Table 1. Baseline Characteristics of Study Participants Overall and According to Age Group.
| Characteristic | Total Cohort (N = 1404) | 14–17 Years of Age (N = 484) | 18–19 Years of Age (N = 920) | P Value* |
|---|---|---|---|---|
| Race — no. (%)† | <0.01 | |||
| Black | 877 (62.5) | 328 (67.8) | 549 (59.7) | |
| White | 416 (29.6) | 119 (24.6) | 297 (32.3) | |
| Other | 111 (7.9) | 37 (7.6) | 74 (8.0) | |
| Low socioeconomic status — no. (%)‡ | 623 (44.4) | 163 (33.7) | 460 (50.0) | <0.01 |
| Health insurance — no./total no. (%) | <0.01 | |||
| None | 392/1361 (28.8) | 78/453 (17.2) | 314/908 (34.6) | |
| Private | 583/1361 (42.8) | 218/453 (48.1) | 365/908 (40.2) | |
| Public | 386/1361 (28.4) | 157/453 (34.7) | 229/908 (59.3) | |
| Lifetime male sex partners — median no. (range) | 3.0 (0–175) | 2.0 (0–30) | 3.0 (0–175) | <0.01 |
| Parity — no. (%) | <0.01 | |||
| 0 | 1059 (75.4) | 397 (82.0) | 662 (72.0) | |
| 1 | 289 (20.6) | 79 (16.3) | 210 (22.8) | |
| ≥2 | 56 (4.0) | 8 (1.7) | 48 (5.2) | |
| Previous unintended pregnancy — no./total no. (%) | 671/1403 (47.8) | 219/484 (45.2) | 452/919 (49.2) | 0.16 |
| History of abortion — no. (%) | 259 (18.4) | 70 (14.5) | 189 (20.5) | <0.01 |
| History of sexually transmitted infection — no. (%)§ | 331 (23.6) | 88 (18.2) | 243 (26.4) | <0.01 |
| Baseline chosen contraceptive method — no. (%)¶ | <0.01 | |||
| Hormonal IUD | 445 (31.7) | 119 (24.6) | 326 (35.4) | |
| Nonhormonal IUD | 75 (5.3) | 14 (2.9) | 61 (6.6) | |
| Etonogestrel implant | 485 (34.5) | 242 (50.0) | 243 (26.4) | |
| DMPA injection | 127 (9.0) | 51 (10.5) | 76 (8.3) | |
| Oral contraceptive pill | 175 (12.5) | 39 (8.1) | 136 (14.8) | |
| Ring | 69 (4.9) | 11 (2.3) | 58 (6.3) | |
| Patch | 28 (2.0) | 8 (1.7) | 20 (2.2) |
*
P values are for the comparison between the age groups (14 to 17 vs. 18 to 19 years of age).
†
Race was self-reported.
‡
Participants were classified as having low socioeconomic status if they reported current receipt of food stamps; vouchers from the Special Supplemental Nutrition Program for Women, Infants, and Children; other welfare benefits; unemployment benefits; or difficulty in paying for transportation, housing, health or medical care, or food.
§
Data are based on a self-reported history of chlamydia infection, gonorrhea, or trichomoniasis.
¶
DMPA denotes depot medroxyprogesterone acetate, and IUD intrauterine device.