Precomparison/post-comparison of continuous variables of the total sample (n=51) and intervention completers only (n=33)
| Variable | Sample | Preintervention mean (SD) | Postintervention mean (SD) | Difference in means (95% CI) | P value† | Effect size (Cohen’s d) |
| Self-–efficacy towards helping CYP who self-harm | Total (n=51) | 28.9 (3.6) | 27.6 (2.37) | −1.25 (-2.46to 0.05) | 0.042* | 0.29 |
| Knowledge of self-harm in CYP | Total (n=51) | 7 (2.53) | 7.96 (2.4) | 1.12 (0.25 to 1.99) | 0.013* | 0.36 |
| Self-efficacy towards helping CYP who self-harm | Intervention completers only (n=33) | 28.81 (3.69) | 27.45 (2.61) | −1.36 (-2.89 to 0.17) | 0.079 | - |
| Knowledge of self-harm in CYP | Intervention completers only (n=33) | 6.69 (2.95) | 8.67 (1.96) | 1.97 (0.95 to 2.99) | 0.000** | 0.69 |
*Statistically significant at 0.05 level.
**Statistically significant at 0.001 level.
†Calculated through a paired sample t-test.
CYP, children and young people.