Sleep disturbance a harbinger of poor quality of life among working adults

Sleep disturbances and the ensuing daytime dysfunction are associated with poor health-related quality of life (HRQoL), reveals a study on working adults in Singapore.

“In a recent study, residents of Singapore … were reported to have the shortest sleep duration of the 20 countries enrolled in the study,” highlighted the researchers led by Dr Gerard Dunleavy of Centre for Population Health Sciences, Nanyang Technological University, Singapore.

“The lack of sleep among residents of Singapore is often linked to the well-established culture of working long hours,” they said. “Therefore, the negative effects of sleep deprivation and poor sleep quality are of concern in Singapore.”

Subjectively measured sleep disturbances (standardized β, -1.829; p<0.05) were inversely related while objectively measured sleep efficiency (standardized β, 0.211; p<0.05) was directly associated with the physical component of HRQoL on SF-36v2* after adjusting for sociodemographic, lifestyle, health, and occupational variables.

For the mental component of HRQoL, participants who reported having more daytime dysfunction had poorer HRQoL (standardized β, -2.945; p<0.001).

“The effects of sleep not only impact our physical, but also our mental health,” stated Dunleavy and co-authors, who said the association between sleep and HRQoL comes as no surprise as previous studies have indicated that those experiencing daytime sleepiness are more likely to be depressive.

“One cause of daytime dysfunction is insufficient sleep, and participants in our study averaged 5.8 hours of sleep a night, more than an hour short of the 7 to 9 hours recommended for optimal health,” they pointed out.

The cross-sectional analysis included 329 full-time employees (mean age 40.7 years, 78.1 percent male, 65.7 percent Chinese) in Singapore. Sleep parameters were measured objectively using the wrist actigraphy and subjectively using the Pittsburgh Sleep Quality index. 

Both objective and subjective sleep measurements were applied to compliment each other, as subjective report of sleep duration could not differentiate between time spent asleep or awake in bed, while objective measures from actigraphy might not accurately identify individuals with sleep disturbances. Also, self-reported data are susceptible to recall bias.

Unlike previous studies on sleep and QoL, the current study involved working individuals instead of clinical population with disease conditions and therefore, the results are more generalizable, according to the researchers.

However, as more than three-quarters of the study population were male, the researchers suggested future studies be done with a larger sample involving more female participants.

“Further study is needed to examine the workplace factors which may be contributing to sleep disturbances, the mechanistic pathways linking sleep disturbances and reduced HRQoL, as well as the impact of low HRQoL on work performance and productivity,” suggested Dunleavy and co-authors.

“Sleep hygiene education in workplaces in Singapore has the potential to improve both the quality and quantity of worker's sleep and may also help improve worker’s HRQoL,” they added. “Workplace health promotion planners should consider programmes that educate workers on better sleep hygiene practices in an effort to improve sleep quality and HRQoL.”