Seong-Sik Cho

Despite ongoing policy debates on working time reform, public perspectives on specific regulatory measures among Korean workers remain underexplored. This study analyzed data from the 5th Wave of the Korean Work, Sleep, and Health Study (KWSHS), an online survey conducted in September 2024 among 5,783 working adults aged 19–70. Participants reported their opinions on six working time regulatory measures: A majority of respondents supported all five proposed regulatory measures. Support was highest for introducing a daily working hours cap (72.1% agree or strongly agree), followed by regulating non-essential night work (63.2%), restricting weekend work for large supermarkets (60.7%), extending the cap to small companies (60.1%), and introducing the weekly cap for exempt industries (52.8%). Findings suggest broad support for strengthening working-time regulations, though results should be interpreted considering the sample’s higher proportion of office workers.

Objectives: To investigate the association between psychosocial safety climate (PSC) and burnout among Korean workers, with particular attention to indirect pathway involving work stress. Methods: Data were analyzed from participants in the fifth wave of the Korean Work, Sleep, and Health Study. PSC, work stress, and burnout were assessed using the PSC-4, KOSS-19, and KBOSS scales, respectively. Logistic regression was used to evaluate burnout risk, and mediation analysis with nonparametric bootstrapping was performed to estimate direct and indirect effects. Results: High-risk PSC was significantly associated with an increased risk of burnout and its subcomponents: exhaustion, cynicism, and inefficacy. Mediation analysis revealed a significant indirect effect of PSC on burnout through overall work stress. Conclusions: The findings suggest an indirect association between PSC and burnout involving work stress, rather than a direct effect.

OBJECTIVES: For employees, work-time control (WTC) may protect against burnout and turnover. However, evidence from Korean workplaces is limited. This study aimed to examine whether WTC is associated with burnout and turnover intention and to test whether burnout mediates this relationship.METHODS: We analyzed data from 4,745 wage workers in the 2024 wave of the Korean Work, Sleep, and Health Study. WTC was assessed across 6 domains, burnout was measured using the Korean Burnout Syndrome Scale, and turnover intention was assessed using a validated 4-item scale. Logistic regression was used to estimate the associations of WTC quartile with burnout and turnover intention, and mediation analysis was used to decompose the association between WTC and turnover intention through burnout.RESULTS: Among 4,745 workers, the prevalence of burnout was 3.9% and turnover intention was 34.5%; both increased stepwise across lower WTC quartiles. In adjusted models, workers in the lowest WTC quartile had higher odds of burnout (odds ratio [OR], 3.95; 95% confidence interval [CI], 2.41 to 6.47) and turnover intention (OR, 2.24; 95% CI, 1.85 to 2.71) than those in the highest quartile. Mediation analysis showed that burnout explained 36.6% (95% CI, 22.3 to 51.0) of the association between WTC and turnover intention.CONCLUSIONS: Lower WTC was linked to higher burnout and turnover intention, with burnout explaining more than one-third of this relationship.

Objectives: Research on the impact of ergonomic risk factors on neuropathic pain is limited. Accordingly, this study investigated the relationship between ergonomic risk exposure and neuropathic pain in a population of South Korean workers. Methods: Data were obtained from the third and fourth rounds of the Korean Work, Sleep, and Health Study. Neuropathic pain was identified using the Douleur Neuropathique 4 (DN4) screening tool. The association between ergonomic risk factors and neuropathic pain was analyzed using multiple logistic regression analysis. Odds ratios (ORs) with 95% CIs were estimated after adjusting for relevant confounding factors. Results: Two-wheeled vehicle operation (OR = 3.66; 95% CI, 1.26-10.58), manual material handling (OR = 2.81; 95% CI, 1.63-4.85), kneeling or squatting (OR = 2.47; 95% CI, 1.35-4.53), repetitive hand or finger motions (OR = 2.10; 95% CI, 1.38-3.19), trunk flexion, extension, or lateral bending (OR = 2.13; 95% CI, 1.25-3.63), and wrist twisting, pushing or pulling with upper limbs (OR = 1.90; 95% CI, 1.08-3.34) were significantly associated with neuropathic pain in the fully-adjusted model. Conclusions: This study supports a link between ergonomic risk factors and neuropathic pain among South Korean workers.

