Related Experiment Video
Updated: Feb 22, 2026
Assessment of Child Anthropometry in a Large Epidemiologic Study
Published on: February 2, 2017
The accuracy of emergency weight estimation systems in children-a systematic review and meta-analysis
Mike Wells1,2, Lara Nicole Goldstein3, Alison Bentley3
1Division of Emergency Medicine, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa. mike.wells@emergencymedicine.co.za.
Insights
Accurate weight estimation in pediatric emergencies is crucial for safe medication dosing. Newer two-dimensional systems, like the PAWPER tape and Mercy method, offer superior accuracy compared to traditional age-based methods.
Area of Science:
- Pediatric Emergency Medicine
- Clinical Pharmacology
- Biostatistics
Background:
- Accurate weight estimation in children is critical for safe and effective medication and fluid administration during medical emergencies.
- Current weight estimation methods often lack sufficient accuracy, necessitating the development and evaluation of improved techniques.
- Two-dimensional, length-based, habitus-modified systems show promise for enhanced accuracy in pediatric weight estimation.
Purpose of the Study:
- To evaluate the accuracy of various pediatric weight estimation systems through a comprehensive meta-analysis.
- To establish appropriate accuracy targets for reliable weight estimation in emergency pediatric care.
- To compare the performance of different estimation methods, including length-based, habitus-modified, and age-based systems.
Main Methods:
- Systematic screening of articles to identify studies on pediatric weight estimation systems.
- Inclusion of studies into two arms: determining accuracy targets and evaluating existing systems.
- Application of standard meta-analysis techniques to quantify the accuracy of different estimation methods.
Main Results:
- No existing evidence supported a specific accuracy goal for weight estimation systems.
- Proposed minimum accuracy benchmarks: 70% within 10% of actual weight (PW10 > 70%) and 95% within 20% (PW20 > 95%).
- Two-dimensional systems, specifically the PAWPER tape and Mercy method, demonstrated the highest accuracy, outperforming the Broselow tape and age-based estimates. Parental estimates also showed considerable accuracy.
Conclusions:
- The PAWPER tape, Mercy method, and parental estimates are recommended as the most accurate weight estimation systems for pediatric emergencies.
- Length-based systems offer better accuracy than age-based systems, which should be abandoned due to their poor performance.
- The proposed accuracy benchmarks (PW10 > 70%, PW20 > 95%) should guide the selection and validation of reliable pediatric weight estimation tools.
Abstract:
The safe and effective administration of fluids and medications during the management of medical emergencies in children depends on an appropriately determined dose, based on body weight. Weight can often not be measured in these circumstances and a convenient, quick and accurate method of weight estimation is required. Most methods in current use are not accurate enough, but the newer length-based, habitus-modified (two-dimensional) systems have shown significantly higher accuracy. This meta-analysis evaluated the accuracy of weight estimation systems in children. Articles were screened for inclusion into two study arms: to determine an appropriate accuracy target for weight estimation systems; and to evaluate the accuracy of existing systems using standard meta-analysis techniques. There was no evidence found to support any specific goal of accuracy. Based on the findings of this study, a proposed minimum accuracy of 70% of estimations within 10% of actual weight (PW10 > 70%), and 95% within 20% of actual weight (PW20 > 95%) should be demonstrated by a weight estimation system before being considered to be accurate. In the meta-analysis, the two-dimensional systems performed best. The Mercy method (PW10 70.9%, PW20 95.3%), the PAWPER tape (PW10 78.0%, PW20 96.6%) and parental estimates (PW10 69.8%, PW20 87.1%) were the most accurate systems investigated, with the Broselow tape (PW10 55.6%, PW20 81.2%) achieving a lesser accuracy. Age-based estimates achieved a very low accuracy. Age- and length-based systems had a substantial difference in over- and underestimation of weight in high-income and low- and middle-income populations. A benchmark for minimum accuracy is recommended for weight estimation studies and a PW10 > 70% with PW20 > 95% is suggested. The Mercy method, the PAWPER tape and parental estimates were the most accurate weight estimation systems followed by length-based and age-based systems. The use of age-based formulas should be abandoned because of their poor accuracy.
Related Concept Videos
03:37Uncertainty in Measurement: Accuracy and Precision
01:20Random and Systematic Errors
01:28Drug Dosing in Renal Diseases: Estimation of Glomerular Filtration Rate Based on Serum Creatinine Concentration
01:21Drug Dosing: Obese Patients
01:29Drug Dosing: Infants and Children