The Heterogeneity of MI Interventions Studies for Treatment of Obesity.

Abstract

* Abbreviation: MI — : motivational interviewing In this issue of Pediatrics , Vallabhan et al1 report the results of a rigorous meta-analysis examining the efficacy of motivational interviewing (MI) on adiposity and cardiometabolic outcomes among overweight adolescents. They conclude “MI alone does not seem effective for treating overweight and obesity in adolescents.”1 The authors appropriately note several mitigating factors that temper their conclusions including the relatively low dose of the active interventions in which MI was used (the core interventions were generally far less than the US Preventive Services Task Force guideline of 26 contact hours2), as well as the lack of information on MI fidelity to allow comparison of outcomes based on practitioner competency. In addition to these concerns, we propose a few other issues that may impact the validity of their analyses and corresponding conclusions. The 3 issues all relate to study design: in particular, the composition of the MI intervention and comparison arms. Perhaps the most salient issue is the nature of the intervention arms in these studies. To determine the effectiveness of MI, the most internally valid design would arguably entail using an evidence-based efficacious program as the comparison group and then adding MI on top of that program or integrating MI within … Address correspondence to Ken Resnicow, PhD, Department of Health Behavior and Health Education, School of Public Health, University of Michigan, 3867 SPH I, 1415 Washington Heights, Ann Arbor, MI 48109-2029. E-mail: kresnic{at}umich.edu