Distinctions between short- and long-term human growth studies.

It is known what the aim is in a complete long-term growth study; the final height is the outcome measure, although the annual height velocity values provide additional information. Strictly, short-term growth studies are also defined in terms of minimum length of observation, i.e. one month, as well as the type of measurement errors to be considered. The poor correlation between short- and long-term growth velocity values has led to the conclusion that the short-term study cannot be interpreted in long-term perspectives, and vice versa. There is a need to debate the way in which results of short-term studies should be interpreted. This is especially important when short-term growth is taken as the outcome measure in a controlled study. Our proposal is that such studies must include information about the growth achieved for a period after the treatment has ended in order to describe possible compensatory growth. Without weighing in some long-term consequences, we may incorrectly document short-term growth as a positive or negative effect of a certain treatment.