Table 1. Demographic characteristics (N = 4,940).
| E4 (n = 2,399) | M1 (n = 2,541) | |||||||
|---|---|---|---|---|---|---|---|---|
| Boy (n = 1,193) | Girl (n = 1,206) | p | Boy (n = 1,375) | Girl (n = 1,166) | p | |||
| Residential area | Metropolis | 501(42.0) | 499(41.4) | 0.953 | 637(46.3) | 507(43.5) | 0.290 | |
| Small and medium city | 494(41.4) | 504(41.8) | 552(40.1) | 483(41.4) | ||||
| Town and village | 198(16.6) | 203(16.8) | 186(13.5) | 176(15.1) | ||||
| Living time | Sleep time (minute) | 552±49 | 548±48 | 0.470 | 489±54 | 464±59 | 0.001 | |
| Study time (average*) | 3.01 | 3.16 | 0.016 | 2.95 | 2.95 | 0.829 | ||
| Leisure time (average*) | 2.95 | 2.81 | 0.003 | 3.15 | 2.92 | 0.001 | ||
| Health | Exercise time | None | 58(4.9) | 151(12.5) | 0.001 | 116(8.4) | 354(30.4) | 0.001 |
| 1 hour | 180(15.1) | 358(29.7) | 273(19.9) | 324(27.8) | ||||
| 2 hours | 176(14.8) | 215(17.8) | 257(18.7) | 211(18.1) | ||||
| 3 hours | 172(14.4) | 186(15.4) | 249(18.1) | 146(12.5) | ||||
| 4 hours over | 607(50.9) | 296(24.5) | 480(34.9) | 131(11.2) | ||||
| Number of breakfasts | 5.8 | 5.9 | 0.896 | 5.1 | 4.7 | 0.008 | ||
| Quality of sleep | Can’t sleep very well | 17(1.4) | 9(0.7) | 0.281 | 11(0.8) | 17(1.5) | 0.061 | |
| Can’t sleep | 110(9.2) | 101(8.4) | 154(11.2) | 159(13.6) | ||||
| Tend to sleep well | 627(52.6) | 663(55.0) | 784(57.0) | 663(56.9) | ||||
| Sleep very well | 439(36.8) | 433(35.9) | 426(31.0) | 327(28.0) | ||||
| BMI | Under weight | 59(4.9) | 77(6.4) | 0.001 | 63(4.6) | 51(4.4) | 0.001 | |
| Normal | 851(71.3) | 919(76.2) | 1,029(74.8) | 954(81.8) | ||||
| Over weight | 77(6.5) | 121(10.0) | 86(6.3) | 95(8.1) | ||||
| Obesity | 206(17.3) | 89(7.4) | 197(14.3) | 66(5.7) | ||||
| Subjective health conditions | Not healthy | 9(0.8) | 2(0.2) | 0.088 | 10(0.7) | 3(0.3) | 0.001 | |
| Not very healthy | 57(4.8) | 53(4.4) | 100(7.3) | 93(8.0) | ||||
| Healthy side | 560(46.9) | 604(50.1) | 705(51.3) | 683(58.6) | ||||
| Very healthy | 567(47.5) | 547(45.4) | 560(40.7) | 387(33.2) | ||||
*1 = not at all, 2 = less than 30 minutes, 3 = 30 minutes to less than an hour, 4 = less than 1 to 2 hours