Inequality in Mortality and Cardiovascular Risk Among Young, Low-Income, Self-Employed Workers: Nationwide Retrospective Cohort Study.

Background: Self-employment is a significant component of South Korea's labor force; yet, it remains relatively understudied in the context of occupational safety and health. Owing to different guidelines for health checkup participation among economically active individuals, disparities in health maintenance may occur across varying employment statuses. Objective: This study aims to address such disparities by comparing the risk of all-cause mortality and comorbidities between the self-employed and employee populations in South Korea, using nationwide data. We sought to provide insights relevant to other countries with similar cultural, social, and economic contexts. Methods: This nationwide retrospective study used data from the Korean National Health Insurance Service database. Participants (aged 20-59 y) who maintained the same insurance type (self-employed or employee insurance) for ≥3 years (at least 2008-2010) were recruited for this study and monitored until death or December 2021-whichever occurred first. The primary outcome was all-cause mortality. The secondary outcomes were ischemic heart disease, ischemic stroke, cancer, and hospitalization with a mental illness. Age-standardized cumulative incidence rates were estimated through an indirect method involving 5-unit age standardization. A multivariable Cox proportional hazards model was used to estimate the adjusted hazard ratio (HR) and 95% CI for each sex stratum. Subgroup analyses and an analysis of the effect modification of health checkup participation were also performed. Results: A total of 11,652,716 participants were analyzed (follow-up: median 10.92, IQR 10.92-10.92 y; age: median 42, IQR 35-50 y; male: n=7,975,116, 68.44%); all-cause mortality occurred in 1.27% (99,542/7,851,282) of employees and 3.29% (124,963/3,801,434) of self-employed individuals (P<.001). The 10-year cumulative incidence rates of all-cause mortality differed significantly by employment status (1.1% for employees and 2.8% for self-employed individuals; P<.001). The risk of all-cause mortality was significantly higher among the self-employed individuals when compared with that among employees, especially among female individuals, according to the final model (male: adjusted HR 1.44, 95% CI 1.42-1.45; female: adjusted HR 1.89, 95% CI 1.84-1.94; P<.001). The risk of the secondary outcomes, except all types of malignancies, was significantly higher among the self-employed individuals (all P values were <.001). According to subgroup analyses, this association was prominent in younger individuals with lower incomes who formed a part of the nonparticipation groups. Furthermore, health checkup participation acted as an effect modifier for the association between employment status and all-cause mortality in both sexes (male: relative excess risk due to interaction [RERI] 0.76, 95% CI 0.74-0.79; female: RERI 1.13, 95% CI 1.05-1.21). Conclusions: This study revealed that self-employed individuals face higher risks of all-cause mortality, cardio-cerebrovascular diseases, and mental illnesses when compared to employees. The mortality risk is particularly elevated in younger, lower-income individuals who do not engage in health checkups, with health checkup nonparticipation acting as an effect modifier for this association.

Impact of early economic activity loss on all-cause mortality in gastric cancer survivors following curative treatment: a nationwide study in Korea.

BACKGROUND: The impact of economic engagement on the health of cancer survivors is notable. Our study aims to explore the association between early loss of economic activity (EA) and the risk of all-cause mortality among gastric cancer survivors. METHODS: This retrospective cohort study utilized data from Korea's National Health Insurance Service, focusing on 30-59-year-old gastric cancer patients who received either surgery or endoscopic procedures from January 2009 to December 2013. The primary outcome measure was all-cause mortality. Early loss of EA was identified when a patient's insurance status shifted to dependent within one year following treatment. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality were estimated using multivariable Cox proportional hazards models, conducting separate analyses for surgical and endoscopic groups. RESULTS: Among 24,159 patients (median follow-up, 9.9 years), 2976 (12.3%) experienced all-cause mortality. Specifically, 2835 of these deaths occurred in patients who underwent surgery, while 141 were in the endoscopic procedure group. Early loss of EA was recorded in 14.4% of the surgery group and 7.7% of the endoscopic procedure group. Adjusted HRs (95% CI) for all-cause mortality associated with early loss of EA were 1.39 (1.27-1.54) for the surgery group and 2.27 (1.46-3.52) for the endoscopic procedure group. CONCLUSIONS: This study highlights a significant association between the early loss of EA and an increased risk of all-cause mortality in those who have undergone curative treatments for gastric cancer. It underscores the crucial role of sustaining EA in enhancing the health outcomes of these survivors.

