Going beyond the individual: how state-level characteristics relate to HPV vaccine rates in the United States.

Background: The human papillomavirus (HPV) vaccine is an underutilized cancer control practice in the United States. Although individual contextual factors are known to impact HPV vaccine coverage rates, the impact of macro-level elements are still unclear. The aim of this analysis was to use HPV vaccination rates to explore the underuse of an evidence-based cancer control intervention and explore broader-level correlates influencing completion rates.

Methods: A comprehensive database was developed using individual-level date from the National Immunization Survey (NIS)-Teen (2016) and state-level data collected from publically available sources to analyze HPV vaccine completion. Multi-level logistic models were fit to identify significant correlates. Level-1 (individual) and level-2 (state) correlates were fitted to a random intercept model. Deviance and AIC assessed model fit and sampling weights were applied.

Results: The analysis included 20,495 adolescents from 50 U.S. states and the District of Columbia. Teen age, gender, race/ethnicity, and maternal education were significant individual predictors of HPV completion rates. Significant state-level predictors included sex education policy, religiosity, and HPV vaccine mandate. States with the lowest HPV coverage rates were found to be conservative and highly religious. Little variation in vaccine exemptions and enacted sex and abstinence education polices were observed between states with high and low HPV vaccine coverage suggesting various contextual and situational factors impact HPV vaccine completion rates.

Conclusions: Given that gender, religiosity, political ideology, and education policies are predictors of HPV vaccine completion, the interaction and underlying mechanism of these factors can be used to address the underutilization of the HPV vaccine.