|
Sex (girl/boy)
|
17.4/18.6
|
0.92 (0.72–1.19)
|
0.53
|
1.00 (0.77–1.31)
|
0.98
|
|
Senior grade (4–6)/junior (1–3)
|
18.4 / 17.6
|
1.06 (0.82–1.36)
|
0.65
|
1.11 (0.84–1.45)
|
0.47
|
|
Wakeup time on week day
|
|
< 6:30 a.m.
|
14.7
|
1
| |
1
| |
|
6:30 to < 7:00
|
20.4
|
1.49 (1.15–1.93)
|
< 0.01
|
1.36 (1.03–1.78)
|
0.03
|
|
≥ 7:00
|
32.3
|
2.77 (1.59–4.81)
|
< 0.001
|
2.48 (1.36–4.50)
|
< 0.01
|
|
Skipping breakfast (yes/no)
|
26.4/17.4
|
1.70 (1.09–2.65)
|
0.02
|
1.10 (0.68–1.78)
|
0.71
|
|
Screen time on week day (≥ 2 h/< 2 h)
|
22.3/15.3
|
1.59 (1.24–2.05)
|
< 0.001
|
1.35 (1.04–1.76)
|
0.03
|
|
Physical activity
| | | | | |
|
Very often
|
15.6
|
1
| |
1
| |
|
Often
|
18.4
|
1.22 (0.89–1.66)
|
0.22
|
1.30 (0.94–1.79)
|
0.11
|
|
Rarely
|
19.8
|
1.34 (0.95–1.88)
|
0.09
|
1.33 (0.93–1.90)
|
0.11
|
|
Bedtime on week day (late/not late) late: ≥ 10 for junior, and ≥ 10:30 for senior grades children
|
20.8/17.5
|
1.23 (0.87–1.76)
|
0.24
|
0.87 (0.59–1.28)
|
0.49
|
|
Daytime sleepiness (yes/no)
|
21.0/17.4
|
1.27 (0.92–1.74)
|
0.15
|
1.10 (0.78–1.54)
|
0.58
|
|
Obesity (yes/no)
|
20.3/17.8
|
1.18 (0.76–1.83)
|
0.47
|
1.07 (0.67–1.70)
|
0.78
|
|
Cram school (no/yes)
|
19.1/14.7
|
1.37 (1.01–1.86)
|
0.04
|
1.01 (0.73–1.40)
|
0.96
|
|
Study duration at home (<1 h/≥ 1 h)
|
21.5/12.5
|
1.89 (1.43–2.50)
|
< 0.001
|
1.82 (1.34–2.49)
|
< 0.001
|
|
Paternal smoke (yes/no)
|
22.2/14.7
|
1.66 (1.29–2.14)
|
< 0.001
|
1.47 (1.12–1.92)
|
< 0.01
|
|
Maternal smoke (yes/no)
|
31.3/16.3
|
2.34 (1.66–3.29)
|
< 0.001
|
1.87 (1.29–2.72)
|
< 0.001
|
|
Subjective SES
|
|
High
|
13.9
|
1
| |
1
| |
|
Middle
|
18.8
|
1.43 (1.04–1.97)
|
0.03
|
1.37 (0.99–1.90)
|
0.06
|
|
Low
|
20.8
|
1.62 (1.14–2.32)
|
< 0.01
|
1.48 (1.03–2.14)
|
0.04
|
