By Lisa Rapaport

Shift-work nurses who have sleep problems are more likely to experience career burnout that has the potential to compromise their job performance, a small Italian study suggests.

Researchers studied 315 nurses who worked rotating shifts in 39 wards of seven Italian hospitals. Each week, nurses worked an average of 36 hours and typically had at least one shift starting in the morning, the afternoon and the evening.

Overall, 52 percent of the nurses reported sleep difficulties and 31 percent reported feelings of career burnout.

Nurses who reported poor sleep quality, disturbed sleep, reliance on sleep medications or daytime impairment related to sleep issues were at least two times more likely to report burnout than nurses who didn’t have these sleep issues, Loreto Lancia of the University of L’Aquila in Italy and colleagues note.

“Burnout syndrome in nurses is associated with decreased patient satisfaction, reduced quality of care, medication errors, higher rates of healthcare related infections and higher mortality rates,” said Meredith Mealer, a researcher at the University of Colorado Anschutz Medical Campus and Denver VA Medical Center who wasn’t involved in the study.

“What this study adds to the literature is that there is a direct association between shift work and burnout syndrome,” Mealer said by email.

Working rotational shifts or night shifts can alter the normal circadian rhythm, the body’s internal clock that regulates sleeping patterns and eating patterns, Mealer added.

“This internal clock adapts slowly to transitions between different shift schedules, leading to issues with metabolism and the release of hormones, body temperature, alertness, sleep and performance,” Mealer said.

In the study, 60 percent of the nurses worked a so-called “long cycle” with two morning shifts, followed by two afternoon shifts, two night shifts, and three days off. The rest worked what researchers called a “short cycle” with one morning shift, one afternoon shift, one night shift and then two days off.

Compared to nurses on the short cycle, people working a long cycle were 41 percent more likely to experience burnout, researchers reported.

A long cycle was also associated with higher odds of impaired sleep quality, but the difference was too small to rule out the possibility that it was due to chance.

One limitation of the study is that the small sample of nurses might make it difficult to draw broad conclusions about how shift work might impact nurses elsewhere.

The rotating shifts in the study may be common in Italy, but they’re not the norm in the U.S., noted Ann Rogers, a researcher at the Nell Hodgson Woodruff School of Nursing at Emory University in Atlanta who wasn’t involved in the study. Many nurses in the U.S., for example, work 12 hour shifts on either days or nights, not both, Rogers said by email.

Because the study wasn’t a controlled experiment, it’s also impossible to know whether sleep caused burnout or if burnout preceded difficulties with sleep, Rogers noted.

“The Italian nurses in this study worked rotating shifts, which means that their circadian rhythms for sleeping, eating, and alertness are never aligned,” Rogers said. “When they get off work in the morning, they have to try to fall asleep in the daylight when their body temperature is rising, making it hard to fall asleep – and if you don’t get enough sleep, your ability to concentrate is impaired.”