The Influence of Shift Work on the Quality of Sleep and Executive Functions.

Abstract

Shift work is an inconsistent and atypical work schedule. This study aimed to investigate the influence of shift work on the Quality of Sleep (QOS) and Executive Functions (EF). Thirty shift workers and thirty day workers first completed a demographic questionnaire. They then were tested using the Pittsburgh Sleep Quality Index (PSQI) and EF tests, including the Corsi Block-Tapping Task (CBTT), Berg's Card Sorting Task (BCST), and the Continuous Performance Task (CPT). Results were subjected to non-parametric Chi-Square Tests, the Mann-Whitney U Test, and Independent T-Tests. Shift workers had significantly poorer sleep quality than day workers, which was shown in PSQI global scale (p = 0.001), sleep duration (p = 0.042), habitual sleep efficiency (p = 0.021), and sleep disturbance (p = 0.021). Concerning EF tests, shift workers performed significantly poorer on CBTT (p = 0.019) and BCST (p = 0.015, 0.047) compared with day workers. Significant differences were also observed between shift workers and day workers in terms of variables of omission errors (p = 0.037) and commission errors (p = 0.041) on CPT, but no significant difference was found between shift workers and day workers in reaction time (p = 0.561). Shift work impaired EF. These findings are related to shift workers' poorer sleep and its detrimental effects on areas of the brain, which are critical for EF, such as the prefrontal area. Our results suggest the evaluation and implication of practices and policies to assuage the consequences of working in shifts.