Table 2—

Polysomnographic outcomes

	Nonconversion group^#			Conversion group^¶			p-value^§
	Baseline	Follow-up	p-value⁺	Baseline	Follow-up	p-value⁺	p-value^§
TST min	309.4±10.4	303.4±9.2	0.85	298.8±19.4	328.3±16.4	0.13	0.13
Mean S_a,O₂ %	93.1±0.4	91.9±1.2	0.34	92.6±0.9	93.7±0.6	0.17	0.39
Minimum S_a,O₂ %	82.6±0.7	81.5±1.0	0.21	80.0±1.8	78.2±4.8	0.58	0.71
Stage 1 sleep %	19.5±1.7	20.5±1.7	0.35	20.0±3.7	15.4±3.1	0.16	0.11
Stage 2 sleep %	57.5±1.5	54.4±1.8	0.08	60.0±3.0	64.7±1.9	0.12	0.05
SWS %	10.4±1.3	11.0±1.2	0.61	7.2±1.8	6.8±1.7	0.78	0.68
REM sleep %	13.0±0.8	13.7±0.9	0.50	12.7±1.8	13.2±1.7	0.74	0.96
Movement arousal index	23.7±2.2	27.8±2.1	0.09	30.7±4.8	27.8±4.1	0.54	0.20
Central apnoea index	15.7±1.8	15.1±1.9	0.72	10.9±3.6	3.6±1.3	0.06	0.12
Obstructive apnoea index	1.6±0.32	1.2±0.28	0.38	2.7±1.1	4.5±1.7	0.06	0.04
Central hypopnoea index	18.5±1.5	17.6±1.2	0.45	21.8±3.2	4.3±1.5	<0.001	<0.001
Obstructive hypopnoea index	2.7±0.4	2.5±0.4	0.84	3.7±1.3	16.5±3.3	<0.001	<0.001

Data are presented as mean±sem, unless otherwise indicated. TST: total sleep time; S_a,O₂: arterial oxygen saturation; SWS: slow wave sleep; REM: rapid eye movement. ^#: n = 80; ^¶: n = 18; ⁺: p-values for within group comparisons; ^§: p-value for between group comparisons.