Finger counting: an alternative method for estimating pediatric weights

Objectives: We compared the accuracy of a conceptually simple pediatric weight estimation technique, the finger counting method, with other commonly used methods.

Methods: We prospectively collected cross-sectional data on a convenience sample of 207 children aged 1 to 9 presenting to our pediatric emergency department. Bland-Altman plots were constructed to compare the finger counting method to the Broselow tape method, parental estimate, the Luscombe formula, and the advanced pediatric life support (APLS) formula. Proportions within 10% and 20% of measured weight were compared.

Results: Mean difference and range of agreement in kilograms for Bland-Altman plots were as follows: -1.8 (95% confidence interval [CI], -2.3 to -1.3) and 15.4 (95% CI, 13.6-17.2) for the finger counting method; -1.4 (95% CI, -2.0 to -0.9) and 15.8 (95% CI, 13.9-17.6) for the Broselow method; -0.02 (95% CI, -0.53 to 0.49) and 14.8 (95% CI, 13-16.6) for parental estimate; 0.2 (95% CI, -0.33 to 0.72) and 15.3 (95% CI, 13.5-17.2) for the Luscombe formula; and -3.8 (95% CI, -4.4 to -3.2) and 17.2 (95% CI, 15.2-19.2) for the APLS formula. The finger counting method estimated weights within 10% in 59% of children (95% CI, 52%-65%) and within 20% in 87% of children (95% CI, 81%-91%). Proportions within 10% were similar for all methods, except the APLS method, which was lower.

Conclusions: The finger counting method is an acceptable alternative to the Broselow method for weight estimation in children aged 1 to 9 years. It outperforms the traditional APLS method but underestimates weights compared with parental estimate and the Luscombe formula.