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Table 1 Demographic characteristics of lung cancer patients and controls in a population based case-control study, Greater Toronto Area, Ontario, 1997- 2002

From: Lung cancer risk in never-smokers: a population-based case-control study of epidemiologic risk factors

  Case, n(%) Control, n(%)  
  Smokers Never smokers Total Smokers Never smokers Total p valuea
Total 289 156 445 482 466 948  
Gender        
   Male 163 (56) 46 (30) 209 (47) 241 (50) 145 (31) 386 (41) p = 0.03
   Female 126 (44) 110 (70) 236 (53) 241 (50) 321 (69) 562 (59)  
Age        
   < 35 1 (< 1) 10 (6) 11 (3) 58 (12) 86 (18) 144 (15)  
   35-45 9 (3) 21 (13) 30 (7) 77 (16) 89 (19) 166 (180  
   45-55 34 (12) 27 (17) 61 (14) 88 (18) 85 (18) 173 (18)  
   55-65 63 (22) 28 (18) 91 (20) 101 (21) 88 (19) 189 (20)  
   65-75 131 (45) 57 (37) 188 (42) 100 (21) 71 (15) 170 (18)  
   > 75 51 (18) 13 (8) 64 (14) 58 (12) 48 (10) 106 (11)  
Age, Mean ± SD 66 ± 10 59 ± 13 64 ± 12 56 ± 16 53 ± 17 54 ± 16 < .0001
Ethnicity        
   White 255 (88) 97 (62) 352 (79) 429 (89) 346 (74) 775 (82) p = 0.07
   Asian 21 (7) 48 (31) 69 (16) 27 (6) 78 (17) 105 (11)  
   Other 13 (5) 11 (7) 24 (5) 26 (5) 42 (9) 68 (7)  
Education        
   < 8 years 97 (34) 36 (23) 137 (31) 55 (11) 68 (15) 140 (15) < .0001
   8-11 years 137 (47) 52 (33) 189 (42) 212 (44) 187 (40) 399 (42)  
   ≥12 years 55 (19) 64 (41) 119 (27) 205 (43) 204 (44) 409 (43)  
All types of smoking combined        
   Never   156 156 (35)   466 466 (49) < .0001
   Former (> 2 yrs. Since quitting) 159 (55)   159 (36) 319 (66)   319 (34)  
   Current 130 (45)   130 (29) 163 (34)   163 (17)  
   Pack-yearsb, Mean ± SD 45 ± 35    25 ± 27    < .0001
Histology        
   Adenocarcinoma 80 (28) 76 (49) 156 (35)     
   Squamous cell carcinoma 68 (24) 9 (6) 77 (17)     
   Small-cell carcinoma 28 (10) 4 (3) 32 (7)     
   Large cell carcinoma 21 (7) 6 (4) 27 (6)     
   Others/Mixed 46 (16) 26 (17) 72 (16)     
Not classified/clinical
diagnosis
46 (16) 35 (22) 81 (18)     
  1. a p-values from χ2 test or t-test across cases and controls
  2. b Pack-years among ever and current smokers