Commuting time, working time, and their link to insomnia symptoms among Korean employees: A cross-sectional study.

OBJECTIVE: Although commuting time is an extension of working hours, few studies have examined the relationship between commuting time and insomnia symptoms in relation to working time. Thus, this study investigated the relationship between commuting time and working time and their link to sleep disturbance. METHODS: This study included employees with ≥35 weekly working hours (n = 30,458) using data from the Sixth Korean Working Conditions Survey conducted in Korea between October 2020 and April 2021. The association between commuting time (≤60, 61-120, and >120 minutes) and insomnia symptoms based on working hours (35-40, 41-52, and >52 h/wk) or shift work was investigated using survey-weighted logistic regression analysis. RESULTS: Long commuting time (>120 min/d) combined with >52 working hours/week (OR: 7.88, 95% CI: 2.51-24.71) or combined with 41-52 h/wk (OR: 3.64, 95% CI: 2.15-6.14) was associated with a higher risk of insomnia symptoms compared with the reference group (working hours: 35-40 h/wk; daily commuting time: ≤60 minutes), after controlling for sex, age, socioeconomic factors, and work-related factors. Among shift workers, those with daily commuting time ≤60 minutes (OR: 1.71, 95% CI: 1.39-2.09), 61-120 minutes (OR: 2.63, 95% CI: 1.21-5.74), and >120 minutes (OR: 5.16, 95% CI: 2.14-12.44) had higher odds of insomnia symptoms than nonshift workers with ≤60 minutes daily commuting time. CONCLUSION: Long working hours and shift work are associated with greater risk of insomnia symptoms.

Association between discrimination in the workplace and insomnia symptoms.

Background: In Korea, little research has focused on the relationship between discrimination in the workplace and sleep health. Thus, this study aims to investigate the association between such discriminatory experiences and insomnia, a common sleep disorder, using Korean employees' data. Methods: This study used data from the 6th Korea Working Conditions Survey. Discrimination experiences due to age, ethnic background, nationality, race, sex, religion, disability, sexual orientation, educational level, hometown, and employment status were investigated. The Minimal Insomnia Symptom Scale estimated insomnia symptoms. The association between discrimination experience and insomnia symptoms were analyzed using survey-weighted logistic regression analysis. Results: Based on experiences of discrimination over the past 12 months, insomnia symptoms were associated with discrimination experience due to religion (odds ratio [OR]: 3.70; 95% confidential interval [CI]: 1.58-8.69), sex (OR: 2.51; 95% CI: 1.87-3.37), age (OR: 2.30; 95% CI: 1.88-2.81), hometown (OR: 2.07; 95% CI: 1.44-2.97), employment status (OR: 1.69; 95% CI: 1.37-2.10), and educational level (OR: 1.67; 95% CI: 1.31-2.14). Furthermore, the prevalence of insomnia symptoms increased with the number of discrimination experiences. Conclusions: In this study, discrimination experiences due to religion, sex, age, hometown, employment status, and educational level were significantly associated with insomnia symptoms. Furthermore, as the number of discrimination experiences increased, so did the prevalence of insomnia. Preventing workplace discrimination may improve workers' sleep health.