Linear Growth Faltering Should Be Assessed in Absolute and Relative Terms

Dear Editor:The concept of standard deviations was first proposed by KarlPearson 120 y ago (1) to account for the fact that an absolutemeasure (e.g., in centimeters or kilograms) may have differentinterpretations depending on how much variability there iswithin a population. Had Pearson still been among us, he wouldnot be surprised by the findings of Leroy et al. (2)—namely,that conflicting results are produced when growth faltering isassessed in...