Table 2.

Sensitivity, specificity, PPV and NPV for the nodularity as the diagnostic test for H. pylori infection.

		Patients H. pylori positive according to criterion standard test			Sum
		Positive	Negative
Nodularity	Positive	98	21	119	82%	PPV*
	Negative	9	213	222	96%	NPV**
Sum		107	234	341
		91.6%	91%
		Sensitivity	Specificity

^*PPV (positive predictive value) – True positive/(True positive + False positive);

^**NPV (negative predictive value) – True negative/(False negative + True negative); Sensitivity – True positive/(True positive + False negative); Specificity – True negative/(False positive + True negative).