Association between Work-related Communication Devices Use during Work Outside of Regular Working Hours and Depressive Symptoms in Wage Workers.

Background: This study aimed to investigate the relationship between work-related communication devices use during work outside of regular working hours and depressive symptoms in wage workers. Methods: Data from 50,538 workers aged 15 years or older who had participated in the 6th Korean Working Condition Survey (KWCS) were used. The final sample was 32,994 wage workers. The questionnaire asked the respondents how often they used communication devices for work during work outside of regular working hours. Depressive symptoms were assessed using WHO-5 Well-Being Index. Multiple logistic regression analysis was used to analyze the association between work-related communication devices use during work outside of regular working hours and depressive symptoms. Results: The rate of depressive symptoms was highest among workers who did not use work-related communication devices during work outside of regular working hours. After adjusting for socio-demographic and work-related factors, the odds ratio of depressive symptoms among workers who used communication devices when working outside of regular working hours was 1.20 (95% CI: 1.09-1.32); the odds ratio of depressive symptoms in the group not using communication devices for free-time work was 1.66 (95% CI: 1.37-2.00), which was higher than that of the reference group, that is, workers who did not work outside of regular working hours, and was statistically significant. Conclusion: Regardless of whether work-related communication devices are used, working outside of regular working hours increases depressive symptoms. The use of work-related communication devices during work outside of regular working hours can reduce the rate of depressive symptoms.

The relationship between working time mismatch and depression according to actual hours worked.

OBJECTIVES: The effect of the combination of working hours and working time mismatch on depression is unknown. This study was undertaken to confirm the relationship between working time mismatch and depression with respect to hours worked. MATERIAL AND METHODS: The data of 45 514 adult workers that participated in the 6th Korean Working Conditions Survey (KWCS-VI 2020) were reviewed. Depression was defined using the World Health Organization 5 Well-Being Index (WHO-5) cut-off score of 50. Working time mismatch was defined as a difference between actual and desired working hours. To identify associations between working hour mismatch and depression according to weekly hours worked, stratification analysis was conducted by dividing the study subjects into 3 groups based on actual hours worked weekly (<40 h, 40-<52 h, or ≥52 h). Multiple logistic regression analysis adjusted for potential confounders was performed to calculate odds ratios of depression. RESULTS: In the <40 h, 40-<52 h, and ≥52 h groups, the odds ratios (OR) of working more hours than desired were 1.51, 95% CI: 1.20-1.92 (<40 h), 1.70, 95% CI: 1.58-1.84 (40-<52 h), and 1.55, 95% CI: 1.41-1.69 (≥52 h), respectively, compared to a matched actual versus desired working hours group (the matched group). On the other hand, the odds ratios of working fewer hours than desired were 1.17, 95% CI: 1.07-1.27 (<40 h), 1.38, 95% CI: 1.20-1.60 (40-<52 h), and 1.98, 95% CI: 1.24-3.17 (≥52 h), respectively. The risk of depression was found to increase significantly with working time mismatch within all 3 working hour groups. CONCLUSIONS: Working time mismatch increases the risk of worker depression regardless of hours worked. Int J Occup Med Environ Health. 2023;36(6):788-97.

Development of Korean Version Burnout Syndrome Scale (KBOSS) Using WHO's Definition of Burnout Syndrome.

BACKGROUND: Burnout syndrome (BOS) is defined by the World Health Organization (WHO) as a syndrome conceptualized as resulting from chronic workplace stress that has not been successfully managed. This study aims to create the Korean version burnout syndrome scale (KBOSS) that conforms to WHO's definition of BOS and present the cut-off points for screening. METHODS: We developed the KBOSS based on WHO's definition of BOS. An online survey was conducted through a specialized online research company. We recruited 444 workers for this research. The validity of the KBOSS was assessed using factor analysis and Pearson's correlation. The KBOSS reliability was assessed using Cronbach's alpha coefficient. The cut-off points for each of the three dimensions were derived using the upper quartile score. RESULTS: The validity and reliability of the KBOSS were good. Regarding reliability, the scale's overall Cronbach's alpha was 0.813. Cronbach's alpha of each three-dimension was as follows: exhaustion, 0.916; cynicism, 0.865; and professional inefficacy, 0.819. The cut-off points of BOS three dimensions are exhaustion ≧ 21; cynicism ≧ 18; and inefficacy ≧ 15. CONCLUSION: The developed questionnaire (KBOSS) can be a useful tool for screening of BOS.