Objectives: Work-time control (WTC) may influence sleep health by allowing workers to align schedules with their personal needs, but findings have been inconsistent. In South Korea, where long working hours and low autonomy are prevalent, further investigation is required. This study aimed to examine the association between WTC, sleep quality, and sleep duration in South Korean workers. Methods: Cross-sectional data from the fifth wave of the Korean Work, Sleep, and Health Study, a nationwide panel survey of South Korean workers aged 19-70, were used. The analytical sample included 5183 paid employees. WTC was categorized as low or high, and sleep quality was measured by the Pittsburgh Sleep Quality Index, with poor sleep quality defined as a score ≥11. Short sleep duration was defined as <7 hours per night. Poisson regression was used to estimate the prevalence ratios (PRs) after adjusting for age, sex, education, income, occupation, working hours, and shift work. Results: Low WTC was associated with a higher prevalence of poor sleep quality (PR: 1.39; 95% CI: 1.09-1.77), adjusting for age, sex, education, income, occupation, working hours, and shift work. No significant association was found between WTC and short sleep duration. In the stratified analysis of weekly working hours among employees working 40-52 hours per week, there was a significant association between low WTC and poor sleep quality. Conclusions: Lower WTC was associated with poorer sleep quality. Improving work-time autonomy may enhance sleep, particularly among workers with moderate weekly working hours (40-52 hours).

Park JW, et al. J Korean Med Sci. 2026 Nov;41:e328. https://doi.org/10.3346/jkms.2026.41.e328

Psychosocial Safety Climate (PSC) is a key organisational factor that reflects management's commitment to protecting employees' psychological health and safety. Although PSC is known to influence work stress and mental health, its association with sleep health remains underexplored. We analysed cross‐sectional data from 4827 daytime wage workers enrolled in the 5th wave of the Korean Work, Sleep, and Health Study (KWSHS). PSC was measured using a validated four‐item scale and categorised into low, moderate, and high‐risk. Sleep quality and insomnia symptoms were assessed using the Korean versions of the Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI), respectively. Linear and logistic regression models were used to examine associations between PSC levels and sleep health outcomes, adjusting for age, sex, and occupation. Lower PSC was significantly associated with poorer sleep quality ( β = −0.05, p < 0.001) and more severe insomnia symptoms ( β = −0.05, p < 0.001). Compared with the low‐risk PSC group, the high‐risk group showed increased odds of poor sleep quality (OR = 1.22, 95% CI: 1.04–1.43). Subgroup analysis revealed that older adults (≥ 60 years), highly educated workers, full‐time employees, and non‐unionised workers were particularly vulnerable to poor sleep health in low PSC environments. PSC plays a protective role in sleep health, and its absence may exacerbate the adverse effects of work‐related stressors. Enhancing PSC at the organisational level may improve sleep health, particularly for vulnerable worker populations.

Objective: This study examined the association of working time control (WTC)—the degree of employee autonomy over work hours—with health-related productivity loss (HRPL) and work engagement among Korean wageworkers. Methods: Data were drawn from 4612 wage workers in the 2024 Korean Work, Sleep, and Health Study. HRPL and work engagement were measured using validated instruments. Generalized linear models and logistic regression were used to assess associations, controlling for demographic and occupational covariates. Results: Lower WTC was linked to higher HRPL and decreased work engagement. A slight HRPL decrease in the lowest control group appeared driven by reduced absenteeism. Men, younger workers, and nonshift workers were more vulnerable to low WTC. Conclusions: WTC is significantly associated with both productivity and work engagement. Enhancing employee autonomy in scheduling may improve health and organizational outcomes in workplaces.

Objective Occupational exposures are hypothesized to contribute to obstructive sleep apnea (OSA) risk, yet evidence from large, population-based studies remains scarce. This study aimed to investigate the association between a wide range of work-related factors and sleep apnea risk among Korean workers. Methods We analyzed data from the Korean Work, Sleep, and Health Study (KWSHS), a nationwide longitudinal panel survey conducted between 2022 and 2024. Work-related exposures included long working hours, shift work, occupational stress, emotional labor, physical or chemical hazards, and ergonomic factors. Sleep apnea risk was assessed using the Berlin Questionnaire. To account for repeated measurements within individuals, generalized estimating equation models were applied to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age, sex, and occupation. Subgroup analyses were performed according to obesity status. Results Among 8,976 workers, long working hours (> 52 h per week; OR 1.22, 95% CI 1.04–1.43), high occupational stress (OR 1.93, 95% CI 1.76–2.12), high emotional labor (OR 1.74, 95% CI 1.50–2.02), physical or chemical exposures (OR 1.37, 95% CI 1.25–1.50), and ergonomic strains (OR 1.36, 95% CI 1.25–1.48) were significantly associated with increased odds of high sleep apnea risk. Shift work was not significantly associated with OSA risk, which may be partially explained by the healthy worker effect or adaptation among long-term shift workers. Associations with physical and chemical exposures were stronger among non-obese participants. Conclusions Work-related psychosocial and environmental factors contribute meaningfully to sleep apnea risk. Addressing workplace conditions may represent an important strategy for sleep apnea prevention.