Persons who awaken frequently during the night experience lower productivity at work, as well as a decline in overall job performance.
SEATTLE—Nearly one-third of employees have three or more awakenings during sleep per night, which leads to poorer productivity and performance at work, according to research presented at the 23rd Annual Meeting of the Associated Professional Sleep Societies. Overall, fewer than one in seven persons consulted with a physician regarding his or her sleep symptoms and used pharmacotherapy, reported Rajesh Balkrishnan, PhD, and colleagues.
A total of 4,188 employees (mean age, 40; 53% male) from four US-based companies completed an online survey that assessed various sleep characteristics, according to Dr. Balkrishnan, Director of the Center for Medication Use, Policy, and Economics and Associate Professor of Health Management and Policy at the University of Michigan in Ann Arbor.
Study participants were asked about their average frequency and length of awakenings during sleep, their general health, and their perceived effects of nighttime awakenings, as well as other sleep characteristics. The Work Limitations Questionnaire (WLQ) was used to measure subjects’ ability to work and related productivity losses based on physical, mental, interpersonal, and time limitations.
A total of 464 persons (11%) reported no nighttime awakenings, 2,373 (58%) had one to two awakenings per night, 984 (24%) had three to four nightly awakenings, and 289 (7%) had five or more nighttime awakenings during an average sleep period. Women, more frequently than men, reported waking up three to four times per night (27% vs 21%, respectively), as well as five or more times per night (8% vs 6%, respectively). Among participants who had three to four awakenings per night, a comorbid medical condition was observed in 22%, and a comorbid psychologic disorder was found in 10%; in persons who had five or more nighttime awakenings, 23% had a comorbid medical condition, and 14% had a psychologic condition. These rates were higher than the rates observed among participants who had two or fewer nighttime awakenings.
Sleep Characteristics and Treatment
The investigators found that nonrestorative sleep was the most frequent insomnia symptom and was significantly greater in those with five or more nighttime awakenings (87.5%) and in those with three to four awakenings per night (80.5%), compared with persons with no nighttime awakenings (50.7%) and those with one to two awakenings per night (62.1%). More participants with three to four nighttime awakenings (48.1%) and five or more nightly awakenings (55.7%) also had difficulty falling asleep, compared with those who had one to two or no nighttime awakenings (33.2% vs 19%, respectively).
Among participants who woke up five or more times per night, 56.4% also had early awakenings, compared with 14.7% of those who had no nighttime awakenings and 36.1% of subjects with one to two nightly awakenings.
“Overall, only 13.4% of respondents reported consulting with a physician about their sleep symptoms,” stated Dr. Balkrishnan’s group. “This proportion was higher among those waking up five or more times per night (22.5%), compared to those waking up three to four times per night (18.9%) or one to two times per night (11.4%).
“Report of prescription drug use to treat insomnia symptoms was most frequent among those with at least five nighttime awakenings (24.9%), compared to those who had three to four nighttime awakenings (16.8%) or one to two nighttime awakenings (11.4%). A small portion (4.3%) of those who did not experience nighttime awakenings reported using pharmacotherapy to treat poor sleep symptoms,” the investigators noted.
Productivity Loss and Performance Outcomes
After assessing productivity loss using the WLQ, the researchers found that persons with five or more nighttime awakenings had a significantly higher amount of impairment in time management, physical and mental demands, and output, compared with participants who had four or fewer nightly awakenings.
To measure the effect on daytime performance, Dr. Balkrishnan and colleagues asked all employees to rate (using a scale of 1 [“not affected at all”] to 9 [“very much affected”]) how their ability to function and their overall work performance were affected due to feeling sleepy or tired during the day. Those measures included ability to concentrate, ability to get the job done, attention, communication, creativity, decision making, energy, judgment, learning, memory, motivation, ability to drive, and interactions with friends or family. The investigators found greater overall impairment in performance among participants who had three or more nighttime awakenings than in those who had two or fewer.
Gauging the Impact of Poor Sleep
In addition to the negative effects regarding productivity loss and performance outcomes, persons with nighttime awakenings also frequently reported other insomnia symptoms, including nonrestorative sleep, “with higher frequencies [occurring] as the number of nighttime awakenings increases,” according to Dr. Balkrishnan and colleagues.