| Characteristic | Full sample(n = 118) | Malignant(n = 53) | Benign(n = 65) | p Value |
| Clinical | ||||
| Mean (SD) age at index test (years) | 65.9 (10.1) | 68.3 (7.7) | 63.9 (11.3) | 0.01 |
| Male | 114 (97) | 51 (96) | 63 (97) | 1.0* |
| Smoking history | ||||
| Current or former smoker | 107 (91) | 50 (94) | 57 (88) | 0.35* |
| Never smoker | 10 (9) | 3 (6) | 7 (11) | |
| Current smoker | 48 (41) | 24 (45) | 24 (37) | 0.56 |
| Former smoker | 52 (44) | 23 (43) | 29 (45) | |
| Mean (SD) pack-years‡ | 49.0 (31.1) | 53.3 (31.7) | 44.9 (30.3) | 0.21 |
| Mean (SD) years quit§ | 15.3 (13.2) | 12.3 (10.1) | 18.0 (15.2) | 0.13 |
| History of other cancer >5 years previously | 7 (6) | 4 (8) | 3 (5) | 0.70¶ |
| Radiological | ||||
| Nodule in right lung | 74 (63) | 34 (64) | 40 (62) | 0.77 |
| Location of nodule | 0.28 | |||
| Upper lobe | 60 (51) | 30 (57) | 30 (46) | |
| Middle or lower lobe | 55 (47) | 22 (42) | 33 (51) | |
| Median (range) nodule size (mm)** | 16.0 (7–30) | 20.0 (8–30) | 13.0 (7–30) | <0.001† |
| Nodule spiculated | 42 (36) | 33 (62) | 9 (14) | <0.001 |
| PET results positive (any uptake) | 55 (47) | 47 (89) | 8 (12) | <0.001 |
For definitions, see footnote to table B2.