Effects of long working hours on the health of food-delivery workers / 中国职业医学

{L-End}Objective To investigate the current status of long working hours of food-delivery workers from food-delivery platform, and analyze its impact on their health such as occupational stress, depressive symptoms, insomnia symptoms, fatigue accumulation, and life satisfaction. {L-End}Methods A total of 2 145 food-delivery workers from two food-delivery platforms in Guangzhou City were selected as the research subjects using convenience sampling method. The occupational stress, depressive symptoms, insomnia symptoms, fatigue accumulation, and life satisfaction were investigated using the Core Occupational Stress Scale, Patient Health Questionnaire-9 items, Self-sleep Management Questionnaire, Self-diagnosis Questionnaire of Fatigue Accumulation of Workers, and World Health Organization Five-item Well Being Index. {L-End}Results The median and the 25th and 75th percentiles of weekly working hours were 63 (49,77) hours. And 92.2% (1 978/2 145) of workers, who worked more than 40 hours per week, were long working hours workers. While 70.1% (1 504/2 145) workers, who worked 55 hours or more per week, were ultra-long working hours workers. The detection rate of occupational stress, depressive symptoms, insomnia symptoms, fatigue accumulation, and low life satisfaction was 30.1%, 27.5%, 34.7%, 40.8%, and 75.1%, respectively. The longer the weekly working hours of the research subjects, the higher the detection rate of occupational stress and fatigue accumulation (all P<0.01). The results of multivariate logistic regression analysis showed that ultra-long working hours (weekly working hours ≥55 hours) was the influencing factor of occupational stress and fatigue accumulation after excluding the influence of confounding factors among workers (all P<0.05). {L-End}Conclusion The food-delivery workers of food-delivery platforms generally work long hours. Ultra-long working hours is a risk factor for occupational stress and fatigue accumulation among these workers.

Effect of long working hours on work-related musculoskeletal disorders among operation and maintenance workers of power supply enterprises / 环境与职业医学

Background Long working hours is harmful to the physical and mental health of occupational groups, and should receive active attention. Objective To evaluate the current status of long working hours among operation and maintenance workers of power supply enterprises, and explore its effects on work-related musculoskeletal disorders (WMSDs) of the population. Methods From March to June 2021, a cross-sectional survey was conducted among 1433 operation and maintenance workers from 10 power supply enterprises in Jilin Province, Shandong Province, and Tianjin Municipality using cluster sampling. A total of 1433 copies of revised Mus-culoskeletal Disorders Questionnaire were distributed, 1343 questionnaires were recovered, and the recovery rate was 93.72%. The questionnaire included general information, personal health behaviors, weekly working hours, work-related factors, and musculoskeletal pain or discomfort in nine body parts in the past 12 months. χ2 test and multiple logistic regression models were used to investigate the relationships between long working hours (>40 h per week) and WMSDs. Results The average age of the workers was (39.42±9.89) years, and the average work experience was 11.00 (5.00, 21.00) years. There were 1158 males (86.22%) and 185 females (13.78%). The average weekly working hours of the workers were (47.98±11.35) h, and the proportion of long working hours (>40 h per week) was 61.06% (820/1343). The proportions of long working hours were higher among the workers with characteristics of male, power distribution, shift work, often/very often long-time standing, often/very often holding awkward postures, often handling heavy objects, limited space to operate, long-time neck tilting backward, keeping arms above shoulders, frequent elbow bending, repeating knee movement every minute, and repeating lower limb or foot movement every minute (all P<0.05). The prevalence rate of WMSDs was 81.53% (1095/1343) among the workers. The results of multiple logistic regression showed that after adjusting education, smoking, exercise, awkward postures, often handling heavy objects, limited space to operate, long-time heavy trunk bending, long-time neck tilting backward, and keeping arms above shoulders, compared with working ≤40 h per week, the risk of WMSDs among workers working >49 h per week was higher (OR=1.406, 95%CI: 1.011-1.955). Conclusion Long working hours is prominent among operation and maintenance workers of power supply enterprises, and increases the risk of reporting WMSDs.

