Table 3. Polysomnographic sleep parameters.

	Afternoon group n = 25	Evening group n = 25	F	P
Sleep latency, min	18.5±9.3	26.0±17.9	3.4	0.072
Sleep period time, min	517.5±12.6	511.2±17.9	2.1	0.154
Sleep efficiency, %	92.0±3.5	90.4±4.7	1.9	0.172
Waking (% SPT)	4.0±2.1	4.5±3.5	0.4	0.528
Stage 1 (% SPT)	4.2±1.7	4.4±2.5	0.1	0.711
Stage 2 (% SPT)	46.3±5.9	44.0±6.6	1.6	0.208
Slow wave sleep (% SPT)	23.8±6.6	27.3±8.2	2.8	0.099
REM sleep (% SPT)	21.8±3.9	19.8±3.8	3.3	0.075

Values represent means ± SD. REM, rapid eye movement; SPT, sleep period time.