Occupation classification model based on DistilKoBERT: using the 5th and 6th Korean Working Condition Surveys.

Background: Accurate occupation classification is essential in various fields, including policy development and epidemiological studies. This study aims to develop an occupation classification model based on DistilKoBERT. Methods: This study used data from the 5th and 6th Korean Working Conditions Surveys conducted in 2017 and 2020, respectively. A total of 99,665 survey participants, who were nationally representative of Korean workers, were included. We used natural language responses regarding their job responsibilities and occupational codes based on the Korean Standard Classification of Occupations (7th version, 3-digit codes). The dataset was randomly split into training and test datasets in a ratio of 7:3. The occupation classification model based on DistilKoBERT was fine-tuned using the training dataset, and the model was evaluated using the test dataset. The accuracy, precision, recall, and F1 score were calculated as evaluation metrics. Results: The final model, which classified 28,996 survey participants in the test dataset into 142 occupational codes, exhibited an accuracy of 84.44%. For the evaluation metrics, the precision, recall, and F1 score of the model, calculated by weighting based on the sample size, were 0.83, 0.84, and 0.83, respectively. The model demonstrated high precision in the classification of service and sales workers yet exhibited low precision in the classification of managers. In addition, it displayed high precision in classifying occupations prominently represented in the training dataset. Conclusions: This study developed an occupation classification system based on DistilKoBERT, which demonstrated reasonable performance. Despite further efforts to enhance the classification accuracy, this automated occupation classification model holds promise for advancing epidemiological studies in the fields of occupational safety and health.

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.

Liver Cancer Risk Across Metabolic Dysfunction-Associated Steatotic Liver Disease and/or Alcohol: A Nationwide Study.

INTRODUCTION: New terminologies of metabolic dysfunction-associated steatotic liver disease (MASLD) have been developed. We assessed hepatocellular carcinoma (HCC) risk across MASLD and/or alcohol intake. METHODS: We included participants aged 40-79 years receiving a national health checkup from 2009 to 2010 in the Republic of Korea, classified as follows: non-MASLD, MASLD, MASLD with increased alcohol intake (MetALD; weekly alcohol 210-420 g for male and 140-350 g for female individuals), and alcohol-associated liver disease (ALD; excessive alcohol intake with weekly alcohol ≥420 g for male or ≥350 g for female individuals). The primary outcome was HCC incidence. HCC risk was estimated using multivariable Cox proportional hazard models. RESULTS: Among 6,412,209 participants, proportions of non-MASLD, MASLD, MetALD, and ALD cases were 59.5%, 32.4%, 4.8%, and 3.4%, respectively. During follow-up (median 13.3 years), 27,118 had newly developed HCC. Compared with non-MASLD, the HCC risk increased from MASLD (adjusted hazard ratio [aHR] 1.66, 95% confidence interval [CI] 1.62-1.71) and MetALD (aHR 2.17, 95% CI 2.08-2.27) to ALD (aHR 2.34, 95% CI 2.24-2.45) in a stepwise manner. Furthermore, the older and non-cirrhosis subgroups were more vulnerable to detrimental effects of MASLD and/or alcohol intake, concerning HCC risk. Among the older, female, and cirrhosis subgroups, MetALD poses similar HCC risks as ALD. DISCUSSION: HCC risk increased from MASLD and MetALD to ALD in a stepwise manner, compared with non-MASLD. For an effective primary prevention of HCC, a comprehensive approach should be required to modify both metabolic dysfunction and alcohol intake habit.

Exploring the relationship between work-family conflict and sleep disturbance: a study on stratification and interaction.

Introduction: Despite several studies on the association between work-family conflict (WFC) and sleep disturbances, a more comprehensive approach considering occupational factors is lacking. We aimed to analyze this association among Korean workers and the combined effects of WFC and job-related factors on sleep disturbance. Methods: Data on paid workers from the sixth Korean Working Conditions Survey were analyzed. Odds ratios (ORs) with 95% confidence intervals (CIs) for sleep disturbances with WFC were calculated using a multiple logistic regression model among Korean workers. Furthermore, stratification and interaction analyses were conducted between WFC and socioeconomic factors related to sleep disturbance. Results: Among the 24,923 workers (male: 11,752, female: 13,171) examined, 35.40% of males and 39.95% of females experienced sleep disturbances. In both sexes, the WFC group was significantly associated with sleep disturbance [adjusted OR (95% CI): male, 2.90 [2.67-3.16]; female, 2.54 [2.35-2.74]]. According to the stratification analysis, the association between sleep disturbance and WFC was prominent among younger and highly educated individuals, those engaged in quick returns, and larger companies in both sexes. In the interactions between WFC, quick return, occupation, and company size on sleep disturbance, there were significant additive associations, except between WFC and occupation among female workers. Conclusion: This study highlights the association between WFC and sleep disturbances in male and female workers and emphasizes the importance of maintaining work-life balance.

