Sleep misalignment and circadian rhythm impairment in long-haul bus drivers under a two-up operations system

DIEZ, JOAQUÍN J.; BELLONE, GIANNINA; CARDINALI, DANIEL P.; VIGO, DANIEL E.; CALDART, CARLOS; BRANGOLD, MAURO; PÉREZ CHADA, DANIEL; CALDART, CARLOS; BRANGOLD, MAURO; PÉREZ CHADA, DANIEL; PLANO, SANTIAGO A.; SIMONELLI, GUIDO; GOLOMBEK, DIEGO; PLANO, SANTIAGO A.; SIMONELLI, GUIDO; GOLOMBEK, DIEGO; DIEZ, JOAQUÍN J.; BELLONE, GIANNINA; CARDINALI, DANIEL P.; VIGO, DANIEL E.

Sleep Health

Elsevier Inc

Año: 2020 vol. 6 p. 374 - 386

2352-7218

Objectives: The objective of the study was to describe working and sleep conditions and to assess how sleep opportunities are associated with obtained sleep and alertness, in a sample of long-haul bus drivers working with a two-up operations system. Methods: Measures of subjective sleep and sleepiness, actigraphy, circadian temperature rhythm, and psychomotor vigilance tasks were obtained from a sample of 122 drivers from Argentina. Variables were compared between high and low fatigue risk groups, which were formed using a median split of a fatigue risk score. The score was calculated based on drivers´ total working hours, maximum shift duration, minimum short break duration, maximum night work per seven days, and long break frequencies. Results: Considering a standardized one-day period, sleep in the bus accounted for 1.9±0.1 h of total sleep (57±1% efficiency), sleep at destination for 1.6±0.2 h of total sleep (90±1% efficiency), and sleep at home for 3.8±0.2 h of total sleep (89±1% nap efficiency and 90±1% anchor sleep efficiency). In drivers exposed to high-risk working schedules, the circadian temperature rhythm was weaker (lower % of variance explained by the model) (22.0±1.7% vs. 27.6±2.0%, p