title: Disregarding population specificity: its influence on the sex assessment methods from the tibia.
abstract: Forensic anthropology has developed classification techniques for sex estimation of unknown skeletal remains, for example population-specific discriminant function analyses. These methods were designed for populations that lived mostly in the late nineteenth and twentieth centuries. Their level of reliability or misclassification is important for practical use in today's forensic practice; it is, however, unknown. We addressed the question of what the likelihood of errors would be if population specificity of discriminant functions of the tibia were disregarded. Moreover, five classification functions in a Czech sample were proposed (accuracies 82.1-87.5 %, sex bias ranged from -1.3 to -5.4 %). We measured ten variables traditionally used for sex assessment of the tibia on a sample of 30 male and 26 female models from recent Czech population. To estimate the classification accuracy and error (misclassification) rates ignoring population specificity, we selected published classification functions of tibia for the Portuguese, south European, and the North American populations. These functions were applied on the dimensions of the Czech population. Comparing the classification success of the reference and the tested Czech sample showed that females from Czech population were significantly overestimated and mostly misclassified as males. Overall accuracy of sex assessment significantly decreased (53.6-69.7 %), sex bias -29.4-100 %, which is most probably caused by secular trend and the generally high variability of body size. Results indicate that the discriminant functions, developed for skeletal series representing geographically and chronologically diverse populations, are not applicable in current forensic investigations. Finally, implications and recommendations for future research are discussed.
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Viničná 7, Praha 2, 128 43, Prague, Czech Republic. koterova.a@seznam.cz.
authors.forename: Anežka
authors.initials: A
authors.lastname: Kotěrová
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Viničná 7, Praha 2, 128 43, Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Velemínská
authors.affiliation: Department of Software and Computer Science, Faculty of Mathematics and Physics, Charles University in Prague, Malostranské nám. 25, 118 00, Prague, Czech Republic.
authors.forename: Ján
authors.initials: J
authors.lastname: Dupej
authors.affiliation: Department of Prehistory, Institute of Archaeology of the Academy of Science, Letenská 4, 118 01, Praha, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Brzobohatá
authors.affiliation: Department of Computer Science, Faculty of Electrical Engineering, Czech Technical University in Prague, Karlovo náměstí 13, 121 35, Prague 2, Czech Republic.
authors.forename: Aleš
authors.initials: A
authors.lastname: Pilný
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Viničná 7, Praha 2, 128 43, Prague, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Brůžek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks; D016002:Discriminant Analysis; D005260:Female; D018732:Forensic Anthropology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016571:Neural Networks, Computer; D054881:Sex Determination by Skeleton; D013977:Tibia / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
keywords: Discriminant function analysis; Forensic anthropology population data; GAME method; Population specificity; Sex determination; Tibia