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 check-ups 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 check-up 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 exposure to violence, job stress and depressive symptoms among gig economy workers in Korea.

Background: Gig workers, also known as platform workers, are independent workers who are not employed by any particular company. The number of gig economy workers has rapidly increased worldwide in the past decade. There is a dearth of occupational health studies among gig economy workers. We aimed to investigate the association between exposure to violence and job stress in gig economy workers and depressive symptoms. Methods: A total of 955 individuals (521 gig workers and 434 general workers) participated in this study and variables were measured through self-report questionnaires. Depressive symptoms were evaluated by the Patient Health Questionnaire-9 when the score was greater than or equal to 10 points. The odds ratio with 95% confidence interval was calculated using multivariable logistic regression adjusted for age, sex, working hours, education level, exposure to violence and job stress. Results: 19% of gig economy workers reported depressive symptoms, while only 11% of general workers reported the depressive symptoms. In association to depressive symptoms among gig economy workers, the mainly result of odds ratios for depressive symptoms were as follows: 1.81 for workers type, 3.53 for humiliating treatment, 2.65 for sexual harassment, 3.55 for less than three meals per day, 3.69 for feeling too tired to do housework after leaving work. Conclusions: Gig economic workers are exposed to violence and job stress in the workplace more than general workers, and the proportion of workers reporting depressive symptoms is also high. These factors are associated to depressive symptoms. Furthermore, the gig workers associated between depressive symptoms and exposure to violence, job stress.

Risk of psychological distress by decrease in economic activity, gender, and age due to COVID-19: A multinational study.

Introduction: Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2-virus. COVID-19 has officially been declared as the latest in the list of pandemics by WHO at the start of 2020. This study investigates the associations among decrease in economic activity, gender, age, and psychological distress during the COVID-19 pandemic considering the economic status and education level of countries using multinational surveys. Methods: Online self-report questionnaires were administered in 15 countries which were spontaneously participate to 14,243 respondents in August 2020. Prevalence of decrease in economic activity and psychological distress was stratified by age, gender, education level, and Human Development Index (HDI). With 7,090 of female (49.8%), mean age 40.67, 5,734 (12.75%) lost their job and 5,734 (40.26%) suffered from psychological distress. Results: Associations among psychological distress and economic status, age, and gender was assessed using multivariate logistic regression, adjusted for country and education as random effects of the mixed model. We then measured the associations between HDI and age using multivariate logistic regression. Women had a higher prevalence of psychological distress than men with 1.067 Odds ratio, and younger age was significantly associated with decrease in economic activity for 0.998 for age increasing. Moreover, countries with lower HDI showed a higher prevalence of decrease in economic activity, especially at lower education levels. Discussion: Psychological distress due to COVID-19 revealed a significant association with decrease in economic activity, women, and younger age. While the proportion of decrease in economic activity population was different for each country, the degree of association of the individual factors was the same. Our findings are relevant, as women in high HDI countries and low education level in lower HDI countries are considered vulnerable. Policies and guidelines for both financial aid and psychological intervention are recommended.

Teleworking Is Significantly Associated with Anxiety Symptoms and Sleep Disturbances among Paid Workers in the COVID-19 Era.

Due to social distancing during COVID-19, teleworking has spread in Korea. Accordingly, the effects of teleworking on physical and mental health have emerged. We aim to determine the association between teleworking and mental health, including anxiety symptoms and sleep disturbance, in paid workers. The data of paid workers from the Sixth Korean Working Conditions Survey, collected between October 2020 and April 2021, were analyzed. Gender stratification analysis and propensity score matching were performed for variables relevant to sociodemographic and occupational characteristics. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for each sex were analyzed using multivariable logistic regression, adjusting for sociodemographic and occupational characteristics. Among 28,633 participants, analyses were performed for anxiety symptoms (teleworkers vs. non-teleworkers; men: 12.1% vs. 4.9%; women: 13.5% vs. 5.3%) and sleep disturbance (men: 33.6% vs. 21.3%; women: 39.7% vs. 25.3%). In male teleworkers, the AORs for anxiety symptoms and sleep disturbance were 1.86 (95% CI: 1.14-3.04) and 1.52 (95% CI: 1.10-2.11), respectively. In female teleworkers, the AORs for anxiety symptoms and sleep disturbance were 1.66 (95% CI: 1.13-2.43) and 1.65 (95% CI: 1.28-2.14), respectively. Our results emphasize the importance of mental health and the need for continuous education and care for teleworkers, given the rapid increase in teleworking.

