Table 2 Linear mixed effect model of factor associated with academic performance (stratified by outdoor time)
Variables | Total population | Outdoor time ≤ 2.3 h/day | Outdoor time > 2.3 h/day | |||
|---|---|---|---|---|---|---|
β (95%CI) | P | β (95%CI) | P | β (95%CI) | P | |
Outdoor time, hrs/day | 6.494(4.148 ~ 8.840) | < 0.001 | 10.126(6.308 ~ 13.945) | < 0.001 | 1.022(-5.702 ~ 7.745) | 0.766 |
Sleeping time, hrs/day | 5.865(3.873 ~ 7.856) | < 0.001 | 5.690(3.430 ~ 7.949) | < 0.001 | 6.460(2.266 ~ 10.653) | 0.003 |
Learning time out of school, hrs/day | -1.800(-2.700 ~ -0.900) | < 0.001 | -1.375(-2.418 ~ -0.333) | 0.010 | -2.803(-4.603 ~ -1.003) | 0.002 |
Gender, girls/boys | 3.445(1.543 ~ 5.348) | < 0.001 | 3.289(1.078 ~ 5.500) | 0.004 | 4.527(0.770 ~ 8.283) | 0.018 |
Age | 2.540(0.945 ~ 4.135) | 0.002 | 2.509(0.649 ~ 4.369) | 0.008 | 3.125(-0.022 ~ 6.273) | 0.052 |
Father education | ||||||
Junior high school and below | — | — | — | |||
High school or vocational school | 3.645(0.722 ~ 6.567) | 0.015 | 3.407(-0.167 ~ 6.980) | 0.062 | 4.036(-1.094 ~ 9.165) | 0.123 |
Undergraduate or junior college | 7.847(4.329 ~ 11.365) | < 0.001 | 8.343(4.180 ~ 12.506) | < 0.001 | 5.240(-1.468 ~ 11.949) | 0.126 |
Master degree or above | 9.122(2.003 ~ 16.241) | 0.012 | 8.582(0.623 ~ 16.542) | 0.035 | 6.938(-9.973 ~ 23.849) | 0.421 |
Mother education | ||||||
Junior high school and below | — | — | — | |||
High school or vocational school | 1.376(-1.510 ~ 4.261) | 0.350 | 1.742(-1.729 ~ 5.213) | 0.325 | 0.874(-4.383 ~ 6.131) | 0.744 |
Undergraduate or junior college | 5.932(2.525 ~ 9.338) | 0.001 | 6.644(2.650 ~ 10.637) | 0.001 | -2.538(-24.239 ~ 19.164) | 0.819 |
Master degree or above | 9.776(0.614 ~ 18.937) | 0.037 | 12.407(2.227 ~ 22.586) | 0.017 | 2.987(-3.551 ~ 9.524) | 0.37 |
Family income (RMB/month) | ||||||
< = 6000 | — | — | — | |||
6000–10,000 | 1.596(-0.909 ~ 4.100) | 0.212 | 2.729(-0.264 ~ 5.723) | 0.074 | -0.633(-5.256 ~ 3.990) | 0.788 |
10,000–20,000 | 4.359(1.544 ~ 7.175) | 0.002* | 4.935(1.626 ~ 8.244) | 0.004* | 4.037(-1.425 ~ 9.500) | 0.147 |
> 20,000 | 3.987(0.385 ~ 7.590) | 0.030* | 4.830(0.760 ~ 8.900) | 0.020* | 2.051(-5.921 ~ 10.024) | 0.614 |