Table 2.

Evolution of Demographic and Behavioral Characteristics Throughout First Three Waves of Enrollment in Contraceptive CHOICE Project, n = 2,500

	Total		Wave 1 1st 500	Wave 2 2nd 1000	Wave 3 3rd 1000		Wave 1 vs. 2	Wave 2 vs. 3	Wave 1 vs. 3
	n	%	%	%	%	p value	p value	p value	p value
Recruitment clinic						<0.001	0.315	<0.001	<0.001
University-affilliated	1845	73.8	78.6	75.1	70.1
Abortion	444	17.8	17.0	19.5	16.4
Family planning/community health	211	8.4	4.4	5.4	13.5
Race						<0.001	<0.001	0.928	<0.001
Black	1086	43.7	32.5	46.7	46.2
White	1209	48.7	60.6	45.6	45.7
Other	190	7.6	6.9	7.6	8.1
Hispanic						0.360	0.461	0.408	0.167
Yes	114	4.6	3.6	4.4	5.2
Age						0.742	0.608	0.620	0.663
<18	99	4.0	3.8	3.5	4.5
18–20	426	17.0	15.8	18.0	16.7
21–25	1053	42.1	44.6	41.6	41.4
>25	922	36.9	35.8	36.9	37.4
Trouble paying						0.025	0.949	0.014	0.040
Yes	968	39.0	36.7	36.9	42.3
Receive public assistance						0.167	0.104	0.811	0.069
Yes	719	28.9	25.5	29.5	29.9
Trouble paying or receiving assistance						0.046	0.254	0.121	0.016
Yes	1281	51.7	47.8	50.9	54.4
Lifetime sex partners						0.233	0.079	0.583	0.268
0–1	364	14.6	13.8	14.0	15.5
2–4	671	26.8	28.6	26.1	26.7
5–9	849	34.0	30.0	36.3	33.6
10+	616	24.6	27.6	23.6	24.2
History of abortion						0.001	0.971	0.001	0.007
Yes	1128	45.1	48.0	48.1	40.7
Any STI diagnosis in lifetimea						0.144	0.733	0.104	0.097
Yes	702	28.4	26.4	27.2	30.6
Any STI at baselineb						<0.001	0.110	0.006	<0.001
Yes	120	4.8	2.4	4.0	6.8
Parity						0.779	0.546	0.661	0.783
0	1236	49.4	50.4	48.5	49.9
1	585	23.4	24.6	23.0	23.2
2	429	17.2	16.0	18.5	16.4
3+	250	10.0	9.0	10.0	10.5
Reached desired parity						0.899	0.707	0.927	0.652
Yes	953	38.1	39.0	38.0	37.8

^aChlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, syphilis, herpes, or HIV.

^bChlamydia trachomatis, Neisseria gonorhoeae, Trichomonas vaginalis.