1.The physical activity paradox in relation to work ability and health-related productivity loss in Korea
Heejoo KO ; Dohwan KIM ; Seong-Sik CHO ; Mo-Yeol KANG
Epidemiology and Health 2023;45(1):e2023096-
OBJECTIVES:
The physical activity paradox suggests that occupational physical activity (OPA), unlike leisure-time physical activity (LTPA), may detrimentally impact health. We explored the relationships of OPA and LTPA with work ability (WA) and health-related productivity loss (HRPL).
METHODS:
This study included 5,501 workers in Korea who were recruited in 2021 through a web-based cross-sectional questionnaire. The questionnaire was utilized to quantify OPA and LTPA in metabolic equivalents, while WA and HRPL were also measured. Non-parametric regression, using a generalized additive model (GAM), was employed to visualize the relationships of LTPA and OPA with WA and HRPL. Mean differences in WA and HRPL, in relation to OPA and LTPA, were examined using linear regression models. These models were adjusted for covariates including sex, age, body mass index, education level, alcohol consumption, smoking history, insomnia, occupation, hours worked, and income.
RESULTS:
The GAM and linear regression analyses revealed that higher LTPA corresponded with higher WA and lower HRPL. In contrast, as OPA increased, WA decreased and HRPL increased. However, within the group with high OPA, HRPL was not significantly lower in the high-LTPA subgroup relative to the low-LTPA subgroup (mean difference=1.92%, p=0.343). This pattern was especially pronounced among workers aged 60 years and older, with an increase in HRPL observed with increasing LTPA among the respondents with high OPA.
CONCLUSIONS
High LTPA levels were associated with elevated WA and diminished HRPL. In contrast, higher levels of OPA were associated with lower WA and higher HRPL.
2.Data profile: Korean Work, Sleep, and Health Study (KWSHS)
Seong-Sik CHO ; Jeehee MIN ; Heejoo KO ; Mo-Yeol KANG
Annals of Occupational and Environmental Medicine 2025;37(1):e3-
The Korean Work, Sleep, and Health Study (KWSHS) was launched in 2022 as a longitudinal panel study to examine the interactions between work conditions, sleep health, and labour market performance among the Korean workforce. Baseline data were collected from 5,517 participants aged 19 to 70, encompassing diverse occupations. Follow-up surveys occur biannually, accommodating seasonal variations in sleep and health dynamics. To ensure stability, refreshment samples were integrated in later waves, maintaining a cohort size of 5,783 participants in wave 5. Key data include socio-demographics, employment characteristics, sleep patterns, health outcomes, and workplace performance. Early findings highlight critical associations, such as the adverse effects of occupational physical activity on productivity, the impact of emotional labour on health-related productivity loss, and the significance of sleep disruptions on mental health. The cohort’s design enables detailed analyses of longitudinal and cross-sectional trends, offering insights into how changing work environments influence health and productivity. The KWSHS could serve as a vital resource for evidence-based interventions aimed at improving occupational health and productivity in Korea's evolving labour landscape. Data access is available through the study’s principal investigator upon request.
3.Data profile: Korean Work, Sleep, and Health Study (KWSHS)
Seong-Sik CHO ; Jeehee MIN ; Heejoo KO ; Mo-Yeol KANG
Annals of Occupational and Environmental Medicine 2025;37(1):e3-
The Korean Work, Sleep, and Health Study (KWSHS) was launched in 2022 as a longitudinal panel study to examine the interactions between work conditions, sleep health, and labour market performance among the Korean workforce. Baseline data were collected from 5,517 participants aged 19 to 70, encompassing diverse occupations. Follow-up surveys occur biannually, accommodating seasonal variations in sleep and health dynamics. To ensure stability, refreshment samples were integrated in later waves, maintaining a cohort size of 5,783 participants in wave 5. Key data include socio-demographics, employment characteristics, sleep patterns, health outcomes, and workplace performance. Early findings highlight critical associations, such as the adverse effects of occupational physical activity on productivity, the impact of emotional labour on health-related productivity loss, and the significance of sleep disruptions on mental health. The cohort’s design enables detailed analyses of longitudinal and cross-sectional trends, offering insights into how changing work environments influence health and productivity. The KWSHS could serve as a vital resource for evidence-based interventions aimed at improving occupational health and productivity in Korea's evolving labour landscape. Data access is available through the study’s principal investigator upon request.
