Table 1.

Sample Characteristics for Men Receiving at Least One PSA Test per Year versus Men with at Least One Year with no PSA Test, During the First 5 Years of Surveillance

	Overall % or mean (SD)	At least one annual test	One or more years with no test	p-value†
Number of observations	10,761	8,155	2,606
Age at diagnosis (in years)	69.5 (3.1)	69.5 (3.0)	69.6 (3.2)	.0285
Age by category (%)				.0592
65-69	57.3	58.0	55.3
70-74	35.6	35.1	37.0
75 +	7.1	7.0	7.7
Married at diagnosis (%)	82.0	82.8	79.5	.0002
State buy-in at diagnosis (%)	6.4	5.7	8.7	<.0001
Tumor Histology (%)				.0029
Well/moderately differentiated	84.5	85.1	82.6
Poorly differentiated	15.5	14.9	17.4
Pathologic classification T2 (%)	82.3	81.3	85.4	<.0001
NCI Comorbidity Index at diagnosis	0.10 (0.25)	0.10 (0.25)	0.11 (0.26)	.3199
NCI Comorbidity Index by category (%)				.4855
0	78.3	78.5	77.8
>0	21.7	21.5	22.2
Race (%)				.0065
Non-Hispanic White	83.3	83.8	81.6
Non-Hispanic Black	5.8	5.6	6.5
Hispanic	6.1	5.7	7.3
Other/Unknown	4.8	4.9	4.6
Year of diagnosis (%)				<.0001
1998	4.3	3.7	6.3
1999	4.5	3.9	6.5
2000	7.8	7.1	9.9
2001	9.5	8.4	13.1
2002	10.5	9.3	14.2
2003	10.7	9.7	14.1
2004	12.4	12.2	12.9
2005	11.8	12.5	9.7
2006	12.8	14.4	7.9
2007	15.6	18.9	5.4
Years in sample	4.5 (2.7)	4.1 (2.6)	5.7 (2.4)	<.0001

^†p-values obtained using t-tests and chi-square tests and apply to differences in percentages or means across columns 3 and 4.

Note: PSA: Prostate-specific antigen; NCI: National Cancer Institute; SD: Standard deviation