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
