Urban, Suburban, and Rural Disparities in HPV Vaccination Rates among a Population of Commercially Insured Adolescent Females in Michigan

Background: The human papillomavirus (HPV) vaccine is newly recommended by the Centers for Disease Control and Prevention for all girls aged 11 and 12 years; however, less than one fifth of girls aged 13-17 had received a complete series of three shots in 2008. We evaluated the relationship between HPV vaccine uptake and urbanicity at the patient level. Methods: We performed a retrospective cohort analysis of commercially insured girls aged 13 through 17 in 2010 who were enrolled for at least 44 months in the four years following June 2006, when the HPV vaccine was initially licensed. Using administrative data and the Health Resources and Services Administration's Area Resource File, we tested whether initiating and/or completing the HPV vaccine series remained independently associated with county urbanicity (urban, suburban, or rural) after controlling for age, county-level race, healthcare seeking behavior, and access to physicians. Results: Among 54,671 girls aged 13 to 17 residing in Michigan, 24% had ≥1 dose of HPV vaccine and 13% completed the series. Girls residing in suburban areas were more likely to initiate (OR=1.16, 95% CI=1.07-1.26) and complete (OR=1.12, 95% CI=1.01-1.25) the HPV vaccine series than their rural counterparts, while girls residing in urban areas were less likely than those living in rural areas to initiate (OR=0.91, 95% CI=0.85-0.98), but not complete the series. Conclusions: Our study suggests that there are disparities in HPV vaccination rates by geographic area that extend beyond differences in health care access. Vaccination campaigns should target metropolitan and rural areas.