Table I.

Baseline characteristics of lung cancer cases and individually matched controls

	Cases (n = 227)	Controls (n = 227)
	Mean (SD)	Mean (SD)	P-valuea
Age at baseline (years)	58.7 (5.0)	58.4 (4.8)	0.57
Smoking
Number of cigarettes per day	18.8 (9.6)	17.0 (9.6)	0.06
Years of smoking	38.5 (7.1)	35.8 (9.2)	<0.01
Body mass index (kg/m2)b	25.6 (3.5)	26.3 (3.9)	0.03
Alcohol consumption (g/day)c	17.1 (18.5)	18.7 (20.0)	0.42
Caloric consumption (kcal/day)c	2696 (727)	2648 (669)	0.48
	N	N	P-valued
Physical activity frequency (leisure)			0.79
<1 per week	103	106
1–2 per week	73	76
≥3 per week	51	45
Supplementation group			0.62
Placebo	52	64
Alpha-Tocopherol	57	55
Beta-Carotene	58	55
Alpha-Tocopherol and Beta-Carotene	60	53

^at-test.

^bData not available for one case.

^cDietary data unavailable for seven cases and 20 controls.

^dchi-squared test.