Materials and Methods: A total of 11,356 working adults (≥18 years) were recruited from a cross-sectional online health and work survey. Sleep duration was self-reported and was categorised as insufficient sleep (<7 h) and sufficient sleep (≥7 h) based on the National Sleep Guidelines' daily sleep time recommendation for adults. The 10-item Kessler scale was used to assess psychological distress levels (cutoff score ≥20). Bivariate and multivariable regression analyses were performed to examine the factors associated with insufficient sleep.
Results: The mean age of the participants was 35.7 years (standard deviation, SD±9.2). There were more female (n=6613; 58.2%) respondents. The mean sleep duration was 6.49 h (SD±1.10). A total of 6212 individuals (54.7%) reported getting <7 h of sleep daily. After adjusting for gender, marital status and educational attainment, older age (odds ratio, OR=2.22, 95% confidence interval, 95% CI: 1.72-2.86), ever smoking (OR=1.38, 95% CI: 1.25-1.53), and high psychological distress (OR=1.33, 95% CI: 1.17-1.53) were found to be associated with insufficient sleep. Factors associated with sleep duration of <7 h per night included having children (OR=1.35, 95% CI: 1.21-1.50), lifestyle factors (OR=1.38, 95% CI: 1.25-1.53), poor sleeping conditions (OR=1.21, 95% CI: 1.07-1.36), and mental health issues (OR=1.32, 95% CI: 1.12-1.54).
Discussion and Conclusion: More than half of the participants reported sleep insufficiency. Older age, ever smoking, and high levels of psychological distress were significantly associated with insufficient sleep. Our findings recognise sleep as an emerging public health issue. Smoking cessation programmes and addressing high psychological distress may be beneficial to improve sleep.