Table 4.

Biomarker gastrin-17, anti-PCA, anti-IFA, and PGI/II ratio area under the ROC ^a curve results based on levels and category of seropositivity.

Biomarker Values	Area under the ROC Curve	SE b	p-Value c	Asymptotic 95% Confidence Interval
				Lower Bound	Upper Bound
Levels
G-17	0.85	0.05	<0.0001	0.75	0.95
PGI/II ratio	0.90	0.03	<0.0001	0.84	0.97
Anti-PCA	0.79	0.06	<0.0001	0.68	0.91
Anti-IFA	0.58	0.07	0.23	0.45	0.72
Seropositivity
G-17	0.74	0.05	<0.0001	0.65	0.84
PGI/II ratio	0.85	0.04	<0.0001	0.76	0.93
Anti-PCA	0.76	0.05	<0.0001	0.66	0.86
Anti-IFA	0.57	0.03	0.03	0.51	0.63

^a ROC, Receiver Operating Characteristic; SE, standard error. ^b Under the nonparametric assumption. ^c Null hypothesis: true area = 0.5.