Implementation of evidence-based strategies to optimize HPV vaccination in rural primary care settings - ABSTRACT Some of the largest disparities in human papillomavirus vaccination (HPVV) rates exist in rural communities, which represent missed opportunities for cancer prevention since incidence of HPV associated cancers have been increasing disproportionately in rural compared to urban areas in the U.S. While there are effective evidence-based strategies to improve adolescent HPVV rates in clinical practices, current gaps include a lack of interventions targeting community-based practices and rural populations. Targeted interventions are desperately needed to expand reach to rural community-based primary care practices to increase HPVV rates and meet the needs of underserved rural communities where HPVV rates have remained low. To address this gap, we developed an implementation science focused intervention for rural primary care practices (PC TEACH) that considers community, culture, and health systems as upstream factors to increase adolescent HPVV rates by engaging the entire medical team using a practice facilitation approach. In the current proposal, we will test the effectiveness of our innovative practice-level intervention approach (PC TEACH) to: (i) increase HPV vaccine uptake and completion rates in adolescent boys and girls, and (ii) lower the average age at vaccination in community-based primary care practices. We hypothesize that HPVV initiation and completion rates will be superior after practice facilitation of evidence-based PC TEACH vaccination strategies compared to rates prior to intervention. We will use a stepped-wedge cluster randomized trial design, which conserves sample size while maintaining power, with an integrated implementation framework, and process and outcome evaluation, to address the following aims: Aim 1 - Implement and test the effectiveness of practice facilitation of PC TEACH, using an implementation science approach, on HPVV initiation and completion in rural community-based primary care practices. Aim 2 - Measure and monitor practice-level characteristics (e.g., size, scope, socioeconomic environment, and vaccination experiences during the COVID-19 pandemic), and patient-level characteristics (e.g., gender, age, insurance type, HPV knowledge, child vaccination history, and vaccine hesitancy), to identify factors that influence HPV vaccine delivery and uptake rates, and may moderate intervention effects. Aim 3 - Evaluate the extent to which practice facilitation activities most readily lead to adoption and implementation of the evidence-based PC TEACH vaccination strategies as delivered by the primary care practice site staff. The proposed study is innovative in that our use of community-engaged methods enhance scalability of the implementation science intervention in underserved rural primary care settings to enable system changes to improve HPVV rates. Findings from this study will be essential in understanding how to implement systematic practice-level changes in rural community-based primary care practices, and how to cultivate a practice culture supportive of HPVV in rural communities, a population underrepresented despite the observed incongruence of increasing incidence of HPV-associated disease and low HPVV rates in rural areas in the U.S.