Background: The prevalence of overweight/obesity in US children has increased over the past several decades. Routine use of weight-based dosing of medications could potentially result in over- or underdosing in these children.
Objective: To determine the percentage of admissions of children with a body mass index (BMI) greater than or equal to the 85th percentile for age and sex and the mean error rate per admission in the overweight versus control group.
Methods: We performed a retrospective, preliminary study of children aged 5-12 years who were admitted to a children's hospital over a period of 6 months. The overweight group included children with a BMI greater than or equal to the 85th percentile; the control group included children with a BMI less than the 85th percentile. Dose appropriateness was assessed, using 2 references. An overdose was defined as: (1) total mg/kg/day or mg/kg/dose greater than or equal to 110% of the maximum recommended pediatric dose, (2) total mg/day greater than the adult maximum recommended dose, or (3) greater than the recommended number of doses per day. An underdose was defined as: (1) total mg/kg/day or mg/kg/dose less than or equal to 90% of the minimum recommended pediatric dose, or (2) fewer than the recommended number of doses per day. Baseline comparisons between groups were done via Student's t-tests and chi2 analysis, when appropriate, with an a priori alpha of p less than or equal to 0.05.
Results: A total of 839 admissions representing 699 patients were included. The overweight group included 278 (33.1%) admissions. Comparison of overall mean error rate per admission revealed a statistically significant increase in dosing errors for overweight patients (0.4 +/- 0.6 vs 0.3 +/- 0.6; p = 0.030), with underdose errors occurring more frequently than overdose errors (0.3 +/- 0.6 vs 0.2 +/- 0.5; p = 0.010).
Conclusions: Overweight children accounted for one-third of admissions, and the results of this study suggest that these patients are at greater risk for errors in dosing than are children of age- and sex-appropriate weight. This study did not assess clinical outcomes; however, overweight children could be at increased risk for therapeutic failures or adverse effects.