Body mass index and pediatric asthma outcomes

The purpose of this study was to determine the association between body mass index (BMI), a measure of obesity, with emergency department admission rate in children with asthma.

This was a prospective study in a tertiary care, urban pediatric emergency department. Treating physicians and academic associates enrolled subjects during June 2005 to April 2008. Eligible subjects with documented weight and height were between ages 6 and 18 years with chief complaint of wheezing. We compared admission rates between overweight children (BMI, > or = 85% percentile) and nonoverweight children (BMI, < 85% percentile). Data were expressed as mean (SD). Group comparisons were made by Student t test or Fisher exact test, as appropriate. All tests were 2-tailed with an alpha set at 0.05.

We studied 183 children, where 108 children were classified overweight. Demographic differences (mean age, male sex, and African-American race) between overweight and nonoverweight children were not statistically significant. In addition, changes in asthma outcome measures (inpatient admissions during the previous year, asthma visits in the last 30 days, and missed school days in the last 30 days) were not statistically significant. Only household tobacco use approached statistical significance (P = 0.07). The admission rate for nonoverweight children was 9.3% (95% confidence interval [CI], 4.3-18.3) compared with the 10.2% (95% CI, 5.6-17.5) for overweight children; a P = 1.0 was equivalent.

Body mass index, a method to quantify overweight children, failed to predict admission of children with ambulatory asthma who presented to the pediatric emergency department.