Table 1. Characteristics of the study subjects (n = 1004).
| Variables | Boys (n = 468) |
Girls (n = 536) |
|
| n (%) | n (%) | ||
| Age (mean ± SD) | 15.84 ± 1.91 | 15.87 ± 1.77 | |
| Daily hours of homework, Monday to Friday (mean ± SD) |
2.56 ± 1.14 | 2.72 ± 1.11 | |
| Daily hours of homework, weekend (mean ± SD) |
3.31 ± 1.55 | 3.54 ± 1.53 | |
| Daily hours of TV watching, Monday to Friday (mean ± SD) |
1.18 ± 1.13 | 1.06 ± 1.04 | |
| Daily hours of TV watching, weekend (mean ± SD) |
2.61 ± 1.69 | 2.67 ± 1.64 | |
| Grade level | 7 | 73 (15.60) | 53 (9.89) |
| 8 | 85 (18.16) | 95 (17.72) | |
| 9 | 76 (16.24) | 98 (18.28) | |
| 10 | 75 (16.03) | 103 (19.22) | |
| 11 | 65 (13.89) | 75 (13.99) | |
| 12 | 94 (20.08) | 112 (20.90) | |
| Smoking | No | 407 (86.97) | 530 (98.88) |
| Yes | 61 (13.03) | 6 (1.12) | |
| Alcohol drinking | No | 333 (71.15) | 480 (89.55) |
| Yes | 135 (28.85) | 56 (10.45) | |
| Physical inactivity | Active | 165 (35.26) | 125 (23.32) |
| Inactive | 303 (64.74) | 411 (76.68) | |
| Family wealth | High | 208 (44.45) | 207 (38.62) |
| Average | 219 (46.79) | 299 (55.78) | |
| Low | 41 (8.76) | 30 (5.60) | |
| Self-rated health | Good | 318 (67.95) | 312 (58.21) |
| Fair | 123 (26.28) | 198 (36.94) | |
| Poor | 27 (5.77) | 26 (4.85) | |