Association of Sleep Behaviors on Mental Health and Quality of Life Among Korean Adults: Analysis of the 7th Korea National Health and Nutrition Examination Survey (2016-2018)

Objectives: This study aimed to investigate the associations between sleep duration, sleep on set time, and mental health status as well as health-related quality of life (HRQoL) among Korean adults, utilizing nationally representative data. Methods: Data were obtained from the 7th Korea National Health and Nutrition Examination Survey (2016–2018), comprising 16,648 individuals aged 20 years and older. Sleep duration and sleep on set time were classified into three and four categories, respectively. Mental health indicators included subjective bad health, stress degree, and depressive mood, while HRQoL was measured using the EQ-5D (EuroQol-5 Dimension) instrument. Complex sample logistic regression models were applied to account for the multistage probability sampling design, adjusting for key covariates including demographic characteristics and health-related behaviors. Results: Delayed sleep onset time (post-midnight) was significantly associated with subjective bad health and EQ-5D domains, particularly in domains of usual activities, discomfort/pain, and anxiety/depression. Both insufficient (≤6 hours) and excessive (>8 hours) sleep durations were independently linked to increased risks of psychological distress and decline in multiple quality of life domains. These associations remained statistically significant after controlling for potential confounders. Conclusions: The findings indicate that insufficient and excessive sleep duration and delayed sleep timing are independently associated with harmful mental health outcomes and decreased quality of life. Encouraging earlier sleep onset time to obtain appropriate sleep duration may have a positive impact on improving quality of life and preventing mental health problems among adults.