Objective 1) To estimate the prevalence of insufficient sleep and poor sleep quality by different shiftwork status in a representative sample of the Taiwan working population. 2) To estimate PARs of sleep-related problems as related to shiftwork.

Methods The data of 22 600 workers aged 20 to 65 years were retrieved from the Survey of Perceptions of Safety and Health in the Work Environment, a nationwide cross-sectional survey conducted in 2010. Insufficient sleep was defined as self-reported short sleep duration interfering with life or work activity. Sleep quality was categorised into very good, good, poor and very poor. Work shifts were classified into fixed daytime, evening, or night, rotating night shift, rotating shift not including night, and irregular. Multivariate logistic regression was used to calculate the ORs and then estimated PARs of sleep-related problems.

Results Among all workers, shift status were as follows: fixed daytime shift 74.7%, fixed evening 10.6%, fixed night 2.3%, rotating night shift 5.3%, rotating shift not including night 2.0%, and irregular 5.2%. The highest prevalence of sleep-related problems was observed among fixed night workers with insufficient sleep of 12.1% and poor sleep quality 3.5%. Fixed night shift was associated with the highest risk of both insufficient sleep (OR=3.20, 95% CI 2.41–4.18, p<0.0001) and poor sleep quality (OR=3.51, 95% CI 2.07–5.62, p<0.0001). The estimated PARs of insufficient sleep and poor sleep quality related to rotating night shift were 9.0% and 8.9%, respectively.

Conclusions Night shiftwork was significantly associated with increased risk of insufficient sleep and poor sleep quality among Taiwanese workers.