4.Data profile: Korean Work, Sleep, and Health Study (KWSHS)
Seong-Sik CHO ; Jeehee MIN ; Heejoo KO ; Mo-Yeol KANG
Annals of Occupational and Environmental Medicine 2025;37(1):e3-
The Korean Work, Sleep, and Health Study (KWSHS) was launched in 2022 as a longitudinal panel study to examine the interactions between work conditions, sleep health, and labour market performance among the Korean workforce. Baseline data were collected from 5,517 participants aged 19 to 70, encompassing diverse occupations. Follow-up surveys occur biannually, accommodating seasonal variations in sleep and health dynamics. To ensure stability, refreshment samples were integrated in later waves, maintaining a cohort size of 5,783 participants in wave 5. Key data include socio-demographics, employment characteristics, sleep patterns, health outcomes, and workplace performance. Early findings highlight critical associations, such as the adverse effects of occupational physical activity on productivity, the impact of emotional labour on health-related productivity loss, and the significance of sleep disruptions on mental health. The cohort’s design enables detailed analyses of longitudinal and cross-sectional trends, offering insights into how changing work environments influence health and productivity. The KWSHS could serve as a vital resource for evidence-based interventions aimed at improving occupational health and productivity in Korea's evolving labour landscape. Data access is available through the study’s principal investigator upon request.
5.The association between occupational stress level and health-related productivity loss among Korean employees
Jonghee CHUNG ; Jin-Hyo KIM ; Jae Yoon LEE ; Hee Seok KANG ; Dong-wook LEE ; Yun-Chul HONG ; Mo-Yeol KANG
Epidemiology and Health 2023;45(1):e2023009-
OBJECTIVES:
Occupational stress management is particularly important for successful business operations, since occupational stress adversely affects workers’ health, eventually lowering their productivity. Therefore, this study aimed to investigate the correlation between occupational stress and health-related productivity loss (HRPL) among Korean workers.
METHODS:
In 2021, 1,078 workers participated in a web-based questionnaire survey. HRPL was measured using the Work Productivity and Activity Impairment Questionnaire, and occupational stress was measured using the Korean Occupational Stress Scale-Short Form. The occupational stress level was divided into tertiles (low, intermediate, and high), and the low occupational stress group was used as the reference group. Using a generalised linear model, differences in labour productivity loss according to the level of occupational stress were tested after adjusting for demographic characteristics such as age, gender, education level, household income, occupation, and underlying medical conditions.
RESULTS:
Non-parametric regression analysis of HRPL according to occupational stress showed a direct association between occupational stress and HRPL. A statistically significant difference was observed in HRPL between participants with intermediate and high occupational stress and those with low occupational stress.
CONCLUSIONS
Our results support the hypothesis that high occupational stress is associated with decreased labour productivity.
6.Association between Cadmium and Cognitive Function in the Elderly.
