Search

Purpose: In developed countries, progressive rapid aging is increasing the need for social care. This study aimed to determine Japanese utility weights for the Adult Social Care Outcomes Toolkit (ASCOT) four-level self-completion questionnaire (SCT4). Methods: We recruited 1050 Japanese respondents from the general population, stratified by sex and age, from five major cities. In the best–worst scaling (BWS) phase, respondents ranked various social care-related quality of life (SCRQoL) states as “best,” “worst,” “second-best,” or “second-worst,” as per the ASCOT. Then, respondents were asked to evaluate eight different SCRQOL states by composite time-trade off (cTTO). A mixed logit model was used to analyze BWS data. The association between cTTO and latent BWS scores was used to estimate a scoring formula that would convert BWS scores to SC-QALY (social care quality-adjusted life year) scores. Results: Japanese BWS weightings for ASCOT-SCT4 were successfully estimated and found generally consistent with the UK utility weights. However, coefficients on level 3 of “Control over daily life” and “Occupation” domains differed markedly between Japan and the UK. The worst Japanese SCRQoL state was lower than that for the UK, as Japanese cTTO results showed more negative valuations. In general, Japanese SC-QALY score (for more than 90% of health states) was lower than that for the UK. Conclusions: We successfully obtained Japanese utility weights for ASCOT SCT4. This will contribute to the measurement and understanding of social care outcomes.

Background: The aim of this study was to develop and perform cross-cultural validation of a Japanese version of the Adult Social Care Outcomes Toolkit (ASCOT) four-level Self-Completion questionnaire (SCT4) instrument to measure Social-Care Related Quality of Life. It was important to develop a Japanese version of the ASCOT-SCT4 and validate it in the Japanese context, given the interest in measuring outcomes of social care services in Japan. Methods: The original version of ASCOT-SCT4 was translated into Japanese following good practice guidelines. Additionally, comments and feedback were obtained from an independent committee engaged in managing and providing social care services to refine the flow of sentences of the newly developed translated version. The resulting version was tested for cross-cultural validation among community-dwelling adults who use social care services to confirm the factorial structure and the scale system of the Japanese version, using Structural Equation Modeling and Item Response Theory. Results: Vigorous discussion was needed to translate the original version into Japanese especially for the items control over daily life and dignity. These two items were linguistically difficult to express in everyday language so potential participants could easily understand the intended concepts. In the cross-cultural validation, we obtained values for model fit within the acceptable range: between 0.706 and 0.550 for factor loadings, 0.923 for the Comparative Fit Index, 0.910 for the Tucker-Lewis Index, and 0.083 for the Root Mean Square Error of Approximation. This confirmed the factorial structure of the Japanese version. The IRT analysis, however, revealed that the scale system needed refinement to facilitate appropriate differentiation between each response option. Conclusions: This study provided preliminary evidence that the Japanese version of ASCOT-SCT4 is valid. As a result, the Japanese version was finalized and approved by the instrument d