The sleep problems don’t appear to get worse over time, however, perhaps because young workers who have a lot of trouble with sleep issues are more likely to quit shift work, according to the study, which was led by Philip Tucker, Ph.D., of Swansea University, Swansea, Wales, U.K.
Using a large employment database, the researchers looked at the relationship between shift work and sleep problems in workers of different ages and over time. As in previous studies, shift workers had a higher rate of sleep problems than day workers. Shift work specifically was related to waking up too early rather than other types of sleep problems.
The effects were most apparent in the early to middle years of working life – workers in their 30s and 40s. Former shift workers had more sleep problems than those who had never done shift work. However, more years of shift work did not lead to greater sleep problems. Instead, workers who gave up shift work seemed to be a "self-selected" group who tended to have more problems with shift work.
The study confirms the previously reported link between shift work and sleep problems, while lending new insights into the course of those problems over time. Sleep problems seem to be a “reversible consequence” of shift work – although it may take awhile after giving up shift work before sleep returns to normal.
The study appeared in the April issue of The Journal of Occupational and Environmental Medicine, the official publication of the American College of Occupational and Environmental Medicine (ACOEM).