Validation of the Total Body Score/Accumulated Degree-Day Model at Three Human Decomposition Facilities

A few studies have examined the accuracy of the Megyesi et al. (2005) total body score/accumulated degree-day (TBS/ADD) method; however, no study has investigated the validity of the method using human remains at known ADD intervals. The current study validates the TBS method for human cadavers placed in three different human decomposition facilities in the United States. Twenty-eight donated cadavers, with known ADD and dates of death, in the first (fresh) stage of decomposition, were placed in sun and shade environments four times per year. The validity of the method was examined by conducting an interobserver error test of the TBS and analyzing the accuracy of the equation at predicting ADD. Nine individuals, experienced with the TBS method, participated in the interobserver error test. The results of the interclass correlation coefficient show that there was no statistically significant difference between observers for any of the body sections (trunk = 0.975, head = 0.959, limbs = 0.940, p < 0.001). Using the TBS regression equation, mean ADD with error ranges was calculated for all subjects and compared to actual ADDs of 100, 300, 500, and 1,000. Results show that mean ADD estimates do not correlate well with actual ADD for any of the actual ADDs (100, 300, 500, and 1,000). The accuracy of the TBS equation is insufficient in estimating mean ADD and error is largely unpredictable, other than it increases with postmortem time.KEYWORDS: forensic anthropology, taphonomy, total body score, accumulated degree-days