Table 1 Characteristics of the sample among Chinese college students [n (%)/M ± SD]
Variables | Overall | Depression symptoms (wave 1) | Increased depressive symptoms | ||||
|---|---|---|---|---|---|---|---|
Yes | No | t/χ2 | Yes | No | t/χ2 | ||
Age | 19.25 ± 1.42 | 19.41 ± 1.56 | 19.22 ± 1.39 | 2.37* | 19.28 ± 1.55 | 19.25 ± 1.41 | 0.29 |
BMI | 20.24 ± 2.40 | 20.11 ± 2.31 | 20.27 ± 2.42 | 1.16 | 20.09 ± 2.45 | 20.25 ± 2.39 | 0.96 |
Sex | Â | Â | Â | 5.02* | Â | Â | 5.01* |
 Male | 917 (43%) | 140 (15.3%) | 777 (84.7) |  | 75 (8.2%) | 842 (91.8) |  |
 Female | 1217 (57%) | 231 (19.0%) | 986 (81.0) |  | 135 (11.1%) | 1082 (88.9) |  |
Residential area | Â | Â | Â | 2.05 | Â | Â | 3.23 |
 Rural | 1217 (57%) | 224 (18.4%) | 993 (81.6) |  | 132 (10.8%) | 1085 (89.2) |  |
 Urban | 917 (43%) | 147 (16.0%) | 770 (84.0) |  | 78 (8.5%) | 839 (91.5) |  |
Perceived family income | Â | Â | Â | 2.11 | Â | Â | 0.49 |
 Low | 680 (31.9%) | 130 (19.1%) | 550 (80.9) |  | 71 (10.4%) | 609 (89.6) |  |
 Medium | 1348 (63.2%) | 224 (16.6%) | 1124 (83.4) |  | 128 (9.5%) | 1220 (90.5) |  |
 High | 106 (5.0%) | 17 (16.0%) | 89 (84.0) |  | 11 (10.4%) | 95 (89.6) |  |
Cigarette use | Â | Â | Â | 0.88 | Â | Â | 1.58 |
 NO | 1639 (76.8%) | 278 (17.0%) | 1361 (83.0) |  | 154 (9.4%) | 1485 (90.6) |  |
 Yes | 495 (23.2%) | 93 (18.8%) | 402 (81.2) |  | 56 (11.3%) | 439 (88.7) |  |
Alcohol use | Â | Â | Â | 4.74* | Â | Â | 6.71* |
 No | 938 (44%) | 182 (19.4%) | 756 (80.6) |  | 110 (11.7%) | 828 (88.3) |  |
 Yes | 1196 (56%) | 189 (15.8%) | 1007 (84.2) |  | 100 (8.4%) | 1096 (91.6) |  |
PMPU | |||||||
 No | 1525 (71.5%) | 144 (9.4%) | 1381 (90.6) | 234.71*** | 117 (7.7%) | 1408 (92.3) | 28.32*** |
 Yes | 609 (28.5%) | 227 (37.3%) | 382 (62.7) |  | 93 (15.3%) | 516 (84.7) |  |
PA | |||||||
 Sufficient | 754 (35.3%) | 109 (14.5%) | 645 (85.5) | 6.96** | 66 (8.8%) | 688 (91.2) | 1.55 |
 Insufficient | 1380 (64.7%) | 262 (19.0) | 1118 (81.0) |  | 144 (10.4%) | 1236 (89.6) |  |
Joint effects of PMPU and IPA | |||||||
 0 | 567 (26.6%) | 43 (7.6%) | 524 (92.4) | 170.88*** | 39 (6.9%) | 528 (93.1) | 22.18*** |
 1 | 1145 (53.7%) | 167 (14.6%) | 978 (85.4) |  | 105 (9.2%) | 1040 (90.8) |  |
 2 | 422 (19.8%) | 161 (38.2%) | 261 (61.8) |  | 66 (15.6%) | 356 (84.4) |  |