Relationship between insomnia and working from home among Korean domestic workers: results from the 5th Korean working condition survey.

BACKGROUND: Social distancing has been increasingly implemented following the COVID-19 pandemic and more people have been working from home. Consequently, the screen time has increased, which can disrupt the natural sleep-wake cycle and delay sleep onset. Given that studies on the health of employees who work from home remain insufficient, particularly with respect to the risk of sleep disorders including insomnia, this study aimed to assess the relationship between working from home and insomnia among workers using data from the 5th Working Conditions Survey conducted in Korea. METHODS: Of 30,108 wage workers, we enrolled 818 employees who worked from home and 4,090 employees who worked from the office, a 1:5 pair sample based on sex and occupational group. Personal and occupational characteristics, working from home, and insomnia were included in the analysis. Age, education, employment status, working years, working hours per week, work-life balance, self-perceived health, depression, and anxiety were all adjusted as potential confounding variables. Conditional logistic regression analysis was performed using working from home as an independent variable and insomnia as a dependent variable to determine the correlation between working from home and insomnia. RESULTS: Working from home was associated with sleep onset latency disorder, OR = 3.23 (95% CI: 2.67-3.91), sleep maintenance disorder, OR = 3.67 (95% CI: 3.02-4.45), and non-restorative sleep, OR = 3.01 (95% CI: 2.46-3.67); working from home had a statistically significant relationship with all three types of insomnia. CONCLUSIONS: Within the limits of the study, these findings can be used as a fundamental basis for the implementation of policies and guidelines to prevent insomnia in workers who work from home.

A Variable Sampling Interval Synthetic Xbar Chart for the Process Mean.

The usual practice of using a control chart to monitor a process is to take samples from the process with fixed sampling interval (FSI). In this paper, a synthetic X control chart with the variable sampling interval (VSI) feature is proposed for monitoring changes in the process mean. The VSI synthetic X chart integrates the VSI X chart and the VSI conforming run length (CRL) chart. The proposed VSI synthetic X chart is evaluated using the average time to signal (ATS) criterion. The optimal charting parameters of the proposed chart are obtained by minimizing the out-of-control ATS for a desired shift. Comparisons between the VSI synthetic X chart and the existing X, synthetic X, VSI X and EWMA X charts, in terms of ATS, are made. The ATS results show that the VSI synthetic X chart outperforms the other X type charts for detecting moderate and large shifts. An illustrative example is also presented to explain the application of the VSI synthetic X chart.