Table 1.
Study Cohort Characteristics at Time of Enrollment
| Characteristics | Study Sample, No. (%) (n = 1139) |
|---|---|
| Age at entry, y | |
| 13–14 | 20 (1.8) |
| 15–16 | 201 (17.7) |
| 17–18 | 540 (47.4) |
| 19–21 | 378 (33.2) |
| Race | |
| Black/African American | 571 (50.1) |
| White | 64 (5.6) |
| Asian | 19 (1.7) |
| Native American/Pacific Islander | 18 (1.6) |
| Unspecified race (Hispanic only) | 467 (41.0) |
| Ethnicitya | |
| Non-Hispanic | 442 (38.8) |
| Hispanic | 678 (59.5) |
| Sexual activity | |
| Male vaginal sex partners, lifetime no. | |
| 1 | 199 (17.5) |
| 2 | 203 (17.8) |
| 3–4 | 334 (29.3) |
| 5–9 | 282 (24.8) |
| ≥10 | 121 (10.6) |
| Age at first vaginal intercourse, ya | |
| <14 | 182 (16.0) |
| 14–15 | 540 (47.4) |
| 16–17 | 355 (31.2) |
| ≥18 | 53 (4.7) |
| Sex partners in past 6 mo, no.a | |
| 0 | 47 (4.1) |
| 1 | 626 (55.0) |
| 2 | 259 (22.7) |
| 3–4 | 156 (13.7) |
| ≥5 | 48 (4.2) |
| Anal intercourse evera | |
| No | 773 (67.9) |
| Yes | 357 (31.3) |
| Anal sex partners, lifetime no.b | |
| 1 | 206 (18.1) |
| ≥2 | 84 (7.4) |
| Age at first anal intercourse, yb | |
| <16 | 57 (5.0) |
| ≥16 | 224 (19.7) |
| Oral sexa | |
| Never | 95 (8.3) |
| Ever (given or received) | 1043 (91.6) |
| HPV vaccine doses received at entry, no. | |
| 0 (vaccine naive) | 182 (16.0) |
| 1 | 143 (12.6) |
| 2 | 144 (12.6) |
| 3 | 670 (58.8) |
| Interval between first sex and vaccinationa | |
| ≥1 y before vaccination | 427 (37.5) |
| Within 1 y of vaccination | 176 (15.5) |
| >1 y after vaccination | 473 (41.5) |
| Age at first HPV vaccine dose, ya | |
| <15 | 482 (42.3) |
| ≥15 | 598 (52.5) |
| Pregnancies, no.a | |
| 0 | 734 (64.4) |
| 1 | 221 (19.4) |
| ≥2 | 87 (7.6) |
| History of STDs | |
| None | 718 (63.0) |
| Any | 421 (37.0) |
Abbreviations: HPV, human papillomavirus; STD, sexually transmitted disease.
a Percentage and total no. may not add up to 100% and 1139, respectively, owing to missing values.
b Total number does not add up to 357, owing to missing values.