Pelvic Metric Sexual Dimorphism and Multivariable Prediction Modeling for Forensic Sex Identification in Unexpected Fatalities in Kabul, Afghanistan

Abstract

Background. Sex estimation is the first step in profiling unidentified skeletal remains, and the pelvis is the most sexually dimorphic skeletal region. Pelvic osteometric standards are population-specific, and none exists for Afghanistan.

Objective. To develop pelvic osteometric standards and prediction models for sex estimation in adult autopsy cases in Kabul, Afghanistan.

Methods. This cross-sectional study analysed pelves of 100 adults (50 males, 50 females; 18–65 years) from unexpected or unnatural deaths examined in Kabul in 2021–2023. Pelvic width, pelvic height, superior and inferior acetabular diameters and subpubic angle were measured with a digital caliper and goniometer and analysed with Student’s t-tests, binary logistic regression and receiver operating characteristic analysis.

Results. Males had larger pelvic width (28.5 ± 2.4 vs 25.2 ± 2.1 cm), pelvic height and acetabular diameters (all p < 0.001); females had a wider subpubic angle (82.3 ± 3.8° vs 75.2 ± 4.1°; p < 0.001). All five dimensions were independent predictors, pelvic width having the largest adjusted odds ratio (aOR 1.52; 95% confidence interval, CI, 1.26–1.83). The full model had an area under the curve (AUC) of 0.89 (95% CI 0.82–0.95) and classified 81.0% of cases correctly at a 0.50 cut-off (sensitivity 80.0%, specificity 82.0%; 80.0% on leave-one-out cross-validation). The subpubic angle alone reached an AUC of 0.90. Iliac and acetabular sub-models, simulated on intact specimens, retained 77.0% and 76.0% accuracy.

Conclusion. Kabul-specific pelvic models correctly classify about four in five adults and offer a low-cost probabilistic tool for sex estimation, pending validation on fragmented remains.