Psychometric Properties of Korean Version of Nonsuicidal Self-injury Inventory: Validation Study of Deliberate Self-harm Inventory.

Objective: This study aimed to develop a Korean version of the Nonsuicidal Self-injury Inventory (K-NSSI) through the Deliberate Self-harm Inventory (DSHI) developed by Gratz for the Korean context and confirm its reliability and validity for clinical application.

Methods: A total of 188 participants were analyzed utilizing the DSHI, the Korean version of the Self-harm Inventory, the Personality Assessment Inventory-Borderline Features (PAI-BOR), and the DSM-5 Level-2-Depression scale (Level-2-Dep). Cronbach's α assessed their reliability, while frequency analysis examined the items of the K-NSSI scales. Validity of the K-NSSI was confirmed through correlation analyses between K-NSSI (tendency for and frequency of nonsuicidal self-injury [NSSI] behavior) and SHI, PAI-BOR total scale, four subscales of PAI-BOR, and Level-2-Dep scale. Polyserial correlations analyzed the correlation between the presence of NSSI behavior and other scales. Confirmatory factor analysis and structural equation modeling explored the relationship between borderline personality features and self-harm.

Results: Cronbach's α was 0.71, indicating an "acceptable" level of reliability. Statistically significant correlations were observed between the presence of NSSI behavior and the total scores of SHI and PAI-BOR, and the four subscales of PAI-BOR. The frequency of NSSI showed statistically significant correlations with the total score of SHI and PAI-BOR, and its four subscales. Notably, 13.8% of participants reported engaging in self-harm behaviors, 26.9% reported a single occurrence, and 73.1% reported two or more instances. Structural equation modeling demonstrated that self-harm adequately predicted borderline personality traits.

Conclusion: This study successfully validated the adaptation of DSHI into K-NSSI. The K-NSSI can facilitate interventions for self-harm incidents.