U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

Standardizing ordinal subadult age indicators: Testing for observer agreement and consistency across modalities

NCJ Number
Forensic Science International Volume: 320 Dated: 2021
L. K. Corron; et al
Date Published

This study evaluated observer agreement of epiphyseal fusion and dental development stages obtained on CT scans of a U.S. sample and the consistency of epiphyseal fusion stages between CT scans and projected scan radiographs/scout images (U.S. CT sample), as well as between dry bones and conventional x-rays (Colombian osteological sample).


Skeletal and dental data for subadult analyses obtained from dry bones or various types of medical images, such as computed tomography (CT) scans or conventional radiographs/x-rays, should be consistent and repeatable to ensure method applicability across modalities and support combining study samples. The results of the current study indicate that both intra- and interobserver agreements of scores on CT scans were high (intra: mean Cohen’s kappa = 0.757–0.939, inter: mean Cohen’s kappa = 0.773–0.836). Agreements were lower for dental data (intra: mean Cohen’s kappa = 0.757, inter: mean Cohen’s kappa = 0.773–0.0.820) compared to epiphyseal fusion data (intra: mean Cohen’s kappa = 0.939, inter: mean Cohen’s kappa = 0.807–0.836). Consistency of epiphyseal fusion stages was higher between dry bones and conventional x-rays than between CT scans and scout images (mean Cohen’s kappa = 0.708–0.824 and 0.726–0.738, respectively). Differences rarely surpassed a one-stage value between observers or modalities. The complexity of some ossification patterns and superimposition had a greater negative impact on agreement and consistency rates than observer experience. Results suggest ordinal subadult skeletal data can be collected and combined across modalities. (publisher abstract modified)