Complex intervention to promote human papillomavirus (HPV) vaccine uptake in school settings: A cluster-randomized trial

Using a cluster-randomized trial design, we aimed to evaluate a complex intervention to increase uptake of human papillomavirus (HPV) vaccination in schools. The study was undertaken in high schools in Western Australia and South Australia between 2013 and 2015 with adolescents aged 12–13 years. Interventions included education, shared decision-making, and logistical strategies. The main outcome was school vaccine uptake. Secondary outcomes included consent forms returned and mean time to vaccinate 50 students. We hypothesised that a complex intervention would increase 3-dose HPV vaccine uptake. We recruited 40 schools (21 intervention, 19 control) with 6, 967 adolescents. There was no difference between intervention and control (3-dose mean 75.7% and 78.9%, respectively). Following adjustment for baseline covariates, absolute differences in coverage in favour of the intervention group were: dose 1, 0.8% (95% CI, −1.4,3.0); dose 2, 0.2% (95% CI, −2.7, 3.1); dose 3, 0.5% (95% CI, −2.6, 3.7). The percentage of returned consent forms in intervention schools (91.4%) was higher than in control schools (difference: 6%, 95% CI, 1.4, 10.7). There was a shorter mean time to vaccinate 50 students at dose 3. The difference for dose 3 was 110 min (95% CI, 42, 177); for dose 2, 90 min (95% CI, −15, 196); and dose 1, 28 min (95% CI, −71, 127). Logs revealed the inconsistent implementation of logistical strategies. The intervention had no impact on uptake. Inadequate resourcing for logistical strategies and advisory board reluctance toward strategies with potential financial implications impacted the implementation of logistical components.