In order to correct height velocities for the confounders age and sex, SD scores can be calculated using the mean and the SD of the height velocity in the normal population. However, current methods are inappropriate for prepubertal children in the age range in which puberty occurs, because reference groups then consist of a mixed prepubertal/pubertal population. The mathematical infancy-childhood-puberty (ICP) model opens up the possibility of dissecting the puberty component from the total growth curve. New references for height velocity for prepubertal children calculated over a 12 month interval up to the ages of 15.5 years (boys) and 13.5 years (girls) have been constructed on the basis of adaptations of the ICP model and the Swedish longitudinal growth study.
