Table 2.

Clinical performance of real-time-PCR detection of H. pylori on stool and gastric biopsy samples

Tests performances	H. pylori detection
Positive in stool samples, n	152 (89.9%)
Positive in gastric biopsy samples, n	153 (90.5%)
Sensitivity	99.3%
Specificity	100%
Misdiagnosis rates	0%
Missed rate	0.9%
Accuracy	99.6%
Youden’s index	99.3%
Positive predictive value	100%
Negative predictive value	91.3%
Kappa	0.963*

The kappa coefficient was classified as follows: >0.90, almost perfect; 0.80 to 0.90, strong; 0.60 to 0.79, moderate; 0.40 to 0.59, week; 0.21 to 0.39, minimal; 0 to 0.20, no agreement. Youden’s index was calculated as sensitivity + specificity - 1.

^* P<0.001.

H. pylori: Helicobacter pylori, real-time PCR: real-time polymerase chain reaction.