Objectives: Although mindfulness has been studied for multiple decades, psychometric research has yet to agree upon the optimal way to measure the mindfulness construct. Prior research has identified eight distinct aspects of mindfulness that were not adequately captured by any of the available measures. Hence, the Comprehensive Inventory of Mindfulness Experiences (CHIME) was developed. The CHIME contains 37 items and was originally developed in the German language. The CHIME has demonstrated excellent psychometric properties in both German and Dutch, but so far, no English version has been validated. The purpose of the present study was to investigate the psychometric characteristics of the translated English-language CHIME scale using Rasch methodology.

Method: The current study utilized Partial Credit Rasch analysis to evaluate the psychometric characteristics of the English CHIME. The sample included responses from 620 participants from the general population residing in the USA. The validity of the English CHIME was examined by correlating its scores with various measures of mindfulness and psychological functioning.

Results: Initial Rasch analysis of the English CHIME showed poor model fit, local dependency, and evidence against the assumption of unidimensionality. Several minor modifications, that involved creating super-items, were required to fit the Rasch model (χ2(45)=31.99, p=0.93). This model displayed evidence of unidimensionality, invariance across personal factors, and a high reliability (PSI=0.92). Ordinal-interval transformation tables were produced, which increase 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.

Conclusions: 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.