Table 1.

Characteristics of Prostate Cancer Cases and Controls in the Carotene and Retinol Efficacy Trial, 1985–2003

Characteristics	Cases			Controls			P Valuea
	Mean (SD)	No.b	%	Mean (SD)	No.b	%
Total		641			1,398
Age, years
Baseline	60.4 (5.7)			60.3 (5.8)			0.56
Diagnosis	66.9 (5.9)			N/A
Race/ethnicity
White		578	90.2		1,229	87.9	0.13
African American		39	6.1		121	8.7
Other		24	3.7		48	3.4
Randomization
Intervention		334	52.1		724	51.8	0.89
Placebo		307	47.9		674	48.2
Family history of prostate cancer, yes		42	6.6		46	3.3	<0.001
Smoking status
Current		332	51.8		741	53.0	0.61
Neverc/former		309	48.2		657	47.0
Smoking, pack-years
<40		238	37.1		530	37.9	0.85
40–59		216	33.7		477	34.1
≥60		187	29.2		391	28.0
Alcohol intake
Nondrinkers		145	22.6		341	24.4	0.010
1–9 g/day		181	28.2		475	34.0
≥10 g/day		262	40.9		472	33.8
Unknown		53	8.3		110	7.9
Body mass indexd
<25.0		147	22.9		305	21.8	0.84
25.0–29.9		309	48.2		689	49.3
≥30.0		185	28.9		404	28.9
Gleason score
<7		361	56.3		N/A
≥7		258	40.3
Unknown		22	3.4
Clinical stage
0, I		168	33.5		N/A
II		280	55.8
III		26	5.2
IV		25	5.0
Unknown		3	0.6
Year of diagnosise					N/A
1986–1993		145	22.6
1994–2003		496	77.4

Abbreviations: CARET, Carotene and Retinol Efficacy Trial; N/A, nonapplicable; PSA, prostate-specific antigen; SD, standard deviation.

^a The t-test for age at baseline and χ² tests for the categorical variables were used.

^b The numbers are numbers of participants and column percentages unless otherwise noted.

^c Never smokers contributed a very small percentage (<2%). They were recruited in the CARET because of their occupational asbestos exposure.

^d Body mass index: weight (kg)/height (m)².

^e 1994 approximates the advent of the PSA era.