School-based HPV immunization of young adolescents: effects of two brief health interventions

Adolescent immunization rates for human papillomavirus (HPV) are low and interventions within school-based health centers (SBHCs) may increase HPV uptake and series completion. We examined the effect of a parent health message intervention on HPV vaccination intent, first dose uptake and series completion among adolescents who received care at SBHCs. Via computer-assisted telephone interviews (CATI), 445 parents of young adolescents were randomly assigned to 2 two-level interventions using a 2 × 2 design (rhetorical question (RQ) or no-RQ and one-sided or two-sided message). The RQ intervention involved asking the parent a question they were likely to endorse (e.g., "Do you want to protect your daughter from cervical cancer?") with the expectation that they would then behave in a manner consistent with their endorsement (i.e., agree to vaccinate). For the one-sided message, parents were given information that emphasized the safety and effectiveness of HPV vaccine, whereas the two-sided message acknowledged that some parents might have concerns about the vaccine, followed by reassurance regarding the safety and effectiveness. At CATI conclusion, parents indicated intentions to have their adolescents vaccinated. Parents who endorsed any intent were sent a consent form to return and all adolescents with signed returned consents were vaccinated at SBHCs. Medical records were reviewed for uptake/completion. Parents were 87% female; adolescents were 66% male and racially/ethnically diverse. 42.5% of parents indicated some intention to immunize, 51.4% were unsure, and 6.1% were not interested. 34% (n = 151) of adolescents received their first dose with series completion rates of 67% (n = 101). The RQ component of the intervention increased intention to vaccinate (RR = 1.45; 95%CI 1.16,1.81), but not first dose uptake or series completion. The 1-sided and 2-sided messages had no effect. This brief, RQ health intervention enhanced intent, but did not impact vaccination rates, likely due to the time delay between the intervention and consent form receipt.