Association Between Flexible Work Arrangement and Sleep Problems Among Paid Workers: Using 6th Korean Working Conditions Survey.

Background: As social distancing persists and interest in work-life balance grows, more companies are adopting flexible work policies. While there have been studies on sleep disorders associated with different types of work, such as shift work, research exploring the relationship between flexible work schedules and sleep disorders is still limited, particularly among Korean workers. Methods: We performed a secondary analysis of the 6th Korean Working Conditions Survey, focusing on 31,243 paid workers out of a total of 50,538 participants. We defined flexible workers as those who set their own working hours. Sleep disorders were divided into three categories: 'difficulty falling asleep,' 'frequent waking during sleep,' and 'waking up feeling exhausted and fatigued.' Using scores derived from three specific symptoms, the Minimal Insomnia Symptoms Scale (MISS) was calculated to assess the prevalence of insomnia. We used chi-square tests to analyze demographic and job-related differences. A multivariate logistic regression analysis was employed to identify any relationship between flexible work schedules and sleep disorders. Results: Significant differences were found between flexible and non-flexible workers regarding age, income level, education level, and job type. Flexible workers reported sleep-related symptoms significantly more often. The odds ratio for insomnia was 1.40 (95% CI 1.21-1.61). For males, the odds ratio was 1.68 (1.36-2.08). Conclusion: This study establishes a correlation between flexible work schedules and sleep disorders among Korean salaried workers. Potential causes could include changes in circadian rhythm, increased work demands, and extended working hours. To precisely determine causality and associated diseases, further research is required.

Association between lone work and self-rated health status: using the 5th Korean Working Conditions Survey.

Background: Lone workers are generally defined as individuals who work alone without supervision, including self-employed people. While lone workers are considered a vulnerable group in some countries, there is a lack of research on their health status in domestic studies. Globally, the number of lone workers has been increasing, and this trend has been further accelerated since the coronavirus disease 2019 (COVID-19) pandemic with the rise of remote work. Methods: The study analyzed data from 44,281 participants, excluding unpaid family workers, soldiers, and those with missing data. Lone workers were defined as individuals who reported having no colleagues with the same job at their current workplace. Self-rated health status was categorized as "good" or "poor." Results: This study found a statistically significant higher number of lone workers among women compare to men. The largest occupational category for lone workers was service and sales workers, followed by agriculture and fisheries workers. A majority of non-lone workers reported working 40 hours or less per week, while the majority of lone workers reported working 53 hours or more per week. In addition, lone workers had significantly poorer health status evaluations compared to non-lone workers (odds ratio: 1.297; 95% confidence interval: 1.165-1.444). Conclusions: Further research is needed to investigate the causal relationship between lone work and health, using data collected after the COVID-19 pandemic.

Standards for recognition and approval rate of occupational cerebro-cardiovascular diseases in Korea.

Background: Although working hours have decreased in Korea, they are still high compared to that of other countries. In Korea, cardiovascular and cerebrovascular diseases (CCVDs) related to overwork in Korea continually occur, and the social burden from overwork is estimated to be high. This study investigated the amendment of regulations affecting the approval rate of occupational CCVDs. Methods: The change in approval rate of occupational CCVDs and related regulations were investigated using the Act and public notice on the standards for recognition of occupational CCVDs and the yearbooks of the Ministry of Employment and Labor. The CCVD mortality was estimated using data on the number of deaths according to the cause of death, the number of employed people, and resident registration population aged 15-64 years. The cumulative mortality of CCVDs was estimated using the Kaplan-Meier method. Results: Since the establishment of the standards for recognition in Korea in 1982, the scope of occupational diseases has been expanded to include intracerebral hemorrhage, subarachnoid hemorrhage, cerebral infarction, myocardial infarction, and aortic dissection. In 2013, the concept of working hours was introduced in chronic overwork. The approval rate of occupational CCVDs was 44.7% in 2006, which decreased to 12.9% in 2011. After the improvement of related regulations, the approval rate increased to 41.3% in 2018. From 2000 to 2017, the CCVD mortality of both the unemployed and employed tended to decrease, and their cumulative CCVD mortalities were 549.3 and 319.7 per 100,000 people, respectively. Conclusions: CCVDs are recognized as occupational diseases in Korea. The amendments to the standards for recognition, the introduction of the Occupational Disease Adjudication Committee, the principle of presumption, and the reduction of working hours have changed the approval rate of occupational CCVDs. A strategic approach is needed to further reduce the incidence of CCVDs.

Analysis of self-reported mental health problems among the self-employed compared with paid workers in the Republic of Korea.

Background: As self-employed workers are vulnerable to health problems, this study aimed to analyze mental health problems and sleep disturbances among self-employed workers compared with paid workers in Korea. Methods: A total of 34,750 workers (23,938 paid workers and 10,812 self-employed workers) were analyzed from the fifth Korean Working Condition Survey, which included 50,205 households collected by stratified sampling in 2017. To compare mental health problems and sleep disturbance among self-employed workers and paid workers, multivariate logistic regression analyses were performed. Results: The odds ratio in self-employed workers compared with paid workers was 1.25 (95% confidence interval [CI]: 1.09-1.42) for anxiety, 1.11 (95% CI: 1.04-1.17) for overall fatigue, 1.11 (95% CI: 1.04-1.20) for difficulty falling asleep, 1.10 (95% CI: 1.02-1.18) for difficulty maintaining sleep and 1.24 (95% CI: 1.16-1.32) for extreme fatigue after waking up. Conclusions: Self-employed workers in Korea have a higher risk of self-reported mental health problems and sleep disturbances than paid workers. Further studies with a longitudinal design and structured evaluation are required to investigate the causal relationship between health problems and self-employment.

Sunlight exposure and eye disorders in an economically active population: data from the KNHANES 2008-2012.

BACKGROUND: Sunlight exposure is a major risk factor for eye disorders. Most outdoor workers cannot avoid sunlight exposure. This study aimed to analyze the relationship between outdoor sunlight exposure and eye disorders in an economically active population. METHODS: This study analyzed the 2008-2012 Korea National Health and Nutritional Examination Survey data. Sunlight exposure was categorized as < 5 hours and > 5 hours. We also analyzed the dose-dependent relationship between exposure to sunlight and eye disorders (cataracts, pterygium, and age-related macular degeneration [AMD]) using data from 2010 to 2012 by subdividing the exposure groups into < 2 hours, 2-5 hours, and ≥ 5 hours. Eye disorders were diagnosed by an ophthalmologist. The study participants were stratified by sex, and the results were analyzed using the χ2 test and multiple logistic regression analysis. RESULTS: In the female group, the odds ratio of pterygium in the high-level sunlight exposure group was 1.47 (95% confidence interval [CI]: 1.15-1.89). Regarding AMD, the odds ratios were 1.42 (95% CI: 1.16-1.73), 1.33 (95% CI: 1.03-1.73), and 1.58 (95% CI: 1.15-2.16) in the total, male, and female groups, respectively. Analysis of the dose-response relationship revealed that the odds ratios of pterygium in the high-level sunlight exposure subgroups of the total and female groups were 1.62 (95% CI: 1.25-2.08) and 2.00 (95% CI: 1.39-2.88), respectively. CONCLUSIONS: This study demonstrated a relationship between sunlight exposure and eye disorders in an economically active population. Women were found to be especially vulnerable to pterygium. However, additional prospective studies to clarify the pathophysiology of pterygium are needed.