Table 1.
Baseline characteristics
| Phase I (n=8324) |
Phase II (n=637) |
Phase III (n=79) |
|
| Age (year) | 9.1 (1.74) | 9.19 (1.61) | 8.09 (0.99) |
| Sex (boy) | 4503 (54.1%) | 328 (51.5%) | 47 (59.5%) |
| Paternal educational level | |||
| High school or below | 2031 (24.4%) | 160 (25.1%) | 12 (15.2%) |
| Junior college | 1923 (23.1%) | 147 (23.1%) | 21 (26.6%) |
| College or above | 4378 (52.6%) | 331 (51.9%) | 46 (58.2%) |
| Maternal educational level | |||
| High school or below | 2247 (27.0%) | 164 (25.8%) | 19 (24.1%) |
| Junior college | 2181 (26.2%) | 162 (25.5%) | 22 (27.8%) |
| College or above | 3896 (46.8%) | 310 (48.7%) | 38 (48.1%) |
| Family income | |||
| 5000 or below | 1748 (21.0%) | 148 (23.3%) | 20 (25.0%) |
| 5000–12 000 | 3579 (43.0%) | 274 (43.0%) | 30 (38.2%) |
| 12 000 or above | 1723 (20.7%) | 135 (21.2%) | 18 (22.4%) |
| Not clear | 1274 (15.3%) | 80 (12.5%) | 11 (14.5%) |
| VPA (min/day) | 27.78 (32.48) | 33.50 (39.32) | 26.68 (31.49) |
| MPA (min/day) | 31.75 (36.73) | 38.96 (48.84) | 29.79 (32.04) |
| MVPA (min/day) | 59.44 (57.72) | 72.46 (73.96) | 56.47 (47.46) |
| Walking (min/day) | 56.33 (71.27) | 60.32 (70.15) | 60.14 (55.67) |
| SB (min/day) | 171.63 (86.05) | 176.48 (110.76) | 156.67 (86.56) |
| Homework time (min/day) | 119.07 (60.23) | 116.18 (72.77) | 108.89 (65.53) |
| TV time (min/day) | 31.40 (38.61) | 35.51 (43.57) | 31.87 (36.08) |
| Game time(min/day) | 21.51 (32.30) | 24.79 (38.63) | 15.91 (22.85) |
| Bus time (min/day) | 19.99 (27.50) | 20.25 (28.41) | 22.24 (39.56) |
Data are n (%) or mean (SD).
MVPA, moderate-to-vigorous physical activity; PA, physical activity; SB, sedentary behaviour.