Table 3.

In the first part: Se and Sp for abnormal fibrinogen, iron, and SAA concentrations for the diagnosis of inflammatory status. In the second part: Optimal cut‐off values based on Youden indices with corresponding Se and Sp for horses with SI versus LI disease.

Analyte	Concentration Outside Reference Interval	Se	Sp
Fibrinogen	>220 mg/dL	37% (29–46)	97% (89–100)
Iron	<80 μg/dL	40% (32–49)	90% (78–96)
SAA	>10 mg/L	82% (75–88)	71% (57–82)
Optimum cut‐off for SI versus LI
Fibrinogen	>181 mg/dL	77% (56–91)	52% (42–61)
Iron	<102 μg/dL	89% (70–98)	54% (44–63)
SAA	>2030 mg/L	46% (27–6)	82% (73–88)

Se and Sp: 95% confidence intervals in parentheses.

Se, sensitivity; Sp, specificity; SAA, serum amyloid A; SI, systemic inflammation; LI, local inflammation.