"Inefficient, inattentive, accident-prone"
"Compared to good sleepers, severe insomniacs...had more problems at work (including decreased concentration, difficulty performing duties, and more work-related accidents)."
Source: Leger D, Guilleminault C, Bader G, Levy E, Paillard M.
"[T]he disruption of nocturnal sleep will invariably impact on daytime activities and often results in daytime fatigue, performance deficits (including memory and other cognitive deficits), an increase in the number of sick days taken by an individual and accidents (some catastrophic)."
Source: Chilcott LA, Shapiro CM.