Psychometric properties of the Japanese version of the Demoralization Scale-II (DS-II) in cancer patients

Demoralization, which is characterized by helplessness, hopelessness, and the loss of meaning, has gained increasing attention in psychiatry and palliative care. Robinson et al. developed the Demoralization Scale-II (DS-II) to assess this construct in a brief and reliable format. However, a validated Japanese version has not been developed to date. The purpose of this study was to develop a Japanese version of the DS-II (DS-II-J) and to evaluate its psychometric properties in cancer patients.

A total of 147 cancer patients from 3 acute care hospitals in Japan were included in the study. Participants completed the DS-II-J, Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder 7-item Scale (GAD-7), and Edmonton Symptom Assessment System Revised Version (ESAS-r). Internal consistency was assessed using Cronbach's α. Convergent validity was evaluated by examining correlations with the PHQ-9, GAD-7, and ESAS-r. Confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were conducted to assess factor structure.

The DS-II-J demonstrated high internal consistency (α = 0.92). Strong positive correlations were found between DS-II-J scores and PHQ-9 and GAD-7 scores, and moderate correlations with selected ESAS-r physical symptoms, supporting convergent validity. CFA results showed a suboptimal model fit for both a one-factor model and the original two-factor model proposed by Robinson et al. EFA supported a two-factor structure, but with a different item composition, suggesting cultural influences.

The DS-II-J is a valid and reliable tool for assessing demoralization in Japanese cancer patients.