Background: Electronic health record (EHR) data have been used increasingly for public health research and surveillance as they enable access to large amounts of timely clinical data to answer important questions. In particular, growth data, including measured heights and weights, can be vital for surveilling weight status, identifying those at-risk for obesity-related health conditions, and facilitating coordination of weight management services. PEDSnet is a clinical data research network, comprising eight large US pediatric health systems, with data on >5.2 million children aged 2-19 years. We aimed to estimate the prevalence of childhood obesity and severe obesity in 2018 using EHR data, overall and by sex, race/ethnicity, and age group. We also compared our estimates to 2015-2018 data from the National Health and Nutrition Examination Survey (NHANES), the gold standard for measuring obesity prevalence. Methods: Measured height and weight values extracted from EHRs were cleaned using Growthcleanr, an open-source R package for cleaning pediatric growth data (https://github.com/carriedaymont/growthcleanr). CDC criteria for biologically implausible values were applied to height and weight measurements and body mass index (BMI) calculations. Obesity was defined as BMI ≥95th percentile for age- and sex-specific BMI. Severe obesity was defined as BMI ≥120% of the 95th percentile and very severe obesity as BMI ≥140% of the 95th percentile. If children had multiple valid BMI measurements during a particular year, one was randomly selected to obtain a cohort with one valid BMI per child per year. The final 2018 dataset included 1,031,016 children aged 2-19 years. Results: In 2018, 15.0% of PEDSnet children had overweight and 17.1% had obesity, including 5.8% with severe obesity and 1.9% with very severe obesity [Table 1]. The prevalence of obesity was 24.5% among Hispanics, 21.3% among non-Hispanic blacks, and 14.5% among non-Hispanic whites. Obesity prevalence was 18.0% among children aged 6-11 years, 20.3% among adolescents, and 11.2% among preschool-aged children. Similar differences were observed for severe obesity categories. Despite not being nationally representative, PEDSnet estimates were fairly comparable to NHANES, particularly for severe obesity categories, although they were slightly lower for obesity [Table 2]. Discussion: Among PEDSnet children in 2018, nearly one-third had overweight or obesity. Consistent with NHANES, disparities existed in the prevalence of childhood obesity and severe obesity. Older children, especially adolescents aged 12-19 years, and children of racial/ethnic minorities exhibited a higher prevalence. Due to very large sample sizes available in EHR data, we were able to examine the severity of obesity at high thresholds of BMI percentile and obtain reliable estimates for demographic sub-groups. EHR datasets offer a wealth of real-world clinical data, including measured heights and weights, which may uniquely complement national surveys and demonstrate value for obesity research and practice.

Table 1

Prevalence of weight status categories in a large cohort of U.S. children and adolescents aged 2-19 years, overall and by sex, race/ethnicity, and age group, PEDSnet 2018

Table 1

Prevalence of weight status categories in a large cohort of U.S. children and adolescents aged 2-19 years, overall and by sex, race/ethnicity, and age group, PEDSnet 2018

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Table 2

Prevalence of obesity, severe obesity, and very severe obesity in a large cohort of U.S. children in PEDSnet (2018) and in two combined NHANES cycles (2015-2016, 2017-2018)

Table 2

Prevalence of obesity, severe obesity, and very severe obesity in a large cohort of U.S. children in PEDSnet (2018) and in two combined NHANES cycles (2015-2016, 2017-2018)

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