Cross-Cultural Adaptation and Initial Psychometric Evaluation of the Japanese Version of the Chronic Kidney Disease Self-Efficacy Scale (CKDSE-J)

Background/Objectives: Self-efficacy is an important determinant of self-care among adults with chronic kidney disease (CKD). The Chronic Kidney Disease Self-Efficacy Scale (CKD-SE) is a disease-specific measure, but its use has not been reported in Japan. This study translated and culturally adapted the CKD-SE into Japanese and conducted an initial psychometric evaluation. Methods: A cross-sectional survey was conducted among Japanese adults with CKD stages G3a–G5 not receiving dialysis. Structural validity and internal consistency were evaluated in 227 participants, and construct validity was evaluated in 222. Structural validity was examined using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM). Results: The original 25-item four-factor CFA showed a poor fit, and ESEM yielded an improper solution involving Item 19. Sequential evaluation resulted in a 23-item structure. The 23-item CFA showed mixed fit, whereas Target ESEM showed improved overall fit (CFI = 0.935, TLI = 0.902, RMSEA = 0.060, SRMR = 0.033). However, several autonomy items showed weak target loadings and cross-loadings. Proposed subscale scores correlated positively with self-care behavior (r = 0.27–0.46), and McDonald’s omega ranged from 0.84 to 0.90. Conclusions: The 23-item CKDSE-J showed improved overall model fit under Target ESEM, but the structural definition of autonomy remained uncertain. Because the structure was refined and evaluated in the same sample, independent replication and further psychometric evaluation are needed.