Table 4

Differences in nodule and participant characteristics between the PanCan data set2 and the NLST data set1 (p values, Student’s t-test or Wilcoxon-Mann-Whitney test or Embedded Image test used when appropriate). For each test, an effect size (ES) was also reported. For Embedded Image tests, Cramér’s V or Embedded Image was calculated (ie, magnitude of the ES; small: Embedded Image , medium: Embedded Image and large: Embedded Image ) and for Student’s t-test and Wilcoxon-Mann-Whitney tests, Embedded Image and Cohen’s Embedded Image (ie, magnitude of the ES; small: Embedded Image , medium: Embedded Image and large: Embedded Image ), respectively

Nodule covariatesPanCan (n=7008)NLST (n=7879)P valueEffect size
Nodule size (mm)4.1 (3.1)6.89 (5.35)<0.0010.003
Nodule type*<0.001 †0.122
 Solid5511 (78.9%)7216 (91.59%)
 Non-solid1105 (15.8%)485 (6.16%)
 Part-solid303 (4.3%)178 (2.26%)
 Perifissural70 (1.0%)
Nodule location (upper lobe)‡3879 (55.70%)2710 (34.40%)<0.0010.21
Nodule count at baseline6.2 (4)2.44 (1.63)<0.0010.733
Spiculation197 (2.8%)1032 (13.1%)<0.0010.186
Participant covariates PanCan (n=1871)NLST (n=5018)P valueEffect size
Age (years) 62.4 (5.8)62.01 (5.12)<0.0010.027
Gender<0.0010.077
 Female 886 (47.4%)1947 (38.80%)
 Male 985 (52.6%) 3071 (61.20%)
Family history of lung cancer 597 (32.4%)1154 (23.0%)<0.0010.091
Emphysema 1110 (60.4%) 1661 (33.10%)<0.0010.238
  • *Only for 6989 nodules in PanCan data set.

  • †Test without perifissural category.

  • ‡Only for 6964 nodules in PanCan data set.

  • NLST, National Lung Screening Trial; PanCan, Pan-Canadian Early Detection of Lung Cancer Study.