying is a serious problem in this group of workers and may lead to health consequences. Feeling that the work environment is supportive appears to have a protective effect in terms of the health outcomes.     

Racial discrimination, ethnicity and work stress

BACKGROUND: Previous research has suggested higher work stress among minority ethnic workers. AIMS: To determine levels of work stress in three ethnic groups, consider the contribution of racial discrimination to the groups' profiles of occupational and demographic associations with stress, and assess the association between work stress and well-being. METHODS: A household quota sample design was used, and 204 black African-Caribbean, 206 Bangladeshi and 216 white (UK born) working people took part in structured interviews. RESULTS: More black African-Caribbean respondents reported high work stress than either Bangladeshi or white respondents. Reported racial discrimination among black African-Caribbean female respondents was strongly associated with perceived work stress. Among the black African-Caribbean respondents, women who reported experiencing racial discrimination at work had higher levels of psychological distress. CONCLUSIONS: Perceived work stress may be underpinned by exposure to racial discrimination at work among black African-Caribbean women, and this may affect their psychological well-being.     

The relationship between occupational psychological stress and female fertility

OBJECTIVE: To investigate the association between occupational psychological stress and female fertility. METHODS: This was a case-control study including consecutive working female patients attending fertility and in vitro fertilization clinics in the Soroka University Medical Center. We compared occupational stress between 64 working patients who had attended the clinics due to female infertility (case group) and 106 working patients who had attended the clinics due to their partner's reproductive impairment (control group). RESULTS: Patients from the female infertility group were older (31.9 +/- 6.2 versus 30.2 +/- 4.6, P = 0.047) and tended to participate more in sporting activity [23.4 versus 10.4%, odds ratio (OR) = 2.6, 95% confidence interval (CI) = 1.05-6.73, P = 0.022] as compared with patients from the male infertility group. Patients from the case group tended to work more weekly hours as compared with the controls (33.6 +/- 16.8 versus 26.9 +/- 17.4, P = 0.028). High reliability was found, as demonstrated by Cronbach's alpha of 0.81-0.90 for the four burnout parameters. Patients from the female infertility group had significantly lower listlessness scores as compared with the control group, using the Mann-Whitney test (2.6 +/- 1.1 versus 3.1 +/- 1.2, P = 0.013). CONCLUSIONS: Patients admitted due to female infertility tended to have lower listlessness scores as compared with patients admitted due to their partner's infertility problem. No significant association was found between other burnout, job strain and job satisfaction scores and women's fertility status.     

Reduction of oxidative stress by compression stockings in standing workers

BACKGROUND: Healthy workers who stand for prolonged periods show enhanced production of reactive oxygen species (ROS) in their systemic circulation. Oxidative stress is thought to be a risk factor for chronic venous insufficiency and other systemic diseases. AIM: To evaluate the effectiveness of compression stockings in the prevention of oxidative stress at work. METHODS: ROS and venous pressure of the lower limbs were measured in 55 theatre nurses who stood in the operating theatre for >6 h, 23 industrial ironers who stood for up to 5 h during their shift and 65 outpatient department nurses and 35 laundry workers who acted as controls. Subjects and controls were examined on two consecutive days before and after work and with and without compression stockings. RESULTS: Without compression stockings, lower limb venous pressure increased significantly after work in all subjects and controls (P < 0.001), while only operating theatre nurses showed significantly higher mean levels of ROS (P < 0.001). There was no significant difference in venous pressures and ROS levels after work in subjects or controls when wearing compression stockings. CONCLUSIONS: Our data suggest a preventive role of compression stockings against oxidative stress in healthy workers with a standing occupation.     

Sources of stress experienced by occupational therapists and social workers in mental health settings

This study examined the sources of stress experienced by occupational therapists and social workers employed in Australian public mental health services and identified the demographic and work-related factors related to stress using a cross-sectional survey design. Participants provided demographic and work-related information and completed the Mental Health Professionals Stress Scale. The overall response rate to the survey was 76.6%, consisting of 196 occupational therapists and 108 social workers. Results indicated that lack of resources, relationships and conflicts with other professionals, workload, and professional self-doubt were correlated with increased stress. Working in case management was associated with stress caused by client-related difficulties, lack of resources, and professional self-doubt. The results of this study suggest that Australian occupational therapists and social workers experience stress, with social workers reporting slightly more overall stress than occupational therapists.     

