Optimising Human Papillomavirus (HPV) Vaccination for Adolescents: Findings from a Cluster Randomised Trial in Australian Schools

Abstract

My thesis presents findings from the HPV.edu study, an Australian cluster randomised trial of a complex educational and logistical intervention about HPV vaccination, including a process evaluation and qualitative study. The intervention comprised an adolescent component to promote knowledge and psychosocial outcomes, shared decisional support, and logistical strategies. HPV.edu recruited 40 schools with 6,967 adolescents aged 12 to 13 at high schools across two jurisdictions (2013-2015). A subsample of case study schools was purposively recruited for the process evaluation and qualitative study (6 intervention, 6 control). Using an ecological approach, I aimed to examine 1) student knowledge, 2) adolescents’ use of mobile technologies to support vaccination, 3) parents' views about HPV vaccination, 4) adolescent psychosocial outcomes, and 5) vaccine uptake. Employing thematic analysis, I analysed focus groups with students (n=111), interviews with parents (n=22), immunisation nurses (n=11), and school personnel (n=13) about HPV vaccination. Process evaluation data are also presented. Through 5 chapters of original research presented as peer-reviewed publications, this thesis demonstrates that HPV vaccination education significantly improved student vaccine literacy and the vaccination experience. Intervention schools had a significantly higher proportion of consent forms returned and, at dose 3 only, a shorter mean time to vaccinate 50 students. While there was no significant difference across groups in mean school vaccine coverage, trial logs showed the inconsistent implementation of logistical strategies. Inadequate resourcing for logistical strategies and advisory board reluctance about strategies with potential financial implications impacted the implementation of logistical components. Further work investigating logistical strategies should be undertaken to understand and overcome barriers to implementation.