Change in working time arrangement (WTA) can be harmful to workers' sleep and health. This study aimed to investigate the association between change in working time arrangement and sleep disturbance.

This study used data from the Fifth Korean Working Condition Survey and included 33,203 paid workers. We performed a stratified analysis by sex. After dividing the participants into 6 groups based on whether or not they experienced WTA changes, and their weekly working hours (≤40, 41–52, ≥53 hours), we calculated odds ratio (OR) using the weekly working hours ≤40 hours and with no WTA change as the reference group.

Of the 33,203 paid workers, participants who experienced change in working time arrangement had higher prevalence of all three types of sleep disturbance symptoms (difficulty in falling asleep, waking up repeatedly during sleep, and waking up with a feeling of exhaustion and fatigue) in both sexes. Compared to the reference group at 95% confidence interval (CI), the group with change in WTA showed elevated OR values of 1.91 (95% CI: 1.73–2.11), 1.93 (95% CI: 1.74–2.14), 2.47 (95% CI: 2.26–2.71) for male workers; and 1.93 (95% CI: 1.73–2.16), 2.02 (95% CI: 1.80–2.27), 2.24 (95% CI: 2.01–2.50) for female workers, for difficulty in falling asleep, waking up repeatedly during the sleep, waking up with a feeling of exhaustion, and fatigue, respectively.

Workers who experience change in work time arrangement show a high risk of sleep disturbance in both sexes.

Dependent self-employment is precarious employment, which can be vulnerable to mental health problems. This study aimed to investigate the association of dependent self-employment with depression, anxiety, and sleep disorder in South Korea.

This study used data from the Fourth Korean Working Conditions Survey and included 32,691 paid workers. Dependent self-employment and self-reported depression/anxiety, and sleep disorder were investigated using a questionnaire. Logistic regression analysis was performed to investigate the association between dependent self-employment and mental health problems.

Of the 32,691 paid workers, 2,371 (7.3%) were dependent self-employed workers. The odds ratio (OR) of dependent self-employment for self-reported depression/anxiety was 1.78 (95% confidence interval [CI]: 1.29–2.45) and the OR of dependent self-employment for self-reported sleep disorder was 1.26 (95% CI: 1.01–1.59) compared to other paid workers.

Dependent self-employment is related to an increased risk of self-reported depression/anxiety and sleep disorder in South Korea.