U.S. HPV vaccination rates are well below national targets and there is a need to identify messaging approaches that can increase acceptance of HPV vaccine. The objective of this study was to determine if messages about the relative safety of HPV vaccination and the strength of the recommendation increased mothers’ willingness to vaccinate against HPV.
1,097 mothers of 9-13-year-olds living in the U.S. completed a national Web-based survey in August 2014. The analyses presented here focused on the 63.9% (n=701) who reported no HPV vaccine administration. The study used a 3x2 randomized between-subjects design (strength of recommendation x safety information). Illustrated vignettes depicted one of 3 levels of provider recommendation strength (brief mention; strong recommendation; strong recommendation + personal disclosure of vaccination of own children), and either the presence or absence of information regarding the relative safety of vaccination compared to common daily activities (e.g., playing soccer). The outcome was willingness to have the child receive HPV vaccine, measured on a continuous sliding scale ranging from 0 (definitely would not) to 100 (definitely would). Perceived benefits of vaccination were assessed with 5 items administered prior to viewing the intervention and included as a covariate in the analysis of covariance (ANCOVA).
Overall mean willingness to receive HPV vaccine was 59.7 (SD = 35.4). ANCOVA indicated that provision of relative safety information increased willingness to vaccinate (M=63.1 vs. M=56.2; F=7.0, p<.01). Perceived benefits were also significantly related to willingness to vaccinate against HPV (F=214.9, p< .001). Strength of recommendation and child sex were not associated with willingness to vaccinate and there were no significant interactions.
Our results suggest that provider communication about the relative safety of HPV vaccine and the benefits of vaccination in general may increase rates of HPV vaccine acceptance. While strength of recommendation did not have an effect, this may have been due to the difficulty associated with replicating a personal physician’s recommendation via an online survey. As a next step it will be important to test the relative safety messaging in settings where HPV vaccine can be administered and the effects on vaccine uptake can therefore be evaluated.