ESTIMATING MEDICAL EXPENDITURES FOR CHILDHOOD OBESITY COST-EFFECTIVENESS ANALYSES

Purpose: To ascertain whether overweight and obesity are significant predictors of medical expenditures during childhood and adolescence.

Method: We analyzed medical expenditures of individuals aged 6-17 in the 2006-2008 Medical Expenditure Panel Survey, a nationally representative cross-sectional survey of annual medical expenditures in the US. Medical expenditures from public insurance programs were adjusted to private insurance reimbursement rates using the American Academy of Pediatrics Pediatric Medical Cost Model (PMCM). Individuals were assigned to categories of weight based on CDC age- and sex-adjusted Body Mass Index (BMI) cutoffs. The impact of overweight and obesity on annual medical expenditures was assessed, controlling for age (adolescent or not), the interaction between age and weight category, sex, race, geographic region, and insurance status. An algorithm by Manning and Mullahy was used to select the appropriate medical expenditure estimation model for the analysis. A two-part model, where part one was a probit regression of incurring positive expenditures and part two was an ordinary least squared regression on logged expenditures, was selected. A Duan smearing factor was used to transform logged expenditures back to the original dollar scale. Medical expenditures were assessed in 2010 US dollars.

Result: Child obesity was a significant predictor of having positive medical expenditures in part one of the model (OR = 0.91, p < 0.05). Among those with positive expenditures, neither child overweight nor child obesity were significant predictors of higher expenditures in part two of the model. Adolescent obesity was a significant predictor of having positive medical expenditures in part one of the model (OR = 1.26, p < 0.001). Among those with positive expenditures, adolescent obesity was a significant predictor of higher expenditures (p < 0.10) in part two of the model.  Race, insurance status, income, and age were also significant predictors of higher medical expenditures in part two of the model.

Conclusion: Because obesity was a significant predictor of medical expenditures, costs associated with weight category warrant inclusion in model-based cost-effectiveness analyses of child and adolescent obesity interventions.