Table 1. Distribution of cases and controls among men and women by socio-demographic characteristics and histological type among cases.

	Male							Female
	Cases		Controls					Cases		Controls
	N	%	N	%	ORa	95% CI	P-value	N	%	N	%	ORa	95% CI	P-value
Total	2275		2780					648		775
Age at interview, years
<50	310	14	663	24	1.0	Ref.		160	25	167	21	1.0	Ref.
50–60	773	34	855	31	1.9	1.6–2.3		224	35	160	21	1.5	1.1–2.1
60–70	824	36	923	33	1.9	1.6–2.2		171	26	263	34	0.7	0.5–1.0
⩾70	368	16	339	12	2.3	1.9–2.9	P<0.001	93	14	185	24	0.6	0.4–0.8	P<0.001
Educational levelb
Elementary school or less	675	34	521	19	1.0	Ref.		204	34	242	32	1.0	Ref.
Middle school	869	43	1081	41	0.6	0.5–0.7		208	35	270	36	0.6	0.5–0.8
High school	185	9	310	12	0.4	0.4–0.6		72	12	90	12	0.7	0.5–1.0
University	274	14	752	28	0.3	0.2–0.3	P<0.001	110	19	149	20	0.5	0.4–0.8	P<0.001
Occupational exposure (list A)c
Non-exposed	1826	81	2450	88	1.0	Ref.		623	97	767	99	1.0	Ref.
Exposed	438	19	329	12	1.8	1.5–2.1	P<0.01	21	3	8	1	3.0	1.3–6.9	P<0.001
Histological types by smoking status
Never smokers (CSI=0)	59		813					188		513
Squamous cell carcinoma	12	20	—					23	12	—
Small cell carcinoma	2	4	—					6	3	—
Adenocarcinoma	32	54	—					133	70	—
Other types	13	22	—					27	14	—
Multiple phenotyped	—							1		—
Ever smokers (CSI>0)	2191		1958					457		260
Squamous cell carcinoma	786	36	—					82	18	—
Small cell carcinoma	330	15	—					89	19	—
Adenocarcinoma	759	35	—					221	48	—
Other types	336	15	—					70	15	—
Multiple phenotyped	20	3	—					5		—

Abbreviations: CI=confidence interval; CSI=comprehensive smoking index; OR=odds ratio.

^aOdds ratio of lung cancer adjusted for age at interview (<50, 50–60, ⩾60) and department.

^bEducational level was not available in the summarized questionnaire.

^cData missing for 12 men (11 cases and 1 control) and 4 women cases.

^dMultiple phenotype corresponds to tumours with several histological entities. Subjects with multiple phenotypes must be subtracted from the total to not be counted more than once.