Table 1. Demographic and socioeconomic information of the study sample (N = 3,146).
| Features | Total (N = 3,146) |
With NSSI (N = 1,480) |
Without NSSI (N = 1,666) |
Statistics | P value |
|---|---|---|---|---|---|
| Demographic | |||||
| Sex: N (%) | 34.91 | <0.01a | |||
| Boy | 1,437 (45.7) | 613 (41.4) | 824 (49.5) | ||
| Girl | 1,709 (54.3) | 867 (58.6) | 842 (50.5) | ||
| Age: Mean (SD) | 13.31 (2.18) | 13.89 (2.05) | 12.80 (2.16) | 4.72 | <0.01b |
| Ethnicity: N (%) | 0.05 | 0.82a | |||
| Han | 2,113 (67.2) | 989 (67.2) | 1,124 (67.5) | ||
| other | 1,033 (32.8) | 491 (32.8) | 542 (32.5) | ||
| Grade: N (%) | 13.05 | <0.01a | |||
| Primary school | 1,132 (36.0) | 351 (23.7) | 781 (46.9) | ||
| Junior high school | 1,069 (34.0) | 553 (37.4) | 516 (31.0) | ||
| Senior high school | 945 (30.0) | 576 (38.9) | 369 (22.1) | ||
| Socioeconomic | |||||
| Father’s education level: N (%) | 2.33 | 0.16a | |||
| Elementary school and below | 885 (28.1) | 453 (30.6) | 432 (25.9) | ||
| Junior high school and above | 1,932 (61.4) | 873 (59.0) | 1,059 (63.6) | ||
| Missing and Unkonws | 329 (10.5) | 154 (10.4) | 175 (10.5) | ||
| Mother’s education level: N (%) | 7.78 | 0.02a | |||
| Elementary school and below | 1,077 (34.2) | 571 (38.6) | 506 (30.4) | ||
| Junior high school and above | 1,816 (57.7) | 804 (54.3) | 1,012 (60.7) | ||
| Missing and Unkonws | 253 (8.1) | 105 (7.1) | 148 (8.9) | ||
| Only child: N (%) | 4.79 | 0.05a | |||
| Yes | 936 (29.8) | 402 (27.2) | 534 (32.1) | ||
| No | 2,210 (70.2) | 1,078 (72.8) | 1,132 (67.9) | ||
| Adolescent self-rating life events: Median (IQR) | |||||
| Combined score | 37 (14) | 42 (15) | 33 (10) | 23.70 | <0.01c |
| IRF (Dimension 1) | 1.50 (1.00) | 1.75 (1.00) | 1.25 (0.50) | 19.55 | <0.01c |
| LPF (Dimension 2) | 1.75 (1.00) | 2.00 (1.25) | 1.50 (1.00) | 13.80 | <0.01c |
| PF (Dimension 3) | 1.14 (0.43) | 1.29 (0.57) | 1.00 (0.29) | 16.55 | <0.01c |
| LF (Dimension 4) | 1.17 (0.50) | 1.33 (0.67) | 1.00 (0.33) | 14.98 | <0.01c |
| HAF (Dimension 5) | 1.20 (0.80) | 1.60 (0.80) | 1.20 (0.40) | 24.23 | <0.01c |
| ASLEC: N (%) | 282.31 | <0.01a | |||
| Low (ASLEC ≤ 37) | 1,643 (52.2) | 464 (31.4) | 1,179 (70.8) | ||
| High (ASLEC > 37) | 1,503 (47.8) | 1016 (68.6) | 487 (29.2) |
Notes:
ASLEC, Adolescent Self-rating Life Events Check-list; NSSI, self-harm; IRF, interpersonal relationship factor; LPF, learning pressure factor; PF, punishment factor; LF, loss factor; HAF, health adaptation factor.
a
Design-based Chi-squared test.
b
Design-based t-test.
c
Design-based rank-sum test.