Table 1. Baseline demographics data of men and women who underwent a chest radiograph or CT for non-screening reasons in two hospitals during 2010 and 2011.

	Men			Women
	Chest Radiograph (11208)	CT (1387)	Total (12595)	Chest Radiograph (11893)	CT (934)	Total (12827)
Age (years)
<50	2485 (22.2)	183 (13.2)	2668 (21.2)	2564 (21.6)	167 (17.9)	2731 (21.3)
50–59	1911 (17)	279 (20.1)	2190 (17.4)	2049 (17.2)	190 (20.3)	2239 (17.5)
60–69	2599 (23.2)	342 (24.7)	2941 (23.3)	2445 (20.6)	226 (24.2)	2671 (20.8)
>70	4206 (37.5)	582 (42)	4788 (38)	4833 (40.6)	351 (37.6)	5184 (40.4)
Not specified	7 (0.1)	1 (0)	8 (0.1)	2 (0)	0 (0)	2 (0)
Setting
Inpatient	1746 (15.6)	383 (27.7)	2129 (16.9)	1569 (13.2)	180 (19.3)	1749 (13.6)
Outpatient	9453 (84.4)	1001 (72.3)	10454 (83.1)	10319 (86.8)	754 (80.7)	11073 (86.4)
Not specified	9 (0.1)	3 (0.2)	12 (0.1)	5 (0)	0 (0)	5 (0)
Reason for requesting imaging test
Respiratory	2103 (18.8)	524 (37.8)	2627 (20.9)	1884 (15.8)	282 (30.2)	2166 (16.9)
Non- respiratory	3107 (27.7)	262 (18.9)	3369 (26.8)	3461 (29.1)	203(21.7)	3664 (28.6)
Extrapulmonary neoplasm	543 (4.8)	198 (14.3)	741 (5.9)	542 (4.6)	152 (16.3)	694 (5.4)
Preoperative	2179 (19.4)	32 (2.3)	2211 (17.5)	2614 (22)	24 (2.6)	2638 (20.6)
Not specified	3276 (23.2)	371 (26.8)	3647 (28.9)	3392 (28.5)	273 (29.2)	3665 (28.6)
Smoking habit
Never	59 (0.5)	51 (3.7)	110 (0.9)	40 (0.3)	41 (4.4)	81 (0.6)
Former and current	178 (1.6)	166 (12)	344 (2.7)	97 (0.8)	86 (9.2)	183 (1.4)
Not specified	10971 (97.9)	1170 (84.4)	12141 (96.4)	11756 (98.9)	807 (86.4)	12563 (97.4)
COPD
No	197 (1.8)	164 (11.8)	361 (66.2)	161 (83)	128 (84.2)	289 (83.5)
Yes	88 (0.7)	96 (6.9)	184 (33.8)	33 (17)	24 (15.8)	57 (16.5)
Not specified	10923 (97.5)	1127 (81.3)	1127 (81.3)	11699 (98.4)	782 (83.7)	12481 (97.3)