Failed validation of the Argall weight formula for estimating children's weight in an Australian emergency department.
BACKGROUND
An estimate of a child's weight is required for critical interventions, particularly pharmacotherapy. Weight measurement is not always practical, so weight estimation methods are used. Recently, a new weight estimation formula was suggested. The Argall formula estimates weight in kilograms as follows: (age in years + 2) x 3.


OBJECTIVE
To validate the Argall weight formula.


METHODS
This was a prospective, observational, cohort study conducted in the pediatric emergency department (ED) of Sunshine Hospital. Children aged up to 11 years who presented to the ED during August 18, 2005, to February 25, 2006, were included. Actual weight, height, age, and ethnicity were obtained. Data were analyzed by descriptive statistics (proportion, mean, median, and SD). Agreement between estimated weight using the Argall formula and measured weight is reported by using mean bias, SD, and root mean square error (RMSE) analysis.


RESULTS
Four hundred ten cases were included, 46% were female, and the median age was 4 years. The Argall formula had a mean bias of -1.66 kg and RMSE of 5.65. Only 37% of Argall estimates were within 10% of the child's actual weight. The formula performed less well in children weighing more than 35 kg but performed better in Asian children than white children.


CONCLUSIONS
The Argall weight estimation formula has poor accuracy for weight estimation in Australian children, in particular those weighing more than 35 kg.
Nguyen
Kevin
K
University of Melbourne, Victoria, Australia.
Krieser
David
D
Kerr
Debra
D
Jolley
Damien
D
Clooney
Megan
M
Kelly
Anne-Maree
AM
D000886:Anthropometry / Q000379:methods*; D015992:Body Mass Index; D001835:Body Weight; D002675:Child, Preschool; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D014739:Victoria