Table 2.

Sleep quality and respiratory parameters.

Categories	Terms	CID (n = 76)	HC (n = 32)	Statistics	P
Subjective sleep	PSQI (score)	16 [15,17]	4 [3,6]	Z = −8.214	<0.001
Objective sleep	TST (min)	375.0 ± 85.0	448.0 ± 48.0	t = 4.56	<0.001
	SOL (min)	25.7 [14.0, 49.9]	8.5[5.0, 17.5]	Z = −4.32	<0.001
	SE (%)	72.3 ± 14.6	86.8 ± 11.5	t = 4.78	<0.001
	N1	114.5[67.0, 175.4]	47.5 [33.9, 61.0]	Z = −6.12	<0.001
	N1%	29.5 [21.0, 46.9]	10.1 [7.7, 14.0]	Z = −7.10	<0.001
	N3	34.2 ± 26.8	83.0 ± 43.1	t = 7.07	<0.001
	N3%	9.6 ± 7.4	18.4 ± 8.7	t = 5.27	<0.001
	REM	39.0 ± 26.3	83.5 ± 23.6	t = 8.31	<0.001
	REM%	9.0 [5.3, 15.5]	18.6 [16.1, 22.7]	Z = −5.47	<0.001
Respiratory parameters	AHI	0.6 [0.1, 1.7]	0.1 [0.0, 1.7]	Z = −1.88	0.060
	ODI	0.7 [0.1, 1.8]	0.1 [0.3, 1.1]	Z = −1.29	0.196
	T90	0.0 [0.0, 2.2]	0.0 [0.0, 2.0]	Z = −0.50	0.615

Normal distribution variables (Mean ± SD); non-normal distribution variables (P50 [P25, P75]).

AHI, apnea hypopnea index; CID, chronic insomnia disorder; HC, healthy control; N1, sleep stage 1; N1%, percentage of the sleep stage 1; N1, sleep stage 1; N3%, percentage of the sleep stage 3; ODI, oxygen desaturation index; PSQI, Pittsburgh Sleep Quality Index; REM, rapid eye movement sleep time; REM%, percentage of the rapid eye movement sleep time; SE, sleep efficiency; SOL, sleep onset latency; TST, total sleep time; TS90, SpO2 time <90%.