Mo Yeol KANG ; Soo Hun CHO ; Youn Hee LEEM ; Jin Hee KIM ; Sang Hyuk BAE ; Yun Chul HONG
Korean Journal of Occupational and Environmental Medicine 2011;23(3):309-316
OBJECTIVES: We conducted this study to investigate the relationship between the blood concentration of cadmium and cognitive function in elderly Koreans. METHODS: This research is a part of the Korean Elderly Environmental Panel Study (KEEPS). A total of 403 subjects were enrolled and analyzed from August 2008 through August 2010. Demographic information and medical histories were obtained using a questionnaire. Blood concentration of cadmium and Mini-Mental State Examination (MMSE) with Functional Activities Questionnaire (FAQ) were evaluated for each subject. RESULTS: The mean age of subjects was 70.67 (SD 5.18, n=403) and 72% were female. The mean blood cadmium level was 1.22 microg/dl (SD 0.56), mean MMSE score was 25.12 out of 30 and mean FAQ score was 2.03 out of 30. Using linear regression analysis to estimate the relationship between blood cadmium concentration and MMSE and FAQ, we observed a significant association between log transformed values of blood cadmium levels and MMSE (p<0.002) or FAQ (p=0.005) scores. After adjusting for age, sex, level of education, alcohol consumption and smoking habits, the relationship between blood cadmium concentration and MMSE and FAQ scores ramained statistically significant (p=0.033 and 0.029, respectively). CONCLUSIONS: These results suggest that blood cadmium concentration is strongly associated with cognitive function and functional activity in the elderly.
Aged
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Alcohol Drinking
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Cadmium
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Female
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Humans
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Linear Models
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Questionnaires
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Smoke
;
Smoking
7.The Analysis of the Outcome of Short- and Long-Segment Posterior Instrumentation for Thoracolumbar Bursting Fractures.
Woo Chul KIM ; Kyu Yeol LEE ; Lih WANG ; Young Hoon LIM ; Jung Mo KANG ; Hyun Su DO
Journal of Korean Society of Spine Surgery 2014;21(4):139-145
STUDY DESIGN: A retrospective study. SUMMARY OF THE LITERATURE REVIEW: The reports comparing short- and long-segment instrumentation are insufficient. OBJECTIVES: To determine the postoperative results and to analyze relative factors affecting results between short- and long-segment instrumentation in thoracolumbar fractures. MATERIALS AND METHODS: From March 2006 to March 2012, 97 patients with thoracolumbar fracture were treated with posterior instrumentation. They were divided into 2 groups, the short- (Group I) and long-segment groups (Group II). To analyze factors affecting results, several factors including age, anterior column height (ACH), and the kyphotic angle were reviewed. For radiologic evaluation, postoperative and follow-up radiographs were evaluated by measuring the kyphotic angle and ACH. Additionally, the presence of complications was reviewed. RESULTS: Groups I and II consisted of 45, 52 cases and had mean ages of 50.3, 55.8 years, respectively. In Group I, the ACH increased from 44.2% to 75.3% postoperatively, and remained 72.8% at follow-up. The kyphotic angle decreased from 19.4degrees to 10.6degrees postoperatively, and remained at 12.8degrees at follow-up. In Group II, the ACH recovered from 41.6% to 76.4% postoperatively, and was 74.8% at follow-up. The kyphotic angle decreased from 21.6degrees to 12.6degrees postoperatively, and was 13.9degrees at follow-up. The canal compromise, age, and comminution were not directly related with results. However, the mean age of the 7 cases showing complications was 72 years, and the 7 cases had severe comminuted fractures. CONCLUSIONS: The short- and long-segment instrumentations of thoracolumbar fractures are not significantly different with respect to the results attained. However, in order to decrease complications, we should pay attention to age and fracture comminution.
Follow-Up Studies
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Fractures, Comminuted
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Humans
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Retrospective Studies
8.Trends in Obesity Prevalence by Occupation Based on Korean National Health and Nutrition Examination Survey From 1998 to 2015
Jae Yong LEE ; Yi-Ryoung LEE ; Hyoung-Ryoul KIM ; Jun-Pyo MYONG ; Mo-Yeol KANG
Safety and Health at Work 2020;11(1):97-102
Background:
It is well known that the prevalence of obesity in Korea is increasing over time, however it is not known how the trends among occupational groups and sex differ in such increasing trends. This study was designed to provide recent trends of obesity among workers in Korea and to identify whether there were differences among occupational groups.
