Article Text

Download PDFPDF
Comparing the usability of paediatric weight estimation methods: a simulation study
  1. Robin D Marlow1,2,
  2. Dora L B Wood3,
  3. Mark D Lyttle2,4
  1. 1 Population Health Sciences, University of Bristol, Bristol, UK
  2. 2 Paediatric Emergency Department, Bristol Royal Children’s Hospital, Bristol, UK
  3. 3 Paediatric Intensive Care, Bristol Royal Children’s Hospital, Bristol, UK
  4. 4 Faculty of Health and Applied Sciences, University of the West of England, Bristol, UK
  1. Correspondence to Dr Robin D Marlow, Bristol Royal Children’s Hospital, Upper Maudlin Street, Bristol BS2 8AE, UK; robin.marlow{at}


Objective Estimating weight is essential in order to prepare appropriate sized equipment and doses of resuscitation drugs in cases where children are critically ill or injured. Many methods exist with varying degrees of complexity and accuracy. The most recent version of the Advanced Paediatric Life Support (APLS) course has changed their teaching from an age-based calculation method to the use of a reference table. We aimed to evaluate the potential implications of this change.

Method Using a bespoke online simulation platform we assessed the ability of acute paediatric staff to apply different methods of weight estimation. Comparing the time taken, rate and magnitude of errors were made using the APLS single and triple age-based formulae, Best Guess and reference table methods. To add urgency and an element of cognitive stress, a time-based competitive component was included.

Results 57 participants performed a total of 2240 estimates of weight. The reference table was the fastest (25 (22–28) vs 35 (31–38) to 48 (43–51) s) and most preferred, but errors were made using all methods. There was no significant difference in the percentage accuracy between methods (93%–97%) but the magnitude of errors made was significantly smaller using the three APLS formulae 10% (6.5–21) compared with reference table (69% (34–133)) mainly from month/year table confusion.

Conclusion In this exploratory study under psychological stress none of the methods of weight estimation were free from error. Reference tables were the fastest method and also had the largest errors and should be designed to minimise the risk of picking errors.

  • weight estimation
  • paediatric
  • APLS
  • human factors
  • simulation

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement All data and scripts used for analysis are available on request from the lead author.