Hip-Hop to Health Jr. Randomized Effectiveness Trial: 1-Year Follow-up Results

Abstract

Introduction: The preschool years provide a unique window of opportunity to intervene on obesity-related lifestyle risk factors during the formative years of a child's life. The purpose of this study was to assess the impact of a preschool-based obesity prevention effectiveness trial at 1-year follow-up.

Design: RCT.

Settings/participants: Primarily African American children (aged 3-5 years, N=618) attending Head Start preschool programs administered by Chicago Public Schools.

Methods: Eighteen preschools were randomly assigned in 2007-2008 to receive either (1) a 14-week teacher-delivered intervention focused on healthy lifestyle behaviors or (2) a 14-week teacher-delivered general health curriculum (control group).

Main outcome measures: The primary outcome, BMI, was measured at baseline, postintervention, and 1-year follow-up. Diet and screen time behaviors were also assessed at these time points. Multilevel mixed effects models were used to test for between-group differences. Data were analyzed in 2014.

Results: Significant between-group differences were observed in diet, but not in BMI z-score or screen time at 1-year follow-up. Diet differences favored the intervention arm over controls in overall diet quality (p=0.02) and in subcomponents of diet quality, as measured by the Healthy Eating Index-2005, and in fruit intake (servings/day, excludes juice) (p=0.02). Diet quality worsened more among controls than the intervention group at 1-year follow-up.

Conclusions: The adaptation of Hip-Hop to Health Jr. produced modest benefits in diet quality but did not significantly impact weight gain trajectory. Not unlike other effectiveness trials, this real-world version delivered by Head Start teachers produced fewer benefits than the more rigorous efficacy trial. It is important to understand and build upon the lessons learned from these types of trials so that we can design, implement, and disseminate successful evidence-based programs more widely and effectively.

Trial registration: This study is registered at www.clinicaltrials.gov NCT00241878.

Figure 1

Study flow diagram. Post-intervention describes the period immediately following the intervention and follow-up is one year from the post-intervention period. Any child with relevant data (BMI, diet, screen time) at baseline, post-intervention (4 months), or 1 year post-intervention (16 months) were included in the multi-level models used to estimate outcomes. Based on dietary intake for a full 24 hour period (e.g. 24 hour recalls plus meal observations).

Figure 2

BMI z-score by study arm. Means were estimated from a multilevel mixed effects model adjusted for age and included any child with BMI data (n=618, intervention: n=325, control n=293). Error bars reflect standard errors (+/−) at each time point. ‘Post-intervention’ refers to the period immediately following the intervention (at approximately 4 months) and ‘1-year follow-up’ refers to the period one year after the intervention was completed (at approximately 16 months)