Table 1.
Frequency characteristics of non-suicidal self-injury (NSSI) in Chinese adolescents (%).
| Variable | Total Sample (n = 22,628) |
NSSI | χ 2 | φ/V | |
|---|---|---|---|---|---|
| No (n = 15,367) | Yes (n = 7261) | ||||
| Gender | 96.332 *** | −0.065 *** | |||
| Male | 10990 (48.6) | 7119 (64.8) | 3871 (35.2) | ||
| Female | 11638 (51.4) | 8248 (70.9) | 3390 (29.1) | ||
| Grade | 65.487 *** | −0.054 *** | |||
| Middle school | 11993 (53.0) | 7861 (65.6) | 4132 (34.4) | ||
| High school | 10635 (47.0) | 7506 (70.6) | 3129 (29.4) | ||
| Registered residence | 26.357 *** | −0.034 *** | |||
| Rural | 10882 (48.1) | 7210 (66.3) | 3672 (33.7) | ||
| Urban | 11746 (51.9) | 8157 (69.4) | 3589 (30.6) | ||
| Any siblings | 0.239 | 0.003 | |||
| Yes | 12908 (57.0) | 8749 (67.8) | 4159 (32.2) | ||
| No | 9720 (43.0) | 6618 (68.1) | 3102 (31.9) | ||
| Accommodation type | 6.952 ** | −0.018 ** | |||
| Boarding student | 11320 (50.0) | 7595 (67.1) | 3725 (32.9) | ||
| Commuting student | 11308 (50.0) | 7772 (68.7) | 3536 (31.3) | ||
| Father’s educational level a | 8.823 ** | −0.020 ** | |||
| < High school degree | 13006 (57.5) | 8735 (67.2) | 4271 (32.8) | ||
| ≥ High school degree | 9424 (41.6) | 6506 (69.0) | 2918 (31.0) | ||
| Mother’s educational level b | 9.751 ** | −0.021 ** | |||
| < High school degree | 14335 (63.4) | 9639 (67.2) | 4696 (32.8) | ||
| ≥ High school degree | 8105 (35.8) | 5614 (69.3) | 2491 (30.7) | ||
| Self-reported family economy | 67.759 *** | 0.055 *** | |||
| Bad | 3240 (14.3) | 2005 (61.9) | 1235 (38.1) | ||
| General | 16345 (72.2) | 11316 (69.2) | 5029 (30.8) | ||
| Good | 3043 (13.4) | 2046 (67.2) | 997 (32.8) | ||
| Number of friends | 37.753 *** | 0.041 *** | |||
| ≤ 2 | 5514 (24.4) | 3560 (64.6) | 1954 (35.4) | ||
| 3-5 | 9620 (42.5) | 6622 (68.8) | 2998 (31.2) | ||
| ≥ 6 | 7494 (33.1) | 5185 (69.2) | 2309 (30.8) | ||
| City | 102.702 *** | 0.067 *** | |||
| Shenyang | 3217(14.2) | 2165(67.3) | 1052(32.7) | ||
| Xinxiang | 3230(14.3) | 2327(72.0) | 903(28.0) | ||
| Yangjiang | 5061(22.4) | 3525(69.7) | 1536(30.3) | ||
| Chongqing | 5588(24.7) | 3865(69.2) | 1723(30.8) | ||
| Ulanchap | 2333(10.3) | 1506(64.6) | 827(35.4) | ||
| Bengbu | 3199(14.1) | 1979(61.9) | 1220(38.1) | ||
| HL | 343.427 *** | 0.123 *** | |||
| High | 5486 (24.2) | 4230 (77.1) | 1256 (22.9) | ||
| Medium | 11842 (52.3) | 7917 (66.9) | 3925 (33.1) | ||
| Low | 5300 (23.4) | 3220 (60.8) | 2080 (39.2) | ||
| PMPU | 623.184 *** | 0.166 *** | |||
| No | 16876 (74.6) | 12224 (72.4) | 4652 (27.6) | ||
| Yes | 5752 (25.4) | 3143 (54.6) | 2609 (45.4) | ||
Statistical methods: Chi-square test, φ/V is the effect size; HL is health literacy; NSSI is non-suicidal self- injury; PMPU is problematic mobile phone use; *** p < 0.001, ** p < 0.01; a 198 students have no father; b 188 students have no mother.