Table 4.

The associations of birth profiles, respiratory complications, sleep variables, and sleep arrangements and DQ scores evaluated by univariate regression analysis (**p < 0.01, *p < 0.05).

DQ-related factors	r	R2	p-value
Birth profiles
Gender	− 0.197	0.039	0.048*
Birth weight	0.169	0.028	0.092
Gestational age	0.160	0.025	0.111
Maternal age at birth	0.073	0.005	0.471
Birth order	0.044	0.002	0.664
Respiratory complications
Prolonged ventilation (> 7 days )	− 0.198	0.039	0.048*
Non-significant CLD	− 0.195	0.038	0.050
RDS	− 0.073	0.005	0.468
Sleep variables
Daily variation in wake time	− 0.346	0.120	0.000**
Daily variation in sleep onset time	− 0.279	0.078	0.005**
Total sleep duration	0.205	0.042	0.040*
Sleep onset time	− 0.189	0.036	0.058
Bed time	− 0.143	0.021	0.152
Nighttime sleep duration	0.125	0.016	0.213
Nap duration	0.088	0.008	0.380
Wake time	− 0.076	0.006	0.449
Total bed duration	0.067	0.005	0.502
Sleep efficiency	0.061	0.004	0.543
Sleep latency	− 0.040	0.000	0.693
Night wakings	0.031	0.001	0.762
WASO	− 0.015	0.000	0.881
Nap end time	− 0.011	0.000	0.912
Nap onset time	0.008	0.000	0.934
Sleep arrangements
Co-sleeping with parents	0.229	0.052	0.021*
Nighttime formula feeding	− 0.812	0.033	0.069
Child attending kindergarten	0.145	0.021	0.148
Putting children to sleep with formula	− 0.109	0.012	0.277
Nighttime breast feeding	0.074	0.015	0.460
No feeding during nighttime	0.061	0.004	0.545
Child having own room	− 0.060	0.004	0.553

RDS respiratory distress syndrome, Non-significant CLD non-significant chronic lung disease.