Health Care Utilization by Body Mass Index in a Pediatric Population

Objective We tested the hypothesis that the frequency of emergency department (ED) visits, outpatient clinic visits, and hospitalizations were higher among children with higher body mass index (BMI) categories, even after controlling for demographics, socioeconomic status, and presence of other chronic medical conditions. Methods We obtained electronic height, weight, and utilization data for all residents of Olmsted County, Minnesota, aged 2 to 18 years on January 1, 2005 (n = 34,335), and calculated baseline BMI (kg/m²). At least 1 BMI measurement and permission to use medical record information was available for 19,771 children (58%); 19,528 with follow-up comprised the final cohort. BMIs were categorized into underweight/healthy weight (<85th percentile), overweight (85th to <95th percentile), and obese (≥95th percentile). Negative binomial models were used to compare the rate of utilization across BMI categories. Multivariable models were used to adjust for the effects of age, race, sex, socioeconomic status, and chronic medical conditions. Results Compared to children with BMI <85th percentile, overweight and obese status were associated with increased ED visits (adjusted incident rate ratio [IRR] 1.16, 95% confidence interval [CI] 1.10, 1.23; and IRR 1.27, 95% CI 1.19, 1.35, respectively; P for trend <.0001), and outpatient clinic visits (IRR 1.05, 95% CI 1.02, 1.08; and IRR 1.07, 95% CI 1.04, 1.11, respectively; P for trend <.0001). No associations were observed between baseline BMI category and hospitalizations in the adjusted analyses. Conclusions Children who are overweight or obese utilize the ED and outpatient clinics more frequently than those who are underweight/healthy weight, but are not hospitalized more frequently.