Table 1.

Characteristics of two comparison groups: Men without prostate cancer on biopsy (Group 1), and men with PSA values in the reference range (Group 2).^*

Variable	Group 1 (n=109)	Group 2 controls (n=101)	p-value
Demographics
Age, mean (sd)	62 (8)	60 (8)	0.10
Race (% Caucasian)	98	97	0.69
Education, mean (sd)	15.2 (3.1)	16.5 (3.4)	0.003
Employment (% retired)	35	32	0.66
Marital status (% married)	84	90	0.22
Source of primary care (% internal medicine)†	69	74	0.43
Comorbidity
Seattle index of comorbidity, median‡	3	3	0.79
History of depression, %	12	10	0.62
History of anxiety disorder, %	6	6	0.92
Prostate items
Family history of prostate cancer, %	23	20	0.68
AUA score, median (IQR)§	7.0 (4–12)	5.5 (2–10)	0.01
Abnormal prostate exam, %	46	13	0.0001
PSA value (ng/ml), mean (sd)**	6.6 (4)	1.4 (1)	0.0001

^*Age, race, and PSA values were obtained from computerized records; all other variables were based on self-report.

^†Missing for 15 biopsy group 1 patients

^‡The Seattle index of comorbidity (SIC) is computed based on the following formula: SIC=Age (in 5-year intervals) + Prior MI + 2*(Cancer) + Lung disease + 2*(CHF) + 2*(Diabetes) + Pneumonia + 2*(Stroke) + 2*(Past smoker) + 4*(Current smoker)

^§AUA (American Urologic Association) score ranges from 0 to 35 (higher scores indicate more symptoms of prostatism); IQR = interquartile range.

^**Missing for 32 group 1 patients and 3 group 2 patients.