Four in 10 Philadelphia high school students have been vaccinated against human papillomavirus (HPV), and two-thirds of those who have not would be willing to get vaccinated if their doctor suggested it, according to ­analyses of data from the 2013 Youth Risk Behavior Survey (YRBS).¹ Females and youth who have had an HIV test have an elevated likelihood of having been vaccinated; students who used condoms the last time they had sex and current marijuana users have reduced odds of expressing willingness to be vaccinated if they have not already been.

The biennial YRBS is conducted among samples of high school students who are representative of 9th–12th graders at the national level or in their state, territory, tribal area or school district. For the Philadelphia survey, a random sample of schools in the city's ­district were invited to participate; within each school, all students in a randomly selected class were eligible to complete the self-­administered survey. Respondents provided information on a broad range of demographic and health-related measures, including whether they had ever received the HPV vaccine and, if not, whether they would get it on a doctor's ­recommendation. The analysts conducted F tests and multivariable regression analyses to identify correlates of these outcomes.

Some 1,080 youth participated in the survey. The sample was about evenly divided by gender and by grade level. Fifty-six percent of students were black, 16% were white, 7% were Asian and 22% belonged to another racial group.

Overall, 43% of students said that they had received the HPV vaccine. The proportion giving this response was greater among females than among males and among students aged 16 or older than among younger participants; it rose with increasing grade level. A number of health-related variables also were correlated with having been vaccinated: having had four or more sexual partners; having been sexually active in the last three months; having been tested for HIV; having considered suicide; and having consumed alcohol, binged on alcohol or used marijuana in the last 30 days. However, in a logistic regression model that controlled for race, age and condom use at last intercourse, only two associations remained: The odds of having been vaccinated were elevated among females (odds ratio, 3.1) and among youth who had ever had an HIV test (2.1).

When students who said they had not been vaccinated were asked whether they would get the vaccine if their doctor recommended doing so, 66% said yes. Only three variables were correlated with this outcome: having had an HIV test, reporting no days of poor mental health in the last 30 days and having used marijuana in the last 30 days. In the multivariable analysis, use of a condom at last intercourse and current marijuana use were inversely associated with the likelihood that unvaccinated students expressed willingness to get vaccinated (odds ratio, 0.4 for each).

In discussing the limitations of their study, the analysts point out that the survey did not describe the HPV vaccine to respondents, that youths’ vaccination status was based solely on their own reports and that the survey did not assess whether participants had received the full vaccine regimen. At the same time, the investigators believe that given the study's strengths, it "provides important clues as to who is and is not willing to be vaccinated." The finding that the majority of youth who have not received the vaccine are open to getting vaccinated, they remark, is "a positive [one] for public health practitioners and the medical community."

—D. Hollander

REFERENCE

1. Bass SB et al., Correlates to human papillomavirus vaccination status and willingness to vaccinate in low-income Philadelphia high school students, Journal of School Health, 2015, 85(8):527–535.