Who benefits from the intervention? Correlates of successful BMI reduction in the Texas Childhood Obesity Demonstration Project (TX‐CORD)

Abstract

Many childhood obesity intervention studies report mean outcomes but do not explore the variation in responses and the characteristics of those who respond well. To identify child and family characteristics associated with improvement in the primary outcome, %BMIp95 , of the Texas Childhood Obesity Research Demonstration project (TX-CORD). The 12-month TX-CORD secondary prevention study randomized 549 children, ages 2 to 12 years, with BMI ≥85th percentile to the intensive intervention vs. the comparison program, with measurements at baseline, 3-, and 12-months. A growth mixture model was used to identify mutually exclusive latent %BMIp95 trajectories. Latent class regression tested associations between baseline characteristics and latent class membership. A 2-class solution emerged after accounting for the effect of intervention randomization. Latent Class 1 participants (86% of sample) were characterized by mild-to-moderate obesity and demonstrated a significantly greater response to the intensive intervention between 0 and 3 months (slope-on-group = -0.931, p = 0.03). A rebound between 3 and 12 months was not significantly different between arms. Latent Class 2 participants (14%), who had severe obesity, demonstrated no difference in response between intervention groups. Characteristics associated with Class 1 membership included younger age (2-5 years vs. 6-12 years: OR 3.70, p = .035) and lower maternal BMI category (< 35 kg/m2 vs. ≥ 35 kg/m2 : OR 7.14, p < .0001). The optimal target population for the intensive intervention are children who have milder obesity, are younger, and do not have a mother with severe obesity. Children with severe obesity may require different approaches.