Validity and reliability of the Japanese Interest Checklist for the Elderly

Abstract

Introduction The validity and reliability of the Japanese Interest Checklist for the Elderly were examined. Method 687 participants responded, using the new scale system: ‘currently participate based on interest,’ ‘participate less because of health status’ or ‘no interest.’ The convergent and discriminant validity of the factorial structure were examined using two-stage Confirmatory Factor Analysis approaches. The discriminant validity and reliability of the scale system were examined using two-stage Item Response Theory approaches. Results The first Confirmatory Factor Analysis stage indicated values representing good (factor loadings: 0.99–0.75; Comparative Fit Index: 0.99; Tucker-Lewis Index: 0.98) to adequate (Root Mean Square Error of Approximation: 0.054) fit levels. Both the discriminant validity and convergent validity were identified to be high. The second Confirmatory Factor Analysis stage with a Path analysis and consideration of age and gender indicated values representing a good fit (factor loadings: 0.99–0.78; Comparative Fit Index: 0.99; Tucker-Lewis Index: 0.98; Root Mean Square Error of Approximation: 0.048). The first Item Response Theory stage indicated the values for the discriminant validity in the expected ranges; however, it displayed lower reliability in some activities. The second Item Response Theory state with the latent-class model-based multi-group Item Response Theory confirmed the pattern of invariance. Conclusion The factorial structure was valid across different groups of people. The scale system has to be improved.