A multicomponent strategy designed to boost human papillomavirus vaccination in pediatric primary care did not significantly increase vaccination rates at individual time points – but showed a growing effect over time, according to a cluster randomized clinical trial published in JAMA Network Open.
Human papillomavirus (HPV) vaccination prevents multiple cancers, and yet uptake by the recommended age remains below national US targets. In this trial, Wang et al. evaluated whether a systems-focused intervention could increase initiation and completion of the HPV vaccine series by age 13 years.
The study randomized 20 pediatric primary care practices in the St Louis, Missouri, metropolitan area (10 intervention, 10 control) and included a total of 86 participating clinicians. The 24-month intervention combined four components: external practice facilitation, regular audit and feedback of vaccination rates, clinician education on HPV guidelines, and training in an announcement-style communication strategy. Follow-up extended to 36 months to assess durability of effect.
At 24 months, HPV vaccine initiation rates were 80.1% in the intervention group versus 75.5% in controls. Completion rates were 52.8% versus 50.1%, respectively. By 36 months – one year after the formal intervention period – initiation reached 82.0% in the intervention group compared with 74.6% in controls, and completion reached 57.8% versus 49.9%. However, in the fully adjusted multilevel model accounting for clinician baseline rates as well as patient and clinician characteristics, between-group differences were not statistically significant at individual time points.
The investigators did observe a significant group-by-time interaction for vaccine initiation (P = .04), indicating that intervention effects increased over time. Completion showed a similar upward trajectory in unadjusted analyses, though this time trend was not statistically significant after full adjustment.
The intervention was also seen to improve clinician behaviors. Compared with controls, clinicians in the intervention group reported more frequent use of announcement-style communication and higher self-efficacy when addressing any parental hesitancy. These gains were most evident at 12 months and attenuated by 24 months.
The study authors note that the COVID-19 pandemic disrupted early implementation of the intervention, shifting facilitation to largely virtual sessions and delaying full rollout of practice-level changes. They suggest that system-focused interventions aimed at building sustainable vaccination workflows may require extended evaluation periods to demonstrate measurable improvements better.
Although the trial did not show statistically significant differences at discrete time points, the progressive widening of vaccination rates between groups suggests that embedding structured facilitation, feedback, and communication training may produce cumulative gains over time. For practices seeking to improve HPV coverage, the findings underscore both the complexity of behavior change and the importance of sustained and long-term system-level support.
Disclosures can be found in the study.
Source: JAMA Network Open
