Results

A total of 50 medico-legal autopsies performed for natural deaths were included, comprising an obese cohort (n = 25) and a non-obese control group (n = 25), examined under identical procedural conditions and applying the same standardized autopsy protocol. The obese cohort included 14 males and 11 females, with a mean age of 67.4 ± 11.2 years, while the control group included 14 males and 11 females, with a mean age of 66.9 ± 10.8 years, indicating close demographic comparability. Body mass index in the obese cohort ranged from 30.2 to 44.6 kg/m² (mean 36.8 ± 4.1 kg/m²), whereas controls ranged from 24.0 to 29.8 kg/m² (mean 27.1 ± 1.6 kg/m²). Within the obese cohort, 9 cases were classified as obesity class I (BMI 30.0–34.9), 8 as class II (BMI 35.0–39.9), and 8 as class III (BMI ≥ 40.0), enabling intra-obesity gradient analyses [9, 10].

Total autopsy duration showed a marked between-group difference. In the obese cohort, duration ranged from 188 to 258 min (mean 219.6 ± 26.9), whereas in controls it ranged from 160 to 210 min (mean 184.2 ± 14.9). The difference in mean duration between obese cases and controls was statistically significant (mean difference 35.4 min; 95% CI: 23.1–47.7; p < 0.001). When the obese cohort was stratified by severity class, a progressive increase in duration was observed (class I: 198.4 ± 14.7; class II: 222.9 ± 16.8; class III: 246.1 ± 12.9 min), with a statistically significant trend (p < 0.001) and minimal overlap between class I and class III.

When BMI was analyzed as a continuous predictor, significant positive associations with procedural duration were confirmed both within the obese cohort and across the full sample. Within the obese cohort, Pearson correlation between BMI and autopsy duration was r = 0.62 (p = 0.001), and linear regression estimated an increase of 4.3 min per BMI unit (β = 4.3, 95% CI: 2.4–6.2; p = 0.001). Across the entire sample (obese + controls), the BMI–duration association remained significant (r = 0.71, p < 0.001), and in a multivariable regression model including age and sex, BMI remained an independent predictor of duration, with no material effect modification by sex and no significant confounding by age. A model including group (obese vs. control) as a categorical predictor confirmed a significant obesity-related increase in autopsy duration even after accounting for BMI as a continuous variable.

Baseline Mackworth Clock Test performance was comparable between groups, indicating similar pre-autopsy vigilance. For the primary operator, baseline missed stimuli averaged 1.2 ± 0.6 in obese cases and 1.1 ± 0.6 in controls. Post-autopsy testing showed a duration-dependent vigilance decrement in both groups, but markedly greater in obese cases. The primary operator’s vigilance decrement (Δ missed stimuli, post minus pre) averaged 4.4 ± 1.2 in obese cases versus 2.4 ± 0.9 in controls (mean difference 2.0; 95% CI: 1.4–2.6; p < 0.001). In the obese cohort, decrement increased with obesity severity, with the highest post-autopsy error burden observed in class III cases, paralleling longer procedural duration. Regression analysis identified an exploratory association between longer procedural duration and increased missed stimuli in the primary operator (β = 1.10, 95% CI: 0.52–1.68;p = 0.002). Secondary operator trends were similar but attenuated (Tables 1, 2, 3, 4 and 5).

Variable | Obese cohort (n = 25) | Controls (n = 25)
Sex (male/female) | 14 / 11 | 14 / 11
Age, mean ± SD (years) | 67.4 ± 11.2 | 66.9 ± 10.8
BMI, mean ± SD (kg/m²) | 36.8 ± 4.1 | 27.1 ± 1.6
BMI range (kg/m²) | 30.2–44.6 | 24.0–29.8
Obesity class I (30.0–34.9), n | 9 | —
Obesity class II (35.0–39.9), n | 8 | —
Obesity class III (≥ 40.0), n | 8 | —

Group | n | Autopsy duration, mean ± SD (min) | Range (min)
Controls (BMI < 30) | 25 | 184.2 ± 14.9 | 160–210
Obese cohort (BMI ≥ 30) | 25 | 219.6 ± 26.9 | 188–258

Obesity class | n | Autopsy duration, mean ± SD (min) | Range (min)
Class I (30.0–34.9) | 9 | 198.4 ± 14.7 | 188–215
Class II (35.0–39.9) | 8 | 222.9 ± 16.8 | 205–240
Class III (≥ 40.0) | 8 | 246.1 ± 12.9 | 230–258

Group | Baseline missed stimuli (mean ± SD) | Post-autopsy missed stimuli (mean ± SD) | Δ missed stimuli (mean ± SD)
Controls (n = 25) | 1.1 ± 0.6 | 3.5 ± 0.9 | 2.4 ± 0.9
Obese (n = 25) | 1.2 ± 0.6 | 5.6 ± 1.1 | 4.4 ± 1.2

Analysis | Estimate | 95% CI | p-value
BMI vs. autopsy duration (obese cohort), Pearson r | 0.62 | 0.30–0.81 | 0.001
BMI → duration (obese cohort), β (min/BMI unit) | 4.3 | 2.4–6.2 | 0.001
BMI vs. autopsy duration (full sample), Pearson r | 0.71 | 0.53–0.83 | < 0.001
Duration → vigilance decrement, β (Δ per + 30 min) | 1.10 | 0.52–1.68 | 0.002

Exploratory analyses suggested that the association between BMI and vigilance decrement was largely related to procedural duration. BMI was significantly associated with autopsy duration, and autopsy duration was associated with vigilance decrement. When duration was included in models predicting vigilance change, attenuation of the direct BMI term was observed. These findings should be interpreted cautiously given the exploratory design and the use of a fixed operator team.

Morphometric and technical observations further corroborated the quantitative findings. In all cases with BMI ≥ 35 kg/m² (obesity classes II–III), the thickness of the subcutaneous adipose tissue at the thoracoabdominal incision site exceeded 4 cm, whereas in controls adipose thickness remained consistently below 4 cm. Increased adipose thickness was associated with deeper incision planes, delayed entry into the cavities, and prolonged dissection times. Organ-specific technical difficulty was most pronounced in obese class II–III cases during exposure and mobilization of liver, pancreas, adrenal glands, and deep pelvic organs, where abundant perivisceral fat and altered anatomical relationships required extended dissection and increased manipulation, closely paralleling increases in duration and vigilance decrement.

The relatively long average duration observed in both groups likely reflects the strict standardization of the protocol and the inclusion of additional procedural assessments.