Mismatch in working hours and workaholism in permanent waged workers.

OBJECTIVES: A cross-sectional study was conducted to investigate whether working hours mismatch is associated with workaholism. MATERIAL AND METHODS: This study used the data from the 17th wave (2014) of the nationwide Korean Labor and Income Panel Study. Workaholism was evaluated using the Workaholism Analysis Questionnaire. The final study involved 3157 subjects who answered questions regarding both workaholism and working hours mismatch. To identify the association between working hours mismatch and workaholism according to weekly working hours, a stratification analysis was conducted by dividing the number of working hours/week into 3 groups (≤40 h, 41-59 h, and ≥60 h). The odds ratios were calculated using a multiple logistic regression model, which was adjusted for potential confounders. RESULTS: The workers working more hours than desired showed the greatest frequency of workaholism. As regards workaholism, in all weekly working hours groups, the odds ratios of the group working more hours than desired were 4.28, 95% CI: 2.29-7.99 (≥40 h), 2.14, 95% CI: 1.34-3.43 (41-59 h), 3.40, 95% CI: 1.60-7.21 (≤60 h), which were statistically significant compared to the reference (matched) group. There was no statistically significant relationship between working hours and workaholism when stratified according to the mismatch in working hours. CONCLUSIONS: The workers' working hours mismatch can be significantly related to workaholism. Int J Occup Med Environ Health. 2020;33(2):187-94.

Differences in suicidal behaviors between self-employed and standardly employed workers.

BACKGROUND: Although self-employed persons have greater autonomy, schedule flexibility, and control over their work than employees, they may be among the most vulnerable workers due to the lack of social benefits and protection from labor law and regulations. We compared suicidal behaviors between the self-employed and standardly employed workers. METHODS: This study used the 2008 Korean Community Health Survey data and included a total of 64 802 working population. Self-employed persons were classified into "small business self-employed persons" with zero to four employees and "middle to large business" with more than five employees. The outcomes were suicidal ideation and suicide attempts. RESULTS: Of the 64 802 participants, 40 422 were engaged in standard employment, and 24 380 were self-employed, with almost 90% (n = 21 970) being engaged in small businesses. Persons self-employed, compared with standard workers, were more likely to report suicidal ideation in both small (odds ratio [OR] = 1.25; 95% confidence interval [CI], 1.15-1.35) and middle to large businesses (OR = 1.32; 95% CI, 1.09-1.61). On the other hand, the likelihood for suicide attempt was only significant in persons self-employed in small businesses (OR = 1.67; 95% CI, 1.11-2.45). CONCLUSION: Self-employed persons were associated with greater odds of reporting suicidal behaviors than workers with standard employment. Among the self-employed, small business owners were particularly vulnerable to suicide attempts.

Experience of Orthodontic Treatment and Symptoms of Temporomandibular Joint in South Korean Adults.

BACKGROUND: No epidemiological studies have targeted the association between experience of orthodontic treatment and symptoms of temporomandibular joint (TMJ) in a large adult population. In this study, we investigated whether experience of orthodontic treatment is associated with symptoms of TMJ in adults. METHODS: We used data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V), conducted in 2011. Trained dentists asked subjects to report their experience of orthodontic treatment and symptoms of TMJ. Overall, 5936 subjects aged over 19 yr were included in this study (2528 males). The data were analyzed using the chi-square test and multiple logistic regression tests. RESULTS: The group with experience of orthodontic treatment had more symptoms of TMJ than the group without orthodontic experience. After adjusting for all covariates (i.e., age, sex, marital status, income, education, stress, teeth injury, and occupation), the adjusted odds ratio was 2.53 (95%CI 1.74-3.67). CONCLUSION: Experience of orthodontic treatment could be related to increased symptoms of TMJ.

