Diagnoses of the target lesions and observation times in each group
| Outcome | WLI group (n=2258) | 2G-NBI group (n=2265) | P value (primary WLI vs primary 2G-NBI) | ||||||
| Primary WLI | Secondary 2G-NBI | Primary 2G-NBI | Secondary WLI | ||||||
| Patients with EGC, n (%) | 44 | (1.9) | 19 | (0.8) | 53 | (2.3) | 17 | (0.8) | 0.412 |
| Patients with a target lesion, n (%) | 308 | (13.8) | 114 | (5.0) | 251 | (11.2) | 124 | (5.5) | |
| Target lesion, n | 371 | 118 | 282 | 132 | |||||
| EGC*, n (%) | 50 | (13.5) | 19 | (16.1) | 59 | (20.9) | 17 | (12.9) | |
| Others*, n (%) | |||||||||
| Low-grade adenoma | 17 | (4.6) | 7 | (5.9) | 20 | (7.1) | 2 | (1.6) | |
| Advanced gastric cancer | 0 | (0) | 0 | (0) | 1 | (0.4) | 0 | (0) | |
| Negative for neoplasia | 287 | (77.4) | 90 | (76.3) | 195 | (69.1) | 107 | (81.1) | |
| Indefinite for neoplasia | 1 | (0.3) | 0 | (0) | 1 | (0.4) | 1 | (0.8) | |
| Not biopsied | 16 | (4.3) | 2 | (1.7) | 6 | (2.1) | 5 | (3.8) | |
| Positive predictive value, % | 13.5 | 16.1 | 20.9 | 12.9 | 0.015 | ||||
| Observation time†, seconds | 233±92 | – | 254±104 | – | <0.001 | ||||
*The common denominator of this set of values is the number of target lesions.
†Observation time was measured in the patients who completed the primary examination: 2234 in the WLI group and 2238 in the 2G-NBI group. Values are expressed as means±SD. An en dash represents no data collected.
WLI, white light imaging; 2G-NBI, second-generation narrow band imaging; EGC, early gastric cancer.