Table 2.

Comparison of driving performance, EEG and ocular measures on postnight-shift drives compared with postsleep drives

Variable	Postnight-shift (n = 16)	Postsleep (n = 16)	P value
Driving performance
Drives with emergency brake maneuvers	6 (37.5%)*	0 (0%)	P = 0.0088
Drive terminations	7 (43.8%)	0 (0%)	P = 0.0034
Rate of lane excursions (overall)	3.09/min	1.49/min	P < 0.0001 rate ratio = 2.08 (95% CI:1.98, 2.19)
Rate of lane excursions (straight)	0.59/min	0.19/min	P < 0.0001 rate ratio = 3.11 (95% CI:2.72, 3.55)
EEG
Microsleep episodes	1.00/h	0.47/h	P = 0.0368 rate ratio = 2.09 (95% CI: 1.05, 4.18)
Ocular measures
Slow eye movements	20.1/h	10.6/hour	P < 0.0001 rate ratio = 1.89 (95% CI: 1.63, 2.19)
IED, mean (SD) (s)	0.12 (0.04)	0.10 (0.02)	P = 0.0192†
Time with eyes closed, mean (SD) (%)	0.36 (0.13)	0.32 (0.12)	P = 0.21‡
Blink time duration, mean (SD) (s)	0.18 (0.10)	0.13 (0.07)	P = 0.18‡
Positive AVR, mean (SD)	0.50 (0.32)	0.36 (21)	P = 0.0684†
JDS, mean (SD)	1.71 (1.32)	0.97 (0.90)	P = 0.0209†
Average maximum JDS, mean (SD)	3.77 (1.77)	2.80 (1.49)	P = 0.0658†

^*Within these six sessions, there were a total of 11 braking maneuvers.

^†Student’s t-test.

^‡Signed test.