Table 2.

Baseline Characteristics of SCCS Participants by Regular Supplement Use

	Non-Regular Supplement Users (n = 43,566)				Regular Supplement Users (n = 38,318)
	N	%	Mean	STD	N	%	Mean	STD
Age at enrollment, years a			51	8.6			53	8.9
Sex b
Female	24,209	55.6			24,398	63.7
Male	19,357	44.4			13,920	36.3
Race b
White	11,276	25.9			13,428	35.0
Black/African American	30,743	70.6			22,770	59.4
Other (His, As, NA, Mix)	1,420	3.3			1,817	4.7
Unknown	127	0.3			303	0.8
Body mass index, [kg/m2] a			30.5	7.7			30.1	7.3
Education b
Less than high school/GED	15,491	35.6			7,799	20.4
High School	15,320	35.2			11,449	29.9
Some/Junior college	9,087	20.9			11,603	30.3
College degree	2,384	5.5			4,229	11.0
More than college	1,149	2.6			2,947	7.7
Unknown	135	0.3			291	0.8
Household income b
<$15,000	27,303	62.7			17,096	44.6
$15,000 – <$25,000	8,876	20.4			8,126	21.2
$25,000 – <$50,000	4,554	10.5			6,871	17.9
$50,000 – <$100,000	1,809	4.2			4,094	10.7
≥$100,000	495	1.1			1,470	3.8
Unknown	529	1.2			661	1.7
Insurance b
No	18,800	43.2			13,116	34.2
Yes	24,701	56.7			25,150	65.6
Unknown	65	0.2			52	0.1
Geographic Deprivation Index Group (Quartile) b
Q1	3,270	7.5			5,444	14.2
Q2	6,156	14.1			6,855	17.9
Q3	8,846	20.3			8,223	21.5
Q4	24,852	57.0			17,067	44.5
Unknown	442	1.0			729	1.9
Family history of gastric cancer
No/unknown	42,199	96.9			37,080	96.8
Yes	1,367	3.1			1,238	3.2
Diabetes b
No	33,825	77.6			30,557	79.8
Yes	9,724	22.3			7,741	20.2
Unknown	17	0.04			20	0.05
Ulcer b
No	38,363	88.1			33,133	86.5
Yes	5,153	11.8			5,148	13.4
Unknown	50	0.1			37	0.1
Reflux b
No	32,732	75.1			26,289	68.6
Yes	10,812	24.8			12,005	31.3
Unknown	22	0.1			24	0.1
Smoking Status b
Never	14,169	32.5			15,143	39.5
Former	8,592	19.7			10,167	26.5
Current, <20 cigs/day	12,877	29.6			8,378	21.9
Current, ≥20 cigs/day	7,661	17.6			4,172	10.9
Unknown	267	0.6			458	1.2
Alcohol b
Never/Rarely	12,668	29.1			11,522	30.1
1-3 times per month	4,145	9.5			4,069	10.6
1-4 times per week	13,346	30.6			12,283	32.1
Daily/Nearly Daily	13,117	30.1			10,064	26.3
Unknown	290	0.7			380	1.0

^aP < 0.05 comparing non-regular supplement users to regular supplement users, ANOVA F test.

^bP < 0.05 comparing non-regular supplement users to regular supplement users, Chi-Square test, two-sided.