Variations in HPV Vaccination Series Completion By Provider Type

BACKGROUND:   The human papillomavirus vaccination (HPV) series consists of 3 doses recommended for adolescents beginning at age 11-12 years and was introduced for females in 2007 and males in 2011; however, uptake and series completion remain low for both female and male adolescents.  Using data on providers participating in the Vaccines for Children (VFC) program, we assessed differences in HPV series completion rates by provider type.

METHODS:   Data from the Washington State Immunization Information System (WSIIS) was assessed to determine series completion rates among King County adolescents aged 13 to 18 years as of December 31, 2013 with ≥1 dose of HPV. Overall completion is defined as receiving 3 doses at any time among all adolescents with ≥1 dose. On-time completion is defined as receiving 3 doses before age 13 among adolescents receiving their first dose before age 13. Overall and on-time completion rates were examined by birth cohort, sex, and provider type administering HPV doses (defined as public only, private only, or mixed using VFC data).

RESULTS:   There were no differences by birth cohort in the proportion of adolescents exclusively using public providers (21%) or private providers (71%) to obtain HPV doses. Male adolescents who exclusively used public providers had significantly higher overall completion rates (39%) compared to males using private providers (36%, p-value=0.0006); on-time completion rates were also significantly higher (p-value=0.0017) among males using public providers (27%) compared to males using only private providers (36%). There was no difference in the overall completion rates among all females using only public (63%) and only private providers (63%). On-time completion rates were significantly higher (p<0.0001) for females receiving doses exclusively from private providers (43%) compared to females using only public providers (39%). However, there was a significant decreasing trend in on-time completion rates for females using private providers, from 51% among those born in 1996 to 40% among those born in 2000, and a significant increasing trend for females exclusively using public providers, from 36% among those born in 1996 to 46% among those born in 2000.

CONCLUSIONS:   Completion of the HPV series is influenced by provider types that administer the doses. These results identify distinctions in overall and on-time completion rates by VFC provider type and can be used to develop targeted interventions at the provider level to increase HPV series completion among adolescents. Variations in completion rates by birth cohort were observed and should be further studied.