Comparison of the Association Between Presenteeism and Absenteeism among Replacement Workers and Paid Workers: Cross-sectional Studies and Machine Learning Techniques

Background@#Replacement drivers represent a significant portion of platform labor in the Republic of Korea, often facing night shifts and the demands of emotional labor. Research on replacement drivers is limited due to their widespread nature. This study examined the levels of presenteeism and absenteeism among replacement drivers in comparison to those of paid male workers in the Republic of Korea. @*Methods@#This study collected data for replacement drivers and used data from the 6th Korean Working Conditions Survey for paid male workers over the age of 20 years. Propensity score matching was performed to balance the differences between paid workers and replacement drivers. Multivariable logistic regression was used to estimate the adjusted odds ratio (OR) and 95% confidence intervals for presenteeism and absenteeism by replacement drivers. Stratified analysis was conducted for age groups, educational levels, income levels, and working hours. The analysis was adjusted for variables including age, education, income, working hours, working days per week, and working duration. @*Results@#Among the 1,417 participants, the prevalence of presenteeism and absenteeism among replacement drivers was 53.6% (n = 210) and 51.3% (n = 201), respectively. The association of presenteeism and absenteeism (adjusted OR [95% CI] = 8.42 [6.36−11.16] and 20.80 [95% CI = 14.60−29.62], respectively) with replacement drivers being significant, with a prominent association among the young age group, high educational, and medium income levels. @*Conclusion@#The results demonstrated that replacement drivers were more significantly associated with presenteeism and absenteeism than paid workers. Further studies are necessary to establish a strategy to decrease the risk factors among replacement drivers.

Investigation of Working Conditions and Health Status in Platform Workers in the Republic of Korea

Background@#The present study aimed to analyze several aspects of the working conditions and health status of platform workers in the Republic of Korea, such as ergonomic and emotional hazards. We also compared the health status of the platform workers with that of the general population. @*Methods@#A total of 1,000 platform workers participated in this survey from August 7 to August 17, 2022. The participants included 400 designated drivers, 400 food-delivery drivers, and 200 housekeeping managers. A face-to-face survey with a structured questionnaire was conducted by researchers who had received specific instructions. The focus of the survey extended to the work environment, encompassing factors such as workplace violence, as well as physical, chemical, and ergonomic hazards. Health-related data for the previous year were also collected, covering a range of issues such as hearing problems, skin problems, musculoskeletal symptoms, headaches, injuries, mental health issues, and digestive problems. Subsequently, we compared the health symptom data of the responders with those of the general population in the Republic of Korea. @*Results@#Platform workers, including designated drivers, food-delivery drivers, and housekeeping managers, existed in the blind spot of social insurance, facing frequent exposure to physical and chemical hazards, ergonomic risk factors, and direct or indirect violence. The prevalence of health problems, including musculoskeletal symptoms, general fatigue, and depressive symptoms, in each occupational group was statistically higher than that in the general population after standardization for age and gender. @*Conclusion@#The results revealed unfavorable working environment and inferior occupational health of platform workers compared with those of the general population.

Mediating Effect of Work–Family Conflict on the Relationship Between Long Commuting Time and Workers' Anxiety and Insomnia

Background@#Our study aimed to investigate the mediating role of work–family conflict (WFC) on the relationship between long commutes and workers' anxiety and insomnia. @*Methods@#Our study measured the two dimensions of WFC, time-related, and strain-related, which were considered multiple mediators. The mediating effect of WFC on anxiety and insomnia was investigated by decomposing the total effect into a direct effect (long commuting time → anxiety or insomnia) and an indirect effect (long commuting time → WFC → anxiety or insomnia). The combined indirect effect (joint indirect effect) of strain-related WFC and time-related WFC was estimated. The effects were presented as odds ratios and 95% confidence intervals (CIs). @*Results@#The direct effect of 120 min or longer of commuting time was 1.39 (95% CI: 1.17–1.65) times increase in the odds of anxiety and 1.64 (95% CI: 1.41–1.90) times increase in the odds of insomnia than those whose commuting time was less than 60 min. In the case of indirect effects, those whose commuting time was 120 min or longer had 1.13 times higher odds of anxiety (95% CI: 1.07–1.18) and 1.12 times higher odds of insomnia (95% CI: 1.07–1.17) via WFC. The joint indirect effects accounted for 26.4% and 18.5% of the total effect on anxiety and insomnia, respectively. The longer the commuting time, the stronger both direct and indirect effects. @*Conclusions@#Our findings highlight the mediating effect of WFC on the relationship between long commuting times and workers' anxiety and insomnia.

