Womack Army Medical Center (WAMC), Fort Bragg, North Carolina, has 6 primary care clinics that serve 117,000 enrollees, including 54,000 military members, 51,000 military family members, and 12,000 military retirees and family members. Approximately 26,000 are pediatric enrollees; more than 96% have at least 1 military parent, and less than 5% are children of retirees. Using electronic medical records (EMRs), we collected the most recent BMI data recorded between January 1, 2008, and December 31, 2009, for 36,000 children aged 2 to 18 years who received primary care exclusively through WAMC. All patients were dependents of active-duty or retired military members. We included in the sample only patients with a BMI on file.
The total eligible sample included all children enrolled during the 2-year period. Nearly 12,000 children were not included because data on height, weight, or sex were missing or because the record lacked administrative identification to match the demographic data, which was required to prevent duplication.
BMI was calculated as weight in kilograms divided by height in meters squared using EMR software. Children at or above the 95th percentile for age were categorized as obese and children between the 85th and 95th percentiles as overweight (5
). We also calculated prevalence estimates for children at or above the 97th percentile. We calculated mean prevalence and 95% confidence intervals by sex and age. We assessed continuous variables for normality of distribution and compared them by using 2-tailed t
tests. We compared categorical variables by using the χ2
test. Statistical significance was established at P
< .05. We compared prevalence data for children of military parents with data that assessed children aged 2 to 19 years from the National Health and Nutrition Examination Survey (NHANES) (2
). We used the z
test for 2 proportions to determine significant differences between military and NHANES prevalence data. We used PASW Statistics for Windows, version 18.0 (SPSS, Inc, Chicago, Illinois) to conduct statistical analysis. The WAMC Institutional Review Board approved this study.