Graveyard Shift Keeping You Up?

Shift work disorder causes drowsiness and can quickly turn into a safety hazard

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Awake, asleep, tired, wired? Non-traditional work shifts can mess with the body’s natural sleep/wake cycle. Physical health deterioration and safety in the workplace are at stake.

Recently, a team of researchers designed a shift work disorder questionnaire and tested it on shift workers at sleep clinics. The questionnaire was found to be an accurate diagnostic test.

“Shift work is a reality of modern economies, but research has shown that there are very real health risks associated with working outside regular hours,” said the lead author.

"Talk to a doctor about sleep trouble."

Shantha Rajaratnam, PhD, associate professor at Monash University in Australia and Harvard University in Boston, Massachusetts, led an investigation into the safety concerns associated with night shift work. Authors said, “Shift work, including extended duration shifts and other variable and non-standard hours, comprises approximately 15 percent of the full-time workforce in the United States.”

For the study, 311 shift workers answered a newly designed 26-item questionnaire at one of 18 sleep clinics in the US to assess their risk for shift work disorder (SWD).

SWD occurs when the circadian rhythm, the body’s natural control over the sleep/wake cycle, becomes disrupted due to early morning, overnight or rotating shifts.

Insomnia and daytime sleepiness can result in and pose safety concerns for the workers and their environment.

A standardized diagnostic tool like the 26-item questionnaire could help primary care physicians identify and treat SWD.

Previous studies have shown that night workers have been more likely to have car accidents, industrial accidents, quality control errors, actual or near-miss injuries in the workplace and lower work capacity. Overall health concerns linked to previous studies on shift work include: diabetes, cardiovascular disease, gastrointestinal problems, mood trouble and cancer.

Non-standard shift work was defined as any shift starting before 7am or after 2pm, shifts that rotate or shifts that regularly include hours outside of 7am-6pm.

Items on the questionnaire included:

  • Problems falling asleep at bedtime
  • Overall amount of sleep
  • Experience sleepiness
  • Problems staying asleep
  • Quality of sleep
  • Problems with waking up too early then not being able to fall back asleep

Out of the shift workers, 37 percent worked 5 non-standard shifts per week, 24 percent worked 4 per week and 15 percent worked 3 per week. A total of 205 were diagnosed as “definitely or likely” having SWD. The questionnaire correctly identified 76 percent of participants diagnosed with SWD by a sleep specialist.

Dr. Rajaratnam said, “This questionnaire is an important step in better understanding causes of vulnerability to shift work, and targeting interventions to those who most need them.”

“More collaboration between researchers, industry and government partners is needed to tackle these significant challenges and make shift work as safe and productive as possible.”

The first step to treating any health issue is proper diagnosis. The questionnaire may help doctors identify SWD in order to begin treating this health and safety issue.

This study was published in December in Sleep. Funding for this study was supported by Cephalon Inc., the Australian Workers’ Union, and National Transport Commission. Several of the doctors involved with this study have received funding from various pharmaceutical companies and medical device manufacturing companies.

Reviewed by: 
Review Date: 
December 6, 2012
Last Updated:
December 10, 2012