Nomogram based Postmortem-interval estimation compared with the Actual death-interval in Tropical environmental conditions.

Autor: Neithiya T; Department of Forensic Medicine and Toxicology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India. Electronic address: neithiyambbs27@gmail.com., Patra AP; Department of Forensic Medicine and Toxicology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India. Electronic address: dr.ambikaa@gmail.com., Shaha KK; Department of Forensic Medicine and Toxicology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India. Electronic address: drkusashaha@yahoo.com., Harichandrakumar KT; Department of Biostatistics, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India. Electronic address: hckumar2001@gmail.com.
Jazyk: angličtina
Zdroj: Journal of forensic and legal medicine [J Forensic Leg Med] 2023 Nov; Vol. 100, pp. 102598. Date of Electronic Publication: 2023 Oct 04.
DOI: 10.1016/j.jflm.2023.102598
Abstrakt: Background: Estimating an accurate postmortem interval (PMI) is essential for death investigators to confirm the offence timing and suspects' alibis. Compared to traditional methods, the Nomogram-based method is claimed to estimate nearly accurate PMI, but most of such studies are based on the Western population. Adequate data for bodies exposed to tropical climate of India and the Indian subcontinent are not available.
Aim: To assess the accuracy and goodness-of-fit of Nomogram based PMI estimation in bodies exposed to Indian climatic conditions after death.
Material and Methods: This is a 3-year-long study on 200 bodies with known death times. The exact PMI was recorded from direct sources: family members, police and hospital records. Before autopsy, the ambient temperature, body weight, length, and rectal temperature were measured, and the details of clothing, sex, and age, were used on a nomogram to calculate the PMI (t N ). One-way ANOVA correlation and Mann-Whitney U test were used to compare the variables. Linear regression analysis was used to establish the relationship between the rectal temperature (Tr) and nomogram estimated PMI (t N ) and the known PMI(t). The consistency and agreement between the t N and t were measured using Intra-class correlation coefficient (ICC). Bland-Altman (BA) plot was used to compare the level of agreement between direct(t) and nomograms method PMIs.
Results: Nomogram-based PMI estimation showed a statistically significant strong relationship with rectal temperature (R 0.77, R2 0.74, adjusted R2 0.76, t-stat 25.83 p < 0.000) and exhibited a relatively consistent agreement with the known death interval (ICC 0.935). Regressing the t N over t showed that the nomogram method can predict PMI with 95 % accuracy. The BA plot between Direct and Nomogram methods exhibited a consistent agreement in PMI estimation though the limits of agreement (LoA) were wide: range 39.09-121.18 min.
Conclusion: The accuracy and reliability of the Nomogram method in PMI estimation is high and recommended for the South Indian population. However, the presence of systematic differences between t N and t can't be ruled out due to wider LoA in BA plot. Hence, these findings highlight the need for further investigation and potential refinement of the PMI estimation methods to enhance accuracy and reduce discrepancies.
Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest regarding the publication of this manuscript titled “Nomogram based Postmortem interval estimation compared with the Actual death interval in Tropical environmental conditions.” There are no financial or personal relationships that could potentially bias or influence the research findings. This study was conducted in accordance with the guidelines and regulations set forth by the Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Pondicherry, India, and the Indian Council of Medical Research in alignment with the international ethical guidelines. Ethics approval was obtained from the relevant institute ethics committee of JIPMER with reference number JIP/IEC/2019/397, dated 30-03-2020. The funding for this research project was provided by the institute intramural fund of Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Pondicherry, India. The grant reference number is JIP/DL/PGRMC/Oct/2019, dated 30/10/2019. The authors would like to express their sincere gratitude to the JIPMER Director, the Dean (Research), and the Institute PG Research Monitoring Committee for their support and for sanctioning the intramural funding that facilitated the successful completion of this research project.
(Copyright © 2023 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)
Databáze: MEDLINE
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