Self-Esteem Trajectories After Occupational Injuries and Diseases and Their Relation to Changes in Subjective Health: Result From the Panel Study of Workers’ Compensation Insurance (PSWCI)

Background@#Occupational injuries and diseases are life events that significantly impact an individuals’ identity. In this study, we examined the trajectories of self-esteem among victims of occupational injury and disease and their relation to health. @*Methods@#The Panel Study of Workers’ Compensation Insurance conducted annual followups on workers who had experienced occupational injury or disease. A total of 2,000 participants, who had completed medical care, were followed from 2013 to 2017. Growth mixture modeling was utilized to identify latent classes in the self-esteem trajectory.Additionally, logistic regressions were conducted to explore the association between trajectory membership, baseline predictors, and outcomes. @*Results@#Three distinct trajectory classes were identified. Total 65.8% of the samples (n = 1,316) followed an increasing self-esteem trajectory, while 31.1% (n = 623) exhibited a constant trajectory, and 3.1% (n = 61) showed a decreasing trajectory. Individuals with an increasing trajectory were more likely to have a higher educational attainment (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.20–2.88), an absence of a moderate-to-severe disability rating (OR, 0.49; 95% CI, 0.25–0.96), no difficulty in daily living activities (OR, 0.81; 95% CI, 0.75–0.88), and were economically active (re-employed: OR, 2.46; 95% CI, 1.52–3.98; returned to original work: OR, 4.46; 9% CI, 2.65–7.50). Those with a decreasing self-esteem trajectory exhibited an increased risk of poor subjective health (OR, 1.89; 95% CI, 0.85–4.85 in 2013 to OR, 3.17; 95% CI, 1.04–13.81 in 2017), whereas individuals with an increasing trajectory showed a decreased risk (OR, 0.54; 95% CI, 0.43–0.68 in 2013 to OR, 0.44; 95% CI, 0.33–0.57 in 2017). @*Conclusion@#Our findings emphasize the diversity of psychological responses to occupational injury or disease. Policymakers should implement interventions to enhance the self-esteem of victims.

Characteristics and Socio-Demographic Distribution of Precarious Employment Among Korean Wage Workers: A Proposition of Multidimensional Approach Using a Summative Score

Methods@#To operationalize precarious employment, we utilized data from the Korean Working Conditions Survey and focused on three distinct dimensions: employment insecurity, income inadequacy, and a lack of rights and protections. By constructing a summative scale ranging from -16 to 2, with lower scores indicating higher precariousness, we measured employment precariousness among Korean wage workers. To compare employment precariousness according to survey participant characteristics, we employed the Wilcoxon Rank Sum Test. @*Results@#We analyzed a weighted number of 38,432 workers. The overall sample showed a median (Q1, Q3) summative scale score of -3 (-6, -1). The median summative score was lower for women compared to men (men: -2; women: -5; p < 0.001), as well as for young or older workers compared to middle-aged workers (young: -4; middle-aged: -2; older: -5; p < 0.001). Similarly, workers with lower educational levels (middle school or below: -8; high school: -5; college or above: -2; p < 0.001) and non-white collar workers (blue collar: -5; service/sales worker: -6; white collar: -2; p < 0.001) experienced higher levels of employment precariousness. @*Conclusion@#Our findings indicate that certain vulnerable groups, such as women, young or older adults, workers with low educational attainment, and caregiving or low-skilled elementary workers, are disproportionately exposed to high employment precariousness. Active policy interventions are needed to improve the employment quality of vulnerable groups.

