Pediatric Weight Estimates: Which Method Is Best?

Kristi L. Koenig, MD, FACEP, FIFEM

In this large Australian study, the Best Guess formula was the most accurate for predicting weight in children older than 1 year.

Accurate determination of drug dosing, equipment size, and defibrillation energy is challenging during pediatric resuscitation. Researchers compared methods of weight estimation in a retrospective observational study of more than 37,000 children (age <14) who presented to a single referral center in Australia during 30 years and for whom data on age and weight or height were available.

Methods tested were the aged-based original Advanced Pediatric Life Support (APLS), new APLS, Luscombe and Owens, and Best Guess formulas, and the length-based Broselow tape. The Best Guess method (see table) was the most accurate for children older than 1 year (mean difference between measured and estimated weight, 0.43 kg), and the new APLS formula (see table) was the most accurate for children younger than 1 year (mean difference, 0.51 kg). The Broselow tape was the most precise method (the highest proportion of estimated weights within 10% of measured weights), but misclassified more than 50% of children, most commonly in the older age groups. All methods had a strong positive correlation with measured weight; the Best Guess was the only one that tended to overestimate weight. 

Citation(s):

Graves L et al. A comparison of actual to estimated weights in Australian children attending a tertiary children's hospital, using the original and updated APLS, Luscombe and Owens, Best Guess formulae and the Broselow tape. Resuscitation 2013 Dec 7; [e-pub ahead of print].