Reported method of NSSI for total sample and by sex
| Method of self-injury (n) | n | Males | Females | χ2 | P value | ||
| n=171 | % | n=225 | % | ||||
| Scratching | 162 | 65 | 38.0 | 97 | 43.1 | 0.465 | 0.470 |
| Biting | 125 | 40 | 23.4 | 85 | 37.8 | 8.500 | 0.004 |
| Hitting | 98 | 51 | 29.8 | 47 | 20.9 | 4.800 | 0.033 |
| Interfering with wound healing | 91 | 23 | 13.5 | 68 | 30.2 | 14.400 | 0.000 |
| Hair pulling | 91 | 35 | 20.5 | 56 | 24.9 | 0.834 | 0.400 |
| Severe nail-biting and/or nail injuries | 87 | 28 | 16.4 | 59 | 26.2 | 4.990 | 0.027 |
| Cutting | 73 | 21 | 12.3 | 52 | 23.1 | 7.050 | 0.009 |
| Piercing skin with sharp pointy object | 66 | 18 | 10.5 | 48 | 21.3 | 7.650 | 0.006 |
| Trying to break bones | 59 | 27 | 15.8 | 32 | 14.2 | 0.286 | 0.670 |
| Piercing of body parts | 22 | 7 | 4.1 | 15 | 6.7 | 1.109 | 0.380 |
| Excessive use of alcohol | 22 | 12 | 7.0 | 10 | 4.4 | 1.362 | 0.270 |
| Trying to break bones | 14 | 4 | 2.3 | 10 | 4.4 | 1.193 | 0.410 |
| Eating or drinking things that are not food | 7 | 3 | 1.8 | 4 | 1.8 | – | 1.000 |
| Burning | 7 | 4 | 2.3 | 3 | 1.3 | – | 0.470 |
| Taking too little medication | 4 | 1 | 0.6 | 3 | 1.3 | – | 0.640 |
| Taking too much medication | 2 | 1 | 0.6 | 1 | 0.4 | – | 1.000 |
| Excessive use of street drugs | 2 | 1 | 0.6 | 1 | 0.4 | – | 1.000 |
Symbol (–) indicates that Fisher’s exact test was computed.
NSSI, non-suicidal self-injury.