Table 2.

Fathers’ Demographic, Exposure, and Interview Characteristics: Cases Without Controls, Cases With Controls, and Controls From a Case-control Study of Retinoblastoma Using Friend Controls, United States, 2002 – 2007.

Exposure/characteristica	Cases without controls N=62b		Cases with controls N=137b		Controls N=247b
	#	%	#	%	#	%
Race/ethnicityc
White, non-Hispanic	23	37	104	76	202	82
Black, non-Hispanic	13	21	17	12	19	8
Hispanic	15	24	10	7	18	7
Other	11	18	6	4	8	3
Education
Less than high school	14	23	5	4	13	5
High school graduate	18	29	36	26	45	18
Some post high school	17	27	33	24	51	21
College graduate	8	13	39	29	88	36
Graduate/professional school	5	8	23	17	50	20
Income
< $25,000	18	37	8	7	21	10
$25 – 35,000	8	17	13	11	19	9
$35 – 50,000	5	10	26	21	37	17
$50 – 75,000	11	23	28	23	50	23
> $75,000	6	12	47	39	86	40
Age at child’s birth
< 25	8	13	11	8	18	7
25 – 29	19	31	30	22	71	29
30 – 34	13	21	43	31	82	33
35 – 39	16	26	40	29	53	21
40 +	5	8	13	9	23	9
Marital status at interview
Married	44	72	125	91	229	93
Not married	17	28	12	9	16	7
Interviewed by proxy
Yes	17	27	16	12	43	17
No	45	73	121	88	204	83
Smoked
Yes	34	55	38	28	55	22
No	28	45	99	72	192	78
# cigarettes/day
None	28	47	99	72	192	78
1–10/day	18	30	19	14	31	13
11–50/day	14	23	19	14	24	10
Binge drinkingd
< 1time/month	47	80	119	87	207	84
≥ 1time/month	12	20	18	13	40	16
Multivitamin use
Yes	17	28	55	40	83	34
No	44	72	82	60	164	66
Vitamin C supplement use
Yes	8	15	38	31	49	22
No	44	85	84	69	174	78
Apple consumption
< 1 serving/week	33	63	75	58	100	43
≥ 1 serving/week	19	36	54	42	130	57
Cured meat intake
< 2 servings/week	28	54	47	39	116	52
≥ 2 servings/week	24	46	75	61	107	48
Body mass index
< 25	18	35	35	29	76	34
≥ 25	33	65	87	71	147	66
History of lower GIe series
Yes	3	6	11	9	8	4
No	49	94	111	91	215	96

^aExposures/characteristics pertain to the father in the year before the index pregnancy except that the time period for history of lower GI series is any time prior to the index child’s conception.

^bMissing data explain the differing number of total subjects among exposures/characteristics. A small proportion of fathers completed shorter questionnaires that did included a shortened supplement section and no diet or medical radiation section. Thus, for vitamin C supplement use, cured meat intake, apple consumption, body mass index, and history of lower GI series, the maximum numbers are 52 cases without controls, 122 cases with controls, and 223 controls.

^cCases with and without controls differ significantly in race/ethnicity (P<0.001), educational level (P <0.001), income (P <0.001), marital status (P =0.001), father interviewed by proxy (P =0.008), smoked (P <0.001), and # cigarettes/day (P=0.002).

^dBinge drinking was defined as consuming 6 or more drinks on one occasion

^eGastrointestinal