TABLE 2.
Baseline Characteristics of Girls and Their Mothers, by Quadrivalent Human Papillomavirus Vaccine (HPV4) Initiation Status: California, October 2006–September 2007
| HPV4 Initiation | No HPV4 Initiation | P | |
| Daughters | |||
| Age, y, mean (SD) | 13.8 (2.1) | 13.0 (2.7) | <.01 |
| Provider specialty, no. (%) | |||
| Pediatrician | 34 407 (85.4) | 84 215 (77.9) | <.01 |
| Family medicine | 2 687 (6.7) | 9 821 (9.1) | |
| Other | 3 194 (7.9) | 14 026 (13.0) | |
| Length of health plan membership, y, mean (SD) | 10.2 (4.2) | 9.2 (4.1) | <.01 |
| Mothers | |||
| Age, y, mean (SD) | 42.1 (6.4) | 41.3 (6.5) | <.01 |
| Race/ethnicity, no. (%) | 9 255 (23.0) | 24 195 (22.4) | <.01 |
| White | 3 797 (9.4) | 11 214 (10.4) | |
| African American | 15 987 (39.7) | 38 798 (35.9) | |
| Hispanic | 2 749 (6.8) | 6 846 (6.3) | |
| Asian/Pacific Islander | 8 500 (21.1) | 27 009 (25.0) | |
| Other or unknown | |||
| % of census block adult education level, mean (SD) | |||
| No high school diploma | 27.7 (19.9) | 27.2 (19.4) | .01 |
| Any college | 51.1 (21.3) | 51.1 (21.7) | .72 |
| Census block median household income, $, mean (SD) | 60 092 (27 403) | 58 940 (26 172) | <.01 |
| Length of health plan membership, y, mean (SD) | 13.5 (7.8) | 12.4 (7.4) | <.01 |
| Pap test in past 3 y, no. (no. per 1000 person-years) | 33 131 (82.2) | 81 841 (75.7) | <.01 |
| History of abnormal Pap test result,a no. (no. per 1000 person-years) | 7 117 (18.0) | 17 227 (17.1) | <.01 |
| History of genital/anal warts,a no. (no. per 1000 person-years) | 1 065 (2.7) | 2 357 (2.3) | <.01 |
| History of other STIs,ab no. (no. per 1000 person-years) | 916 (2.3) | 2 311 (2.4) | .13 |
Note. Pap = Papanicolaou; STI = sexually transmitted infection. For HPV4 vaccine initiation, n = 40 288. For no HPV4 vaccination initiation, n = 108 062.
a
Adjusted for length of membership with Kaiser Permanente.
b
Chlamydia, gonorrhea, genital herpes, trichomoniasis, or syphilis.