Comparing the performance of pediatric weight estimation methods

Andrew Shieh; Alexander J Rogers; Chiu-Mei Chen; Sriram Ramgopal

doi:10.1016/j.ajem.2024.04.053

Comparing the performance of pediatric weight estimation methods

Am J Emerg Med. 2024 May 3:82:26-32. doi: 10.1016/j.ajem.2024.04.053. Online ahead of print.

Authors

Andrew Shieh¹, Alexander J Rogers², Chiu-Mei Chen³, Sriram Ramgopal⁴

Affiliations

¹ Department of Emergency Medicine, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI 48109, United States of America. Electronic address: shandrew@med.umich.edu.
² Department of Emergency Medicine, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI 48109, United States of America; Department of Pediatrics, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI 48109, United States of America.
³ Department of Emergency Medicine, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI 48109, United States of America.
⁴ Division of Pediatric Emergency Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave., Chicago, IL 60611, United States of America.

PMID: 38759251
DOI: 10.1016/j.ajem.2024.04.053

Abstract

Background: Weight estimation is essential in the care of ill children when a weight cannot be obtained. This is particularly important for children with medical complexity, who are at higher risk for adverse drug events. Our objective was to compare the accuracy of different methods of weight estimation in children and stratify by the presence of medical complexity.

Methods: We performed a retrospective cross-sectional study of children (<18 years) seen in the emergency department (ED) or ambulatory clinic from January 1, 2013 to December 31, 2022 at a tertiary academic pediatric center. We compared the performance of nine age-based formulae and two length-based methods using metrics of mean average error (MAE), root mean square error (RMSE), and agreement within 10% and 20% of measured weight. We additionally evaluated the approaches stratified by body mass index (BMI) and the presence of medical complexity.

Results: Of 361,755 children (median age 8.2 years, IQR 2.5-14.2 years; 51.5% male), 59,283 (16.4%) were seen in the ED. Length was measured or available in 21,330 (36.0%) patients in the ED and 293,410 (97%) patients in clinics. The Broselow tape outperformed all methods, with 50.7% estimates within 10% of measured weight, 80.0% estimates within 20% of measured weight, the lowest MAE (2.5 kg), and lowest RMSE (4.5 kg). The Antevy formula was the most accurate age-based formula, with 49.2% estimates within 10% of measured weight, 80.1% estimates within 20% of measured weight, MAE of 2.8 kg, and RMSE of 4.7 kg. Estimates became less accurate as BMI and estimated weight increased for all methods. Among children with medical complexity (14.1%), the Broselow tape consistently outperformed age-based formulae, with 47.7% estimates within 10% of measured weight, 77.1% estimates within 20% of measured weight, MAE of 2.6 kg, and RMSE of 5.4 kg. The Antevy formula remained the most accurate age-based method among children with medical complexity.

Conclusion: The Broselow tape predicted weight most accurately in this large sample of children, including among those with medical complexity. The Antevy formula is the most accurate age-based method for pediatric weight estimation.

Keywords: Body mass index; Body weight; Complex chronic conditions; Emergency department; Estimation; Pediatrics.