Cost-Effectiveness and Long-Term Savings of the Bright Bodies Intervention for Childhood Obesity

Abstract

Objectives: To estimate the cost and cost-effectiveness of Bright Bodies, a high-intensity, family-based intervention that has been demonstrated to improve body mass index (BMI) among children with obesity in a randomized controlled trial.

Methods: We developed a microsimulation model to project 10-year BMI trajectories of 8 to 16-year-old children with obesity, using data from the National Longitudinal Surveys and Centers for Disease Control and Prevention growth charts, and we validated the model using data from the Bright Bodies trial and a follow-up study. We used the trial data to estimate the average reduction in BMI per person-year over 10 years and the incremental costs of Bright Bodies, compared with the traditional clinical weight management (control), from a health system's perspective in 2020 US dollars. Using results from studies of Medical Expenditure Panel Survey data, we projected the long-term obesity-related medical expenditure.

Results: In the primary analysis, assuming depreciating effects postintervention, Bright Bodies is expected to reduce a participant's BMI by 1.67 kg/m² (95% uncertainty interval 1.43-1.94) per year over 10 years as compared with control. The incremental intervention cost of Bright Bodies was $360 ($292-$421) per person compared with the clinical control. Nevertheless, savings in obesity-related healthcare expenditure offset these costs and the expected cost-savings of Bright Bodies is $1126 ($689-$1693) per person over 10-years. The projected time to achieve cost-savings compared with clinical control was 3.58 (2.63-5.17) years.

Conclusions: Although resource-intensive, our findings suggest that Bright Bodies is cost-saving compared to the clinical control by averting future obesity-related healthcare costs among children with obesity.

Keywords: computer simulation; economic evaluation; modeling; obesity management; pediatric obesity.

Fig. 1.. Using data from NLS to build BMI trajectories to use in our simulation model.

*Physician-reported height and weight values were prioritized for inclusion in our BMI calculations, with self-reported, or parent-reported, used when physician-reported was unavailable. ^¶CDC thresholds for obesity, defined as BMI at or above the 95^th percentile for age and sex, are provided in Table S3.

Fig. 2.

Model validation: difference in average change in BMI by intervention group between baseline and year 1 and between year 1 and year 2 in the Bright Bodies RCT and in the simulation model.

Fig. 3.. Model validation: average reduction in BMI between Bright Bodies and clinical control over the 10-year simulation under the primary scenario of depreciating intervention effect.

For model validation results under the other scenarios for the maintenance of intervention effect, see Figure S2 and Figure S3.

Fig. 4.

Average BMI over 10-year simulation of Bright Bodies and clinical control under the primary scenario of depreciating intervention effect.

Fig. 5.. Time to cost savings of Bright Bodies relative to the clinical control under the primary scenario of depreciating intervention effect.

Curves shows the difference in cumulative discounted cost per person over the 10-year simulation.

Fig. 6.. Cost-effectiveness analysis of Bright Bodies under the primary scenario of depreciating intervention effect.

The origin represents the clinical control in the Bright Bodies RCT. All costs are discounted to 2020.