Table 2.
Sensitivity, specificity, positive predictive value (PPV), positive negative value (PNV), accuracy, likelihood ratio and comparison of area under the ROC curves (AUC) of the four diagnostic modalities in group A.
| Indicator | NBI | WLE 1 + 2 | WLE 2 | WLE 1 + 2 and NBI |
|---|---|---|---|---|
| Sensitivity | 95.0 % | 95.0 % | 77.5 % | 90.0 % |
| Specificity | 96.8 % | 40.6 % | 89.0 % | 94.2 % |
| PPV | 88.3 % | 29.2 % | 64.6 % | 80.0 % |
| NPV | 98.7 % | 96.9 % | 93.9 % | 97.3 % |
| Accuracy | 96.4 % | 51.8 % | 86.7 % | 93.3 % |
| Positive likelihood ratio | 29.68 | 1.59 | 7.04 | 15.51 |
| Negative likelihood ratio | 0.05 | 0.13 | 0.25 | 0.10 |
| Mode | Area | Lower limit 95% CI | Upper limit 95% CI | p |
| NBI | 0.96 | 0.91 | 0.99 | <0.0001 |
| WLE 1 + 2 | 0.67 | 0.59 | 0.75 | <0.0001 |
| WLE 2 | 0.83 | 0.75 | 0.91 | <0.0001 |
| WLE 1 + 2 and NBI | 0.92 | 0.86 | 0.97 | <0.0001 |
| Mode comparison | z | Lower limit 95% CI | Upper limit 95% CI | p |
| WLE 1 + 2 vs. WLE 2 | −4.168 | −0.227 | −0.082 | <0.0001 |
| WLE 1 + 2 vs. NBI | −8.699 | −0.344 | −0.217 | <0.0001 |
| WLE 1 + 2 vs. WLE + NBI | −6.608 | −0.315 | −0.171 | <0.0001 |
| WLE 2 vs. NBI | −3.420 | −0.0199 | −0.054 | <0.001 |
| WLE 2 vs. WLE + NBI | −2.091 | −0.171 | −0.006 | 0.037 |
| NBI vs. WLE + NBI | 2.040 | 0.001 | 0.074 | 0.041 |
CI: confidence interval; NBI: narrow band imaging; NPV: negative predictive value; PPV: positive predictive value; WLE: white light endoscopy.