. 2017 Oct 19;12(10):e0186643. doi: 10.1371/journal.pone.0186643

Table 2. Demographic characteristics of the study participants, SEER-Medicare 2000–2011.

	ICC Cases (n = 2,092)		ICC vs controls, P value	ECC Cases (n = 2,981)		ECC vs controls, P value	Controls (n = 323,615)		ICC vs ECC, P value
	n	%	ICC vs controls, P value	n	%	ECC vs controls, P value	n	%	ICC vs ECC, P value
Mean age, y (SD)	78.0	6.5	<0.0001	79.2	6.8	<0.0001	76.5	7.7	<0.0001
Sex			<0.0001			<0.0001			0.001
Female	1,118	53.4		1,455	48.8		199,583	61.7
Male	974	46.6		1,526	51.2		124,032	38.3
Race/ethnicity			<0.0001			<0.0001			0.2
White	1,729	82.7		2,411	80.9		270,885	83.7
Black	111	5.3		193	6.5		25,458	7.9
Hispanic	47	2.3		82	2.8		7,177	2.2
Asian	117	5.6		190	6.4		11,177	3.5
Other/Missing¹	88	4.2		105	3.5		8,918	2.8
Geographic location			<0.0001			<0.0001			0.006
San Francisco	110	5.3		149	5.0		10,954	3.4
Connecticut	150	7.2		204	6.8		18,821	5.8
Detroit	113	5.4		203	6.8		20,701	6.4
Hawaii	53	2.5		49	1.6		4,377	1.4
Iowa	163	7.8		203	6.8		19,432	6.0
New Mexico	49	2.3		58	2.0		9,038	2.8
Seattle	144	6.9		132	4.4		16,522	5.1
Utah	36	1.7		54	1.8		8,099	2.5
Atlanta	59	2.8		76	2.6		9,116	2.8
San Jose	43	2.1		76	2.6		6,992	2.2
Los Angeles	196	9.4		280	9.4		23,271	7.2
Greater California	317	15.2		528	17.7		56,730	17.5
Kentucky	131	6.3		197	6.6		24,867	7.7
Louisiana	86	4.1		142	4.8		20,005	6.2
New Jersey	311	14.9		438	14.7		44,178	13.7
Greater/Rural Georgia¹	131	6.3		192	6.4		30,512	9.4
State Buy-in Status²			0.3			0.5			0.2
Ever	398	19.0		609	20.4		64,663	20.0

¹Combined due to limited sample size.

²State buy-in status is a proxy of lower socioeconomic status and indicates that a third-party (i.e., state of residence) paid a beneficiary's Medicare Part B premium.