• Improving HPV Vaccination Rates: A Stepped-Wedge Randomized Trial

    Elsa Pearson, MPH, is a senior policy analyst at Boston University School of Public Health. She tweets at @epearsonbusph. 

    Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States, with almost 80 million individuals infected. HPV causes genital warts and a variety of cancers. Thankfully, there is a highly effective vaccine available, shown to decrease rates of cervical cancer among young women. It’s recommended that all adolescents get vaccinated against HPV but persistent concerns about safety and provider- and system-level challenges can negatively impact vaccination rates. Thus, interventions to increase initiation and completion of the HPV vaccine series are critical to improve public health.

    Study Design

    In an effort to determine if clinic-level education initiatives could improve HPV vaccination rates, Rebecca B. Perkins, et al. piloted the Development of Systems and Education for Human Papillomavirus Vaccination (DOSE HPV) intervention.

    (The authors hail from a variety of academic and medical institutions. From Boston University: Department of Health Law, Policy and Management, School of Public Health; Continuing Medical Education Office; Evans Center for Implementation and Improvement Sciences; Sections of Infectious Diseases and General Internal Medicine, Department of Medicine; Departments of Obstetrics and Gynecology and Pediatrics and Adolescent Medicine, School of Medicine and Boston Medical Center. Additionally: Department of Sociology, Stanford University; South Boston Community Health Center; East Boston Neighborhood Health Center; Center for Outcomes, Research, and Evaluation, Maine Medical Center Research Institute.)

    DOSE HPV’s three pillars were education and communication training, data assessment and feedback, and clinic-driven action planning. During seven educational sessions, providers learned about clinic-specific pre-intervention data trends, HPV more generally, motivational interviewing, barriers to HPV vaccination, and action plan implementation. Each clinic then developed its own action plan, including systems changes, aimed at improving clinic-wide HPV vaccination uptake. As part of the process, all clinics chose to initiate the vaccine series before age 11.

    DOSE HPV was implemented at five clinic sites in the greater Boston area that predominantly serve low-income, minority patients. The 6-8 month study took place between 2016 and 2018. Using a stepped-wedge cluster randomized trial design, clinic sites began DOSE HPV in staggered six-month intervals.

    The study population included over 16,000 patients aged 9-17 years who had an assigned primary care provider and at least one clinic visit in the study period.

    The primary outcome was series initiation: the likelihood an eligible patient would receive an HPV vaccine dose at a clinic visit, stratified by age. The secondary outcome was on-time series completion: the rate of series completion by the 13th birthday for patients aged 12-13 years. The authors also studied series initiation and completion at the population-level, including all eligible patients.

    Results

    For 9-10 year olds and 11-12 year olds, the authors found a statistically significant increase in the likelihood an eligible patient would receive an HPV vaccine dose at a clinic visit in the intervention and post-intervention periods. For 13-17 year olds, there was a statistically significant increase during the intervention period but it was not sustained.

    The likelihood of vaccination at a clinic visit decreased over time in older age groups compared to youngest (9-10 year olds). This may be because of a “ceiling effect,” as most of the older patients had already initiated the vaccine series.

    Perkins, et al. also found a statistically significant increase in the likelihood of on-time completion of the vaccine series in the intervention and post-intervention periods. Lastly, they found DOSE HPV led to statistically significant increases in population-level HPV vaccine coverage; vaccine series initiation and completion rates increased considerably in the intervention and post-intervention periods.

    As expected, the study had a few limitations. For example, it was implemented in a specific location and population; generalizability to other geographic areas and demographic groups may be limited. Another challenge was that two clinics transitioned to new electronic medical records during the study period, limiting the authors’ ability to collect specific patient information.

    Discussion

    The HPV vaccine is a critical public health tool with the potential to greatly reduce sexually transmitted infections and HPV-related cancers. Thus, interventions aimed at improving acceptance and uptake of the vaccine series are vital.

    Improving HPV vaccination rates involves a partnership between providers, parents, and health care systems. Providers can help parents by giving clear, evidence-based recommendations, and having the necessary knowledge to answer specific questions. Parents can help providers by entering into a trusting partnership to ensure the best care for the child. Lastly, health care systems can prompt patients, parents, and providers when vaccinations and other preventive services are needed to ensure timely care.

    Sustaining improvements in vaccination rates relies heavily on system-level intervention, as Perkins, et al. point out in their paper. An advantage to DOSE HPV was that it was a clinic-level intervention. Thus, the program relied on systems changes and was not entirely dependent on individual providers. It could be more easily sustained over time, with fewer required resources, even when accounting for provider turnover.

    Vaccines are one of the most powerful weapons we have against preventable disease. The authors’ findings that DOSE HPV increased HPV vaccination rates is encouraging. Public health experts and clinicians must prioritize vaccine acceptance and uptake through a variety of approaches, including system-level education interventions.

     
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