Korean J Occup Health Nurs.  2020 Nov;29(4):306-315. 10.5807/kjohn.2020.29.4.306.

Effect of Ingested Caffeine on the Sleep Quality among Shift Workers

• Kim Hs
• Lee JE

• KMID: 2509001
• DOI: http://doi.org/10.5807/kjohn.2020.29.4.306

Abstract

Purpose
This study was conducted to identify the effects of caffeine intake by shift workers on sleep, considering various variable related to the sleep health of shift workers.
Methods
A descriptive survey study was conducted with 128 employees who worked shifts. Respondents were surveyed on their of caffeine intake behavior, schedule type, quality of sleep, health promotion behavior, and occupational stress. Differences in their quality of sleep were assessed using the t-test and analysis of variance, while factors influencing the effect of caffeine intake on the quality of sleep were analyzed using hierarchical logistic regression.
Results
The average Pittsburgh Sleep Index, Korean Version score of those surveyed was 7.3±3.25, indicating that their quality of sleep was low. On the other hand, their aveage daily intake of caffeine was 1.6±0.99 cups (1 cup =150 mL) and 116.4±77.58 mg/dL of caffeine. When the various variables that could have affected the quality of sleep were corrected, an increase in the amount of caffeine consumed was found to lead to a decrease in the quality of sleep (p=.015).
Conclusion
Caffeine intake by shift workers has a significant bearing on their quality of sleep; therefore, such intake should be adjusted to improve their sleep health.

Keyword

Shift work schedule; Caffeine; Sleep