Validation of general job satisfaction in the Korean Labor and Income Panel Study.

BACKGROUND: The purpose of this study is to assess the validity and reliability of general job satisfaction (JS) in the Korean Labor and Income Panel Study (KLIPS). METHODS: We used the data from the 17th wave (2014) of the nationwide KLIPS, which selected a representative panel sample of Korean households and individuals aged 15 or older residing in urban areas. We included in this study 7679 employed subjects (4529 males and 3150 females). The general JS instrument consisted of five items rated on a scale from 1 (strongly disagree) to 5 (strongly agree). The general JS reliability was assessed using the corrected item-total correlation and Cronbach's alpha coefficient. The validity of general JS was assessed using confirmatory factor analysis (CFA) and Pearson's correlation. RESULTS: The corrected item-total correlations ranged from 0.736 to 0.837. Therefore, no items were removed. Cronbach's alpha for general JS was 0.925, indicating excellent internal consistency. The CFA of the general JS model showed a good fit. Pearson's correlation coefficients for convergent validity showed moderate or strong correlations. CONCLUSION: The results obtained in our study confirm the validity and reliability of general JS.

Disparities in precarious workers' health care access in South Korea.

BACKGROUND: This study explored whether precarious workers have difficulties in health care access as compared with non-precarious workers. METHODS: The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 51,322 participants (40,514 non-precarious workers and 10,808 precarious workers). Precarious workers were defined as part-time or contingent workers. RESULTS: Precarious workers had significantly higher risk of limited access to hospitals (OR = 1.14; 95% CI: 1.06-1.22) and dentists (OR = 1.28; 95% CI: 1.21-1.36) than non-precarious workers; disparities in doctor contacts among precarious workers were mostly linked to not having enough money. The risk of not receiving preventive care-medical checkups (OR = 0.52; 95% CI: 0.49-0.55) or cancer screenings (OR = 0.82; 95% CI: 0.77-0.86)-was also significantly elevated among precarious workers. CONCLUSION: We found that precarious workers had more difficulty accessing health care or receiving health checkups or cancer screenings than their non-precarious counterparts. Am. J. Ind. Med. 59:1136-1144, 2016. © 2016 Wiley Periodicals, Inc.

Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome.

BACKGROUND: Dry eye syndrome (DES) is a common tear film and ocular surface disease that results in discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. Systemic diseases associated with DES include diabetes mellitus, rheumatoid arthritis, depression, anxiety, thyroid disease, allergic diseases, irritable bowel syndrome, chronic pain syndrome, and hyperlipidemia. Interestingly, it has been found that most of these are associated with low levels of serum 25-hydroxyvitamin D (25(OH)D) or inadequate sunlight exposure. METHODS: In this cross-sectional data analysis, noninstitutionalized adults aged ≥19 years (N = 17,542) who participated in Korean National Health and Nutrition Examination Survey 2010-2012 were included. Information regarding duration of sunlight exposure was collected from the survey participants. Serum 25(OH)D and zinc levels were measured. The confounding variables were age, gender, sunlight exposure time, region of residence, obesity, serum 25(OH)D level, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and walking exercise. RESULTS: Mean serum 25(OH)D levels of subjects with and without DES were 16.90 ± 6.0 and 17.52 ± 6.07 (p<0.001). Inadequate sunlight exposure time (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.307-1.848), urban residence (OR, 1.669; 95% CI, 1.456-1.913), indoor occupation (OR, 1.578; 95% CI, 1.389-1.814), and low serum 25(OH)D level (OR, 1.158; 95% CI, 1.026-1.308) were the risk factors for DES. After adjusting for age, sex, obesity, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and occupation, low serum 25(OH)D level (OR, 1.178; 95% CI, 1.010-1.372) and deficient sunlight exposure time (OR, 1.383; 95% CI, 1.094-1.749) were the risk factors for diagnosed DES. CONCLUSION: Low serum 25(OH)D levels and inadequate sunlight exposure are associated with DES in Korean adults. These results suggest that sufficient sunlight exposure or vitamin D supplementation may be useful in DES treatment.

Two subtypes of positional obstructive sleep apnea: Supine-predominant and supine-isolated.

OBJECTIVES: The body position has a strong influence on obstructive sleep apnea (OSA). The purpose of this study is to compare the clinical features of two subtypes of positional OSA (POSA), namely supine-predominant OSA (spOSA) and supine-isolated OSA (siOSA), so as to discuss whether the two groups can be classified separately. METHODS: A total of 279 consecutive patients with OSA were enrolled. The POSA was defined as having an overall apnea-hypopnea index (AHI) ⩾ 5 with supine AHI > 2 times the non-supine AHI. Only those with ⩾ 30 min spent in the supine and non-supine sleeping positions were included, and split night studies were excluded from the study. Patients were considered spOSA unless their non-supine AHI was negligible (<5) (siOSA). The clinical and polysomnographic characteristics of both groups were compared. RESULTS: Two hundred and sixteen subjects (77.4%) met the criteria for POSA, with 158 (73.1%) of them classified as spOSA, and 58 (26.9%) as siOSA. The siOSA patients had lower arousal indices, but poorer quality of sleep, and were more depressed and anxious compared with the spOSA subjects. CONCLUSIONS: Those with siOSA and spOSA show different clinical features. SIGNIFICANCE: These findings suggest that a more detailed sub-classification of POSA is needed.

Precarious employment and the risk of suicidal ideation and suicide attempts.

OBJECTIVE: Although the effect of occupation or employment status on suicide risk is notable, there are few studies on the effect of precarious employment on suicide. We compared suicidal ideation and suicide attempts in precarious workers and their non-precarious counterparts using a representative sample from South Korea. METHOD: The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 52,161 participants (41,063 employees with non-precarious work and 11,098 employees with precarious work). The outcome of the logistic regression model was the presence of suicidal thoughts and attempts, and the independent variables were the demographics, socioeconomic status, and health status. RESULTS: Employees with precarious work were more likely to exhibit suicidal ideation (OR=1.41; 95% CI, 1.28-1.55) and suicide attempts (OR=1.52; 95% CI, 1.02-2.27) than employees with non-precarious work. After controlling for income and education (Model 2) depressive feelings (Model 6), compared with unadjusted model, remained significant but the odds ratio was largely attenuated, indicating a strong association between suicidal risk and socioeconomic and feelings of depression. CONCLUSION: Precarious workers had a higher risk of suicidal ideation and suicide attempts than non-precarious workers. Our study suggests that precarious employment is an important risk for suicide.

The relationship between working condition factors and well-being.

OBJECTIVES: Working conditions can exert influence on the physical, mental, and even social health of workers. Well-being is an appropriate index for the evaluation of a person's overall health. This paper investigated the association between various working conditions and worker's well-being. METHODS: Data from 10,019 interviews were collected from the second wave of the Korean Working Conditions Survey (2010) conducted by the Korea Occupational Safety and Health Agency between June and October 2010. The data from 5,995 employed workers were examined in this study. Well-being was measured through the WHO Five Well-Being Index (1998 version). Sociodemographic and working conditions were analyzed. Adjusted odds ratios for well-being were calculated with adjusted sociodemographic factors, working condition factors, or both. RESULTS: Workers' well-being was significantly higher when they were satisfied with their working conditions (OR = 1.656, 95% CI = 1.454-1.885), when their actual working hours were the same as their anticipated working hours (OR = 1.366, 95% CI: 1.120-1.666) or exceeding less than 10 hours (OR = 1.245, 95% CI: 1.004-1.543), and when their employment was stable (OR = 1.269, 95% CI: 1.098-1.467). CONCLUSIONS: This study supports the association between working condition factors and well-being in workers.

Depressive symptoms as a risk factor for the common cold among employees: a 4-month follow-up study.

