Table 2.: Results of Polysomnography Studies

Parameter Value
Sleep efficiency (%)* 87 (82 – 92) 56 - 98
Latency to 1st stage of sleep (minutes)* 16 (12-21) 0 - 59
Latency to REM (minutes)* 89 (74 – 128) 50 - 339
N1 (%)* 14 (12 – 19) 3.2 - 52
N2 (%)* 51 (46 – 58) 37 - 71
N3 (%)* 16 (10 – 21) 0.6 - 31
NREM (%)* 85 (82 – 88) 72 - 92
REM (%)* 15 (13 -18) 9 - 27
Index of arousals* 30 (23 – 42) 8 - 82
Index of respiratory arousals* 16 (5 – 26) 0 - 66
Central apneas* 1 (0 – 5) 0 - 97
Mixed apneas* 0.2 (0 – 2.4) 0 - 60
Obstructive apneas* 54 (9 – 146) 1 - 637
Hypopneas* 169 (82 – 219) 0 - 327
Central apnea index (events/hr)* 0.1 (0- 0.7) 0.1 – 14.2
Obstructive apnea index (events/hr)* 9 (1.3 – 20) 0.1 – 84
AHI (events/hr)* 34 (22 – 57) 3.3 – 108
AHI <5 n (%) 1 (3)
AHI ≥5 and <15, n (%) 7 (20)
AHI ≥15 and <30, n (%) 6 (17)
AHI ≥30, n (%) 21 (60)
SpO2 while laying awake* 93 (90 – 94) 82 – 96
Average SpO2 during sleep* 90 (87 – 92) 62 – 95
REM SpO2* 89 (86 – 92) 56 – 95
NREM SpO2* 90 (87 – 92) 67 – 95
AHI ≥ 5 and Epworth ≥ 10, n (%) 19 (54)

REM: rapid eye-movement sleep, NREM: non-rapid eye-movement sleep, AHI: apneahypopnea index, SpO2: percentage of saturation by pulse oxymetry.
* Mean (interquartile interval) min. – max.