Table 3. Sleep-wake pattern and media use by educational status among children in kindergarten, elementary school, and junior high school.
| Kindergarten | Elementary school | Junior high school | P-valueb | |
| n (%) | n (%) | n (%) | ||
| Feeling upon awakening | ||||
| good | 213 (86.2) | 877 (76.5) | 389 (61.6) | |
| bad | 34 (13.8) | 270 (23.5) | 243 (38.5) | |
| total | 247 | 1147 | 632 | <0.01 |
| Time of awakening | ||||
| <6:30 | 40 (16.2) | 414 (36.3) | 168 (26.6) | |
| ≥6:30 | 207 (83.8) | 726 (63.7) | 464 (73.4) | |
| total | 247 | 1140 | 632 | <0.01 |
| Bedtime | ||||
| <22:00 | 232 (93.9) | 816 (71.1) | 60 (9.5) | |
| ≥22:00 | 15 (6.1) | 331 (28.9) | 572 (90.5) | |
| total | 247 | 1147 | 632 | <0.01 |
| Sleep duration | ||||
| ≥8 h | 244 (98.8) | 432 (76.5) | 177 (28.0) | |
| <8 h | 3 (1.2) | 133 (23.5) | 455 (72.0) | |
| total | 247 | 565 | 632 | <0.01 |
| Television | ||||
| <2 h | 166 (67.2) | 786 (68.6) | 292 (46.2) | |
| ≥2 h | 81 (32.8) | 360 (31.4) | 340 (53.8) | |
| total | 247 | 1146 | 632 | <0.01 |
| Video games | ||||
| <30 min | 221 (89.5) | 731 (64.1) | 411 (65.0) | |
| ≥30 min | 26 (10.5) | 409 (35.9) | 221 (35.0) | |
| total | 247 | 1140 | 632 | <0.01 |
| Personal computera | ||||
| <30 min | — | 1007 (88.0) | 437 (69.2) | |
| ≥30 min | — | 138 (12.1) | 195 (30.9) | |
| total | — | 1145 | 632 | <0.01 |
| Cellular phonea | ||||
| <30 min | — | 1096 (95.6) | 526 (83.2) | |
| ≥30 min | — | 51 (4.5) | 106 (16.8) | |
| total | — | 1147 | 632 | <0.01 |
aThis question was intended for elementary and junior high school students.
bThe chi-square test was performed.