The Motivational Interviewing Treatment Integrity Code (MITI 4): Rationale, Preliminary Reliability and Validity

The Motivational Interviewing Treatment Integrity code has been revised to address new evidence-based elements of motivational interviewing (MI). This new version (MITI 4) includes new global ratings to assess clinician's attention to client language, increased rigor in assessing autonomy support and client choice, and items to evaluate the use of persuasion when giving information and advice. Method: Four undergraduate, non-professional raters were trained in the MITI and used it to review 50 audiotapes of clinicians conducting MI in actual treatments sessions. Both kappa and intraclass correlation indices were calculated for all coders, for the best rater pair and for a 20% randomly selected sample from the best rater pair. Results: Reliability across raters, with the exception of Emphasize Autonomy and % Complex Reflections, were in the good to excellent range. Reliability estimates decrease when smaller samples are used and when fewer raters contribute. Conclusion: The advantages and drawbacks of this revision are discussed including implications for research and clinical applications. The MITI 4.0 represents a reliable method for assessing the integrity of MI including both the technical and relational components of the method.