Meta-analysis of motivational interviewing for adolescent health behavior: efficacy beyond substance use

We sought to systematically review and meta-analyze the literature comparing motivational interviewing (MI) with a control condition for adolescent health behavior change. In the current article, we reviewed only studies targeting health behaviors other than substance use (e.g., sexual risk behavior, physical activity, diet).

Systematic literature searches of PsycINFO, PubMed/Medline, and ERIC were conducted through June 2013. Databases were combined, and studies were screened for inclusion or exclusion. To be included in the current review, studies were required to (a) compare the efficacy of at least 1 session of MI intervention with a control condition using a between-groups design and (b) examine a non-substance-use health behavior in adolescents. Fifteen studies met criteria for inclusion and were described qualitatively and quantitatively.

Using a fixed-effects model, we found that MI interventions produced a small, but significant, aggregate effect size for short-term postintervention effects-g = .16; 95% confidence interval (CI) [.05, .27]-compared with control conditions. Moreover, this effect was sustained at follow-up assessments averaging 33.6 weeks postintervention, n = 8, g = .18, 95% CI [.05, .32].

MI interventions for adolescent health behavior appear to be effective. In addition, the magnitude of the aggregate effect size does not appear to differ meaningfully from reports of interventions targeting only substance use in adolescents. However, significant lack of clarity exists regarding interventionist training requirements necessary to ensure intervention effectiveness.