Disabling low back pain associated with night shift duration: sleep problems as a potentiator

BACKGROUND: We investigated how night shift duration and sleep problems were jointly associated with disabling low back pain (LBP) among workers in different occupations. METHODS: An online-survey was conducted regarding work schedules, disabling LBP, sleep problems, and other relevant factors in 5,008 workers who were randomly selected from a market research panel. Multiple logistic regression analyses determined the joint associations of night shift duration (0 [permanent day shift], <8, 8-9.9, 10-15.9, ≥16 hr) and sleep problems (no, yes) with disabling LBP adjusted for potential confounders. RESULTS: A night shift ≥16 hr was associated with a significant increase in the likelihood of disabling LBP. The magnitude of this association was elevated when participants perceived sleep problems including both sleep duration and quality. CONCLUSION: Associations between extended night shifts and disabling LBP became stronger in the presence of short or poor quality sleep.