TABLE 1.

Distributions of Selected Demographic and Potential Confounding Factors

	No. (%)
Variable	Lung cancer cases, n = 558	Controls, n = 837
Mean ± SD age, y	52 ± 5	50 ±7
Sex
Women	274 (49.1)	339 (40.5)
Men	284 (50.9)	498 (59.5)
Race-ethnicity
Non-Hispanic white	332 (59.5)	530 (63.3)
Black	86 (15.4)	83 (9.9)
Hispanic	61 (10.9)	146 (17.5)
Other	79 (14.2)	78 (9.3)
Mean ± SD schooling, y	13 ± 3	14 ±4
Smoking status
Never	96 (17.2)	390 (46.6)
Ever	462 (82.8)	447 (53.4)
Median pack-years for ever-smokers [interquartile range]	35 [26]	12 [27]
Mean ± SD daily energy intake, calories	1529 ± 667	1480 ± 597

SD indicates standard deviation.