Motivational interviewing in medical care settings: a systematic review and meta-analysis of randomized controlled trials.

Objective: Motivational Interviewing (MI) is a method for encouraging people to make behavioral changes to improve health outcomes. We used systematic review and meta-analysis to investigate MI's efficacy in medical care settings.

Methods: Database searches located randomized clinical trials that compared MI to comparison conditions and isolated the unique effect of MI within medical care settings.

Results: Forty-eight studies (9618 participants) were included. The overall effect showed a statistically significant, modest advantage for MI: Odd ratio=1.55 (CI: 1.40-1.71), z=8.67, p<.001. MI showed particular promise in areas such as HIV viral load, dental outcomes, death rate, body weight, alcohol and tobacco use, sedentary behavior, self-monitoring, confidence in change, and approach to treatment. MI was not particularly effective with eating disorder or self-care behaviors or some medical outcomes such as heart rate.

Conclusion: MI was robust across moderators such as delivery location and patient characteristics, and appears efficacious when delivered in brief consultations.

Practice Implications: The emerging evidence for MI in medical care settings suggests it provides a moderate advantage over comparison interventions and could be used for a wide range of behavioral issues in health care.