0771 Association Between Shift Work Adaptability and Quality of Life Among Night Shift Workers: The Moderating Role of Age

Abstract Introduction Working at night leads to misalignment between the timing of biological clock and the work/sleep schedule, resulting in shortened and poor sleep. Workers’ adaptability to shift work is also frequently linked to their sleep and health outcomes. The objectives of this study were to examine the association between shift work adaptability and quality of life and to explore the moderating role of age in this association among regular night shift workers. Methods Night shift workers (n=474, age 39.5±15.1, 52.7% female) from various occupations who reported working regular night shifts completed an online survey. The survey included questions on socio-demographics, shift work adaptability (flexibility-rigidity & languidness-vigorousness assessed by the Circadian Type Inventory) and quality of life (assessed by the WHO-Quality of Life). Baron and Kenny’s Mediating & Moderating Method was used to assess the moderating effect. Results Multivariable linear regressions suggested significant associations between shift work adaptability and quality of life among night shift workers, with higher flexibility (β=0.67, p< 0.001) and higher rigorousness (β=0.38, p< 0.001) linking to better quality of life, after adjusting for age, gender, marital status, education, shift duration, number of successive shifts, night shift tenure, and childcare responsibility. Age moderated this association, with a stronger relationship between flexibility-rigidity (not languidness-vigorousness) and quality of life in younger (< 50 y) compared to older (≥50 y) shift workers (β=0.95 vs. 0.37, p< 0.001). Lower education and having childcare responsibility were associated with poorer quality of life. Conclusion Shift work adaptability was positively associated with quality of life in night shift workers, and the association was stronger in younger than older shift workers. One possible explanation is that older workers who have greater difficulty adapting to shift work leave jobs that require shift work. Another possibility is that older shift workers, who are less likely to have childcare responsibilities, have more flexibility and thus can cope better with a shift work schedule. This highlights the importance of circadian type-informed shift scheduling for night shift workers to improve their quality of life, especially for younger workers. Support (if any) The study was supported by grant R01 AG044416 from the US National Institutes on Aging (NIA).