| N | Univariate OR for myopia (95%CI) | P value | Multivariate OR for myopia (95%CI) | P value | |
| Age (y) | |||||
| 6 to 9 | 3107 | 1 (referent) | 1 (referent) | ||
| 10 to 13 | 4120 | 3.60 (3.21, 4.02) | <0.001 | 4.05 (3.59, 4.58) | <0.001 |
| 14 to 16 | 4547 | 7.84 (7.01, 8.77) | (trend) | 7.87 (6.89, 8.98) | (trend) |
| 17 or more | 3542 | 10.87 (9.65, 12.24) | 11.27 (9.74,13.05) | ||
| Gender | |||||
| Male | 7434 | 1 (referent) | |||
| Female | 7882 | 1.33 (1.25, 1.42) | <0.001 | 1.27 (1.18, 1.36) | |
| Number of parent with myopia | |||||
| 0 | 9893 | 1 (referent) | |||
| 1 | 3883 | 1.53 (1.42, 1.65) | <0.001 | 1.91 (1.75, 2.10) | <0.001 |
| 2 | 1540 | 1.88 (1.69, 2.10) | (trend) | 2.83 (2.47, 3.24) | (trend) |
| Father’s completed level of education | |||||
| Primary education | 425 | 1 (referent) | |||
| Secondary education | 3969 | 1.16 (0.94, 1.43) | 0.17 | 1.27 (1.00, 1.60) | 0.044 |
| Polytechnic education | 4004 | 1.43 (1.16, 1.76) | <0.001 | 1.54 (1.22, 1.94) | <0.001 |
| Tertiary education | 6644 | 1.71 (1.40, 2.10) | (trend) | 1.70 (1.34, 2.14) | (trend) |
| Reading or writing distance | |||||
| Greater than 33cm | 1374 | 1 (referent) | |||
| About 33cm | 7280 | 1.67 (1.48, 1.89) | <0.001 | 1.39 (1.21, 1.60) | <0.001 |
| Less than 33cm | 6556 | 2.51 (2.21, 2.84) | (trend) | 1.95 (1.69, 2.24) | (trend) |
| Hours of sports per day | |||||
| 30 min or less | 4448 | 1 (referent) | 1 (referent) | ||
| 30 min to 1 hour | 6990 | 1.15 (1.06, 1.24) | 1.05 (0.96, 1.15) | 0.181 | |
| 1 hour or more | 3708 | 1.17 (1.07, 1.27) | 0.97 (0.88, 1.08) | 0.753 | |
| Hours of watching TV per day | |||||
| 1 hour or less | 6400 | 1 (referent) | |||
| 1 to 2 hours | 5680 | 0.96 (0.87, 1.05) | 0.38 | 1.04 (0.94, 1.15) | 0.39 |
| 2 hours or more | 2974 | 1.15 (1.06, 1.26) | 0.001 | 1.11 (1.00, 1.23) | 0.04 |
| Hours of studying per day | |||||
| 6 hours or less | 3365 | 1 (referent) | 1 (referent) | ||
| 6 to 8 hours | 6457 | 1.30 (1.20, 1.42) | <0.001 | 1.14 (1.04, 1.26) | 0.015 |
| 8 to10 hours | 3265 | 2.37 (2.15, 2.62) | (trend) | 1.39 (1.24, 1.56) | <0.001 |
| 10 hours or more | 2085 | 3.06 (2.72, 3.44) | 1.43 (1.25, 1.64) | (trend) | |
| Hours of sleep per day | |||||
| 9 hours or more | 5675 | 1 (referent) | |||
| About 8 hours | 4859 | 2.39 (2.21, 2.59) | <0.001 | 2.12 (1.94, 2.31) | <0.001 |
| 7 hours or less | 4567 | 4.07 (3.74, 4.43) | (trend) | 3.37 (3.07, 3.70) | <0.001 |