Fig. 1
From: Sleepiness while driving and shiftwork patterns among Korean bus drivers
The adjusted prevalence ratios of severe sleepiness. The adjusted prevalence ratios (95% CI) of severe sleepiness (KSS ≥ 7) while driving for Alternating day shift bus drivers relative to Daily two shift bus drivers for five different time periods (Adjusted for job duration, alcohol consumption and sleeping time on workdays)