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What the Research Says… About Motivational Interviewing

Defining what the research says

It was the early 70’s. Common thinking at the time was that non-systematic observation, theory and experience were sufficient to determine what was effective in improving health. This began to change. Professor Archie Cochrane, a Scottish epidemiologist, published Effectiveness and Efficiency: Random Reflections on Health Services (1972). His book and subsequent advocacy led to increasing acceptance of the concepts behind evidence-based medicine1.

In that same period, in the US, “controlled evaluations (studies)” of psychotherapy effectiveness were being carried out2. Additionally, Joel Fischer, a recently graduated Social Work doctoral student, had taken a position at the University of Hawaii. His thesis was published as his seminal paper in 1973, “Is casework effective: A review”3. That was followed three years later by a book arguing for the use of evidence in Social Work practice4.

I saw this focus on proof as a means to sift through theories and models, to understand what motivated health behavior change. I learned that randomized controlled trials (RCTs) provided one of the highest forms of evidence for what was effective5. RCTs assign subjects randomly to control and treatment groups, to help account for extraneous factors that could affect outcome.

Then, a decade later, William Miller described Motivational Interviewing (MI) in a 1983 paper6. He wrote the article during a sabbatical at the Hjellestad Clinic outside Bergen, Norway7. While the first studies followed shortly after, Dr. Miller and colleagues published the first RCT in 19888. More than 200 RCTs on MI effectiveness have now been published internationally. I will ask later if discussion of these studies holds interest for you.

In the 1990’s, I came to better understand systematic reviews9. These aim to provide an exhaustive summary of literature relevant to a research question. Of particular interest to this blog is the question: “Is MI effective?”

So, reading RCTs and systematic reviews are two means of learning what the research says. However, not all studies or reviews are effectively implemented. Fortunately, there is a method by which to evaluate research design and reporting. This is “critical appraisal”10. Critical appraisal applies rules of evidence to factors such as randomization and how conclusions are drawn. You can use critical appraisal to determine guidelines and to assist clinical decision-making. Thus, critical appraisal of MI studies and reviews are another form of what the research says that we could discuss in future blogs. However, there is more.

More than effective practice

There are other questions that the research can help us to answer. These include, what makes MI efficacious (for example, to what extent does client “change talk” contribute to outcome), what is effective in training practitioners and what does research in other fields tell us about why MI works? The first two questions were the focus of several columns in the MINT Bulletin. You will find links to these in the references11. Those contributions included one on the MI Spirit (2009), two on MI training (2006) and three on “change talk” (2004-5). More recent studies may provide a reason to revisit what the research says about these topics.


The last question, about what research in other fields might offer to understand how MI has it’s effect, was touched upon in several columns. Why might this be important? One answer is so that we do not revert again to the 1970’s. This includes making assumptions, from theory or our experience, about why MI works.

For example, a common statement about the importance of reflections (one of the four basic micro-skills of MI) is that it assures the client that “you understand”. I am unaware of research that shows that clinician understanding is critical to outcomes12. In fact, a recent study in consumer research found the opposite. Social Psychologists Uma Karmarkar and Zakary Tormala in a recent paper, “Believe me, I have no idea what I’m talking about”, found that when high expertise sources violate an expectancy and express uncertainty, this “stimulates involvement and promotes persuasion…”13. In their research, this was done by “expressing minor doubts about their own opinion”14

Their findings have implications for a strategy used in MI. This is “prefacing”, before giving information or advice15. Prefacing has been described as telling the client that they are free to “disregard” what we say, as a way of acknowledging autonomy. However, I believe that this disregard prefacing may not be effective, if the client concludes that ignoring the clinician may have negative consequences (i.e., how the professional will view or support them, if they do not accept what is said).

Karmarkar and Tormola’s study suggests an alternate form of prefacing. This is expressing “uncertainty” as to whether the information or advice, that we are about to offer, will be helpful. A tentative preface allows us, after providing our thoughts or guidance, to ask the client whether anything we have said helps and if so, how. How does this facilitate change?

