. 2014 Dec 16;14:303. doi: 10.1186/s12887-014-0303-6

Table 2.

Subjective and objective sleep problems of premature infants

Questionnaire	Objective sleep measure	r	P value
CBISQ	Criterion of sleep diary	0.757	0.011*
Nocturnal sleep duration	Nocturnal sleep duration	0.757	0.011*
Number of night awakenings	Nocturnal awake time	0.632	0.002*
	Numbers of night awakening	0.580	0.001*
	Nocturnal sleep efficiency	−0.644	<0.001*
Daytime sleep duration	Daytime sleep duration	0.630	0.002*
Loud-noisy breathing	Daytime sleep duration	0.348	0.064⁺
CBISQ	Actigraphy criterion
Time spent with mouth breathing	Awakening time during sleep	0.514	0.042*
Time spent with mouth breathing	Nocturnal sleep efficiency	−0.255	0.013*
CBISQ	PSG criteria
Nocturnal sleep duration	Nocturnal sleep duration	0.545	0.002*
Number of night awakenings	Desaturation index	0.636	0.003*
Daytime sleep duration	AHI in sleep	0.767	0.075⁺
Daytime sleep duration	Awakening after sleep onset	0.350	0.080⁺
Time spent with mouth breathing	Obstructive apnea count	0.509	0.026*
Loud-noisy breathing	Arousal count	0.401	0.089⁺
Loud-noisy breathing	Obstructive apnea count	0.535	0.018*

*P value < 0.05. ⁺P value < 0.10.

AHI: Apnea-Hypopnea Index (events/hour); Desaturation index: desaturation events/hour; “Arousal count” means total number of arousal during sleep; “Obstructive apnea count” means total number of obstructive apnea during sleep.