Association of long working hours and shift work with occupational stress in level A tertiary hospitals / 预防医学

Objective@#To examine the association of long working hours and shift work with occupational stress among medical staff in level A tertiary hospitals, so as to provide insights into promotion of physical and mental health among medical personnel. @*Methods@#One level A tertiary hospital was sampled using a stratified cluster sampling method from southern and northern Xinjiang Uygur Autonomous Region, and all medical personnel were recruited from these two hospitals. Participants' demographics, working duration, and working in shifts were collected using questionnaires, and occupational stress was measured using the Core Scale for Measurement of Occupational Stress proposed by National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention. The associations of long working hours (weekly working duration of >40 hours) and shift work with occupational stress were examined using a multiple linear regression model.@*Results@#A total of 2 529 questionnaires were allocated, and 2 262 were valid, with an effective rate of 89.44%. The respondents had a mean age of (35.12±8.71) years, and included 1 696 women (74.98%). Of all respondents, there were 722 doctors (31.92%), 1 033 nurses (45.67%), 361 medical or pharmaceutical technicians (15.96%), 1 808 with long working hours (79.93%) and 1 264 with shift work (55.88%). The score of occupational stress was (44.79±8.49) points, and the prevalence of occupational stress was 28.69% among respondents. Multiple linear regression analysis showed that after adjustment for age, marital status, length of service, position, smoking and physical exercise, long working hours (>40 h, β'=0.124; >48 h, β'=0.175; ≥55 h, β'=0.323) and shift work (β'=0.203) were influencing factors for occupational stress among medical personnel（P<0.05）; however, there was no interaction between long working hours and shift work (P>0.05). @*Conclusion@#Long working hours and shift work may increase the risk of occupational stress among medical personnel in level A tertiary hospitals.

Association between long working hours and occupational stress/fatigue accumulation in medical staff of tertiary grade A hospitals in Shanghai / 环境与职业医学

Background Long working hours are a common occupational health risk factor. The problem of long working hours and its impact on health of medical staff cannot be ignored. Objective To investigate long working hours in medical staff of tertiary grade A hospitals in Shanghai, and evaluate the relationships of long working hours with occupational stress and fatigue accumulation. Methods A total of 1531 medical staff in departments of emergency, internal medicine, surgery, intensive care unit (ICU), anesthesiology, and obstetrics and gynecology from 6 hospitals in 6 districts of Shanghai were selected using stratified random sampling. A structured questionnaire was used to collect information on social demographics, occupational characteristics, andbehavior and lifestyle. The Core Occupational Stress Scale (COSS) and the Self-diagnostic Questionnaire on the Accumulation of Fatigue of Laborers were used to assess occupational stress and fatigue accumulation condition. Chi-square test and Kruskal-Wallis H test were used to analyze the distributions of long working hours, occupational stress, and fatigue accumulation, log-binomial models were used to analyze the relationships of long working hours with occupational stress and fatigue accumulation, and job title stratified models were also constructed. Results The average weekly working hours of the study subjects was (47.84±11.40) h, 65.90% of the medical staff worked more than 40 h every week. The percentages of the weekly working hours categories of 41-48 h, 49-54 h, and ≥55 h were 31.42%, 13.46%, and 21.03%, respectively. The positive rates of occupational stress and fatigue accumulation were 25.87% and 65.64% respectively, and the differences among different age, gender, job title, education, length of service, and shift system groups were statistically significant (P<0.05). The results of log-binomial regression showed that after adjusting for gender, age, monthly income, marital status, education, physical exercise, smoking, job position, length of service, and shift system, weekly working hours were an influencing factor of occupational stress and fatigue accumulation (P<0.05). Compared with weekly working hours≤40 h, the risk, PR(95%CI), of reporting occupational stress and fatigue accumulation increased to 2.595 (1.989, 3.385) and 1.578 (1.349, 1.845) times respectively for weekly working hours≥55 h (P<0.001). The results of job title stratification analysis showed that the risk of occupational stress among physicians, nurses, and medical technicians increased when weekly working hours≥55 h versus ≤40 h, and the PR (95%CI) values were 2.003 (1.383, 2.902), 1.971 (1.068, 3.636), and 2.770 (1.220, 6.288), respectively (P<0.05). The risk of fatigue accumulation was increased in physicians when weekly working hour≥55 h versus ≤40 h, with a PR (95%CI) value of 1.594 (1.208, 2.103) (P<0.001). Conclusion Long working hours are common among medical personnel and related to the occurrence of occupational stress and fatigue accumulation.

