Investigation of the relationship between sleep quality, sleepiness and sickness absence

Sleep disorder is very common among employees and is considered as one of the crucial health problems. There are strong correlations between poor sleep and sickness absence. The present study concerns the relationship between sleep quality and sleepiness and sickness absence.
this cross-sectional study was conducted on 400 employees of a gas company. The study data were collected using the Pittsburg Sleep Quality Index (PSQI) and the Karolinska Sleepiness Scale (KSS). Mann-Whitney U test, and Spearman’s correlation coefficient were applied for data analysis.
While 43.2% of the participants enjoyed satisfactory sleep quality, 56.8% had unsatisfactory sleep quality. The mean (SD) of KSS for the sample was 5.65 (2.19). Statistical tests indicated a significant difference between sickness absence of the personnel groups with good and poor sleep quality (p=0.0001). Spearman correlation coefficient (ρ = 0.777) indicated a statistically significant correlation between sleepiness index and sickness absence (p=0.0001).
The results showed a strong positive correlation between sleep quality and sleepiness index of the personnel and sickness absence; i.e. along with decline in sleep quality and incline in sleepiness, the personnel’s sickness absence increases.