The Centers for Disease and Prevention provides several tables for describing development from birth to 20 years of age.
Patient selection: age from 0 to 3 years of age (0 to 36 months)
Parameters:
(1) birthdate
(2) date of exam
(3) gender
(4) length in centimeters
age in months =
= ((age of exam) - (birthdate)) / 30.4375
For each specified month in the tables, 3 variables are given:
(1) L = power in the Box-Cox transformation
(2) M = median
(3) S = generalized coefficient of variation
When L is not equal to 0:
Z-score for a value =
= ((((value) / M) ^ (L)) - 1) / (L * S)
