Validation of the comprehensive inventory of mindfulness experiences using Rasch methodology

Abstract

Although mindfulness has now been studied for multiple decades, the field of psychometric research has yet to agree upon the optimal way to measure the mindfulness construct. Prior research has identified eight distinct aspects of mindfulness, which were not adequately captured by any available measures until the development of the Comprehensive Inventory of Mindfulness Experiences (CHIME). The CHIME contains 37 items and has demonstrated excellent psychometric properties in both the German and Dutch languages, but an English version for adults has not been validated to date. The purpose of the present study was to investigate the psychometric characteristics of the translated English CHIME scale using Rasch methodology. The current study utilized the unrestricted Partial Credit Rasch model to evaluate the psychometric characteristics of the English CHIME. The sample included 620 participants from the general population. The validity of the English CHIME was examined by correlating its scores with various measures of mindfulness and psychological functioning. Initial Rasch analysis of the English CHIME showed poor model fit, local dependency, and evidence against the assumption of unidimensionality. Several minor modifications, which involved creating Super-Items, were required to achieve good fit to the Rasch model (ꭕ²45)=31.99, p=0.93). The modified scale displayed evidence of unidimensionality, invariance across personal factors, and ahigh reliability (PSI=0.92). The developed Rasch algorithm permitted the transformation of ordinal responses into interval scale scores, increasing the English CHIME’s precision of measurement. The English CHIME’s external validity was established by moderate–high correlations with other measures of mindfulness and various measures of psychological functioning. The results of this study provide evidence for the validity of the English CHIME scale, which can be used to assess the overarching construct of mindfulness.