Evaluating a method of assessing competence in Motivational Interviewing: A study using simulated patients in the United Kingdom

In this evaluation of a method of assessing competence in Motivational Interviewing (MI), participants were asked to interview an actor simulating a substance abuser who was ambivalent about an important issue. The interviews were videotaped and subsequently rated for competence in MI using the Motivational Interviewing Treatment Integrity code (MITI). Ratings of 43 interviews made independently by trained judges found high levels of inter-rater agreement. Ratings of 11 pairs of interviews carried out by the same interviewer with different simulated patients, a mean of 26 days apart, resembled each other closely. Participants who had been trained in MI were significantly more competent than others. There was a significant association between researchers' and patients' ratings of the extent to which the interviewer demonstrated the spirit of MI. These findings imply that the assessment method produces reasonably reliable and valid ratings of competence in MI and can be used for both clinical and research purposes.