Table 1 Characteristics of adolescents included in analyses
Variablea | All (n = 12,570) | Depressive symptoms | Anxiety symptoms | ||||
|---|---|---|---|---|---|---|---|
Yes (n = 5017) | No (n = 7553) | P-value b | Yes (n = 4674) | No (n = 7904) | P-valueb | ||
Age, mean (SD), years | 13.0 (1.9) | 13.4 (1.8) | 12.7 (1.9) | < 0.001 | 13.4 (1.8) | 12.8 (1.9) | < 0.001 |
Sex | |||||||
 Boys | 6560 (52.2) | 2200 (43.9) | 4360 (57.7) | < 0.001 | 2027 (43.4) | 4533 (57.4) | < 0.001 |
 Girls | 6010 (47.8) | 2817 (56.1) | 3193 (42.3) |  | 2646 (56.6) | 3364 (42.6) |  |
Ethnicity | |||||||
 Han | 11,888 (94.6) | 4760 (94.9) | 7128 (94.4) | 0.460 | 4425 (94.7) | 7463 (94.5) | 0.899 |
 Others | 455 (3.6) | 170 (3.4) | 285 (3.8) |  | 166 (3.6) | 289 (3.7) |  |
 Missing data | 227 (1.8) | 87 (1.7) | 140 (1.9) |  | 82 (1.8) | 145 (1.8) |  |
Academic pressure | |||||||
 Below average | 3129 (24.9) | 745 (14.8) | 2384 (31.6) | < 0.001 | 645 (13.8) | 2484 (31.5) | < 0.001 |
 Average | 7371 (58.6) | 2976 (59.3) | 4395 (58.2) |  | 2785 (59.6) | 4586 (58.1) |  |
 Above average | 1985 (15.7) | 1267 (25.2) | 718 (9.5) |  | 1215 (26.0) | 770 (9.8) |  |
 Missing data | 85 (0.7) | 29 (0.6) | 56 (0.7) |  | 28 (0.6) | 57 (0.7) |  |
Smoking status | |||||||
 No | 12,234 (97.3) | 4846 (96.6) | 7388 (97.8) | < 0.001 | 4519 (96.7) | 7715 (97.7) | 0.002 |
 Yes | 297 (2.4) | 155 (3.1) | 142 (1.9) |  | 140 (3.0) | 157 (2.0) |  |
 Missing data | 39 (0.3) | 16 (0.3) | 23 (0.3) |  | 14 (0.3) | 25 (0.3) |  |
Drinking status | |||||||
 No | 8381 (66.7) | 2921 (58.2) | 5460 (72.3) | < 0.001 | 2760 (59.1) | 5621 (71.2) | < 0.001 |
 Yes | 4110 (32.7) | 2067 (41.2) | 2043 (27.0) |  | 1884 (40.3) | 2226 (28.2) |  |
 Missing data | 79 (0.6) | 29 (0.6) | 50 (0.7) |  | 29 (0.6) | 50 (0.6) |  |
Screen time guideline | |||||||
 Persistent non-adherence | 4907 (39.0) | 2296 (45.8) | 2611 (34.6) | < 0.001 | 2880 (61.6) | 4315 (54.6) | < 0.001 |
 Adherence to non-adherence | 403 (3.2) | 159 (3.2) | 244 (3.2) |  | 666 (14.3) | 1272 (16.1) |  |
 Non-adherence to adherence | 6005 (47.8) | 2190 (43.7) | 3815 (50.5) |  | 574 (12.3) | 1111 (14.1) |  |
 Persistent adherence | 1255 (10.0) | 372 (7.4) | 883 (11.7) |  | 553 (11.8) | 1199 (15.2) |  |
Sleep duration guideline | |||||||
 Persistent non-adherence | 9357 (74.4) | 4083 (81.4) | 5274 (69.8) | < 0.001 | 3790 (81.1) | 5567 (70.5) | < 0.001 |
 Adherence to non-adherence | 1279 (10.2) | 431 (8.6) | 848 (11.2) |  | 409 (8.8) | 870 (11.0) |  |
 Non-adherence to adherence | 1002 (8.0) | 307 (6.1) | 695 (9.2) |  | 285 (6.1) | 717 (9.1) |  |
 Persistent adherence | 932 (7.4) | 196 (3.9) | 736 (9.7) |  | 189 (4.0) | 743 (9.4) |  |
Physical activity guideline | |||||||
 Persistent non-adherence | 7195 (57.2) | 3140 (62.6) | 4055 (53.7) | < 0.001 | 2880 (61.6) | 4315 (54.6) | < 0.001 |
 Adherence to non-adherence | 1938 (15.4) | 715 (14.3) | 1223 (16.2) |  | 666 (14.3) | 1272 (16.1) |  |
 Non-adherence to adherence | 1685 (13.4) | 586 (11.7) | 1099 (14.6) |  | 574 (12.3) | 1111 (14.1) |  |
 Persistent adherence | 1752 (13.9) | 576 (11.5) | 1176 (15.6) |  | 553 (11.8) | 1199 (15.2) |  |
Changes in the numbers of adherence to the 24-HMG (continuous), mean (SD)c | 0.40 (0.88) | 0.35 (0.84) | 0.44 (0.91) | < 0.001 | 0.36 (0.85) | 0.43 (0.90) | < 0.001 |
Changes in the numbers of adherence to the 24-HMG (categorical) | |||||||
 Unchanged (scores = 0) | 4972 (39.6) | 2140 (42.7) | 2832 (37.5) | < 0.001 | 1943 (41.6) | 3029 (38.4) | < 0.001 |
 Increasing (scores > 0) | 5881 (46.8) | 2199 (43.8) | 3682 (48.7) |  | 2082 (44.6) | 3799 (48.1) |  |
 Decreasing (scores < 0) | 1717 (13.7) | 678 (13.5) | 1039 (13.8) |  | 648 (13.9) | 1069 (13.5) |  |
PHQ-9 scores at follow-up, mean (SD)d | 4.63 (5.13) | 9.59 (4.67) | 1.33 (1.47) | < 0.001 | 8.96 (5.41) | 2.06 (2.63) | < 0.001 |
GAD-7 scores at follow-up, mean (SD)e | 4.08 (4.69) | 7.81 (4.94) | 1.61 (2.27) | < 0.001 | 8.98 (4.20) | 1.18 (1.42) | < 0.001 |