A probability model for estimating age in young individuals relative to key legal thresholds: 15, 18 or 21-year
International Journal of Legal Medicine · Published 18 September 2024
In plain language
No medical test can pin down a young person's exact age, yet courts and asylum services often need to know whether someone is under or over 15, 18 or 21. This international study pooled data from 34 published studies on wisdom teeth, hand and wrist, collarbone and knee development, covering around 27,000 people, into one statistical model. Instead of a single guessed age, it gives the probability that a person is above or below each legal threshold, with a margin of error, and was validated against data from 5,000 individuals.
Abstract
Age estimations are relevant for pre-trial detention, sentencing in criminal cases and as part of the evaluation in asylum processes to protect the rights and privileges of minors. No current method can determine an exact chronological age due to individual variations in biological development. This study seeks to develop a validated statistical model for estimating an age relative to key legal thresholds (15, 18, and 21 years) based on a skeletal (CT-clavicle, radiography-hand/wrist or MR-knee) and tooth (radiography-third molar) developmental stages. The whole model is based on 34 scientific studies, divided into examinations of the hand/wrist (15 studies), clavicle (5 studies), distal femur (4 studies), and third molars (10 studies). In total, data from approximately 27,000 individuals have been incorporated and the model has subsequently been validated with data from 5,000 individuals. The core framework of the model is built upon transition analysis and is further developed by a combination of a type of parametric bootstrapping and Bayesian theory. Validation of the model includes testing the models on independent datasets of individuals with known ages and shows a high precision with separate populations aligning closely with the model's predictions. The practical use of the complex statistical model requires a user-friendly tool to provide probabilities together with the margin of error. The assessment based on the model forms the medical component for the overall evaluation of an individual's age.
Authors
Nina Heldring, Ali-Reza Rezaie, André Larsson, Rebecca Gahn, Britta Zilg, Simon Camilleri, Antoine Saade, Philipp Wesp, Elias Palm, Ola Kvist
Citation
Heldring N, Rezaie A-R, Larsson A, Gahn R, Zilg B, Camilleri S, Saade A, Wesp P, Palm E, Kvist O (2024) A probability model for estimating age in young individuals relative to key legal thresholds: 15, 18 or 21-year. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-024-03324-x
Abstract and PDF reproduced under the CC BY 4.0 licence. Summary written by Dental Experts Center.
