Table 1 Clinical and radiographic characteristics of the 375 patients in the study cohort

Age

62 (55, 69)

68 (63, 75)

65 (57, 71)

< 0.001

Sex

0.006

Female

60 (39%)

73 (58%)

50 (51%)

Male

92 (61%)

52 (42%)

48 (49%)

Physician Assessed Risk

< 0.001

High

27 (18%)

54 (43%)

9 (9.2%)

Intermediate

107 (70%)

65 (52%)

71 (72%)

Low

18 (12%)

6 (4.8%)

18 (18%)

Smoking Status

0.4

Current

57 (38%)

45 (36%)

45 (46%)

Former

94 (62%)

80 (64%)

53 (54%)

Never

1 (0.7%)

0 (0%)

0 (0%)

Pack Years Smoked

34 (17, 50)

40 (23, 54)

35 (20, 50)

0.10

Years Since Quit

6 (1, 22)

6 (2, 18)

1 (0, 14)

0.2

Nodule Length (mm)

0.001

(0–10]

18 (12%)

9 (7.2%)

15 (15%)

(10–20]

53 (35%)

63 (50%)

43 (44%)

(20–30]

29 (19%)

33 (26%)

12 (12%)

(30+]

52 (34%)

20 (16%)

28 (29%)

Nodule Location

0.2

Central

13 (8.6%)

4 (3.2%)

8 (8.2%)

Peripheral

139 (91%)

121 (97%)

90 (92%)

Lobe Location

0.7

Lower

56 (37%)

45 (36%)

33 (34%)

Middle

16 (11%)

8 (6.4%)

8 (8.2%)

Upper

80 (53%)

72 (58%)

57 (58%)

Nodule Density

0.5

Ground glass opacity

8 (5.3%)

4 (3.2%)

7 (7.1%)

Partial solid

9 (5.9%)

13 (10%)

7 (7.1%)

Solid

135 (89%)

108 (86%)

84 (86%)

Nodule Margins

< 0.001

Irregular

95 (62%)

58 (46%)

56 (57%)

Lobulated

6 (3.9%)

5 (4.0%)

5 (5.1%)

Smooth

15 (9.9%)

3 (2.4%)

12 (12%)

Spiculated

36 (24%)

59 (47%)

25 (26%)