Effects of long working hours exposure on occupational stress and depression symptoms in couriers in Zhejiang Province / 中华劳动卫生职业病杂志

Objective: To understand the current situation of long working hours exposure of couriers in Zhejiang Province, and to analyze the influence of long working hours exposure levels on their occupational stress and depression symptoms, and provide a basis for promoting the physical and mental health of couriers. Methods: From September to December 2021 , 1159 couriers from Zhejiang Express Transport Companies were selected as respondents by cluster sampling, and their basic information were collected. The occupational stress and depression symptoms of the couriers were assessed using the Core Occupational Stress Scale (COSS) and the Patient Health Questionnaire-9 (PHQ-9). The effects of long work hours (>48 h per week) on the occupational stress and depression symptoms of the couriers were analyzed. Results: The average age of 1159 courier in Zhejiang Province was (33.24±8.42) years, the average weekly working hours were (63.21±18.77) h, and 75.15% (871/1159) were long-term workers. The detection rates of occupational stress and depression symptoms in courier were 32.44% (376/1159) and 32.53% (377/1159), respectively. There were significant differences in the detection rates of occupational stress and depression symptoms among couriers with different ages, educational background, marital status, monthly average income, length of service, position or post, shift status, drinking status, and average weekly working hours (P <0.05). The adjusted logistic regression analysis showed that, after adjusting for the influence of confounding factors such as age, educational background, marital status, monthly average income, length of service, position or post, shift status and drinking status, compared with the weekly working hours ≤48 h, weekly working hours of 63-77 h, 78-92 h, ≥93 h were the risk factors for occupational stress (OR=1.547, 95%CI: 1.019-2.350; OR=1.886, 95%CI: 1.184-3.006; OR=2.338, 95%CI: 1.188-4.062) and depression symptoms (OR=1.897, 95%CI: 1.258-2.860; OR=2.041, 95%CI: 1.290-3.230; OR=4.978, 95%CI: 2.551-9.715) of couriers (P<0.05) . Conclusion: Long working hours could increase the risk of occupational stress and depression symptoms among couriers. It is necessary to arrange working hours reasonably to reduce the occurrence of occupational stress and depression symptoms of couriers.

Research progress on health effects associated with exposure to long working hours / 环境与职业医学

The phenomenon of workers working beyond standard working hours is called long working hours. In recent years, more and more relevant studies at home and abroad have shown the association between long working hours and adverse health effects of occupational populations, such as increased risks of cardiovascular diseases, diabetes, and various psychological conditions such as depression and occupational stress. However, the current research has not yet reached a consistent conclusion. The main reason is that the physiological and psychological effects of exposure to long working hours need to be explored in depth. Therefore, based on the relevant research progress at home and abroad, this article introduced the health effects of long working hours from both physical and psychological aspects, including hypertension, cardiovascular diseases, diabetes, depression, and job burnout, expounded related mechanisms involved, and indicated deficiencies in current research on long working hours and the next research directions.

Correlations of long working hours and shift work with sleep of migrant workers / 环境与职业医学

