Table 3. AUC, sensitivity, specificity, PPV and NPV of IgA-gH/gL and EBV DNA in IgA-VCA-negative NPC patients in the training cohort.

Test	AUC (95%)	pa	Sensitivity		pb	Specificity		pb	PPV		pc	NPV		pc
			%	95% CI		%	95% CI		%	95% CI		%	95% CI
gH/gL	0.879 (0.820-0.937)		78.1	63.6-92.4		82.3	77.0-87.6		42.0	29.5-54.5		96.0	93.0-99.0
EBV DNA	0.750 (0.637-0.863)		53.1	35.8-70.4		94.9	91.8-98.0		63.0	44.8-81.2		92.6	89.0-96.2
gH/gL vs. EBV DNA		0.003			0.021			<0.001			NS			NS

PPV, positive predictive value; NPV, negative predictive value; NS, not significant; gH/gL, enzyme-linked immunosorbent assay detection of IgA antibodies against EBV glycoprotein complex gH/gL; VCA, immunofluorescence assay for IgA antibodies against viral capsid antigen; EBV DNA, qPCR test for plasma circulating EBV DNA.

^aZ test.

^bMcNemar's paired-sample test.

^cChi-squared test