Psychometric properties of the German version of the Motivational Interviewing Treatment Integrity Code

Motivational interviewing (MI) is effective in the treatment of addictions. To evaluate MI adherence of therapists, the Motivational Interviewing Treatment Integrity Code (MITI) was developed. MI is used in German-speaking countries, but there is no equivalent to the MITI. Our aim was to adapt the MITI for use in German language settings (MITI-d). Twenty-eight session tapes of Alcoholism Specific Psychotherapy utilizing MI were rated by two student raters and the MITI-d instructor. To evaluate interrater reliability, intraclass correlation coefficients (ICCs) were computed. ICCs were good to excellent for relevant MI constructs, except for Complex Reflections, MI-nonadherent Behaviors, Empathy, and MI Spirit. The evaluation of test-retest reliability for the student raters showed good to excellent results. The MITI-d is a psychometrically sound instrument for evaluating basic MI competence in German language settings.