Proper sleep reduces 'sick leaves' from work

Washington: A new research shows that proper sleep of 7 to 8 hours per night reduces risk of absence from work due to falling ill.

The study, which was part of the Sleep Well, Be Well campaign launched earlier in 2014 to increase awareness of the importance of sleep in healthy lifestyle, involved a nationally representative survey of 3,760 men and women in Finland who had been working at any time in the prior year.

Participants were 30-64 years old at baseline. Sleep characteristics were determined by questionnaire, and health measures were derived from physical examination conducted by field physicians. Data for work absences due to sickness were gathered from the Social Insurance Institution of Finland, which tracks all sickness absences lasting more than 10 days. The average follow-up period was seven years.

A novel statistical method developed by study co-authors Tommi Harkanen, PhD, and Risto Kaikkonen, MSc, was used to predict adjusted average sickness absence days per working year. Additional statistical estimates found that the direct costs of sickness absence to the Finnish government and employers could decrease by up to 28 percent if sleep disturbances could be fully addressed.

Results showed that the risk of an extended absence from work due to sickness rose sharply among those who reported sleeping less than 6 hours or more than 9 hours per night. Further analysis found that the optimal sleep duration with the lowest risk of sickness absence from work was between 7 and 8 hours per night: 7 hours, 38 minutes for women and 7 hours, 46 minutes for men. Insomnia-related symptoms, early morning awakenings, feeling more tired than others, and using sleeping pills also were consistently associated with a significant increase in workdays lost due to sickness.

The study results are published in the journal Sleep.