Socioeconomic Disparities in the Association Between All-Cause Mortality and Health Check-Up Participation Among Healthy Middle-Aged Workers:A Nationwide Study

Background@#This study assessed the relationship between non-participation in health checkups and all-cause mortality and morbidity, considering socioeconomic status. @*Methods@#Healthy, middle-aged (35–54 years) working individuals who maintained either self-employed or employee status from 2006–2010 were recruited in this retrospective cohort study from the National Health Insurance Service in Korea. Health check-up participation was calculated as the sum of the number of health check-ups in 2007–2008 and 2009–2010.Adjusted hazard ratio (HR) and 95% confidence interval (CI) of all-cause mortality were estimated for each gender using multivariable Cox proportional hazard models, adjusting for age, income, residential area, and employment status. Interaction of non-participation in health check-ups and employment status on the risk of all-cause mortality was further analyzed. @*Results@#Among 4,267,243 individuals with a median 12-year follow-up (median age, 44;men, 74.43%), 89,030 (2.09%) died. The proportion (number) of deaths of individuals with no, one-time, and two-time participation in health check-ups was 3.53% (n = 47,496), 1.66% (n = 13,835), and 1.33% (n = 27,699), respectively. The association between health checkup participation and all-cause mortality showed a reverse J-shaped curve with the highest adjusted HR (95% CI) of 1.575 (1.541–1.611) and 1.718 (1.628–1.813) for men and women who did not attend any health check-ups, respectively. According to the interaction analysis, both genders showed significant additive and multiplicative interaction, with more pronounced additive interaction among women who did not attend health check-ups (relative excess risk due to interaction, 1.014 [0.871−1.158]). @*Conclusion@#Our study highlights the significant reverse J-shaped association between health check-up participation and all-cause mortality. A pronounced association was found among self-employed individuals, regardless of gender.

Association Between Insomnia and Constipation: A Multicenter Three-year Cross-sectional Study Using Shift Workers' Health Check-up Data

Background@#Although insomnia and constipation are highly prevalent worldwide, studies examining a possible association between them are lacking. We examined the relationship between insomnia and constipation in shift workers who have a high prevalence of insomnia and other diseases. @*Methods@#This study had a multicenter cross-sectional design and conducted using health examination data including self-reported questionnaires. In total, 12,879 and 4,650 shift workers were enrolled in Severance Hospital and Wonju Severance Hospital, respectively, during 2015-2017. Multivariate logistic regression models and subgroup analysis were performed in each center with the same protocol, using a common data model. @*Results@#The mean age of the total population was 44.35 (standard deviation = 8.75); the proportion of males was 56.9%. Female sex, being underweight and non-smoker were strongly associated with an increased risk of constipation symptom (p < 0.001). Pooled odds ratios (ORs) were calculated using ORs of both centers with weights; there was a significant dose–response relationship (sub-threshold 1.76 [95% confidence interval [CI] 1.62–1.91]; moderate 2.28 [95% CI 2.01–2.60]; severe 4.15 [95% CI 3.18–5.41] in the final model, p for trend < 0.001). Subgroup analysis performed by stratifying sex and pooled ORs showed a similar trend to that of the entire group. @*Conclusion@#We observed a strong correlation between insomnia and constipation in this population. Our findings may help in formulating guidelines and policies to improve quality of life in shift workers through the management of sleep quality and proper bowel function. This study is the first to report this relationship among people working in shifts.

How Is the Suicide Ideation in the Korean Armed Forces Affected by Mental Illness, Traumatic Events, and Social Support?

Background@#Suicide is one of the leading causes of death in the military as in the general population. To mitigate such a serious public health problem, identifying the risk or protective factors of suicide behaviors is crucial. @*Methods@#We analyzed the representative data of the 2014 Korean Armed Forces to explore the relationship between past year adverse events (PAE), accumulated lifetime trauma (ALT), mental illness vulnerability, perceived social support, and suicidal ideation in the previous year. @*Results@#Among the 6,377 subjects, 3.7% of males and 6.2% of females reported suicidal ideation in the previous year. Multivariate analytic models identified significant associations of PAE and ALT with suicidal ideation with a dose-response pattern. The mental illness vulnerability showed the most significant association with suicidal ideation even after controlling PAE or ALT. We found that perceived social support may be potentially linked with a reduced risk of suicidal ideation. @*Conclusion@#This Korean military representative data demonstrates mental illness vulnerability; PAE; and lifetime trauma as significant risk factors of suicidal ideation, while perceived social support was found as a potential protective factor. Given the importance of the prevention of suicide in the military, those risk and protective factors may be used to screen soldiers at risk of suicide and provide further support on mental health services as needed.

