Table 1. Distribution of 68 lung cancer cases and 337 controls, according to matching variables.

	Lung cancer		Controls
	N	(%)	N	(%)
Centre
Basel	11	16.2	55	16.3
Bern	9	13.2	42	12.5
Geneva	15	22.1	75	22.3
St Gallen	7	10.3	35	10.4
Vaud	13	19.1	65	19.3
Zurich	13	19.1	65	19.3
Gender
Male	54	79.4	270	80.1
Female	14	20.6	67	19.9
HIV-transmission category
MSM	19	27.9	95	28.2
IDU	25	36.8	125	37.1
Het/other	24	35.3	117	34.7
Age at lung cancera (years)
25–44	24	35.3	132	39.2
45–54	26	38.2	122	36.2
55–64	13	19.1	61	18.1
⩾65	5	7.4	22	6.5
Duration of follow-up before lung cancera (months)
<24	11	16.2	55	16.3
24–59	13	19.1	65	19.3
⩾60	44	64.7	217	64.4
Calendar period at lung cancer a
1985–1991	3	4.4	15	4.5
1992–1996	6	8.8	30	8.9
1997–April 2000	6	8.8	31	9.2
May 2000b–2005	28	41.2	146	43.3
2006–2010	25	36.8	115	34.1

Abbreviations: Het=heterosexual; IDU=intravenous drug user; MSM=men having sex with men.

^aOr reference date for controls (date after a similar length of follow-up in the SHCS as matched cases).

^bTruncation in mid-2000 to match for availability of smoking information.