Background Long working hours (LWH) and shift work are harmful to the physical and mental health of occupational groups. Objective To understand the status quo of LWH and shift work of migrant workers in Shanghai, and to analyze the influence of the above two factors on sleep of the population. Methods From July to September 2018, a cross-sectional survey using questionnaires was conducted among 3215 in-service employees at seven workplaces with more than 300 employees in six selected districts of Shanghai using multi-stage random sampling method. A total of 2976 valid questionnaires were collected, with a valid response rate of 92.6%. The questionnaires included general demographic characteristics, personal health behavior, work-related factors, weekly working hours, shift work, and sleep. Univariate analysis and logistic regression analysis were used to investigate the relationships of LWH and shift work with sleep, and an interaction item was included to evaluate potential interaction between LWH and shift work. Result The average age of the subjects was (30.98±9.49) years old, the male to female ratio was 1∶1.20, and 2382 workers were reported without local residency (80.0%). Among the migrant workers, the average weekly working hours was (57.23±13.14) h, the proportions of LWH (weekly working hours>40 h), extra LWH (weekly working hours>55 h), and shift work were 80.6% (1919/2382), 60.3% (1436/2382), and 25.4% (600/2366), respectively, all above were significantly higher than those of local workers. The prevalence rates of insomnia and lack of sleep among the migrant workers were 46.3% (1091/2356) and 25.4% (597/2354), respectively. The results of logistic regression model showed that after adjusting demographic characteristics such as gender, age, education level, and monthly income, as well as occupation and personal health behavior, compared with working hours ≤40 h per week, working 55-60 h per week was a risk factor for insomnia of migrant workers (OR=1.33, 95%CI: 1.02-1.72), while working >60 h per week was a risk factor for both insomnia (OR=1.37, 95%CI: 1.05-1.78) and insufficient sleep (OR=1.73, 95%CI: 1.28-2.35) of migrant workers. Shift work was only associated with insomnia (OR=1.37, 95%CI: 1.11-1.69). Meanwhile, working hours>60 h per week and shift work had an interaction effect on insomnia of migrant workers (OR=2.35, 95%CI: 1.20-4.60). Conclusion LWH and shift work are prominent among migrant workers, and there is an interaction between LWH and shift work with insomnia.

Relationship between working hours and probability to take alopecia medicine among Korean male workers: a 4-year follow-up study

BACKGROUND: Many studies have reported the negative effects of long working hours on various health problems. However, whether hair loss is associated with working hours has been rarely investigated so far. The main purpose of this study is to explore the relationship between long working hours and the development of alopecia among Korean male workers. METHODS: A total of 13,391 male workers not to take alopecia medicine in 2013 were followed up to see if they have alopecia medicine after 4 years, and that was used to confirm the alopecia development. Weekly working hours were categorized into three groups: reference working hours (RWH; 52 hours/week). Multiple logistic regression analyses were conducted to investigate the relationship between long working hours and the development of alopecia after adjusting age, marital status, education, monthly household income, smoking, and work schedule within strata of the covariates. RESULTS: Long working hours was significantly related to the development of alopecia. The adjusted odds ratios (ORs) for the development of alopecia were 1.57 (95% confidence interval [CI]: 1.21–2.05) for LWH group and 1.74 (95% CI: 1.23–2.47) for MLWH group relative to RWH group. CONCLUSIONS: Our findings suggest that unintentional development of alopecia is another potential health consequence of long working hours among Korean male workers. Preventive interventions to promote appropriate and reasonable working hours are required in our society.

Association between Long Working Hours and Job Stress and Depression among Employees from a State Grid Company / 中华劳动卫生职业病杂志

Objective@#This study was to understand the current situation of long working hours and identify the association of long working hours and job stress and depression among workers from one district company of state grid. @*Methods@#The project was done with the cross-sectional survey. All questionnaires were completed by self-administered with informed consent. Employees’ weekly working hours was reported by themselves; Using the PHQ-9 scale to assess depression, the JDC Model to evaluate job stress, and SPSS software to analyze data, the single factor chi-square test and multivariate Logistic analysis were performed to identify the association between long working hours and job stress, depression. @*Results@#there were 35.3 percent employees with over 44 hours a week. The association between increasing weekly working hours and job stress and depression was statistically significant. Compared to the reference group (≤44 h) , for those who worked more than 44 hours per week, the odds ratio of job stress was 2.02 (95%CI=1.27-3.23) times increased, and the odds ratio of depression was 1.60 (95%CI=1.01-2.55) times increased, especially for those (≥60 h) , the odds ratio was 3.69 (95%CI=1.45-9.41) and 2.76 (95%CI=1.09-7.03) respectively. @*Conclusion@#Long working hours can significantly increase the risk of job stress and depression among workers. When their weekly working hours exceeds 60, long working hours will be the independent risk factor for both job stress and depression.

