Effects of long working hours and the night shift on severe sleepiness among workers with 12‐hour shift systems for 5 to 7 consecutive days in the automobile factories of Korea

Nov 22, 2008Journal of sleep research

Long working hours and night shifts linked to severe sleepiness in Korean auto factory workers on 12-hour shifts for 5 to 7 days

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

The risk of severe sleepiness at work for night shift workers can be 7.5 times greater than for day shift workers.

Severe sleepiness is defined as a Karolinska Sleepiness Scale score of 7 or higher.
Working a night shift increases the risk of severe sleepiness with an odds ratio of 4.7.
Daily overtime is associated with an odds ratio of 2.2 for severe sleepiness.
Weekly overtime has an odds ratio of 1.6 for severe sleepiness.
Night overtime also shows an odds ratio of 1.6, but with a wider confidence interval.
Long working hours and shift work interact significantly to increase the risk of severe sleepiness.

AI simplified

We investigated the effects of 12-hour shift work for five to seven consecutive days and overtime on the prevalence of severe sleepiness in the automobile industry in Korea. [Correction added after online publication 28 Nov: Opening sentence of the summary has been rephrased for better clarity.] A total of 288 randomly selected male workers from two automobile factories were selected and investigated using questionnaires and sleep-wake diaries in South Korea. The prevalence of severe sleepiness at work [i.e. Karolinska Sleepiness Scale (KSS) score of 7 or higher] was modeled using marginal logistic regression and included theoretical risk factors related to working hours and potential confounding factors related to socio-economic status, work demands, and health behaviors. Factors related to working hours increased the risk for severe sleepiness at the end of the shift in the following order: the night shift [odds ratio (OR): 4.7; 95% confidence interval (CI): 3.6-6.0)], daily overtime (OR: 2.2; 95% CI: 1.7-2.9), weekly overtime (OR: 1.6; 95% CI: 1.0-2.6), and night overtime (OR: 1.6; 95% CI: 0.8-3.0). Long working hours and shift work had a significant interactive effect for severe sleepiness at work. Night shift workers who worked for 12 h or more a day were exposed to a risk of severe sleepiness that was 7.5 times greater than day shift workers who worked less than 11 h. Night shifts and long working hours were the main risk factors for severe sleepiness among automobile factory workers in Korea. Night shifts and long working hours have a high degree of interactive effects resulting in severe sleepiness at work, which highlight the need for immediate measures to address these characteristics among South Korean labor force patterns.

Full Text

Full text is available at the source.

View full text ↗

Effects of long working hours and the night shift on severe sleepiness among workers with 12‐hour shift systems for 5 to 7 consecutive days in the automobile factories of Korea

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief