Sleep quality, sleep quantity, and sleep disturbances among hospital night workers

BACKGROUND: Night work impacts sleep and is unavoidable in healthcare. Different sleep components have been studied, such as quality, duration and disturbances, which need to be considered different fundamental components of sleep. In the general population sociodemographic, lifestyle and work factors are associated with these sleep components, but less is known among night workers. Therefore, this study assessed among hospital night workers i) to what extent sleep quality, sleep duration and sleep disturbances overlap, and ii) associations between sociodemographic, lifestyle and work factors and these sleep components. METHODS: Data were used from 467 hospital night workers from the Klokwerk+ study, a prospective cohort study with two measurements. Sleep quality was measured by the Pittsburgh Sleep Quality Index, sleep duration and disturbances were measured by the Medical Outcomes Study Sleep Scale. The proportions of overlap between the three sleep measures were calculated and visualized with a Venn diagram. Associations of sociodemographic, lifestyle, and work factors with the three sleep outcomes were estimated using between-within Poisson regression models. RESULTS: About 50% of the hospital night workers had at least one poor sleep outcome. Overlap in poor sleep outcomes was apparent for 36.8% of these workers, while the majority had a poor outcome in only one sleep component (63.1%). Former smoking had a significant association with poor sleep quality. For most independent variables no associations with poor sleep outcomes were observed. CONCLUSIONS: Our findings suggest that sleep quality, duration and disturbances are separate entities and should be studied separately. Lifestyle and work factors were generally not associated with poor sleep. Since these factors can have acute effects on sleep, future research should consider ecological momentary assessment to examine how exposure and outcomes (co)vary within-persons, over time, and across contexts. KEY MESSAGES: • Sleep quality, sleep duration and sleep disturbances are separate entities of sleep and should be studied as such. • Lifestyle factors and work characteristics were generally not associated with poor sleep among hospital night workers.