First, this affirms (i.e., values) that the person is not only autonomous but also capable of deciding what is helpful to them. Additionally, the uncertainty of this tentative prefacing may create expectancy violation, to ‘stimulate involvement and promote persuasion’. This is an example of how we can seek to understand or modify how we implement MI skills and techniques, with research from across disciplines. To end, is this topic and blog relevant and useful to you? Your answer to that question will guide future entries. Thus, I would appreciate your taking a minute now to answer two questions in the comments field below:

Was this first blog of “What the research says about MI” helpful to you? 

What questions would you like answered and/or what would you like to read about in the months ahead?


Thank you. Grant Corbett Principal Behavior Change Solutions, Inc.

1 For background on evidence-based medicine and practice, see http://en.wikipedia.org/wiki/Evidence-based_medicine.

2 Smith, M.L. and Glass, G.V. (1977). Meta-analysis of psychotherapy outcome studies. American Psychologist, 32, 752-60.

3 Fischer, J. (1973). Is casework effective: A review. Social Work, 17, 1-5.

4 Fischer, J. (ed.) (1976). The Effectiveness of Social Casework, Springfield, IL: Charles C Thomas.

5For a discussion of forms of evidence, see Evans, D. (2003). Hierarchy of evidence: a framework for ranking evidence evaluating healthcare interventions. Journal of Clinical Nursing, 12(1), 77-84. Located online February 27, 2011 at http://cys.bvsalud.org/lildbi/docsonline/5/9/195-52.pdf.

6 Miller, W. R. (1983). Motivational interviewing with problem drinkers. Behavioural Psychotherapy, 11, 147-172.

7 W.R. Miller, personal communication, March 08, 2008. See also: Moyers, T. B. (2004). History and happenstance: How motivational interviewing got its start. Journal of Cognitive Psychotherapy, 18(4), 291-298.

8 Miller, W. R., Sovereign, R. G., & Krege, B. (1988). Motivational interviewing with problem drinkers: II. The Drinker's Check-up as a preventive intervention. Behavioural Psychotherapy, 16, 251-268.

9 http://en.wikipedia.org/wiki/Systematic_review

10 See http://en.wikipedia.org/wiki/Critical_appraisal for links to critical appraisal resources.

11 Corbett, G. (2009). What the research says about the MI “Spirit” and the “Competence Worldview”. Bulletin, 15(1), 3-5. Corbett, G. (2008). What the research says about MI – Where do you start. Bulletin, 14(1), 6-8. Corbett, G. (2006). What the research says about MI training. Bulletin, 13(2), 14-16. Corbett, G. (2006). What the research says about MI training. Bulletin, 13(1), 12-14. Corbett, G. (2005). What the research says about Change Talk – Commitment Language: Part III. MINUET, 12(2), 7-8. Corbett, G. (2005). What the research says about Change Talk: Part II. MINUET, 12(1), 7-8. Corbett, G. (2004). What the research says about Change Talk: Part I. MINUET, 11(3), 9-10. Corbett, G. (2004). What the research says about MI skills. MINUET, 11(2), 6-9.

12 In fact, you may have experienced reflecting content and feelings that you did not fully understand, and having clients report increased understanding of what they were exploring.

13 Karmarkar, U.R., & Tormala, Z.L. (2010). Believe me, I have no idea what I'm talking about: The effects of source certainty on consumer involvement and persuasion. Journal of Consumer Research, 46, 1033-1049.

14 http://www.gsb.stanford.edu/news/research/tormala_certainty.html

15 Rollnick, S., Miller, WR, & Butler, C. (2008). Motivational interviewing in health care: Helping patients change behavior. New York: Guilford Press, p. 92.

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Thank you for putting this information together for us Grant.
I want to find out where the research is regarding "resistance"
and MI. I understood that Bill Miller had some research findings
in this area. His research and/or the research of others
in this area will be appreciated.
Thank you in advance.

What a nice compilation. Thanks, Grant, for taking the time to supply one of our first posts!

Debby Westcott aka: Probie15

Submitted by GuyUndrill on

Thanks Grant for this posting. I look forward to subsequent editions!