How Is the Suicide Ideation in the Korean Armed Forces Affected by Mental Illness, Traumatic Events, and Social Support?

Background@#Suicide is one of the leading causes of death in the military as in the general population. To mitigate such a serious public health problem, identifying the risk or protective factors of suicide behaviors is crucial. @*Methods@#We analyzed the representative data of the 2014 Korean Armed Forces to explore the relationship between past year adverse events (PAE), accumulated lifetime trauma (ALT), mental illness vulnerability, perceived social support, and suicidal ideation in the previous year. @*Results@#Among the 6,377 subjects, 3.7% of males and 6.2% of females reported suicidal ideation in the previous year. Multivariate analytic models identified significant associations of PAE and ALT with suicidal ideation with a dose-response pattern. The mental illness vulnerability showed the most significant association with suicidal ideation even after controlling PAE or ALT. We found that perceived social support may be potentially linked with a reduced risk of suicidal ideation. @*Conclusion@#This Korean military representative data demonstrates mental illness vulnerability; PAE; and lifetime trauma as significant risk factors of suicidal ideation, while perceived social support was found as a potential protective factor. Given the importance of the prevention of suicide in the military, those risk and protective factors may be used to screen soldiers at risk of suicide and provide further support on mental health services as needed.

Occupational Safety and Health Act for the Protection of Workers’ Mental Health / 신경정신의학

The job is one of the essential elements of human happiness. On the other hand, workers are exposed to many hazardous environments that cause disease. The Occupational Safety and Health Act aims to “maintain and promote the safety and health of those who provide labor,” by “establishing standards regarding occupational safety and health,” and “clearly addressing the responsibility.” The law is based on the duties of the employer and government and the rights and duties of workers. The law generally describes the minimum standard, and the user should extend the concept of protection in law. This article describes the Occupational Safety and Health Act related to mental health protection. The data is expected to help medical doctors better understand and apply the law as a concept of protection.

Depressive symptoms among dance artists in South Korea: balance between self- and social identity on job value

BACKGROUND: The balance between self- and social identity on job value of Korean dance artists, considered as performing artists, was measured to investigate the relationship between balance and depressive symptoms. METHODS: Data of 139 dance artists were analyzed for depressive symptoms assessed by their responses to questionnaires from the Center for Epidemiologic Studies Depression (CESD) translated into Korean. The balance score of each aspect of social identity compared to that of self-identity on job value was measured and classified as lower, equal, or higher. Following a graphical approach, we performed locally weighted scatterplot smoothing algorithm, simple linear regression, and quadric equation regression. RESULTS: The mean of CESD was highest in the higher balance group and lowest in the lower balance group. There was a linear relationship between balance score and CESD regarding specific audience, unspecified audience, and unspecified public. Balance score showed no association with other aspects of social identity. In the balance score range of 1 or higher, it was associated with CESD with respect to artist colleague, unspecified audience, and unspecified public. CONCLUSIONS: Dance artists should maintain a balance between self- and social identity in job value to prevent depressive symptoms.

Long Commute Time and Sleep Problems with Gender Difference in Work–Life Balance: A Cross-sectional Study of More than 25,000 Workers

