Working the night shift affects duration and quality of sleep: study

Cincinnati – Night-shift workers have the highest risk for sleep problems compared with all other workers, according to a recent study from NIOSH.

Researchers examined data for nearly 6,350 adults from the National Health and Nutrition Examination Survey. Participants answered questions about the length and quality of their sleep, sleep disorders, and “impairment of sleep-related activities of daily living.” They also had to identify if their work shift was during the day (between 6 a.m. and 6 p.m.), evening (between 4 p.m. and midnight), night (between 7 p.m. and 8 a.m.), rotating or other.

Researchers then placed participants into two categories: those who had slept less than seven hours, and those who had gotten seven or more hours of sleep.

After adjustments for factors such as long work hours and socio-demographic traits, results showed that 61.8 percent of night-shift workers slept less than seven hours, compared with 35.9 percent of daytime workers. The National Sleep Foundation recommends adults sleep seven to nine hours each night.

Additional study results:

• 30.7 percent of night-shift workers reported poor quality sleep.
• 22.3 percent said they felt extra sleepy during the day.
• 21.7 percent reported difficulty falling asleep, in contrast with 12.7 of daytime workers.

“Particularly in light of the likely continuing increase in nontraditional working schedules, work-based prevention strategies and policies should be adopted to improve the quantity and quality of sleep among workers,” Dr. Geoffrey Calvert, study author and senior medical epidemiologist in the NIOSH Division of Surveillance, Hazard Evaluations, and Field Studies, wrote in an Oct. 5 blog post.

Policy changes can include taking frequent breaks, limiting night shifts to eight hours, and napping before a night shift, Calvert added.

The study was published online Sept. 8 in the journal Occupational & Environmental Medicine.