Evaluating short versions of the five facet mindfulness questionnaire using rasch analysis

The 39-item Five Facet Mindfulness Questionnaire (FFMQ) is a widely used mindfulness measure that includes five subscales: Act with Awareness, Describe, Nonjudge, Nonreact, and Observe. Short versions of the FFMQ are available in various languages, but these have not been explicitly compared, nor has their compliance with fundamental measurement principles been evaluated using Rasch analysis. A Partial Credit Rasch model was applied to investigate the psychometric properties of four different versions of the FFMQ, ranging from 15 to 24 items, in a sample of 400 participants who completed FFMQ items in English. The best fit to the Rasch model was achieved after the 24-item Dutch FFMQ version was reduced to 18 items by removing locally dependent and misfitting items and combining subscales items into super-items. These results support the psychometric properties and internal validity of the modified 18-item FFMQ (FFMQ-18) as a global short measure of the mindfulness construct and its individual facets. Ordinal responses to the FFMQ-18 can be transformed into interval-level data, using the ordinal-to-interval conversion tables presented here and thus increase accuracy of measurement for the total and subscale scores. This short version is useful for comparisons of mindfulness and its facets at a group level or when investigating the associations of mindfulness with other variables, but the full-scale version is recommended for comparison of individuals’ pre- and post-intervention mindfulness levels.