Analysis of interrater reliability in age assessment of minors: how does expertise influence the evaluation?

Nowadays, the clinical forensic medical management of migration flows comprises the age assessment of unaccompanied minors. The process of age estimation is a fundamental pillar for legally ensuring the minors’ rights and their protection needs. The procedure is complex and involves different phases and actors, from medical doctors to law enforcement officers. The present study aimed to investigate the performance of Greulich and Pyle, Demirjian, and Mincer methods when performed by raters both trained and without training. Also, the interrater reliability within groups of raters from different areas of expertise was evaluated. A total of 36 participants were enrolled for this study, divided in two groups according to their level of experience with age estimation methods. Each rater was asked to allocate stages and standards for age assessment, evaluating ten orthopantomograms and ten hand-wrist roentgenograms. The interrater reliability expressed through the Fleiss Kappa coefficient and the agreement with the reference standard were calculated. The results showed that none of the categories analyzed could reach a good interrater reliability (ĸ > 0.8) for both methods. The study results highlighted variation and disagreement in the interpretation of the sample among raters and in the subsequent stages and standards allocation. In conclusion, the results of this study highlight that expertise does influence the reliability of the most utilized methods of age estimation of living individuals and stress the importance of proper training and practice, which could greatly increase the accuracy of age assessments. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00414-021-02707-8.