Table 2. Characteristics of different components of Polysomnography .

Item	Mean ± SD	Median	Range
Total sleep time, min	379.1 ± 81.4	380.5	90 – 553
Sleep latency, min	16.9 ± 24.6	8.0	5.0 – 190.5
Sleep efficiency, %	84.3 ± 14.2	88.4	15.2 – 100.0
REM period time, min	53.2 ± 40.5	48.0	0 – 300.0
REM latency, min	141.8 ± 83.5	131.5	0 – 398.0
Events (apnea, hypopnea)	271.2 ± 203.2	220.0	6.0 – 1136.0
Mean oxygen saturation, %	92.1 ± 4.5	93.0	61.4 – 98.0