Table 1.

Distribution of matching variables and variables from the Spitz risk model among cases and controls in the MDACC and MGH populations

MDACC overall (N = 995)MGH overall (N = 511)
Case (N = 527)Controls (N = 468)PCase (N = 239)Controls (N = 272)P
Matching variables
 Sex, n (%) male260 (49.3)243 (51.9)0.951107 (44.8)114 (41.9)0.515
 Age, mean ± SD62 ± 10.859 ± 12.1<0.00165 ± 10.764 ± 11.00.222
Smoking status, n (%)
 Never111 (21.1)104 (22.2)37 (15.5)60 (22.1)
 Former221 (41.9)185 (39.5)118 (49.4)122 (44.8)
 Current195 (37.0)179 (38.3)0.73884 (35.1)90 (33.1)0.166
Spitz model variables
 Second-hand smoke, n (%)N = 111N = 104N = 37N = 60
  among NS86 (77.5)84 (80.8)0.55327 (73.0)47 (78.3)0.626
 Quitting age, n (%)
  among FSN = 221N = 185N = 117N = 122
  <4275 (40.5)65 (29.4)45 (38.5)63 (51.6)
  42–5351 (27.6)68 (30.8)30 (25.6)32 (26.2)
  ≥5459 (31.9)88 (39.8)<0.00142 (35.9)27 (22.1)0.045
 Emphysema, n (%)N = 416N = 364N = 167N = 2120.004
  among FS and CS91 (21.9)25 (6.8)<0.00131 (18.6)18 (8.5)
 Dust exposure, n (%)N = 416N = 364N = 202N = 2120.809
  among FS and CS81 (19.5)44 (12.1)0.00526 (12.9)29 (13.7)
 No hay fever, n (%)N = 416N = 364N = 212
  among FS and CS374 (89.9)312 (85.7)0.073NA32 (15.1)
 Asbestos exposure, n (%)N = 195N = 179N = 84N = 90
  among FS and CS59 (30.3)25 (14.0)<0.00114 (16.7)18 (20.0)0.571
 Family history of cancer, n (%)N = 332N = 289N = 150N = 1820.240
  among NS and FS101 (30.4)64 (22.2)0.02051 (34.0)51 (28.0)
 Family history of smoking-related cancers, n (%)N = 195N = 179N = 80N = 90
  among CS75 (38.5)57 (31.8)0.18123 (28.7)23 (25.6)0.640
 Pack-years, n (%)
  among CSN = 195N = 179N = 69N = 90
  <2836 (18.5)76 (42.5)18 (26.1)49 (54.4)
  28–41.945 (23.1)38 (21.2)17 (24.6)16 (17.8)
  42–57.456 (28.7)35 (19.6)16 (23.2)16 (17.8)
  ≥57.558 (29.7)30 (16.8)<0.00118 (26.1)9 (10.0)0.002

Abbreviations: P, P value from the χ2 test of association (for categorical variables) and Student test (for continuous variables); NS, never smokers; FS, former smokers; CS, current smokers.