Table 1.

Selected Study Population Characteristics by Lung Cancer Status and EC Exposure

Characteristics	Ever Exposed to EC				Never Exposed to EC
	Cases	%	Control Subjects	%	Cases	%	Control Subjects	%
Sex
M	8,045	95.4	8,181	94.1	5,560	65.6	8,270	67.4
F	386	4.6	512	5.9	2,910	34.4	4,002	32.6
Age group
<45 yr	267	3.2	359	4.1	448	5.3	1,012	8.2
45–64 yr	4,195	49.8	4,120	47.4	4,568	53.9	6,234	50.8
>64 yr	3,969	47.1	4,214	48.5	3,454	40.8	5,026	41.0
Smoking status
Never-smoker	379	4.5	2,287	26.3	990	11.7	4,866	39.7
Former smoker	2,966	35.2	3,880	44.6	2,466	29.1	4,340	35.4
Current smoker	5,086	60.3	2,526	29.1	5,014	59.2	3,066	25.0
Smoking pack-years
Never-smoker	379	4.5	2,287	26.3	990	11.7	4,866	39.7
<10	381	4.5	1,287	14.8	428	5.1	1,782	14.5
10–19	765	9.1	1,206	13.9	837	9.9	1,656	13.5
>19	6,906	81.9	3,913	45.0	6,215	73.4	3,968	32.3
Years since quitting smoking
Never-smoker	379	4.5	2,287	26.3	990	11.7	4,866	39.7
>0–7 yr	1,085	12.9	644	7.4	941	11.1	778	6.3
8–15 yr	836	9.9	883	10.2	695	8.2	1,015	8.3
16–25 yr	637	7.6	1,088	12.5	534	6.3	1,258	10.3
>25 yr	408	4.8	1,265	14.6	296	3.5	1,289	10.5
Current smoker	5,086	60.3	2,526	29.1	5,014	59.2	3,066	25.0
List A job
Ever employment	1,143	13.6	866	10.0	644	7.6	498	4.1
Never employment	7,288	86.4	7,827	90.0	7,712	92.4	11,629	95.9
Lung cancer subtype
Adenocarcinoma	1,953	23.2	—	—	2,799	33.0	—	—
Large cell carcinoma	390	4.6	—	—	420	5.0	—	—
Small cell carcinoma	1,427	16.9	—	—	1,303	15.4	—	—
Squamous cell carcinoma	3,704	43.9	—	—	2,799	33.0	—	—
Other/unspecified	914	10.8	—	—	1,098	13.0	—	—
Not available	43	0.5	—	—	51	0.6	—	—

Definition of abbreviation: EC = elemental carbon.