每个参加者按照结合工作模式的十个方面和前一周的睡眠状况得出一个疲劳危险分数，按照一个公认的困倦状况分级，这些回复者中有30%被分类为“极度困倦”。

• Each participant was given a fatigue risk score by combining 10 aspects of work patterns and sleep in the preceding week. 30%25 of those who responded were classified as "excessively sleepy" according to a recognised sleepiness scale.