Table 1 Patient characteristics
Variables | Total (n = 2851) | Training Cohort (n = 1999) | Validation Cohort (n = 852) | P value |
|---|---|---|---|---|
Age (year)n(%) | Â | Â | Â | 0.521 |
 60–69 | 1297(45.5) | 912(45.6) | 385(45.2) |  |
 70–79 | 1145(40.2) | 792(39.6) | 353(41.4) |  |
  ≥ 80 | 409(14.3) | 295(14.8) | 114(13.4) |  |
Sex n(%) | Â | Â | Â | 0.472 |
 Female | 1485(52.1) | 1050(52.5) | 435(51.1) |  |
 Male | 1366(47.9) | 949(47.5) | 417(48.9) |  |
Race n(%) | Â | Â | Â | 0.993 |
 Black | 242(8.5) | 170(8.5) | 72(8.5) |  |
 White | 2497(87.6) | 1751(87.6) | 746(88.7) |  |
 Others | 112(3.9) | 78(3.9) | 34(3.8) |  |
Marital status n(%) | Â | Â | Â | 0.838 |
 Married | 1474(51.7) | 1036(51.8) | 438(51.4) |  |
 Unmarried/single | 1377(48.3) | 963(48.2) | 414(48.6) |  |
Insurance n(%) | Â | Â | Â | 0.368 |
 Insured | 2442(85.6) | 1722(86.1) | 720(84.5) |  |
 Any medicaid | 361(12.7) | 242(12.1) | 119(14.0) |  |
 Uninsured | 48(1.7) | 35(1.8) | 13(1.5) |  |
Location n(%) | Â | Â | Â | 0.120 |
 main bronchus | 301(10.6) | 195(9.8) | 106(12.4) |  |
 upper lobe,lung | 1582(55.5) | 1132(56.6) | 450(52.8) |  |
 middle lobe,lung | 139(4.9) | 102(5.1) | 37(4.3) |  |
 low lobe,lung | 776(27.2) | 532(26.6) | 244(28.6) |  |
 overlapping lesion | 53(1.8) | 38(1.9) | 15(1.9) |  |
Grade n(%) | Â | Â | Â | 0.122 |
 I | 43(1.5) | 26(1.3) | 17(2.0) |  |
 II | 1082(38.0) | 778(38.9) | 304(35.7) |  |
 III/IV | 1726(60.5) | 1195(59.8) | 531(62.3) |  |
AJCC TNM stage(7th) n(%) | Â | Â | Â | 0.326 |
 I | 190(6.7) | 135(6.7) | 55(6.5) |  |
 II | 147(5.1) | 96(4.8) | 51(5.9) |  |
 III | 778(27.3) | 561(28.1) | 217(25.5) |  |
 IV | 1736(60.9) | 1207(60.4) | 529(62.1) |  |
Surgery n(%) | Â | Â | Â | 0.698 |
 No | 2659(93.3) | 1862(93.1) | 797(93.5) |  |
 Yes | 192(6.7) | 137(6.9) | 55(6.5) |  |
Chemotherapy n(%) | Â | Â | Â | 0.452 |
 No/unknown | 804(28.2) | 572(28.6) | 232(27.2) |  |
 Yes | 2047(71.8) | 1427(71.4) | 620(72.8) |  |
Radiation n(%) | Â | Â | Â | 0.426 |
 No/unknown | 1448(50.8) | 1025(51.3) | 423(49.6) |  |
 Yes | 1403(49.2) | 974(48.7) | 429(50.4) |  |
Bone metastasis n(%) | Â | Â | Â | 0.436 |
 No | 2271(79.7) | 1600(80.0) | 671(78.8) |  |
 Yes | 580(20.3) | 399(20.0) | 181(21.2) |  |
Brain metastasis n(%) | Â | Â | Â | 0.672 |
 No | 2425(85.1) | 1704(85.2) | 721(84.6) |  |
 Yes | 426(14.9) | 295(14.8) | 131(15.4) |  |
Liver metastasis n(%) | Â | Â | Â | 0.789 |
 No | 2151(75.4) | 1511(75.6) | 640(75.1) |  |
 Yes | 700(24.6) | 488(24.4) | 212(24.9) |  |
Lung metastasis n(%) | Â | Â | Â | 0.806 |
 No | 2473(86.7) | 1736(86.8) | 737(86.5) |  |
 Yes | 378(13.3) | 263(13.2) | 115(13.5) |  |
Size n(%) | Â | Â | Â | 0.315 |
  ≤ 3 cm | 811(28.4) | 576(28.8) | 235(27.6) |  |
 3.1-5 cm | 789(27.7) | 568(28.4) | 221(25.9) |  |
 5.1-7 cm | 567(19.9) | 389(19.5) | 178(20.9) |  |
 >7 cm | 684(24.0) | 466(23.3) | 218(25.6) |  |