Good Sleep Quality and Progressive Increments in Vigilance During Extended Night Shifts: A 14-Day Actigraphic Study in Underground Miners

• Published in: Journal of occupational and environmental medicine Vol. 62; no. 12; pp. e754 - e759
• Main Authors: Lavigne, Andrée-Anne, Hébert, Marc, Auclair, Julie, Laberge, Luc
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins 01-12-2020; Copyright by the American College of Occupational and Environmental Medicine
• ISSN: 1076-2752; 1536-5948
• DOI: 10.1097/JOM.0000000000002056

OBJECTIVE:Assess the change in sleep and vigilance of underground miners during long periods of extended shifts.
METHODS:Seventy miners worked 14 consecutive 12-hour day and/or night shifts. Also, they wore an actigraph and completed a visual analog scale for vigilance four times per shift. Linear regression models with mixed effects were used.
RESULTS:Sleep efficiency was higher during day shifts than during night shifts (86,5 vs 85.5, P < 0.05) but sleep duration did not differ (6:34 vs 6:44, n.s.). Mean vigilance level at Time 3 (02h00) was significantly lower than that at Time 1 (19h00) during the first 10 night shifts whereas mean vigilance level at Time 4 (05h30) remained significantly lower for the 14 night shifts.
CONCLUSIONS:Underground miners exhibit good sleep quality despite evidence of limited circadian adaptation in terms of nighttime vigilance.