Adult Height Predictor

The BoneXpert adult height prediction (AHP) method is founded in the classical Bayley-Pinneau method from 1952, but it includes various improvements in the math and the underlying clinical data, and it adds various features, including some from the more recent Tanner-Whitehouse-3 method.

From gender, age, height and bone age, it predicts the adult height. Optionally, one can enter parental height, which improves the accuracy.

The uncertainties of the predictions of adult height are given as a standard deviation (±SD), i.e. the true values will be within the indicated range with 68% probability.

The predictor is intended to be used with Greulich-Pyle (GP) bone age determined by BoneXpert; however, it can also be used with manual GP bone age, but the uncertainties of the predictions are then considerably larger than indicated, due to the rater variability.

Enter the Adult Height Predictor here:

The full manual can be downloaded here – the following is a summary:

The tool gives four different adult height predictions

They all depend on population height.

The most accurate of these predictions is highlighted in green and shown on the growth chart:

  • AHP(x-ray) is the prediction based on age, bone age and height
  • AHP (parental) is the prediction based solely on the parents’ heights. This is similar, but not identical, to the conventional “target height” (which is mid-parental height ± 6.5 cm), but it is more accurate, because it includes a drawing towards the population height
  • AHP(x+p) is the prediction based on age, bone age, height and parental height
  • AHP(x+m) is the prediction based on age, bone age, height and height at menarche
  • A large discrepancy between AHP(x-ray) and AHP(parental) indicates that the child grows differently from what is expected from its parental heritage, i.e. it could be a sign of disorder. The evaluating of this is the task of a pediatric endocrinologist – the tool implements the most accurate statistical model, but is not in itself a diagnostic tool.

The Age of Peak Height Velocity (APHV) and the growth path

For Caucasian children, the tool also predicts the APHV, and based on that it draws the most likely growth path from the current height to the predicted adult height in a growth chart.

The nine population groups

The AHP depends on the ethnicity, and within each ethnicity it depends on the assumed population height. One can choose among nine population groups. There are five Caucasian populations with different population heights.

For the Asian Chinese and Asian American populations, the tool uses a preliminary AHP model presented at ESPE 2012. For Hispanic and African-American ethnicities, the Caucasian AHP model is used, which renders it only approximately correct.

The choice of population also affects the computation of standard deviation scores (SDS).