The association between long working hours and work-related musculoskeletal symptoms of Korean wage workers: data from the fourth Korean working conditions survey (a cross-sectional study)

BACKGROUND: It has been reported that long working hours are hazardous to the workers’ health. Especially, work-related musculoskeletal disorders (WMSDs) have been considered as one of the significant health issues in workplace. The objective of this study was to identify the association between long working hours and work-related musculoskeletal symptoms. METHODS: The analysis was conducted using data from the Fourth Korean Working Conditions Survey (KWCS). Subjects of this study were 24,783 wage workers and divided into three groups according to the weekly working hours, which were ≤ 40, 41–52 and > 52 h. The relationship between long working hours and work-related musculoskeletal symptoms was analyzed by multivariate logistic regression method after adjusting for general, occupational characteristics including specific working motions or postures and psychosocial factors. RESULTS: Approximately 18.4% of subjects worked more than 52 h per week and 26.4 and 16.4% of male subjects and 33.0 and 23.4% of female subjects experienced work-related upper and lower limb pains, respectively, over the last 12 months. Moreover, the prevalence of upper and lower limb pain was increased in both genders as the weekly working hours increased. The odds ratios (ORs) of upper limb pain for those working 41–52 h and more than 52 h per week when adjusted for general, occupational characteristics including specific motions or postures and psychosocial factors were 1.36 and 1.40 for male workers and 1.26 and 1.66 for female workers compared to the reference group, respectively. Furthermore, ORs of lower limb pain for the same weekly working hour groups were 1.26 and 1.47 for male workers and 1.20 and 1.47 for female workers, respectively. CONCLUSIONS: Long working hours were significantly related to work-related musculoskeletal symptoms in Korean wage workers and appropriate interventions should be implemented to reduce long working hours that can negatively affect workers’ health.

The effect of long working hours on 10-year risk of coronary heart disease and stroke in the Korean population: the Korea National Health and Nutrition Examination Survey (KNHANES), 2007 to 2013

BACKGROUND: Recently, the emergence of long working hours and the associated conditions such as coronary heart disease (CHD) and stroke have gained attention. The aim of this study was to investigate the association between long working hours and the 10-year-risk of CHD and stroke, estimated by Jee’s health risk-appraisal model for ischemic heart disease. METHODS: We analyzed data from Koreans who randomly enrolled in Korean National Health and Nutrition Examination Survey 2008–2012 and finally included 13,799 participants. The participants were classified as per their working hours: 0–30 h/week, 31–39 h/week, 40 h/week, 41–50 h/week, 51–60 h/week, 61–70 h/week, 71–80 h/week, and >80 h/week. The risks for CHD and stroke were determined using Jee’s health risk-appraisal model. Multiple logistic regression was used to analyze the association between working hours and 10-year risk for CHD. RESULTS: The 10-year risks for CHD and stroke were significantly and positively associated with working hours in both men and women. Furthermore, higher risks for CHD and stroke were associated with longer working hours in women. CONCLUSION: Long working hours are significantly associated with the risks of CHD and stroke, estimated by Jee’s health risk-appraisal model. This study suggests the need for proper management of working hours to reduce CHD risk and stroke risk in the Korean population. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-016-0149-5) contains supplementary material, which is available to authorized users.

The association between long working hours and hearing impairment in noise unexposed workers: data from the 5th Korea National Health and Nutrition Examination Survey (KNHANES 2010–2012)

