Translation, Cultural Adaptation, and Content Validity of the Japanese Version of the Strain in Dementia Care Scale (SDCS)

Background/Objective: Dementia-care-related strain can affect care professionals’ well-being, retention, and long-term care quality. However, no Japanese-language instrument specifically assesses such strain among care staff. This study translated and culturally adapted the Strain in Dementia Care Scale (SDCS) for Japanese care staff and evaluated the content validity of the Japanese version (J-SDCS). Methods: This methodological study comprises two phases. First, the SDCS underwent forward translation, reconciliation, back-translation, review by the original developer, and a written clarification test with care staff. Second, eight gerontological experts assessed content validity using a five-point rating scale (1 = not valid to 5 = valid). Ratings of 4 or 5 were classified as favorable. Item-level and scale-level content validity indices (I-CVI and S-CVI) were calculated. Results: The adaptation process identified linguistic and cultural issues, including potentially ambiguous wording in Item 4 and a culturally dependent example in Item 21, which was removed while retaining the core statement. All 27 items were retained. The S-CVI/Ave was 0.93 for the frequency component and 0.91 for the stress component, whereas the S-CVI/UA was 0.63 and 0.44, respectively. Several items had I-CVI values below the reference value of 0.78. Item-level decisions considered expert ratings and comments, feedback from intended respondents, and consistency with the original SDCS. Conclusions: The multistep adaptation process provided initial evidence supporting the content validity and cultural appropriateness of the J-SDCS. However, potential item ambiguity, cultural adaptation decisions, and limitations of the content validity assessment warrant cautious interpretation. Further research is needed to evaluate structural validity, reliability, construct validity, and cross-cultural measurement equivalence.