Disparities in HPV Vaccine Series Completion by Adolescent Males: A Retrospective Cohort Study

Abstract [from journal] 

Objective: Human papillomavirus (HPV) vaccine has been recommended for males for prevention of genital warts and precancerous anal lesions since 2009. Our objective was to characterize race and insurance-based disparities in HPV vaccine completion among males who initiated the HPV vaccine series.

Methods: Retrospective cohort study of adolescent males in a primary care network who initiated the HPV vaccine series 10/09-12/13. We measured vaccine series completion as the primary outcome. We evaluated associations between outcomes and race and insurance status, controlling for potential confounders and effect modification with multivariable logistic regression. Analyses were stratified by vaccine recommendation era (permissive vs. routine).

Results: 42% of males in the cohort (16,691) completed the vaccine series. In the permissive vaccine era (2009 - 2011), non-black patients (53%) were more likely to complete than Black patients (32%), and non-Medicaid were more likely to complete than Medicaid patients (33%). These differences persisted in the routine recommendation era (2012 - 2013). In both the permissive and routine eras Medicaid insurance was associated with a larger reduction in the predicted probability of vaccine series completion for non-black patients. Adherence to the recommended vaccination schedule was low with a median time to completion of 8.9 months. Using the updated completion schedule (2016), completion rates were higher (54.1%) with continued differences based on race (60% vs. 45.7% for non-black vs. black patients) and insurance (57.4% vs. 46.4% completion for non-Medicaid vs. Medicaid patients).

Conclusions: There are significant disparities in HPV vaccine series completion rates among males based on race and insurance, unchanged based on era of initiation or visit frequency.