Identifying Area-Level Disparities in Human Papillomavirus Vaccination Coverage Using Geospatial Analysis

Background: Human papillomavirus (HPV) is the most common sexually transmitted infection within the United States (US). Despite clinical agreement on the effectiveness and widespread availability of the prophylactic HPV vaccine, vaccination coverage in the US is suboptimal and varies by geographic region and area-level variables. The goals of this article were to model the variation in vaccination rates among boys and girls within ZIP Codes in Virginia, determine whether neighborhood sociodemographic variables explain variation in HPV vaccination, and identify areas with significantly depressed vaccination coverage. Methods: We used Bayesian hierarchical spatial regression models with statewide immunization registry data to consider the correlation in vaccination among boys and girls, as well as the spatial correlation in vaccination for each sex. Results: The results showed low vaccination coverage in our birth cohort (28.9% in girls and 23.8% in boys) relative to the national level (56.8% and 51.8%, respectively). Several area-level variables were significantly and positively associated with vaccination coverage, including population density, percentage of Hispanic population, and average number of vehicles. In addition, there were several areas of significantly lowered vaccination coverage, including predominantly rural ones, and overall large geographic disparities in HPV vaccination. Conclusions: Determining the geospatial patterning and area-level factors associated with HPV vaccination within a prescribed geographic area helps to inform future planning efforts. Impact: The results of this study will help inform future planning efforts for geographically targeted interventions and policies, as well as drive new research to implement clinical and community strategies to increase HPV vaccination.