Guide
Bayley-Pinneau limitations
Where Bayley-Pinneau predicted adult height goes wrong: tempo-dependent error, input quality, and what the method was never built to do.
A method with a known error pattern
Bayley-Pinneau is a 1952 table method, and its errors are not random. Tarim (Turk J Pediatr 2013; 55: 485-492) compared Bayley-Pinneau predictions against projected adult height and found the method tends to overestimate in children with advanced bone age and underestimate when bone age is delayed.
That direction matters in clinic. In precocious puberty the prediction can look reassuring while the growth window is closing. In constitutional delay the prediction can look worse than the likely outcome. Read the number with the tempo in mind.
Bad bone age in, fancy number out
The prediction is only as good as the skeletal age you feed it. Bone age scoring carries inter-reader variability, and a six month scoring difference moves the predicted adult height.
That is why the app asks for a scored bone age instead of pretending to read the film. Note the bone-age source and reader in your documentation, because the prediction inherits their uncertainty.
What the app does not do
Height Predictor does not score radiographs, does not implement Greulich and Pyle or TW3 scoring, does not diagnose growth disorders, and does not guarantee an adult height. It looks up published tables from four inputs and shows the result.
The result is an approximation for clinical context, not a promise to a family. Counseling, workup decisions, and method choice stay with the clinician.
Using the number honestly
Treat Bayley-Pinneau output as one input into a growth evaluation: pair it with the growth curve, mid-parental target height, and exam findings. The comparison guide covers how those two numbers differ. When you need the lookup itself, Height Predictor does it on device in a few seconds.
Frequently asked questions
How accurate is Bayley-Pinneau?
It is an approximation with a documented bias pattern: overestimation with advanced bone age and underestimation with delayed bone age, per Tarim (Turk J Pediatr 2013). Accuracy also depends directly on the quality of the bone age score.
Should I use a different method instead?
Sometimes. Method choice depends on the clinical question, the child's age, and local practice. This page documents Bayley-Pinneau's limits; it does not rank methods for you.
Does the app correct for the known bias?
No. It reports the published table value for the inputs you enter. Interpreting that value against tempo and context is clinical work.
Can parents use this to plan for a child's height?
No. The app and these pages are for healthcare professionals and trainees evaluating growth with a scored bone age, not for home prediction.
Built around Height Predictor in the Pediatric medicine tools hub.