BACKGROUND: This study is aimed at finding out the relationship between long working hours, one of major job stress elements, and hearing impairment in unexposed workers to occupational and environmental noise. METHODS: This study was performed on 1628 regular, full-time wage workers between the age of 25-64 who indicated in the survey of having no experience of exposure to noise, normal otoscopic findings, and not suffering from diabetes based on the data from the fifth Korea National Health and Nutrition Examination Survey (KNHANES 2010–2012). The average working hours per week was categorized into 40 h and lower group, more than 40 to 48 h group, more than 48 to 60 h group, and more than 60 h group. The groups were defined as suffering from low or high frequencies hearing impairment if the average hearing threshold for 0.5, 1, 2 kHz or 3, 4, 6 kHz in both ears exceeds 25 dB based on the pure tone audiometry. The association between average weekly working hours and hearing impairment was analyzed using logistic regression after gender stratification. RESULTS: The prevalences of low and high frequencies hearing impairment in male workers were 4.3 and 28.6 %, respectively, which were much higher than female’s prevalence of 2.7 and 11.1 %. For male workers, no significant association was found between average weekly working hours and low and high frequencies hearing impairment. For female workers, odds ratios (OR) of low and high frequencies hearing impairment were 4.22 (95 % confidence interval (CI) 1.09–16.27) and 4.49 (95 % CI 1.73–11.67), respectively, after controlling for several related factors, such as, age, Body Mass Index (BMI), socio-economic status, health-related behavioral, and occupational characteristics variables, in the final model in the group working more than 60 h compared to the group working 40 h and lower. In addition, a dose-response relationship was observed that ORs of low and high frequencies hearing impairment were increased according to increasing average weekly working hours. CONCLUSIONS: The association between long working hours and hearing impairment in both low and high frequencies was significant in Korean female workers with a dose-response relationship. Therefore, the law to change the culture of long working hours should be enacted in order to protect the workers’ health and improve the quality of life in Korean workers.

Long working hours and overweight and obesity in working adults

BACKGROUND: Previous studies have identified a link between gender and the various risk factors associated with obesity. We examined obesity risk factors in working adults to identify the effects of differences in body mass index (BMI) and percentage body fat (PBF) between women and men. METHODS: A total of 1,120 adults agreed to participate in the study. Data from 711 participants, including 411 women and 300 men, were analyzed. Multiple logistic regression analysis was used to estimate the effects of risk factors on obesity and being overweight. In addition, the least-squares (LS) means of both BMI and PBF were estimated by analysis of covariance (ANCOVA) in a generalized linear model.  RESULTS: Increases in BMI and PBF were significantly related to an age > 50 years and long working hours in women after compensating for confounding factors. Using the PBF criterion, the odds ratio (OR) of being overweight or obese in women > 50 years of age who worked for > 9 h a day was 3.9 (95% confidence interval [CI], 1.05–11.00). For BMI, women who were > 50 years of age and worked for > 9 h a day were 3.82 times (95% CI, 1.31–11.14) more likely to be overweight or obese than those who were 50 years of age and long working hours in women. Further studies are needed to investigate the underlying mechanisms of this relationship and its potential implications for the prevention and management of excess weight and obesity.

Self-Reported Recovery from 2-Week 12-Hour Shift Work Schedules: A 14-Day Follow-Up

BACKGROUND: Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. METHODS: Sixty-one male offshore employeesd-20 night workers, 16 swing shift workers, and 25 day workersdrated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1-11) for 14 days after an offshore tour. After the two night-work schedules, differences on the 1st day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. RESULTS: After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05-1.89) and swing shift workers (1.42, 95% confidence interval 1.03-1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. CONCLUSION: After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the 1st day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality.

The association between long working hours and the metabolic syndrome: evidences from the 5th Korean National Health and Nutrition Examination Survey of 2010 and 2012

OBJECTIVES: This study was conducted in order to evaluate the association between the working hours of Korean employees and the metabolic syndrome and the effects of long working hours on metabolic syndrome based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012). METHODS: Based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012), 4,456 Korean employees without shift work, aged over 15, who work 30 hours or more per week were targeted in this study. The association between the general characteristics, including age, smoking, alcohol drinking, exercise, and the metabolic syndrome criteria defined by International Diabetes Federation (IDF) and weekly working hours were analyzed. In addition, the association between weekly working hours and the metabolic syndrome of the subjects stratified by gender was analyzed through multiple logistic regression analyses and generalized linear mixed model after adjusting the general characteristics. RESULTS: In the results of stratified analysis by gender, in male subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In female subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In addition, no trend associations were observed among weekly working hour groups in both stratified genders. CONCLUSION: No significant differences in prevalence of metabolic syndrome of the subjects stratified by gender were found according to weekly increasing working hours. However, due to some limitations of this study, further prospective studies may be necessary for verification.

