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 (9,618 participants) were included. The overall effect showed a statistically significant, modest advantage for MI: Odd Ratio = 1.55 (CI: 1.40 to 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. MI was robust across moderators such as delivery location and patient characteristics, and appears efficacious when delivered in brief consultations. Conclusion & 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.