Table 1.

Characteristics of cases and controls in the SEER-Medicare database from 1997 to 2005

Characteristic	Cases (n = 552 951)		Controls (n = 100 000)		p-value
	N	Percent %	N	Percent %
Sex
Male	280 034	50.6	50 644	50.6	1.00
Female	272 917	49.4	49 356	49.4
Age at diagnosis or selection (years)
70–74	159 254	28.8	28 800	28.8	1.00
75–79	167 536	30.3	30 299	30.3
80–84	126 165	22.8	22 817	22.8
85–99	99 996	18.1	18 084	18.1
Median (Range)	78 (70–99)		78 (70–99)
Selection year
1997–1999	110 534	20.0	19 989	20.0	1.00
2000–2001	153 125	27.7	27 692	27.7
2002–2003	147 348	26.7	26 648	26.7
2004–2005	141 944	25.7	25 671	25.7
Race
White	482 412	87.2	85 394	85.4	<.0001
Black	39 249	7.1	6 462	6.5
Asian	13 105	2.4	3 378	3.4
Other or unknown	18 185	3.3	4 766	4.8
Any Condition 0–12 months
No	42 331	7.7	8 488	8.5	<.0001
Yes	510 620	92.3	91 512	91.5
Any Condition 13–30 months
No	49 773	9.0	9 496	9.5	<.0001
Yes	503 178	91.0	90 504	90.5
Any Condition 31–48 months
No	60 592	11.0	11 153	11.2	0.070
Yes	492 359	89.0	88 847	88.9
Total number of conditions 0–12 months
0	42 331	7.7	8 488	8.5	<.0001
1	40 163	7.3	7 537	7.5
2	50 909	9.2	9 711	9.7
3+	419 548	75.9	74 264	74.3
Median (Range)	5 (0–44)		5 (0–36)
Total number of conditions 13–30 months
0	49 773	9.0	9 496	9.5	<.0001
1	46 054	8.3	8 570	8.6
2	56 767	10.3	10 657	10.7
3+	400 357	72.4	71 277	71.3
Median (Range)	4 (0–40)		4 (0–34)
Total number of conditions 31–48 months
0	60 592	11.0	11 153	11.2	0.006
1	54 677	9.9	9 923	9.9
2	64 258	11.6	11 913	11.9
3+	373 424	67.5	67 011	67.0
Median (Range)	4 (0–38)		4 (0–31)