Predictors of Human Papillomavirus Vaccination and Participation in Vaccination Decision-Making among High School Girls

Background:
Health policy decisions about legally mandating the human papillomavirus (HPV) vaccine require better understanding of the extent to which girls participate in deciding to be vaccinated (or not) and of knowledge and attitudinal factors that predict vaccination in the absence of legislative mandate.

Objectives:
To determine the association between vaccination and participation in the decision to be vaccinated and vaccine-related knowledge and socio-demographic and attitudinal factors.

Methods:
This was a two-part cross-sectional study in which 170 girls in 2 California high schools completed a 62-item survey. I conducted the main study (n = 95) at a single-sex private school and a follow-up expansion study (n = 75) at a public co-educational school. In the main study, I selected a random sample of girls, stratified by grade.

Results:
Within the main study, 36% had been vaccinated and 31% participated in the vaccination decision. However, there were serious gaps in the girls' vaccine-related knowledge (mean score, 67% correct). For example, 33% of all girls did not know that a virus could cause cancer and only ~50% knew that boys/men could get HPV infections. Girls significantly overestimated the lifetime risk of contracting cervical cancer and prevalence of genital warts by about 30-fold. Vaccination was significantly associated with older age and better knowledge, but not with risk estimates, parental education, or vaccine information sources. Girls rated parents and doctors as the most important sources of vaccine information, whereas peers, advertising, and significant others rated least important. Vaccination and decision-making rates were similar in the private and public schools despite significant differences in socio-demographic factors.

Conclusions:
A high percentage of high school girls are participating in the vaccination decision-making, but they have significant knowledge gaps. These findings have broad implications for adolescent health education and provide new information relevant to the current public policy debates over mandatory vaccination.