Motivational Interviewing in Primary Care Reduces Obesity

Mary Beth Nierengarten

March 30, 2015

Overweight children whose parents received motivational interviewing (MI) from primary care providers (PCPs) and registered dietitians (RDs) showed a significant reduction in body mass index over the course of 2 years compared with children who received usual care.

"This is among the first counseling interventions using MI and delivered in primary care to yield significant effects on adiposity," write Kenneth Resnicow, PhD, from the Department of Health Behavior & Health Education, School of Public Health, University of Michigan, Ann Arbor, and colleagues.

The study, published online March 30 in Pediatrics, included 645 patients from 42 practices from the Pediatric Research in Office Settings Network of the American Academy of Pediatrics. Children in the study were between the ages of 2 and 8 years, with a BMI of between the 85th and 97th percentiles.

The researchers excluded children with type 1 or 2 diabetes, chronic medical disorders, or chromosomal disorders; who were taking medications that affected growth; who were enrolled in a weight loss program or were seen by a weight loss specialist in the past 12 months; or who had parents who did not speak English or had no working telephone.

In the study, patients were randomly assigned to one of three treatment groups: group 1 (usual care) received routine care by the PCP along with standard education materials for parents, group 2 (PCP only) included four sessions of MI by a PCP, and group 3 (PCP and RD) included four sessions of MI by a PCP plus six MI sessions from an RD.

Motivational interviewing uses specific patient-centered communication style techniques, including autonomy support, shared decision-making, and reflective listening. In the study, PCPs and RDs used this intervention to counsel patients on discrete behaviors that affect children's weight, such as food choices (ie, snacks, sweetened beverages, fruits/vegetables) and activities (ie, exercise/physical activity, television/screen time).

In the usual care group, parents received educational materials that addressed healthy eating and physical activity.

At a 2-year follow-up, the researchers found an adjusted BMI percentile of 90.3, 88.1, and 87.1 for groups 1, 2, and 3, respectively. Mean changes from baseline in BMI percentile for groups 1, 2, and 3 were 1.8, 3.8, and 4.9, respectively. A significantly lower mean BMI at 2 years was seen in patients in group 3 compared with in those in group 1 (P = .02), which was the primary endpoint of the trial.

On the basis of these successful trial results, the authors suggest that future research should look at how this intervention can be brought to scale, and "in particular, how to train physicians to effectively use MI and how best to train RDs and integrate them into primary care settings."

The current trial provides impressive data on the effectiveness of MI to reduce BMI in primary care, write Cara B. Ebbeling, PhD, from the New Balance Foundation Obesity Prevention Center, Boston, and Richard C. Antonelli, MD, from the Division of General Pediatrics, Department of Medicine, Boston Children's Hospital, Massachusetts, in an accompanying commentary.

The increased weight loss between the PCP-only group and the PCP and RD group might indicate that the intensity of treatment was a factor in the interventions success, the editorialists note.

However, the rate of session completion was lower with RDs, at less than 50%, compared with PCPs, at less than 75%. Thus, even in a structured trial, coordination of care, which could boost success, was less than ideal.

"Substantial effort must be directed toward coordinating care across settings to integrate services centered on the comprehensive needs of patients/families and measuring performance of care-coordination activities," they conclude.

The authors have disclosed no relevant financial relationships.

Pediatrics. Published online March 30, 2015. Article abstract


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.