Coding counsellor behaviour in motivational interviewing sessions: inter-rater reliability for the Swedish Motivational Interviewing Treatment Integrity Code (MITI).

The aim of this study was to evaluate inter-rater reliability when using the Swedish version of the Motivational Interviewing Treatment Code (MITI) as an adjunct to MI training, clinical practice and research. Coders were trained to use the MITI for scoring taped sessions. The 4-month basic training had a duration of 39 hours. Following training, 60 audio-taped live interviews were randomly assigned for MITI coding. Mean intra-class correlation (ICC) coefficients were calculated for 7 coders across all pairs of coders. Cronbach's alpha was calculated to estimate the covariance between each pair across their common interviews. Six months later, a second inter-rater reliability test was performed, when 5 coders coded the same 15 randomly selected tapes. At the second reliability testing the mean ICC was 0.81 and the mean Cronbach's alpha was 0.96. However, the ICC varied for different sub-variables of the MITI, ranging from 0.42 empathy to 0.79 for number of Closed questions. In conclusion, MITI shows promising potential to be a reliable tool to confirm and enhance MI training as well as practice in clinical settings and in evaluating MI integrity in clinical MI research. However, coder assessment of empathy and MI-spirit, "global" variables, requires further refinement.