Methods:
We used data from the Korean National Health and Nutrition Examination Survey, Phases I to VI (1998–2015), to analyze trends in the prevalence of obesity in adult Korean workers. Obesity was defined as a body mass index of 25 kg/m2 or higher. Occupations were classified into 3 groups: (a) nonmanual workers, (b) service/sales workers, and (c) manual workers.
Results:
During the period of the Korean National Health and Nutrition Examination Survey Phases I to VI, the prevalence of obesity in male workers increased in all occupations (31.1% to 39.5% in manual workers, 32.3% to 38.2% in service/sales workers, and 25.3% to 39.7% in manual workers). However, female workers did not show any particular tendency toward obesity, except for a significant decrease in the prevalence rate in service/sales workers (30.8% to 23.9%, p for trend = 0.0048).
Conclusion
The trends of obesity prevalence by sex and occupation were different. For male manual workers, the prevalence rate increased steadily during the data period, while it decreased steadily in female sales/service workers.
9.Exploring the impact of age and socioeconomic factors on health-related unemployment using propensity score matching: results from Korea National Health and Nutrition Examination Survey (2015–2017)
Ye-Seo LEE ; Dong-Wook LEE ; Mo-Yeol KANG
Annals of Occupational and Environmental Medicine 2024;36(1):e16-
Previous reports showed that age and socioeconomic factors mediated health-related unemployment. However, those studies had limitations controlling for confounding factors. This study examines age and socioeconomic factors contributing to health-related unemployment using propensity score matching (PSM) to control for various confounding variables. Data were obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) from 2015–2017. We applied a 1:1 PSM to align health factors, and examined the association between health-related unemployment and age or socioeconomic factors through conditional logistic regression. The health-related unemployment group was compared with the employment group. Among the 9,917 participants (5,817 women, 4,100 men), 1,182 (853 women, 329 men) were in the health-related unemployment group. Total 911 pairs (629 women pairs and 282 men pairs) were retained after PSM for health factors. The results of conditional logistic regression showed that older age, low individual and household income levels, low education level, receipt of the Basic Livelihood Security Program benefits and longest-held job characteristics were linked to health-related unemployment, despite having similar health levels. Older age and low socioeconomic status can increase the risk of health-related unemployment, highlighting the presence of age discrimination and socioeconomic inequality. These findings underscore the importance of proactive management strategies aimed at addressing these disparities, which are crucial for reducing the heightened risk of health-related unemployment.
10.Association between work from home and health-related productivity loss among Korean employees
Hyo Jeong KIM ; Dong Wook LEE ; Jaesung CHOI ; Yun-Chul HONG ; Mo-Yeol KANG
Annals of Occupational and Environmental Medicine 2024;36(1):e13-
After the coronavirus disease 2019 pandemic, the widespread adoption of working from home, or teleworking, has prompted extensive research regarding its effects on work productivity and the physical and mental health of employees. In this context, our study aimed to investigate the association between working from home and health-related productivity loss (HRPL). An online survey was conducted with a sample of 1,078 workers. HRPL was estimated by the Work Productivity and Activity Impairment Questionnaire: General Health version. Workers that have been working from home in the last 6 months were categorized into the “work from home” group. Generalized linear models were used to compare the mean difference of HRPL between “work from home” and “commuters” group. Stratified analyses were conducted based on various factors including gender, age, income level, occupation, education level, previous diagnosis of chronic disease, presence of preschool children, living in studio apartment, living alone, commuting time, working hours and regular exercise. The overall HRPL was higher in the “work from home” group than in the “commuters” group with a mean difference of 4.05 (95% confidence interval [CI]: 0.09–8.01). In the stratified analyses, significant differences were observed in workers with chronic diseases (mean difference: 8.23, 95% CI: 0.38–16.09), who do not live alone (mean difference: 4.84, 95% CI: 0.35–9.33), and workers that do not exercise regularly (mean difference: 4.96, 95% CI: 0.12–9.80). Working from home is associated with an increased HRPL in the Korean working population, especially among those with chronic diseases, those who do not live alone, and those who do not exercise regularly.