Performance of DRNNAGE for macroscopic age-at-death estimation in contemporary Brazilian identified skeletons

In global forensic literature, methods for estimating age in young individuals are more commonly addressed than those applicable to adults. This trend is also evident in Brazil. This study aimed to evaluate the performance of the DRNNAGE software for age estimation in Brazilian identified human skeletons. The sample consisted of 400 skeletons (200 females and 200 males), aged 20 years and older, from the osteological collection of the Center for Studies in Forensic Anthropology at the University of Pernambuco (CEAF/UPE). The DRNNAGE trait scoring system was applied to analyze morphological features of the cranial sutures, vertebrae, upper and lower limbs, fusion of the first and second sacral vertebrae, clavicles, first rib, pubic symphysis, sacroiliac joint, and acetabulum. Cohen's Kappa was used to assess inter- and intra-observer agreement. Descriptive and statistical analyses were performed in IBM™ SPSS® (version 22.0), R (version 4.3.3), and RStudio IDE (version 2023.12.1). Neither sex nor antimeric variation influenced the classification of bone maturation stages. DRNNAGE achieves 6.54-year MAE and 90.2% empirical coverage (90% nominal) in a Brazilian sample. The software performed satisfactorily in this sample and reinforces the importance of further regional studies to assess its nationwide applicability, considering Brazil's continental dimensions and diverse population structure, taking into account the well-known intra- and inter-population variability in human aging patterns.