BACKGROUND: There is a lack of statistical analysis investigating the relationship between sleep problems and commute time in Korea. We aimed to analyze the association between representative health symptoms, sleep disturbances, and commute time according to working hours in Korea.METHODS: The 4th Korean Working Conditions Survey data were used for analysis, and unpaid family workers and workers who work fewer than three days in a week were excluded. Commute time, working hours, and sleep hours were assessed using self-reported questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) for sleep problems were calculated using a multivariate logistic regression model with ≤10 min commute time as the reference group.RESULTS: Among a total of 28,804 workers (men = 14,945, women = 13,859), 2.6% of men and 3.2% of women experienced sleep problems. In both sexes, long commute time (51–60 minutes and >60 minutes) showed an increased OR [men, 2.03 (CI = 1.32–3.13) and 2.05 (CI = 1.33–3.17); women, 1.58 (CI = 1.05–2.39) and 1.63 (CI = 1.06–2.50), respectively]. In stratification analysis of working hours, long commute time (51–60 and > 60 minutes) showed an increased OR in men working >40 hours/week [2.08 (CI = 1.16–3.71) and 1.92 (CI = 1.08–3.41), respectively]. Furthermore, long commute time (41–50, 51–60, and >60 minutes) showed an increased OR in women working >40 hours/week [2.40 (CI = 1.27–4.55), 2.28 (CI = 1.25–4.16), and 2.19 (CI = 1.17–4.16), respectively]. Moreover, commute time >60 minutes showed an increased OR in women working ≤40 hours/week [1.96 (CI = 1.06–3.62)].CONCLUSION: This large cross-sectional study highlights that long commute time is related to sleep problems in both sexes. Shorter commute times and decreased working hours are needed to prevent sleep problems in workers.

The role of customer service manual on workplace emotional burden in nationwide cross sectional study

BACKGROUND: We aim to discuss the overall effect of customer service manual (CSM) on service industry workers using Korean Working Condition Survey. METHODS: Out of 50,007 total survey participants, 11,946 customer service workers were included in the current study (5613 men, 6333 women). Answers to survey questions were used to define the use of CSM, emotional burden, emotional dissonance, engaging angry customers and other covariates. Emotional burden included either depressive event or stress level. Odds ratio (OR) with 95% confidence interval (95% CI) of experiencing emotional burden was calculated by logistic regression model. Interaction effect between CSM and engaging angry customer on emotional burden was also estimated. RESULTS: Out of 11,946 subjects, total of 3279 (27.4%) have experienced emotional burden. OR (95% CI) of experiencing emotional burden was 1.40 (1.19–1.64) in men and 1.25 (1.09–1.44) in women. There was gender difference in interaction effect between the use of CSM and engaging angry customers. In men, OR (95% CI) was 3.16 (1.38–7.23) with additive effect when always engaging angry customers with CSM compared to rarely engaging without CSM, while in women OR (95% CI) was 8.85 (3.96–19.75) with synergistic effect. Moreover, the risk of depressive event increased only in women with OR (95% CI) 2.22 (1.42–3.48). CONCLUSIONS: Our current study highlighted association between emotional burden and CSM in both men and women service workers. Furthermore, women were affected more severely by CSM. The results from current study suggest that CSM should be changed appropriately to benefit workers.

Effect of Burnout on Post-traumatic Stress Disorder Symptoms Among Firefighters in Korea: Data From the Firefighter Research on Enhancement of Safety & Health (FRESH) / 예방의학회지

OBJECTIVES@#It is well-known that post-traumatic stress disorder (PTSD) among firefighters contributes to their job-related stress. However, the relationship between burnout and PTSD in firefighters has rarely been studied. This study therefore explored the association between burnout and its related factors, such as trauma and violence, and PTSD symptoms among firefighters in Korea.@*METHODS@#A total of 535 firefighters participated in the Firefighter Research on Enhancement of Safety & Health study at 3 university hospitals from 2016 to 2017. The 535 participants received a baseline health examination, including questionnaires assessing their mental health. A Web-based survey was also conducted to collect data on job-related stress, history of exposure to violence, burnout, and trauma experience. The associations among burnout, its related factors, and PTSD symptoms were investigated using structural equation modeling.@*RESULTS@#Job demands (β=0.411, p<0.001) and effort-reward balance (β=-0.290, p<0.001) were significantly related to burnout. Burnout (β=0.237, p<0.001) and violence (β=0.123, p=0.014) were significantly related to PTSD risk. Trauma (β=0.131, p=0.001) was significantly related to burnout; however, trauma was not directly associated with PTSD scores (β=0.085, p=0.081).@*CONCLUSIONS@#Our results show that burnout and psychological, sexual, and physical violence at the hands of clients directly affected participants’ PTSD symptoms. Burnout mediated the relationship between trauma experience and PTSD.

