Anthropometric weight estimation is less accurate than visual weight estimation in forensic postmortem cases in a Swiss population.

Abstract

When the time since death must be calculated forensic pathologists often consider a calculation based on the Henssge nomogram. This calculation requires an estimated body weight. Previous research has indicated that healthcare workers generally inaccurately guessed patients' body weights. In recent years, weight estimation methods based on anthropometric parameters, such as mid-arm or waist circumference, have been shown to improve estimation accuracy. This study aimed to examine whether anthropometric weight estimation methods could improve weight estimation accuracy compared to visual estimation in forensic pathology. In 199 cases from a Swiss population, we measured the actual body weight, mid-arm circumference, waist circumference, and body height before autopsy. Additionally, two forensic pathologists visually estimated the body weight. We found mid-arm circumferences to correlate the strongest with actual body weight (Pearson 'sr 0.87, 95% CI 0.83-0.90). However, all mid-arm circumference-based estimation methods performed worse than those previously described. A statistical bias between -12.3% and -14.5% indicated a systematic weight underestimation. Combined two-physician visual estimation performed significantly better than anthropometric measurements in our population but showed no difference from anthropometric estimation methods previously described in the literature. Further research is needed on novel body weight estimation methods that are currently not applicable for the global population.