Table 1.
Descriptive statistics (n = 1,508)
| Variable | Mean | SD |
|---|---|---|
| Age (years) | 10.9 | 2.0 |
| BMI (kg/m2) | 18.5 | 3.6 |
| MVPA (hr/wk) | 11.6 | 15.5 |
| Variable | Frequency | Percentage |
| Sex | ||
| Male | 748 | 49.6 |
| Female | 760 | 50.4 |
| Smartphone usage (min/day) | ||
| 0–60 | 277 | 18.4 |
| 61–120 | 171 | 11.3 |
| 121–180 | 134 | 8.9 |
| 181–240 | 160 | 10.6 |
| 241 + | 766 | 50.8 |
| Tablet usage (min/day) | ||
| 0–60 | 932 | 61.8 |
| 61–120 | 180 | 11.9 |
| 121–180 | 110 | 7.3 |
| 181–240 | 69 | 4.6 |
| 241 + | 217 | 14.4 |
| Parents' short sightedness | ||
| Both | 281 | 18.7 |
| Only father | 296 | 19.7 |
| Only mother | 225 | 15.0 |
| Neither | 505 | 33.7 |
| Don't know | 192 | 12.8 |
| Type of accommodation | ||
| Public housing | 964 | 67.5 |
| Home ownership scheme | 182 | 12.7 |
| Private housing | 282 | 19.7 |
| Primary caregiver's level of education | ||
| No formal education | 16 | 1.1 |
| Primary | 170 | 12.1 |
| Secondary | 1,067 | 76.0 |
| Tertiary or above | 151 | 10.8 |
| Monthly household income (Hong Kong dollar) | ||
| 0–9,999 | 207 | 14.9 |
| 10,000–19,999 | 553 | 39.9 |
| 20,000–29,999 | 329 | 23.7 |
| 30,000–39,999 | 154 | 11.1 |
| 40,000–49,999 | 70 | 5.1 |
| 50,000 + | 73 | 5.3 |
BMI: Body Mass Index, MVPA: moderate-to-vigorous physical activity (MVPA)