A brief review of relationship between occupational benzene exposure and hematopoietic cancer

We reviewed articles to clarify the current evidence status for 1) types of cancer which related to benzene exposure, and 2) certain benzene exposure level which might cause the hematopoietic cancers. Hematopoietic function of the bone marrow is involved in the production of all blood cells types. The benzene metabolites including benzoquinone and mucoaldehyde affect hematopoietic stem cells as well as differentiation steps of progenitor cells for each blood cell. Hence, we concluded that benzene was associated with all lymphohematic carcinogenesis. First, it is supported by biological plausibility. Second, it is supported by meta-analysis although sing study did not show relationship due to lack of sample size or statistical power. More recent studies show lesser exposed level related to risk of cancer, compare to past studies did. Actually, early studies show the risk of malignancies in workers who exposed more than 200 ppm-years. However, only 0.5 to 1 ppm-year benzene exposed show significant linking to risk of malignancies in recent study. As reviewed research articles, we concluded that the relatively lower exposure level, such as 0.5–1 ppm-year, will be considering at risk of hematopoietic cancer. However, more research needs to be done on dose-response analysis.

Differences in the performance of health officers at the workplace according to their qualifications

BACKGROUND: Health officers are an integral part of the occupational health service, and there have been studies to identify and improve the role of health officers in the workplace in order to improve the level of health care in the workplace. This study aimed to determine the contribution of health officers to the role of a health officer as prescribed by law and the percentage of health management work performed during work according to their qualifications. METHODS: Questionnaires were distributed to a total of 4584 workplaces where health officers were hired, and a total of 806 copies (17.58%) were returned. Of these, 336 questionnaires were finally analyzed, after excluding questionnaires missing the main variables. Using the data, the difference of role contributions and the percentage of health care work performed during the whole day according to the qualification of the health officer was analyzed. RESULTS: Nurses were highly rated in the field of medical care, and industrial hygienists and air environmental engineers were highly rated in terms of chemicals and risk factor management. The percentage of health care work performed during the whole day differed according to the size of the workplace and industrial classification, but it was generally the lowest among air environmental engineers. CONCLUSIONS: Health officers play a very different role in the workplace depending on their qualification, and they need support for areas of other qualification. In order to effectively manage the health of the staff at a workplace, it is necessary to consider the development of a support system for small- and medium-sized enterprises and adjust the conditions of employment of the health officer according to the law.

Mental disorders among workers in the healthcare industry: 2014 national health insurance data

BACKGROUND: Numerous studies have shown that healthcare professionals are exposed to psychological distress. However, since most of these studies assessed psychological distress using self-reporting questionnaires, the magnitude of the problem is largely unknown. We evaluated the risks of mood disorders, anxiety disorders, sleep disorders, and any psychiatric disorders in workers in healthcare industry using Korea National Health Insurance (NHI) claims data from 2014, which are based on actual diagnoses instead of self-evaluation. METHODS: We used Korea 2014 NHI claims data and classified employees as workers in the healthcare industry, based on companies in the NHI database that were registered with hospitals, clinics, public healthcare, and other medical services. To estimate the standardized prevalence of the selected mental health disorders, we calculated the prevalence of diseases in each age group and sex using the age distribution of the Korea population. To compare the risk of selected mental disorders among workers in the healthcare industry with those in other industries, we considered age, sex, and income quartile characteristics and conducted propensity scored matching. RESULTS: In the matching study, workers in healthcare industry had higher odds ratios for mood disorders (1.13, 95% CI: 1.11–1.15), anxiety disorders (1.15, 95% CI: 1.13–1.17), sleep disorders (2.21, 95% CI: 2.18–2.24), and any psychiatric disorders (1.44, 95% CI: 1.43–1.46) than the reference group did. Among workers in healthcare industry, females had higher prevalence of psychiatric disorders than males, but the odds ratios for psychiatric disorders, compared to the reference group, were higher in male workers in healthcare industry than in females. CONCLUSIONS: The prevalence of mood disorders, anxiety disorders, sleep disorders, and all psychiatric disorders for workers in the healthcare industry was higher than that of other Korean workers. The strikingly high prevalence of sleep disorders could be related to the frequent night-shifts in these professions. The high prevalence of mental health problems among workers in healthcare industry is alarming and requires prompt action to protect the health of the “protectors.”

