A Longitudinal Cohort Study of the Costs of Adolescent Obesity Into Young Adulthood.

Introduction: Adolescent obesity is a strong predictor of adult obesity and increases the risk of costly comorbidities. Estimating the long-term individual medical expenditures associated with adolescent weight status is critical for evaluating the cost-effectiveness of prevention and treatment strategies. Objective: Measure the association between adolescent weight status and health care expenditures in early adulthood.adulthood. Methods: This longitudinal cohort study linked students' 10th grade body weight to health care expenditures (total medical, outpatient, inpatient, emergency department, and pharmacy) during the 30th year of life. A two-part model was used to assess differences in costs within the extensive (having "any" spending) or intensive (amount of spending among those with spending) margins. Marginal effects were used to estimate the difference in health care expenditures at age 30 between individuals with higher weight status in the 10th grade (overweight, obesity, or severe obesity) compared with those with a healthy weight. Results: Individuals with obesity in the 10th grade had greater total annual expenditures at age 30 ($542, 95% CI $139-$945) compared to individuals with a healthy weight. Individuals with severe obesity had higher expenditures across all outcomes. Total medical expenditures were $874 more than individuals with a healthy weight, while inpatient expenditures were $159 more, outpatient expenditures were $387 more, and pharmacy expenditures were $222 more. Differences in inpatient expenditures were primarily at the intensive margin, while emergency department expenditures differed mainly at the extensive margin. Outpatient expenditures varied at both margins. Conclusions: Higher weight status in adolescence is associated with higher health expenditures in young adulthood, with the highest spending among 10th graders with severe obesity.