Comparable Mortality Between Asian Patients with Chronic Hepatitis B Under Long-Term Antiviral Therapy vs Matched Control: A Population-Based Study.

INTRODUCTION: Antiviral therapy (AVT) substantially improved the prognosis for patients with chronic hepatitis B (CHB). Head-to-head comparisons of prognosis between treated patients with CHB and the general population are scarce. We directly compared the prognosis between Asian patients with CHB receiving AVT and the general population. METHODS: From the South Korean National Health Insurance Service database, patients with CHB receiving AVT ≥3 years, aged 40-64 years, who underwent health examinations between 2011 and 2012 (AVT-CHB group) were recruited. As a control, propensity score-matched general population was chosen among patients without CHB. The primary outcome was all-cause mortality; secondary outcomes were cardiovascular disease (CVD), hepatocellular carcinoma (HCC), and all types of non-HCC malignancies. RESULTS: During follow-up (median 7.2 years), 26,467 and 75,469 individuals in the AVT-CHB group and matched general population were analyzed. The 5- and 7-year cumulative all-cause mortality rates were 0.40% and 1.0% for the AVT-CHB group vs 0.50% and 1.0% for the matched general population (adjusted hazard ratio [aHR] 0.96, 95% confidence interval [CI] 0.83-1.10; P = 0.51). The AVT-CHB group had a lower risk of CVD than the matched general population (aHR 0.70, 95% CI: 0.62-0.79; P < 0.001). Although the AVT-CHB group was more likely to develop HCC than the matched general population (aHR 13.16, 95% CI: 10.90-15.89; P < 0.001), the non-HCC malignancy risks in the AVT-CHB group were comparable to the matched general population (aHR 1.05, 95% CI 0.98-1.13; P = 0.137). DISCUSSION: The AVT-CHB group had a similar risk of all-cause mortality and non-HCC malignancies and a lower risk of CVD than the matched general population.

Post-operative recurrence of liver cancer according to antiviral therapy for detectable hepatitis B viremia: A nationwide study.

BACKGROUND: High postoperative recurrence of hepatitis B virus (HBV)-infected hepatocellular carcinoma (HCC) remains a significant challenge. Here, we aimed to compare the postoperative HCC recurrence between patients with AVT for detectable serum HBV-DNA vs. those without. METHODS: Data of patients undergoing curative resection of HBV-infected HCC as an initial therapy from 2015 to 2017 were obtained from the National Health Insurance Service database in South Korea. AVT was initiated when serum HBV-DNA was detectable. The primary outcome was HCC recurrence. The cumulative risk of HCC recurrence between AVT users and non-users was estimated using the Kaplan-Meier method. RESULTS: During follow-up (median 2.7 years) with 3034 patients, 25.7% and 23.6% of AVT users and non-users experienced HCC recurrence, respectively. The 1-, 2-, and 3-year cumulative recurrence rates were similar (p = 0.57): 15.6%, 23.3%, and 26.4% in AVT users versus 15.3%, 22.0%, and 24.9% in non-users, respectively. After adjusting for covariates, multivariable Cox regression analysis showed comparable outcomes between the two groups with adjusted hazard ratios (aHR 1.08, 95% confidence interval [CI] 0.89-1.31; p = 0.439). Similar outcomes between the two groups were reproduced after stratification of liver cirrhosis. Inverse probability treatment weighting analysis also showed comparable outcomes between the two groups in the subgroups with liver cirrhosis (aHR 1.01, 95% CI 0.80-1.29; p = 0.92) and non-cirrhosis (aHR 1.08, 95% CI 0.87-1.34; p = 0.472). CONCLUSIONS: Initiating AVT based on detectable serum HBV-DNA provided the similar risk of postoperative HCC recurrence in HBV-infected HCC patients with and without detectable serum HBV-DNA.

