### Description

Cattermole et al reported an equation for estimating body weight from age for children from 1 to 10 years of age. The authors are from the Chinese University of Hong Kong, University of Melbourne.

Patient selection: Chinese children from 1 to 10 years of age

estimated body weight in kilograms =

= (3 * (age at last birthday)) + 5

This was considered accurate and precise for children < 7 years of age.

Observations:

(1) The relationship between age and weight is linear up to 6 to 7 years of age then becomes nonlinear.

(2) The spread between the 5th and 95th percentile starts to increase significantly after 7 years of age.

(3) After 9 or 10 years of age a simple linear model no longer is adequate.

If the lines in Figure 1 (page 391) are analyzed:

line for 5th percentile weight in kilograms =

= (1.698 * (age)) + 5.94

line for 50th percentile weight in kilograms =

= (2.496 * *age)) + 6.153 =

= (0.08977 * ((age)^2)) + (1.508 * (age)) + 8.128

line for 95th percentile weight in kilograms =

= (0.2182 * ((age)^2)) + (1.843 * (age)) + 9.513