TABLE 1—

Characteristics of Participants in the Study of Reliability of 3 Questionnaires: United States, 2002

	San Diego (n = 93)		South Carolina (n = 97)		St Louis (n = 99)		Total Sample Test–Retest Agreement/Reliability
Characteristic	n	%	n	%	n	%	%	ICC
Gender
Female	66	71.0	59	62.8	57	60.6	99.2	0.98
Male	27	2.0	38	37.2	42	39.4
Race
White	78	83.9	73	75.3	78	79.6	95.4	0.85
Black or African American	11	11.8	20	20.6	18	18.4
Othera	4	4.4	4	4.1	2	2.0
Age, y
< 30	16	17.2	23	23.7	17	17.2	98.2	0.98
30–39	24	25.8	10	10.3	19	19.2
40–49	18	19.4	13	13.4	17	17.1
50–59	22	23.6	21	21.7	16	16.2
> 60	13	14.0	30	30.9	32	30.3
Education
Less than high school	4	4.3	14	14.5	11	11.2	72.3	0.87
High school or GED	21	22.6	31	32.0	29	29.6
Some college/technical school	30	32.3	24	24.7	33	33.7
College graduate	21	22.6	19	19.6	16	16.3
Post graduate/professional degree	17	18.3	9	9.3	9	9.2
Annual income
< $20 000	13	15.2	19	21.6	20	23.3	73.6	0.82
$20 000–$34 999	21	24.7	30	34.1	25	29.1
$35 000–< $49 999	17	20.0	14	15.9	15	17.4
> $50 000	34	40.0	25	28.4	26	30.3
Employment status
Employed for wages—full-time	46	49.5	35	36.1	37	37.8	73.7	0.86
Employed for wages—part-time	12	12.9	13	13.4	9	9.2
Self-employed	12	12.9	2	2.1	8	8.2
Out of work, retired, disabled or unable to work	15	16.1	36	37.2	29	29.6
Homemaker/student	8	8.7	11	11.4	15	15.3

Note: ICC = intraclass correlation coefficient.

^aOther includes Asians/Pacific Islanders and American Indians/Alaska Natives.