Effect of Long Working Hours on Self-reported Hypertension among Middle-aged and Older Wage Workers

OBJECTIVES: Many studies have reported an association between overwork and hypertension. However, research on the health effects of long working hours has yielded inconclusive results. The objective of this study was to identify an association between overtime work and hypertension in wage workers 45 years and over of age using prospective data. METHODS: Wage workers in Korea aged 45 years and over were selected for inclusion in this study from among 10,254 subjects from the Korean Longitudinal Study of Ageing. Workers with baseline hypertension and those with other major diseases were excluded. In the end, a total of 1,079 subjects were included. A Cox proportional hazards model was used to calculate hazard ratios and adjust for baseline characteristics such as sex, age, education, income, occupation, form of employment, body mass index, alcohol habit, smoking habit, regular exercise, and number of working days per week. Additional models were used to calculate hazard ratios after gender stratification. RESULTS: Among the 1,079 subjects, 85 workers were diagnosed with hypertension during 3974.2 person-months. The average number of working hours per week for all subjects was 47.68. The proportion of overtime workers was 61.0% (cutoff, 40 h per week). Compared with those working 40 h and less per week, the hazard ratio of subjects in the final model, which adjusted for all selected variables, working 41-50 h per week was 2.20 (95% confidence interval [CI], 1.19-4.06), that of subjects working 51-60 h per week was 2.40 (95% CI, 1.07-5.39), and that of subjects working 61 h and over per week was 2.87 (95% CI, 1.33-6.20). In gender stratification models, the hazard ratio of the females tended to be higher than that of the males. CONCLUSION: As the number of working hours per week increased, the hazard ratio for diagnosis of hypertension significantly increased. This result suggests a positive association between overtime work and the risk of hypertension.

Association between long working hours and serum gamma-glutamyltransferase levels in female workers: data from the fifth Korean National Health and Nutrition Examination Survey (2010-2011)

OBJECTIVES: The present study investigated the association between long working hours and serum gamma-glutamyltransferase (GGT) levels, a factor influencing the incidence of cardiovascular disease. METHODS: Data from the fifth Korean National Health and Nutrition Examination Survey (2010-2011) were used to analyze 1,809 women. Subjects were divided into three groups based on the number of weekly working hours: or =52 hours per week. Complex samples logistic regression was performed after adjusting for general and occupational factors to determine the association between long working hours and high serum GGT levels. RESULTS: The prevalence of high serum GGT levels in groups with or =52 working hours per week was 22.0%, 16.9%, and 26.6%, respectively. Even after adjusting for general and occupational factors, those working 30-51 hours per week had the lowest prevalence of high serum GGT levels. Compared to those working 30-51 hours per week, the odds ratios (OR) of having high serum GGT levels in the groups with > or =52 and < or =29 working hours per week were 1.56 (95% confidence interval [CI], 1.10-2.23) and 1.53 (95% CI, 1.05-2.24), respectively. CONCLUSIONS: Long working hours were significantly associated with high serum GGT levels in Korean women.

