Development, validity, and reliability of the Japanese version of the 7C of vaccination readiness scale

Abstract

Background: The 7C of the vaccination readiness scale measures the 7 psychological components that structure people's vaccination readiness. We aimed to develop the Japanese version of this scale (7C scale Japanese version) and to assess its validity and reliability.

Methods: The full and short versions of 7C scale Japanese were developed based on translation guidelines provided by the ISPOR Task Force. An Internet survey, including 709 participants, was performed to assess the scale's validity and reliability within a confirmatory factor analysis (CFA) framework (men: 38.8%, age range: 20-92 years). Invariance analysis using multiple-group CFA was conducted to test cross-cultural validity between participants in this study and those in the 7C original version study. McDonald's omega and intraclass correlation coefficient were calculated to evaluate internal consistency and test-retest reliability, respectively. To clarify the criterion validity, regression analysis, with previous COVID-19 vaccination status as the dependent variable, was performed to calculate pseudo R².

Results: The 7C scale Japanese version exhibited good content validity, structural validity, configural invariance, and criterion validity. The results showed good internal consistency, and test-retest reliability, except for the "calculation" component.

Conclusions: 7C scale Japanese version exhibited acceptable reliability and validity; however, "calculation" may be a less reliable subscale.

Keywords: Measurement; Questionnaire; Vaccine acceptance; Vaccine hesitancy.