School day sleep duration | Variables | Regression coefficient | β | P | |||
95% CI | |||||||
More than 7 hours | Constant | −0.06 | −0.42 | to | 0.30 | −0.06 | 0.746 |
Grade | 0.02 | −0.02 | to | 0.05 | 0.02 | 0.396 | |
Gender (male: 1; female: 2) | 0.33 | 0.22 | to | 0.45 | 0.15 | <0.001 | |
Standardized BMI | −0.06 | −0.11 | to | −0.01 | −0.05 | 0.030 | |
Self-reported academic performance | 0.00 | −0.07 | to | 0.07 | 0.00 | 0.952 | |
Sleepiness during class | 0.06 | −0.02 | to | 0.14 | 0.04 | 0.171 | |
Breakfast taking | 0.09 | −0.03 | to | 0.22 | 0.04 | 0.143 | |
Defecation frequency | 0.00 | −0.06 | to | 0.06 | 0.00 | 0.971 | |
After-school activity (hrs./week) | −0.02 | −0.03 | to | −0.01 | −0.09 | <0.001 | |
Physical activity (days/week) | −0.03 | −0.05 | to | −0.01 | −0.09 | 0.001 | |
Average screen time a day (hrs) | 0.11 | 0.04 | to | 0.19 | 0.08 | 0.004 | |
7 hours or less | Constant | 1.58 | 0.97 | to | 2.19 | 1.58 | <0.001 |
Grade | 0.00 | −0.04 | to | 0.05 | 0.00 | 0.883 | |
Gender (male: 1; female: 2) | 0.15 | −0.01 | to | 0.32 | 0.05 | 0.064 | |
Standardized BMI | −0.03 | −0.10 | to | 0.05 | −0.02 | 0.492 | |
Self-reported academic performance | 0.05 | −0.05 | to | 0.14 | 0.03 | 0.348 | |
Sleepiness during class | 0.04 | −0.06 | to | 0.14 | 0.02 | 0.409 | |
Breakfast taking | −0.03 | −0.15 | to | 0.09 | −0.01 | 0.641 | |
Defecation frequency | −0.05 | −0.13 | to | 0.04 | −0.03 | 0.308 | |
After-school activity (hrs./week) | −0.01 | −0.02 | to | 0.00 | −0.07 | 0.012 | |
Physical activity (days/week) | −0.12 | −0.14 | to | −0.09 | −0.26 | <0.001 | |
Average screen time a day (hrs) | 0.06 | −0.03 | to | 0.14 | 0.04 | 0.192 |