Occupational exposure and health problems in small-scale industry workers in Dar es Salaam, Tanzania: a situation analysis

BACKGROUND: Workers in informal small-scale industries (SSI) in developing countries involved in welding, spray painting, woodwork and metalwork are exposed to various hazards with consequent risk to health. Aim To assess occupational exposure and health problems in SSI in Dar es Salaam, Tanzania. METHODS: Focused group discussions (FGD) were conducted among SSI workers. Participants were assessed for exposure to occupational and environmental hazards, the use of protective equipment and health complaints by interview. The findings were discussed with participants and potential interventions identified. RESULTS: Three hundred and ten workers were interviewed (response rate 98%). There was a high level (>90%) of self-reported exposure to either dust, fumes, noise or sunlight in certain occupational groups. There was low reported use of personal protective equipment. There was a high level of self-reported occupational health problems, particularly amongst welders and metalworkers. Workers reported their needs as permanent workplaces, information on work related hazards, water and sanitation, and legislation for SSI. CONCLUSIONS: In SSI in Tanzania, our study suggests that workers have high levels of exposure to multiple health hazards and that use of protective equipment is poor. This group of workers warrants improved occupational health and safety provision.     

Audit of immunization policy and practice of health care workers within National Health Service Trusts in England and Wales.

The purpose of this study was to identify the variation in occupational health immunization policies and practice within NHS Trusts throughout England and Wales. Questionnaires were sent to 440 NHS Trusts and 279 were returned (a response rate of 63%). The results were compared with current Department of Health Guidelines. They highlighted the fact that NHS Trusts do not adopt a consistent approach to immunization practice and that these policies often do not reflect Department of Health Guidance. Of those responding, 249 (89%) stated that they would like additional guidance on immunization practice within the NHS workplace. The production of updated, evidence-based guidelines for immunization practice, may help to ensure that a more consistent approach is taken throughout the NHS. This would benefit both the Trusts and their employees who at present may be confused by being given different advice when moving between Trusts.     

职业紧张对化工工人工作能力的影响

目的　为了解化工工人的职业紧张水平及工作能力状况 ,探讨影响工作能力的相关性因素。方法　应用工作能力指数问卷 (WAI)和职业紧张问卷 (OSQ) ,对某市化工行业10 30名工人 (研究组 4 81名 ,对照组 5 49名 )进行调查和工作能力降低的危险度评价。结果　研究组的WAI和OSQ评分与对照组均有显著性差异 (P <0 0 1)。两组的工作能力与职业紧张均存在显著的负相关关系 (P <0 0 1) ,研究组的相关程度明显高于对照组 ,且工作能力随着紧张程度的增高而降低。研究组工人随年龄的增长工作能力逐渐降低。以工作能力降低为结局变量 ,经多元logistic回归分析显示 ,在研究组中引起工作能力降低的主要紧张危险因素是肌肉骨骼疼痛 (OR =2 884 )、健康状况估计 (OR =2 6 5 1)、疾病的影响 (OR =2 4 98)、情绪情况 (OR =2 4 0 7)、缺乏体育锻炼 (OR =1 95 6 )、体力负荷 (OR =1 2 5 4)等 ,这些紧张因子都与工作能力降低有密切关系。结论　化工工人的职业紧张水平及不同紧张因素对工作能力降低有一定的影响 ,为工人的健康监测和提高工作能力水平提供了有益的帮助。     

Applicability of survey feedback for an occupational health method in stress management

The main stressors in work organizations have been determinedin the research on mental stress. This has prompted occupationalhealth personnel to actively look for new tools in reducingstress. However, only a few workplaces have implemented actionmodels for health promotion by reducing stressors. The aim ofthis project was to investigate the applicability of surveyfeedback for an occupational health method of stress management.The survey feedback process, which has been one of the mainapproaches in organization development, was applied for stressorreduction. The employee's commitment to the programme was confirmedby participation. The occupational health personnel were responsiblefor carrying out the programme. The project was carried outin selected departments of one factory of an international papercompany. On the basis of the survey feedback, the departmentsmade changes in their action models, environment and instructionand guidance systems. According to the follow-up in one department,the variability of work increased, and overall mental and physicalstrenousness decreased. The OH personnel shifted their workingmodel towards more active co-operation with the work units.Today the survey feedback is a routine method of the occupationalhealth service of the company.