Statin use is associated with better post-operative prognosis among patients with hepatitis B virus-related hepatocellular carcinoma.

BACKGROUND: The high postoperative recurrence rate of hepatocellular carcinoma (HCC) is a significant challenge. Patient metabolic factors are potential disease modifiers and should be examined as risk factors for postoperative prognosis. Here, we assessed the association between long-term statin use and HCC recurrence after surgical resection of hepatitis B virus (HBV)-related HCC. METHODS: Patients who initially underwent curative resection for HBV-related HCC between 2005 and 2015 were recruited and followed up until December 2019. Patients were classified into statin user and non-statin user groups based on whether or not they had been prescribed statins for ≥2 years. The primary outcome was HCC recurrence, and the secondary outcome was liver-related mortality. The cumulative incidence by statin use was estimated using the Kaplan-Meier method and compared using the log-rank test. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression. RESULTS: Among 5653 patients with a median 6.1 years of follow-up, HCC recurrence and liver-related mortality occurred in 1603 and 316 patients, respectively. The 5-year cumulative incidence of HCC recurrence in the statin user group (15.9%) was significantly lower than that in the non-user group (21.3%; p = .019). From multivariable Cox regression analysis, statin use was significantly associated with a reduced risk of HCC recurrence (aHR 0.77, 95% CI: 0.61-0.98; p = .035) and liver-related mortality (aHR 0.48, 95% CI: 0.25-0.90; p = .023). CONCLUSION: Long-term statin use was significantly associated with reduced risk of HCC recurrence and liver-related mortality after curative resection of HBV-related HCC.

Prognostic Impact of MAFLD Following Surgical Resection of Hepatitis B Virus-Related Hepatocellular Carcinoma: A Nationwide Cohort Study.

The association between the metabolic effects of hepatic steatosis as a part of postoperative outcomes of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) has rarely been studied. This study aimed to assess the relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and patients' prognoses following curative resection of HBV-related HCC. Patients who underwent surgical resection for HBV-related HCC between 2009 and 2015 were recruited. The study endpoints were postoperative hepatocellular carcinoma (HCC) recurrence and all-cause mortality. Adjusted hazard ratios (aHRs) for the outcomes were estimated using multivariate Cox regression models. The mean age of the 2032 enrolled patients was 55.0 years, and 77.9% were men. During follow-up (median 5.3 years), HCC recurrence and all-cause mortality occurred in 954 (47.0%) and 422 (20.8%) patients, respectively. HCC recurrence and all-cause mortality were significantly associated with MAFLD, with aHRs of 1.22 (p = 0.003) and 1.44 (p < 0.001), respectively. Propensity score matching and inverse probability treatment weighting analyses confirmed similar results (p < 0.05). MAFLD was associated with significantly poor prognoses in terms of HCC recurrence and all-cause mortality following surgical resection of HBV-related HCC. Further studies are needed to develop an effective preventive strategy through the management of metabolic health.

The significant association between quick return and depressive symptoms and sleep disturbances in paid workers: A nationwide survey.

Objectives: Although many studies have examined the association between shift work and depression or insomnia, few studies have examined the relationship between quick return (QR) to work and depressive symptoms, regardless of shift work. Thus, in this study, we aimed to assess the association between depressive symptoms (DS)/sleep disturbances (SDs) and QR. Methods: Data from the 6th Korean Working Conditions Survey (2020) were used for this study. Paid workers aged between 20 and 65 years were included. DS were defined using the World Health Organization Well-Being Index (WHO-5) with a cut-off 50, and SD was defined as the occurrence of the following symptoms several times per month: difficulty in falling asleep, waking up in the middle of the night, or feeling tired even after waking up. QR was defined as "at least one case where the working interval between leaving work and the next day's work was < 11 h in the past month." Multivariable logistic regression was performed to estimate the adjusted odd ratios (aORs) and 95% confidence intervals (CIs). Mediation analysis was conducted to examine whether SD was a significant mediator in the association between QR and DS. Results: Among the 27,554 participants, DS occurred in 8,277 patients, while SD occurred in 6,264 patients. The aORs (95% CIs) of DS and SD by QR were 2.01 (1.78-2.27) and 3.24 (2.87-3.66), respectively, after adjusting for age, gender, income, education, working hours, job status, working duration, region, shift work, and occupation. SD was a significant mediator in the association between QR and DS. Conclusion: QR is significantly associated with DS or SD regardless of demographic factors and the working environment. The significant relationship between QR and DS may be mediated by SD.

