Effectiveness of a behavioural incentive scheme linked to goal achievement in overweight children: a cluster randomized controlled trial

Abstract

Background: The prevalence of childhood overweight and obesity is becoming an increasing concern worldwide. This study aimed to determine effectiveness of a structured goal setting incentive scheme, delivered within a community program, on health outcomes in overweight children at 6 and 18 months. Methods: Single-blind, cluster randomized controlled trial with 10 weeks, 6 month and 18 month follow-up. Community weight-loss programs for children were randomized to (i) standard program plus incentive scheme (intervention) or (ii) standard program alone (control). Primary outcome was mean BMIz score at 18 months. Secondary outcomes included anthropometric and behavioural measures. Results: A total of 37 sites (33 urban and 4 regional) and 512 children were recruited. Compared to baseline, at 18 month follow-up, the total cohort achieved significant reductions in the mean BMIz score (1.7 v 1.0, p<0.001), median screen time (16.5 v 15.8 hours/week p=0.0414), median number of fast food meals per week (1.0 v 0.7, p<0.001) and significant increases in physical activity (6.0 v 10.0 hours/week, p<0.001) and self-esteem score (20.7 v 22.0, p<0.002). There were no significant differences between the control and intervention groups at any follow-up time-points. There were significantly more participants in the intervention than control group who completed 10 sessions of the weight management program (23% v 13%, p=0.015). Conclusions: The incentive scheme, delivered in addition to the standard program, did not have a significant impact on health outcomes in overweight children. However, the intervention increased program attendance and overall cohort achieved sustained improvements in clinical and lifestyle outcomes.