Independent predictors of non-suicidal self-injury among adolescents: a logistic regression model development study based on coping styles

Objective Non-suicidal self-injury (NSSI) is an urgent and substantial public health concern among adolescents. This study is aimed at identifying the independent psychological predictors of NSSI and developing and validating a logistic regression-based risk discrimination model focused on coping styles. Methods A cross-sectional study involving 206 adolescents (104 with NSSI and 102 healthy controls) was conducted. All the participants provided general demographic data, and completed the Experiences in Close Relationships Inventory (ECR), the Childhood Trauma Questionnaire-Short Form Version (CTQ-SF), and the Coping Styles Questionnaire (CSQ). Univariate and multivariate logistic regression analyses were performed to identify the independent predictors of NSSI. A nomogram was constructed in accordance with the final multivariate model. Model performance was evaluated using receiver operating characteristic (ROC) curves, calibration plots, the Hosmer-Lemeshow (HL) test, and a decision curve analysis (DCA). Results Multivariate logistic regression revealed that a higher level of self-blame (OR = 1.062; 95% CI: 1.023–1.102; P = 0.002) was an independent risk factor, whereas a better problem-solving capacity (OR = 0.911; 95% CI: 0.867–0.957; P < 0.001) was an independent protective factor for adolescents with NSSI. Attachment dimensions and childhood trauma did not retain independent significance after adjustment. The nomogram showed excellent discrimination (AUC = 0.951, 95% CI: 0.922–0.980), good calibration (HL test P > 0.05), and superior clinical net benefit across a wide threshold (0.01–0.99). Conclusion Targeting self-blame and enhancing problem-solving skills may be effective styles for the prevention of adolescent NSSI. As a preliminary finding, the nomogram developed in our study is a useful tool for exploratory differentiation.