Table 1

Summary of ANOVA results for the sleep indices, cumulative sleep debt, prior wakefulness, circadian phase, and RT performance

	Shift week		Shift week and baseline night
	F_5,70	P*	F_6,84	P*
*Corrected by Greenhouse-Geisser epsilon.
†Based on data from 12 subjects; DF=5,55 (shift week) or DF=6,66 (with baseline night).
‡Including the first night shift; DF=6,84.
§Excluding the first night shift; DF=5,70.
Mean relative performance	6.76	0.0004
PSG sleep variables
Total sleep time (min)	1.15	0.3371	1.67	0.1818
Sleep efficiency	2.23	0.0830	2.53	0.0576
Sleep onset latency	7.77	0.0003	12.92	0.0001
NREM sleep (min)	2.51	0.0726	3.84	0.0112
REM sleep (min)	2.67	0.0439	2.38	0.0538
SWS (min)	0.49	0.6667	0.75	0.5328
WASO (min)	3.38	0.0271	2.62	0.0682
Subjective measures†
Sleep quality	1.71	0.1781	1.98	0.1161
Pre-sleep alertness	7.94	0.0002	7.03	0.0008
Post-sleep alertness	3.88	0.0127	2.51	0.0818
Prior wakefulness (min)	99.62	0.0001‡	1.23	0.3096§
Cumulative sleep debt	5.10	0.0351
Cumulative phase shift	67.28	0.0001	99.46	0.0001