( @ ) Epworth sleepiness scale ( ESS ) score , apnea-hypopnea index ( AHI ) and arousal index were significantly lower ( @ @ vs. @ @ , @ @ vs. @ @ and @ @ vs. @ @ , P < @ ) while not rapid eye movement ( NREM ) III and rapid eye movement stage of sleep time and lowest pulse oxygen saturation ( LSaO@ ) were significantly higher in NPPV group than in control group -LSB- ( @ @ ) % vs. ( @ @ ) % , ( @ @ ) % vs. ( @ @ ) % , ( @ @ ) % vs. ( @ @ ) % , P < @ -RSB- after @ months therapy .