Regression analysis: Simple Linear Regression Multiple Linear Regression
Lundahl final icmi motivational interviewing 25 years
1. Motivational Interviewing: A meta-analysis of 25 years of researchInternational Conference on Motivational Interviewing Sweden – 2010 Brad Lundahl, PhDUniversity of UtahUSA
2. Acknowledgements Co-authors Lundahl, B. W., Kunz, C., Brownell, C., Tollefson, D., & Burke, B. (2010). A meta-Analysis of Motivational Interviewing: Twenty-five years of Empirical Studies. Research on Social Work Practice, 20, 137-160. Dr. William Miller – List of published articles
3. Context: Growth of MI Research PsycINFO (May 2010) “Motivational Interviewing”
4. Consolidating Findings Meta-analysis statistically combines data from empirical studies to provide: An estimate of the overall effect An estimate of variability Indications of moderator effects – conditions which may alter effects
5. Study Objective Examine the unique effect of MI by Including studies with designs that isolated MI’s contribution Including studies that compared MI to another treatment
6. Method Study Selection Criteria Employed a comparison group Design that isolated MI’s unique effect (i.e., not combined w/ other treatment) or compared MI to another treatment Published in peer reviewed source Published in English 119 studies met selection criteria 11 databases, grossed 1,128 possible studies
7. Method Dependent Variable Examples Substance abuse Health-related behaviors Risky behaviors Emotional wellbeing Engagement in treatment Independent Variable Examples (Moderators) Study design features Participant characteristics Delivery, role
11. Does 14% or 4% matter? If your take home salary went up or down by 14% … would you notice? If the number of missed appointments went down by 14% would it matter? If the number of people helped went up by 14% would it matter?
13. Reach: Targeted Behaviors* Alcohol (68) Marijuana (17) Tobacco (24) Misc drugs (27) Increase healthy beh (11) Decrease risky beh (10) Drinking safe water (1) Gambling (3) Emotional wellbeing (7) Eating problems (1) Parenting practices (2) Engagement (34) Intention to change (23) Confidence (11) *Number in ( ) is number of studies contributing effect size data
14. Reach of MI Compared to WEAK comparison groups: On 11 of 14 targeted behaviors, MI showed statistically significant advantage 3 of 14 were positive, not statistically significant: Confidence (n = 7) Eating problems (n = 1) Emotional wellbeing (n = 11)
15. Reach of MI Compared to STRONG comparison groups: MI was NOT statistically better or worse on 14 of 14 targeted behaviors 2 of 14 targeted behaviors showed a negative, nonsignificantvalence Tobacco Misc. Drugs
16. Target Behaviors x Comparison Type Superior = Statistically Significant at p < .05
17. Target Behaviors x Comparison Type Superior = Statistically Significant at p < .05
22. MI Delivered via Group Only 8 studies…. Limited inference making Weak Comparison Groups: Do not simply rely on group-based MI – include individual Strong Comparison Groups: Too early to tell
23. Is More MI Better? Probably … especially when MI was compared to WEAK comparison groups Positive correlation between minutes spent and time
24. Quick Questions / Answers Does degree of person delivering MI matter? NO Does MI’s role influence outcome? Prelude, Additive, Head-to-Head Does NOT matter
25. Quick Questions / Answers Does age matter? Mixed … probably a lower limit based on cognitive processing skills Is MI better suited to males or females? Neither
26. Summary Robust: Reach & Moderators Equivalent to other active treatments Superior, in most cases, to no treatment or weak treatment Efficient Not a silver bullet … our results show a smaller effect than previous meta-analyses investigating MI
27. Future Directions Investigate moderator effects within targeted behavior areas Empirically investigate why MI works Assess cost-effectiveness of implementing MI into practice at individual and system level
28. Thank you for having me! Brad.Lundahl@socwk.utah.edu
29. Meta-Analyses Examining MI Burke, B., Arkowitz, H., & Menchola, M. (2003). The efficacy of motivational interviewing: A meta-analysis of controlled clinical trials. Journal of Consulting and Clinical Psychology, 71, 843-861. Hettema, J., Steele, J., & Miller, W. (2005). Motivational Interviewing. Annual Review of Clinical Psychology, (1), 91-111. Vasilaki, E., Hosier, S., & Cox, W. (2006). The efficacy of motivational interviewing as a brief intervention for excessive drinking: A meta-analytic review. Alcohol and Alcoholism, 41, 328-335. Lundahl, B. W., Tollefson, D., Kunz, C., Brownell, C., & Burke, B. (2010). Meta-analysis of Motivational interviewing: Twenty Five years of research. Research on Social Work Practice.
30. Motivational Interviewing: A meta-analysis of 25 years of researchBrad Lundahl, PhDUniversity of Utah College of Social Workwww.socwk.utah.edu