Impacts of Return-to-Work Type and Period on Job Retention in Workers with Occupational Injuries and Diseases

BACKGROUND: Despite the necessity of job retention in achieving return-to-work (RTW) goals, many workers leave their jobs after returning to work. The objective of this study was to examine the impacts of RTW type and period on job retention in Korean workers with occupational injuries and diseases. METHODS: Data were derived from the Panel Study of Worker's Compensation Insurance, including data from 2,000 systemically sampled workers who had finished recuperation in 2012; three waves of survey data were included in the analyses. Workers who returned to work (n = 1,610) were included in the analysis of the relationship between RTW type and job retention, and 664 workers who returned to their original workplaces were included in the analysis of the relationship between RTW period and job retention. The participants completed a questionnaire, and administrative data were provided by workers' compensation insurance. RESULTS: A Cox proportional-hazards regression analysis showed an increased hazard ratio (HR) for non-retention of 2.66 (95% confidence interval, 2.11–3.35) in reemployed workers compared to that in workers returning to their original workplaces. Among workers returning to their original workplaces, HRs for non-retention were increased in workers with a RTW period of 13–24 months (3.03 [1.52–6.04]) and > 24 months (5.33 [2.14–13.25]) compared to workers with a RTW period of ≤ 3 months. CONCLUSION: RTW type and period were significantly related to job retention, suggesting that policies for promoting job retention rate should be implemented.

The Association between Involuntary Smoking Exposure with Urine Cotinine Level and Blood Cadmium Level in General Non-Smoking Populations

Unintentional environmental exposure to toxicants is associated with an aggravated health status of the general population. Involuntary smoking (IS) exposure is one of the main routes to involuntary toxicants exposure. However, few studies have attempted to understand the environmental cadmium exposure by IS exposure in the general, non-smoking population. The purpose of the current study was to examine the relationship between blood cadmium level and IS level according to gender and age. We used the Korea National Health and Nutrition Examination Survey (KNHANES) IV–VI data that included heavy metal and urine cotinine sampling with IS exposure history. The final analysis comprised 3,493 adults (1,231 males and 2,262 females) and 395 adolescents (210 males and 185 females). Linear regression was performed to estimate the association between self-reported IS exposure with urine cotinine level and blood cadmium level in non-smokers with gender and age group stratification. In final regression model, the effect values (B) (standard errors [SE]) between blood cadmium and urine cotinine level in men was 0.0004 (0.0001) and 0.0006 (0.0002) in adults and adolescents, the B (SE) in women was 0.0006 (0.0002) and 0.0016 (0.0006) in adults and adolescents. Our study revealed, for the first time, a significant association between blood cadmium and IS exposure in non-smokers. Greater efforts are needed to improve environmental justices of the general population from IS, considering the severe harmful effects of involuntary exposure to even a low level of cadmium.

Association of Emotional Labor, Self-efficacy, and Type A Personality with Burnout in Korean Dental Hygienists

The purpose of this study was to examine the relationship between emotional labor and burnout, and whether the levels of self-efficacy and type A personality characteristics increase the risk of burnout in a sample of Korean female dental hygienists. Participants were 807 female dental hygienists with experience in performing customer service for one year or more in dental clinics, dental hospitals, or general hospitals in Korea. Data were collected using a structured self-administered questionnaire. A hierarchical multiple linear regression analysis was used to examine the effects of emotional labor on burnout, and to elucidate the additive effects of self-efficacy and type A personality on burnout. The results showed that “overload and conflict in customer service,”“emotional disharmony and hurt,” and “lack of a supportive and protective system in the organization” were positively associated with burnout. With reference to the relationship between personality traits and burnout, we found that personal traits such as self-efficacy and type A personality were significantly related to burnout, which confirmed the additive effects of self-efficacy and type A personality on burnout. These results indicate that engaging in excessive and prolonged emotional work in customer service roles is more likely to increase burnout. Additionally, an insufficient organizational supportive and protective system toward the negative consequences of emotional labor was found to accelerate burnout. The present findings also revealed that personality traits such as self-efficacy and type A personality are also important in understanding the relationship between emotional labor and burnout.