Abstract Background Standardized diagnostic interviews are essential tools for accurate assessment in child and adolescent psychiatry (CAP). However, many existing interviews are restricted by licensing costs, platform dependencies, limited clinical adaptability, or legal ambiguity regarding digital implementation. To address these limitations, the Electronic Psychiatric Semi-structured Interview for Children and Adolescents (EPSI-C) was developed as an open-access, platform-independent instrument aligned with the DSM-5. The modular structure, comprising 22 modules covering the full range of common psychiatric disorders, allows for both systematic and targeted administration. This instrument development and psychometric validation study evaluated the content validity and internal consistency of the EPSI-C. Methods Content validity was assessed by ten independent experts who rated the relevance of the instrument for assessing DSM-5 diagnostic criteria. Additionally, experts rated six global aspects of clinical utility. Internal consistency was examined in a large naturalistic sample of 3,506 patients (mean age = 12.0 years, SD = 3.2, range 5–18 years; 54.5% girls) assessed with a digital implementation of the EPSI-C during routine outpatient CAP assessments in Sweden. Results The EPSI-C demonstrated excellent scale-level average content validity for both the screening sections (S-CVI/Ave = 0.95) and full modules (S-CVI/Ave = 0.94). Expert consensus was high (90–100%) regarding overall clinical utility. Internal consistency was acceptable to excellent (α range 0.71 – 0.90) for 87.5% of eligible modules. Lower consistency was observed for modules assessing psychotic disorders (α = 0.53) and anorexia nervosa (α = 0.49), reflecting limited DSM-5 criteria and sub-threshold presentations. Conclusions The findings support the foundational psychometric properties of the EPSI-C and indicate its clinical feasibility within a high-volume, naturalistic CAP outpatient setting. The current study establishes content validity and internal consistency, while criterion validity remains to be evaluated. As an open-access, modular instrument, EPSI-C offers a scalable solution for the digital implementation of standardized diagnostic interviews in routine clinical practice.
Olofsdotter et al. (Wed,) studied this question.