Sleep duration and results of the psychomotor vigilance test in construction workers: a preliminary study

Abstract

The construction industry is known by its high rate of accidents. Among the different possible causes of this situation we could find lack of sleep and fatigue. Chronic sleep deprivation is a determining factor in the deterioration of vigilance and alert, and consequently a risk factor for occupational accidents. Fatigue is the answer of our organism to sustained physical and mental effort. Construction workers are prone to fatigue, since their work is characterized by heavy lifting and awkward work postures, so it is relevant to study it more thoroughly, especially regarding its association with sleep efficiency and quality. Regretfully, those topics have been very poorly studied in the construction industry. To understand better these phenomena and to propose strategies to mitigate it and contribute to the reduction of accidents in construction projects, the objective of this study was to understand if there is a relation among sleep duration and fatigue. We worked with 154 male construction workers from one Chilean construction company. To asses sleep quality we used the Pittsburgh Sleep Quality Index. One of their questions asked for average sleep hours in the last 4 weeks. To evaluate fatigue, we used a personal computer version of the Psychomotor Vigilance Test (PC-PVT) that measure alertness and vigilance. This 5-minute test was performed by construction workers on site in the morning. People was classified into groups according to self-reported sleep hours, namely: 79 hours (26%), 5-7 hours (61.7%) and <5 hours (12.3%). These results were compared for 3 variables (Mean Reaction Time, 10% faster and 10% slower) using an ANOVA test. Differences were found for Mean RT and Slowest10%, the difference being greater in the group that reported sleeping <5 hours, but without statistical significance. Studies with a greater number of subjects and measurements are required throughout the working day.