Table 3. Associations (indicated by regression coefficients) of weekday habitual after-school activity factors and sleep duration by school level and sex.
| School level | Elementary school (Grade 4 and 5) | Secondary school (Grade 6,7 and 8) | ||
|---|---|---|---|---|
| Beta | P | Beta | P | |
| Boys | ||||
| Commuting time (hour) | -0.097 | 0.004 | -0.088 | 0.003 |
| After-school LTPA (hour) | 0.029 | 0.40 | 0.026 | 0.38 |
| Homework time (hour) | -0.124 | <0.001 | -0.184 | <0.001 |
| Screen time (0= < 2 hours/ day, 1 = ≥ 2 hours/ day) | -0.016 | 0.65 | -0.075 | 0.013 |
| Playing mobile phone (hour) | -0.081 | 0.024 | -0.119 | <0.001 |
| Girls | ||||
| Commuting time (hour) | -0.081 | 0.017 | -0.079 | 0.003 |
| After-school LTPA (hour) | -0.025 | 0.47 | 0.059 | 0.030 |
| Homework time (hour) | -0.095 | 0.005 | -0.294 | <0.001 |
| Screen time (0= < 2 hours/ day, 1 = ≥ 2 hours/ day) | -0.034 | 0.34 | 0.018 | 0.53 |
| Playing mobile phone (hour) | -0.100 | 0.004 | -0.092 | 0.001 |
All models were adjusted for age, BMI categories, parents’ education, whether or not lived with a sibling and academic pressure.