Psychometric properties of the Japanese version of the communication confidence rating scale for aphasia: a reliability and validity study of chronic phase people with aphasia

Background: Japan’s aging population presents challenges to speech-language pathologists and community volunteers in supporting the growing number of people with aphasia (PWA) after stroke. PWA’s self-efficacy or confidence may affect how much they engage in situations that require them to communicate. The Communication Confidence Rating Scale for Aphasia (CCRSA) is a patient-reported scale that assesses how confident a person with aphasia feels about their ability to communicate in different situations. Aim: The purpose of this study was to describe the development of a Japanese version of CCRSA (J-CCRSA) and examine its psychometric properties for use in speech-language therapy (SLT) in Japan. Methods and procedures: In this cross-sectional study, we examined J-CCRSA acceptability, internal consistency reliability, test-retest reliability, structural validity, convergent validity, and known-groups validity. Participants were PWA in the chronic phase and healthy controls with no history of stroke (HC). Outcomes and results: Analysis of 76 PWA and 23 HC showed that J-CCRSA has psychometric properties that can be considered favorable. Specifically, there were no missing values, no bias in the distribution of the measured data, and no ceiling or floor effects. Cronbach’s α for internal consistency reliability was α = 0.89, and the intraclass correlation coefficient for test-retest reliability (n = 33) was intraclass correlation coefficient = 0.79 (p < 0.001). In addition, two factors were extracted in the exploratory factor analysis of the structural validity study, with loadings of 0.64–0.90 for the first factor and 0.78–0.90 for the second factor. The Spearman’s correlation coefficient for the convergent validity index was rho = 0.31–0.63 (p < 0.05), and the known-groups validity, examined by comparing the PWA and HC scores, showed a significant difference between the two groups (p = 0.002, r = -0.35). Conclusions: Our analysis of the psychometric properties of the J-CCRSA provides evidence that J-CCRSA can be used to assess Japanese-speaking PWA, thereby expanding assessment options and providing potential new directions for SLT in Japan.