摘要：Objectives. We examined the association between insurance continuity and human papillomavirus (HPV) vaccine uptake in a network of federally qualified health clinics (FQHCs). Methods. We analyzed retrospective electronic health record data for females, aged 9–26 years in 2008 through 2010. Based on electronic health record insurance coverage information, patients were categorized by percent of time insured during the study period (0%, 1%–32%, 33%–65%, 66%–99%, or 100%). We used bilevel multivariable Poisson regression to compare vaccine-initiation prevalence between insurance groups, stratified by race/ethnicity and age. We also examined vaccine series completion among initiators who had at least 12 months to complete all 3 doses. Results. Significant interactions were observed between insurance category, age, and race/ethnicity. Juxtaposed with their continuously insured peers, patients were less likely to initiate the HPV vaccine if they were insured for less than 66% of the study period, aged 13 years or older, and identified as a racial/ethnic minority. Insurance coverage was not associated with vaccine series completion. Conclusions. Disparities in vaccine uptake by insurance status were present in the FQHCs studied here, despite the fact that HPV vaccines are available to many patients regardless of ability to pay. Cervical cancer is a significant public health challenge in the United States. Approximately 12 300 women were expected to be diagnosed with cervical cancer in 2013, and 4030 were expected to die from the disease. 1 The burden of cervical cancer disproportionately affects minority, low-income, and uninsured populations. 2–4 The primary risk factor for virtually all cervical cancer is infection with certain types of human papillomavirus (HPV). Effective vaccines have been developed against HPV-16 and HPV-18, which alone are responsible for approximately 70% of cervical cancer cases. 5–7 These vaccines hold great potential for reducing disparities in cervical cancer morbidity and mortality, if utilization can be encouraged in populations most at risk for cervical cancer. Federally Qualified Health Centers (FQHCs) serve the primary health care needs of more than 20 million patients in the United States, many of whom are low income, minorities or uninsured, 8 and are thus an ideal setting in which to study the utilization of HPV vaccination among populations at highest risk for cervical cancer. 9 However, few investigators have directly examined HPV vaccination rates in such settings, 9–11 in part because of a lack of readily available data. Consequently, factors affecting HPV vaccine uptake in FQHCs are not well understood. In particular, the role of insurance coverage remains unclear. To date, studies of HPV vaccination rates in FQHCs have modeled insurance as a static variable, determined at a single visit or at the time services were rendered. 9–11 This approach might be unsuitable when considering the association between insurance and HPV vaccine series completion, which requires multiple visits over several months, 12 and may not accurately reflect the experience of FQHC patients whose coverage can change frequently affecting health care utilization. 13–16 Furthermore, defining insurance status from a single visit prevents consideration of insurance duration or coverage continuity as potential factors influencing vaccine uptake. Among Medicaid enrolled patients, who constitute almost 40% of FQHC patients nationally, 8 duration of insurance enrollment has been associated with HPV vaccine initiation, with longer enrollment being a predictor for initiating the vaccine series. 17,18 Other researchers have demonstrated that, compared with being uninsured or sporadically insured, having continuous insurance coverage is positively associated with the receipt of preventive services in FQHCs, despite the fact that patients can receive care regardless of insurance coverage in these settings. 16,19,20 Existing studies of HPV vaccination in FQHCs have also been limited to patients younger than 19 years, 9–11 precluding examination of insurance effects across the full age range for which the vaccine is recommended (9–26 years). 12 In FQHC settings, the role insurance plays in vaccine uptake likely differs with age, as HPV vaccine is free for eligible children and adolescents younger than 19 years through the federal Vaccine for Children (VFC) program, 21 but no similar program exists for patients aged 19 to 26 years. A better understanding of how insurance coverage and other factors affect uptake among female FQHC patients aged 19 to 26 years is needed to allow design of future interventions to reduce cervical cancer disparities in underserved populations. We leveraged electronic health record (EHR) data from a network of FQHCs to examine the association between insurance continuity and HPV vaccination in a large cohort of female patients (9–26 years of age) who accessed care between 2008 and 2010. We hypothesized that HPV vaccine uptake in our study population would be affected by insurance continuity, with lower rates of vaccine series initiation and completion among uninsured and discontinuously insured patients, compared with the continuously insured. We also hypothesized that insurance-related disparities would be most pronounced among women older than 18 years, who are ineligible for VFC. Our study helps fill a gap in published research by assessing the uptake of HPV vaccine in FQHC patients, including those older than 18 years, and applying EHRs to gather objective longitudinal data on insurance coverage and HPV vaccination rates in this population.