Association between physical risk factors and sleep disturbance among workers in Korea: The 5th Korean Working Conditions Survey.

OBJECTIVE: Sleep disturbance is associated with negative effects to workers' health and productivity; hence, it is important to find which population of workers are associated with sleep disturbance. This study aimed to investigate the association between physical risk factors (vibration, noise, high, and low temperatures) and sleep disturbance in the Korean working population. METHODS: We analyzed data on 29,213 paid workers from the 5th Korean Working Conditions Survey. Individual and occupational characteristics, physical risk factors exposure, and sleep disturbance were collected using self-reported questionnaires. To assess the association between physical risk factors and sleep disturbance, the chi-square test and multivariable logistic regression models were conducted. All statistical analyses were performed in sex-based subgroups. RESULTS: We observed that all physical risk factors are associated with sleep disturbance. The adjusted odds ratios (95% confidence interval [CI]) of severe exposure to vibration, noise, high and low temperature were 1.69 (CI:1.47-1.94), 2.52 (CI:2.17-2.92), 3.09 (CI:2.69-3.56), and 1.96 (CI:1.68-2.28) in male workers and 2.27 (CI:1.89-2.72), 3.52 (CI:2.92-4.24), 3.30 (CI:2.81-3.87), and 2.87 (CI:2.44-3.38) in female workers, respectively. The prevalence of sleep disturbance increased with increased exposure to physical risk factors, indicating a dose-response relationship. CONCLUSIONS: Physical risk factors exposure in the workplace was associated with sleep disturbance of workers, indicating a dose-response relationship. Given the impact of sleep disturbance on workers' health and efficiency, it may be important to control exposure to physical risk factors in the working environment with regards to sleep conditions.

The Association between New-Onset Depressive Symptoms and Participating in Medical Check-Ups among Elderly Individuals.

The association between adherence to medical check-ups and new-onset depressive symptoms, after adjusting for comprehensive risk factors such as social characteristics, remains unclear. This study aimed to assess the association between mental health and participating in medical check-ups. The survey data of participants aged 60 to 89 were recruited from the seventh Korean Longitudinal Study on Aging. The primary outcome was new-onset depressive symptoms within 2 years measured using the Center for Epidemiologic Studies Depression Scale. Participating in medical check-ups was defined as undergoing biennial medical check-ups. Multivariable logistic regression was performed to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) with consideration of a 2-year time lag. Among 4255 participants, the prevalence of new-onset depressive symptoms was 7.36% (n = 313). The prevalence of non-participation in medical check-ups was 11.96% (n = 509). The adjusted OR of new-onset depressive symptoms by non-participation in medical check-ups was 1.65 [95% CI 1.22-2.24; p = 0.001] after adjusting for various demographic, behavioral, occupational, and social participation characteristics. Our findings demonstrated a significant inverse relationship between participation in medical check-ups and new-onset depressive symptoms. It is necessary to monitor and manage depressive symptoms in vulnerable elderly individuals who do not participate in medical check-ups.

Resilience and Depressive Symptoms among Medical Staff in a Military Hospital Dedicated to the Treatment of COVID-19.

Coronavirus disease 2019 (COVID-19) is prevalent around the world, and many studies suggest that depression among medical staff is on the rise during the pandemic. This study aims to assess the relationship between depressive symptoms and individual resilience among military hospital personnel responsible for treating patients with COVID-19. Individuals from the Armed Forces Daejeon Hospital who responded to the questionnaires from 8 February to 15 February 2022 participated in this study. Resilience and depressive symptoms were measured via the Korean Resilience Quotient Test-53 and Patient Health Questionnaire-9, respectively. We employed multivariable logistic regression analysis to estimate Odds Ratios (ORs) and 95% Confidence Intervals (CIs) of depressive symptoms. Among 181 participants, the individuals with depressive symptoms and high resilience accounted for 8.8% and 61.9%, respectively. Significant correlations between depressive symptoms and both the low resilience and low resilience positivity groups were found (adjusted OR 10.30 [95% CI 1.74-61.01] and OR 13.90 [95% CI 1.93-100.02], respectively). This study notes a significant inverse relationship between depressive symptoms and resilience even after adjusting for demographic and occupational characteristics. To overcome depressive symptoms among hospital personnel, it is necessary to seek ways to improve individual resilience, especially positivity.