Table 1 Clinical characteristics across the training, internal validation, and independent test sets (test set 1 and test set 2) in patients
Characteristics | Training Set | Internal Validation Set | Independent Test Set 1 | Independent Test Set 2 | P-value | ||||
|---|---|---|---|---|---|---|---|---|---|
pN+ (n = 235) | pN- (n = 235) | pN+ (n = 101) | pN- (n = 101) | pN+ (n = 43) | pN- (n = 184) | pN+ (n = 99) | pN- (n = 327) | ||
Agea (years) | 59.9 ± 9.2 | 59.1 ± 9.9 | 60.0 ± 9.7 | 61.7 ± 9.0 | 59.4 ± 10.6 | 61.9 ± 9.6 | 59.7 ± 9.4 | 59.7 ± 9.7 | 0.048 |
Gender |  |  |  |  |  |  |  |  | < 0.001 |
 Male | 108 (46.0) | 101 (43.0) | 47 (46.5) | 42 (41.6) | 21 (48.8) | 90 (48.9) | 46 (46.5) | 146 (44.6) |  |
 Female | 127 (54.0) | 134 (57.0) | 54 (53.5) | 59 (58.4) | 22 (51.2) | 94 (51.1) | 53 (53.5) | 181 (55.4) |  |
Maximum Diametera (cm) | 1.8 ± 0.4 | 1.6 ± 0.4 | 1.8 ± 0.4 | 1.6 ± 0.3 | 1.8 ± 0.4 | 1.8 ± 0.6 | 1.8 ± 0.5 | 1.6 ± 0.4 | 0.040 |
Density |  |  |  |  |  |  |  |  | < 0.001 |
 Solid | 201 (85.5) | 198 (84.3) | 85 (84.2) | 88 (87.1) | 39 (90.7) | 137 (74.5) | 83 (83.8) | 239 (73.1) |  |
 Part-Solid | 34 (14.5) | 37 (15.7) | 16 (15.8) | 13 (12.9) | 4 (9.3) | 47 (25.5) | 16 (16.2) | 88 (26.9) |  |
Location |  |  |  |  |  |  |  |  | < 0.001 |
 Inner | 21 (8.9) | 11 (4.7) | 12 (11.9) | 5 (5.0) | 8 (18.6) | 8 (4.3) | 8 (8.1) | 17 (5.2) |  |
 Middle | 59 (25.1) | 54 (23.0) | 29 (28.7) | 34 (33.7) | 9 (20.9) | 41 (22.3) | 24 (24.2) | 106 (32.4) |  |
 Outer | 155 (66.0) | 170 (72.3) | 60 (59.4) | 62 (61.4) | 26 (60.5) | 135 (73.4) | 67 (67.7) | 204 (62.4) |  |