The Association between Long Working Hours and Self-Rated Health

OBJECTIVES: This study was conducted to determine the number of hours worked per week by full-time wage workers by using the data of the Korean Labor and Income Panel Study (KLIPS), which represents the domestic urban area household, and to determine the association between weekly working hours and the level of self-rated health. METHODS: We used data from the 11th KLIPS conducted in 2008. The subjects of this study were 3,699 full-time wage workers between the ages of 25 and 64 years. The association between weekly working hours and self-rated health was analyzed considering socio-demographic characteristics, work environment, and health-related behaviors. RESULTS: Among the workers, 29.7% worked less than 40 hours per week; 39.7%, more than 40 to 52 hours; 19.7%, more than 52 to 60 hours; and 10.9%, more than 60 hours per week. After controlling for socio-demographic variables, work environment-related variables, and health-related behavior variables, the odds ratio (OR) for poor self-rated health for the group working more than 40 hours and up to 52 hours was calculated to be 1.06 (95% confidence interval (CI), 0.89-1.27) when the group working less than 40 hours per week was considered the reference. The OR for the group working more than 60 hours was 1.42 (95% CI, 1.10-1.83) and that for the group working more than 52 hours and up to 60 hours was 1.07 (95% CI, 0.86-1.33). After stratification by gender and tenure, the OR of the female workers group and that of the group with a tenure of more than 1 year were found to be significantly higher than those of the other groups. CONCLUSIONS: This study showed that workers working more than 60 hours per week have a significantly higher risk of poor self-rated health than workers working less than 40 hours per week. This effect was more obvious for the female workers group and the group with a tenure of more than 1 year. In the future, longitudinal studies may be needed to determine the association between long working hours and various health effects in Korean workers.

Association Between Work Conditions and Smoking in South Korea

BACKGROUND: A variety of sociodemographic factors, such as gender, age, household income, and educational level, influence individuals' likelihood of smoking. Work-related factors may also be linked to smoking behavior. We sought to investigate the relationship between smoking and work environment in South Korea. METHODS: We analyzed data from the Fifth Korean National Health and Nutrition Examination Survey to determine whether there was an association between smoking and occupation type (e.g., manual, nonmanual, or service work), night-shift work, and hours worked/week (e.g., 60 hours) for 4,685 workers. Regression models were adjusted for sociodemographic variables such as age, recent alcohol consumption, hours slept, educational level, and household income. RESULTS: The prevalence of smoking was 50.1% in men and 7.2% in women. For women, manual workers had 2.34 times [95% confidence interval (CI): 1.02-5.36] greater odds of smoking compared with nonmanual workers, whereas service workers had 2.37 times greater odds (95% CI: 1.28-4.40). Furthermore, women who worked 49-60 hours had 2.21 times greater odds of smoking (95% CI: 1.10-3.75) as compared with women who worked 40-48 hours. CONCLUSION: Women who work long hours or who are employed in service or manual positions are more likely to smoke. These results indicate a need in South Korea to target these specific groups when creating nonsmoking policies.

The relationship of working hours and work intensity with sleep disturbance among continuous 12 hours day and night shift workers in the automobile factory in Korea / 대한산업의학회지

BACKGROUNDS: The objective of this study is to explore the relationships of working hours and work intensity with sleep disturbance among 12-hour shift workers in the automobile factory in Korea. METHODS: A questionnaire and a sleep diary were distributed among 2200 (25% of total workers) and 300 workers who were randomly selected in the 8700 workers in one car factory. Among the 300 randomely selected workers, who were randomly selected, 262 workers filled out a sleep diary. For a questionnaire, 2200 (25%) among 8700 workers were randomly selected, 1200 (54% response rate) of whom filled out the questionnaire. The cross-sectional questionnaire and the sleep diary during 14 consecutive days were distributed and collected by workers' representatives, who were trained for the participatory action research in this study. One hundred and sixty workers' sleep diaries and questionnaires were merged by the same worker and used for the analysis in this study. Logistic regression analysis for repeated measurements was modeled using the prevalence of severe sleepiness at work (i.e. Karonlinska Sleepiness Scale 7 or higher) as dependent variable and working hours, sleep pattern, work intensity and health behaviours as independent variables. RESULTS: The prevalence of severe sleepiness at the end of work was more than 60% after finishing night shift in the automobile factory. The main risk factors related to the severe sleepiness at the end of work were the night shift, long working hours more than 10 hours, the higher frequency of night shift per month, less free time between shifts, poor quality of sleep, deficit of sleeping hours and intensified work (reducing tendency of rest time per day and increasing tendency of additional working time) such as increasing tendency of absolute surplus value. DISCUSSION: We suggest that the 12-hour shift system, long working hours, intensified work and poor quantity as well as quality of sleep were the main risk factors for the severe sleepiness among the shift workers in the automobile factory in Korea.