Characteristic Training (n=82) No. of patients (%) Testing (n=40) No. of patients (%) P value
Age (Median, range) 65(33-84) 67(43-78) 0.8198
No. of pack/year(Median, range) 64(0-162) 60(0-114) 0.629
Gender     0.8006
Male 54(65.8) 28(70)  
Female 28(34.2) 12(30)  
Cancer type     0.2211
squamous 38(46.3) 24(60)  
adenocarcinoma 44(53.7) 16(40)  
Tumor stage     0.6089
Stage I 37(45.6) 22(55)  
Stage II 18(22.2) 8(20)  
Stage III&VI 26(32.1) 10(25)  
Unknown 01(-) 0(-)  
History     0.7635
<15 years 51(62.2) 23(57.5)  
»15 years 31(47.8) 17(42.5)  
Table 1: Characteristics of clinical features: Training data vs. testing data.