Table 1.

Performance of Scedosporium boydii specific IgG at different cut-off values with 25 serum samples of Cystic Fibrosis patients with Scedosporium/Lomentospora positive sputum cultures and 190 negative sera.

Cut-off value (Relative A450nm)	Criteria	Test validation parameters (%)
		SE	SP	EFF	PPV*	NPV*	K
0.5837	J, CZ, IU, ER	100	93.58	94.29	65.71	100	0.76
0.6042	SE=SP	95.65	94.12	94.29	66.67	99.44	0.75
0.6404	$(\overline{X}+2SD)$	91.30	95.72	95.24	72.41	98.90	0.78
0.7099	MLR+	86.96	99.47	98.10	95.24	98.41	0.89

J, Youden Index; CZ, Concordance Probability Method; IU, Index of Union; ER, Closest to [0,1]; $\overline{X}$, mean value of control sera absorbance; SD, standard deviation; MLR+, maximum positive likelihood ratio; SE, sensitivity; SP, specificity; EFF, efficiency or correct classification rate; PPV, predictive value of positive test; NPV, predictive value of negative test; K, Cohen’s Kappa index.

(*) Theoretical values considering a prevalence of Scedosporium/Lomentospora of 11.43% observed in this study.