Table 2.

Sleep and Sleep-Disordered Breathing Event Characteristics in 480 Children

Sleep Characteristics		Mean	SD	Min	Max	p value
Time in bed, min	Boy	538.9	86.3	276	687
	Girl	546.5	85.2	275	786
	All	542.7	85.7	275	786	.33
Sleep time, min	Boy	483.6	78.4	215	634
	Girl	490.4	81.1	217	744
	All	487	79.7	215	744	.35
Sleep efficiency, %	Boy	89.9	5.5	59.0	97.5
	Girl	89.8	6.2	52.2	97.5
	All	89.8	5.8	52.2	97.5	.90
Stage 1, %	Boy	5.0	3.6	0.5	23.8
	Girl	4.2	3.0	0.6	23.6
	All	4.6	3.3	0.5	23.8	.01
Stage 2, %	Boy	52.0	6.4	34.3	69.2
	Girl	52.1	5.9	35.3	67.9
	All	52.0	6.1	34.3	69.2	.84
Stage 3/4, %	Boy	21.8	6.3	9.2	46.2
	Girl	22.0	5.8	9.3	47.7
	All	21.9	6.1	9.2	47.7	.71
REM, %	Boy	21.2	5.1	5.3	32.4
	Girl	21.7	4.8	2.3	35.0
	All	21.5	5.0	2.3	35.0	.32
Sleep latency, min	Boy	17.2	18.2	0	113
	Girl	19.8	23.3	0	174
	All	18.5	21.0	0	174	.18
REM latency, min	Boy	136.6	51.3	5	362
	Girl	125.1	49.6	6	346
	All	130.9	50.8	5	362	.01
Respiratory disturbance index	Boy	0.90	1.2	0	7.4
	Girl	0.87	2.4	0	29.1
	All	0.90	1.91	0	29.1	.11*
Obstructive apnea index	Boy	0.01	0.03	0	0.24
	Girl	0.03	0.39	0	5.9
	All	0.02	0.27	0	5.9	.83*
Central apnea index	Boy	0.25	0.47	0	4.3
	Girl	0.30	1.1	0	15.4
	All	0.28	0.84	0	15.4	.91*
Obstructive hypopnea index	Boy	0.67	0.97	0	6.6
Time in bed, min	Girl	0.57	1.5	0	15.8
	All	0.62	1.23	0	15.8	.04*

^*Mann-Whitney test for non-parametric data. REM refers to rapid eye movement.