Table 1.
Characteristics of the Sample Population
| Characteristic | Overall (n = 1814) | Vaccinated (n = 1355) | Unvaccinated (n = 459) | P |
|---|---|---|---|---|
| Age, y | 20.5 ± 0.7 | 20.5 ± 0.7 | 20.7 ± 0.6 | <.01c |
| Fiscal year of birth | ||||
| 1993 | 224 (12.3) | 0 (0.0) | 224 (48.8) | <.01d |
| 1994 | 686 (37.8) | 563 (41.5) | 123 (26.8) | |
| 1995 | 494 (27.2) | 418 (30.8) | 76 (16.6) | |
| 1996 | 410 (22.6) | 374 (27.6) | 36 (7.8) | |
| Age at first inoculation, y | 15.2 ± 0.9 | 15.2 ± 0.9 | NA | |
| Doses, no. | ||||
| 3 | 1294 (71.3) | 1294 (95.5) | NA | |
| 2 | 45 (2.5) | 45 (3.3) | NA | |
| 1 | 16 (0.9) | 16 (1.2) | NA | |
| Ever had intercoursea | ||||
| Yes | 1351 (81.2) | 958 (79.2) | 393 (86.6) | <.01e |
| No | 313 (18.8) | 252 (20.8) | 61 (13.4) | |
| Sex partners, lifetime no.a | ||||
| ≥10 | 118 (7.1) | 73 (6.0) | 45 (9.9) | <.01d |
| 6–9 | 131 (7.9) | 84 (6.9) | 47 (10.4) | |
| 2–5 | 645 (38.8) | 463 (38.3) | 182 (40.1) | |
| 1 | 457 (27.5) | 338 (27.9) | 119 (26.2) | |
| 0 | 313 (18.8) | 252 (20.8) | 61 (13.4) | |
| Age at sexual debut, ya | ||||
| ≤15 | 235 (14.1) | 162 (13.4) | 73 (16.1) | <.01d |
| 16–18 | 661 (39.7) | 468 (38.7) | 193 (42.5) | |
| ≥19 | 455 (27.3) | 328 (27.1) | 127 (28.0) | |
| NA | 313 (18.8) | 252 (20.8) | 61 (13.4) | |
| Overall | 17.4 ± 1.9 | 17.4 ± 1.9 | 17.3 ± 2.0 | .19c |
| Timing of sexual debuta | ||||
| Before vaccination | 85 (5.1) | 85 (7.0) | NA | |
| Same year as vaccination | 125 (7.5) | 125 (10.3) | NA | |
| After vaccinationb | 1000 (60.1) | 1000 (82.6) | NA |
Data are no. (%) of participants or mean ±SD
Abbreviation: NA, not applicable.
aData are for 1210 vaccinated subjects and 454 unvaccinated subjects who answered questions about sexual behavior.
bData include subjects who were sexually naive.
cBy the t test.
dBy the χ2 test.
eBy the Fisher exact test.