Impact of motivational interviewing on engagement in a parent-exclusive paediatric obesity intervention: randomized controlled trial of NOURISH+MI.

BACKGROUND: Attrition and treatment adherence are notorious challenges in paediatric obesity interventions. OBJECTIVE: To evaluate if brief, pretreatment motivational interviewing (MI) can improve retention (at baseline, post-assessment and follow-up assessment) and adherence (i.e. attendance) in a parent-exclusive paediatric obesity intervention. METHODS: MI was implemented with parents as an adjunct to a larger randomized controlled trial of Nourishing Our Understanding of Role-modeling to Improve Support and Health (NOURISH+ ), a parent intervention for children with overweight ages 5-11 years. Parents (N = 112) were randomized to receive two MI sessions (one telephone and one in person) or reminder calls. RESULTS: Parents (91% women; 52% African American) who completed one telephone MI session were more likely to attend baseline (74%) compared with parents who received reminder calls only (53%, p < .001). After a second MI session, there were no group differences in treatment initiation (p > .05). Treatment attendance, post or 4-month follow-up assessment completion did not differ between conditions (p > .05). CONCLUSION: One MI session implemented prior to treatment can improve baseline attendance; a second MI session did not enhance these effects. A single-session telephone-based MI pretreatment might be a cost and time-effective strategy to enhance recruitment efforts. Further strategies to address retention and treatment attendance are needed.