Sleep quality, posttraumatic stress, depression, and human errors in train drivers: a population-based nationwide study in South Korea

Abstract

Study Objectives: Human error is defined as an unintended error that is attributable to humans rather than machines, and that is important to avoid to prevent accidents. We aimed to investigate the association between sleep quality and human errors among train drivers. Design: Cross-sectional. Setting: Population-based. Participants: A sample of 5,480 subjects who were actively working as train drivers were recruited in South Korea. The participants were 4,634 drivers who completed all questionnaires (response rate 84.6%). Interventions: None Measurements: The Pittsburgh Sleep Quality Index (PSQI), the Center for Epidemiologic Studies Depression Scale (CES-D), the Impact of Event Scale-Revised (IES-R), the State-Trait Anxiety Inventory (STAI), and the Korean Occupational Stress Scale (KOSS). Results: Of 4,634 train drivers, 349 (7.5%) showed more than one human error per 5 y. Human errors were associated with poor sleep quality, higher PSQI total scores, short sleep duration at night, and longer sleep latency. Among train drivers with poor sleep quality, those who experienced severe posttraumatic stress showed a significantly higher number of human errors than those without. Multiple logistic regression analysis showed that human errors were significantly associated with poor sleep quality and posttraumatic stress, whereas there were no significant associations with depression, trait and state anxiety, and work stress after adjusting for age, sex, education years, marital status, and career duration. Conclusions: Poor sleep quality was found to be associated with more human errors in train drivers, especially in those who experienced severe posttraumatic stress.