OBJECTIVE: The purpose of this study was to investigate the correlation between symptoms of depression in workers and the common cold. METHODS: A follow-up survey of workers at 44 small- to medium-sized companies was conducted; 1350 questionnaires were used in the final analysis. The first survey requested information regarding personal information, work characteristics and symptoms of depression (Center for Epidemiologic Studies Depression Scale); the second survey queried participants who answered the first survey about manifestations of the common cold during the previous four months. Odds ratios (ORs) were calculated using a logistic regression model, which was adjusted for potential confounders. All analyses were stratified according to gender separately. RESULTS: The ORs for reporting symptoms of the common cold were 1.36 (95% confidence interval [CI]: 1.01-1.83) and 2.27 (95% CI: 1.49-3.45) in males and females, respectively. When adjusted for age, marital status, educational level, smoking habits, alcohol consumption, exercise, sleep duration and job type, the ORs remained significant for both genders (male: 1.38; 95% CI: 1.01-1.89; female: 2.08; 95% CI: 1.32-3.23). CONCLUSIONS: The risk of self-reported manifestations of the common cold was higher in workers who reported symptoms of depression.

Association between job stress and insomnia in Korean workers.

OBJECTIVE: We investigated the association between job stress and insomnia in a large nationwide samples of Korean workers. METHODS: In this cross-sectional study, a total of 8,155 workers from a nationwide sample were recruited. We surveyed the subjects' socio-demographic and work-related characteristics and seven subscales of occupational stress using the Korean Occupational Stress Scale Short Form. Each subscales of job stress was dichotomized into higher or lower group by respective median scores. Insomnia was defined as having at least one of the three sleep symptoms. we performed multivariate logistic regression analysis to identify association between job stress and insomnia. RESULTS: We found that individuals with relatively high job stress experienced insomnia significantly more frequently, and the significance was maintained even after adjustment for confounding variables(high job demand: OR: 1.30, 95% CI: 1.14-1.47; insufficient job control: OR: 1.13, 95% CI: 0.99-1.29; inadequate social support: OR: 1.30, 95% CI: 1.14-1.47; job insecurity: OR: 1.25, 95% CI: 1.11-1.44; organizational injustice: OR: 1.27, 95% CI: 1.12-1.44; lack of reward: OR: 1.18, 95% CI: 1.04-1.34; discomfort in occupational climate: OR: 1.38, 95% CI: 1.22-1.57; total job stress: OR: 1.45, 95% CI: 1.28-1.64). CONCLUSION: This study suggested that job stress is possible risk factor for insomnia and that particularly discomfort in occupational climate and inadequate social support have more strong relation to insomnia in Korea.

Aspirin induces apoptosis in YD-8 human oral squamous carcinoma cells through activation of caspases, down-regulation of Mcl-1, and inactivation of ERK-1/2 and AKT.

NSAIDs and COX-2 inhibitors show anti-cancer activities in many cancer cells. In this study, we investigated the effects of NSAIDs (aspirin or indomethacin) and COX-2 inhibitor (NS-398) on growth of YD-8 human oral squamous carcinoma cells. Interestingly, among drugs tested, aspirin showed strongest inhibitory effects on viability and survival of YD-8 cells. Profoundly, aspirin treatment resulted in severe cell shrinkage and nuclear DNA fragmentation in YD-8 cells, suggesting the aspirin-induced apoptosis in YD-8 cells. Data of Western blot further demonstrated that aspirin treatment caused activation of caspases, down-regulation of Mcl-1 protein, dephosphorylation of ERK-1/2 and AKT, and also IkappaB-alpha proteolysis-dependent NF-kappaB activation in YD-8 cells. Aspirin, however, had no effect on expressions of Bcl-2, XIAP, and HIAP-1 in YD-8 cells. Importantly, pretreatment with z-VAD-fmk, a pan-caspase inhibitor blocked the aspirin-induced apoptosis and Mcl-1 down-regulation in YD-8 cells. These findings collectively suggest that aspirin induces apoptosis in YD-8 cells and the induction may be correlated to activation of caspases, caspase-dependent Mcl-1 proteolysis, inactivation of ERK-1/2 and AKT, and activation of NF-kappaB. It is suggested that aspirin may be applied a potential anti-cancer drug against human oral squamous carcinoma.