Table 4.

Estimated costs of BAR-N model variables and abdominal CT examinations based on institutional billing data

Item	Estimated Cost (RMB)
BAR-N Model Components	71
AST	46
N (neutrophil percentage)	25
Rebound tenderness	0
BMI	0
Imaging Examinations
Non-contrast abdominal CT	690
Contrast-enhanced abdominal CT	1250

All costs are based on standard hospital billing at our institution (RMB, 2024 rates). The BAR-N model relies on simple clinical and laboratory parameters with substantially lower direct costs compared to abdominal imaging