Abstract
BACKGROUND: The accurate diagnosis of mental disorders, such as depression, requires comprehensive, valid, and reliable tools to ensure evidence-based treatments and effective outcome monitoring. Existing diagnostic practices often lack standardization, leading to missed comorbidities and variable diagnostic accuracy. The Klenico system is an innovative, web-based diagnostic tool that integrates patient self-reports with clinical validations by mental health professionals. This system covers a broad spectrum of mental disorders, including depression. OBJECTIVE: This research aimed to evaluate the psychometric properties of the Klenico Depression Domain (KDD), the component of the Klenico system that measures depressive symptomatology, in a real-world clinical setting. Specifically, the evaluation focused on the assessment of its construct validity, internal consistency, and sensitivity to change in symptom severity. METHODS: Anonymized data from 496 inpatients with mental disorders collected between 2019 and 2022 were analyzed. Patients completed the KDD alongside parts of the Patient Health Questionnaire (PHQ), Beck Depression Inventory (BDI-II), and Satisfaction With Life Scale (SWLS) at both admission and discharge. Internal consistency was measured using Cronbach α. Exploratory factor analysis was conducted to examine the factor structure. Construct validity was assessed via Pearson correlations with PHQ-9 and BDI-II, while divergent validity was tested against the PHQ Somatic Symptoms Scale (PHQ-15), PHQ-Generalized Anxiety Disorder-7, and SWLS. Sensitivity to change was evaluated using paired 1-tailed t tests, effect sizes, and repeated measures correlations. RESULTS: The KDD demonstrated excellent internal consistency (Cronbach α=0.91 at admission and 0.93 at discharge). Factor analysis revealed a 7-factor structure encompassing dimensions like "inadequacy," "anhedonia," and "self-hatred," aligning with core depressive symptoms outlined in the International Statistical Classification of Diseases, Tenth Revision. The correlations with the convergent questionnaires PHQ-9 (r=0.68; P<.001) and BDI-II (r=0.70; P<.001) were high. While the KDD showed a moderate correlation with the divergent PHQ-15 (r=0.35; P<.001), it was more strongly associated with the divergent SWLS (r=-0.51; P<.001) and Generalized Anxiety Disorder-7 (r=0.51; P<.001). Sensitivity to change was high, with significant reductions in KDD scores for patients with improved symptoms (t(27)=5.36, P<.001; Cohen d=0.79) and high repeated measures correlation with both the BDI-II (r=0.61; P<.001) and the PHQ-9 (r=0.59; P<.001). CONCLUSIONS: The KDD shows promise as a reliable and valid instrument for diagnosing depression and monitoring treatment outcomes in psychotherapeutic settings. Its alignment with International Statistical Classification of Diseases, Tenth Revision diagnostic criteria and sensitivity to symptom change underlines its potential utility. These findings highlight the Klenico system's potential to enhance clinical diagnostics by addressing current gaps in mental health care, thus improving diagnostic accuracy and consistency. Further research is recommended to validate its performance across different populations and settings.