A Systematic Review and Meta-Analysis of Motivational Interviewing Training Effectiveness Among Students-in-Training

Effectively using motivational interviewing (MI) in practice can be difficult. However, there are a number of studies that examine training students across helping professions, with the goal of promoting more effective use of MI. The purpose of this systematic review and meta-analysis was to quantify the effectiveness of teaching students MI. In total, 15 randomized and nonrandomized studies met inclusion criteria and were examined in the current review of 8 dependent variables. A large and significant overall Hedges’ g of 0.90 (95% CI [0.45, 1.35]) was found. When restricted to randomized controlled trials only, it decreased to moderate-in-size (g = 0.74, CI [0.41, 1.56]). Significant effects were observed with the knowledge, empathy, and change plan outcomes. Moderation analyses revealed training length was a significant moderator, with greater effects being associated with longer trainings. Limitations of the current metaanalysis included the small sample size and lack of consistency among training duration, measurement, and data collection, as well as the resulting heterogeneity. Future research appears warranted to further assess student MI training effectiveness, especially using more rigorous and standardized procedures and in determining enduring effects of the training.