Compared with insured adults, uninsured adults in California had less knowledge of the human papillomavirus vaccine and were less likely to be vaccinated.
Published Online: June 15, 2012
Nadereh Pourat, PhD; and Jenna M. Jones, MPH
Objectives: To examine knowledge of and financial barriers to early adoption of human papillomavirus (HPV) vaccination, specifically the role played by insurance, income, and affordability (measured by forgoing or delaying needed medical care due to cost/no insurance).
Study Design: We used the 2007 California Health Interview Survey. Females aged 18 to 26 years (n = 1840) and parents with daughters aged 8 to 17 years (n = 5765) were analyzed separately.
Methods: Logistic regression models were used with the following dependent variables: (1) heard of the HPV vaccine, (2) received 1 dose only, (3) completed the series, (4) have not previously heard of HPV vaccine but interested in receiving it, and (5) interested and willing to pay $360 for it.
Results: Individuals enrolled in private health maintenance organizations (HMOs) were more likely to have heard of the vaccine compared with the uninsured and those enrolled in public HMOs. Young adults enrolled in private HMOs were also more likely to have initiated HPV vaccination or completed the series compared with uninsured
young adults or those insured in non-HMO plans. Higher income parents were more willing to pay the cost of the vaccine. Forgoing needed care due
to costs led to lower odds of initiating HPV vaccination among parents and completing the series among young adults.
Conclusions: Strategies to increase HPV vaccination rates should consider insurance or cost barriers for adults and those with high medical care expenditures. Disparities in receipt of the HPV vaccine are likely to continue without targeted outreach to more vulnerable populations.
(Am J Manag Care. 2012;18(6):320-330)
Insurance coverage, income, and other indicators of affordability affect human papillomavirus (HPV) vaccination rates.
To ensure effective prevention of HPV, it is important to provide targeted education to subgroups, particularly young adults aged 22 to 26 years, parents 56 years and older with young daughters aged 8 to 17 years, Latinos and Asian Americans, and members of public HMOs.
Strategies to increase HPV vaccination rates should consider insurance or cost barriers for adults and those with high medical care expenditures.
Infection with human papillomavirus (HPV) is a serious public health concern with significant morbidity and financial consequences. The most prevalent strains of HPV, subtypes 16 and 18, are leading causes of cervical and anal cancers nationally.1,2 Cervical cancers caused by persistent HPV infections have led to an estimated 8.1 deaths per 100,000 women nationally and 8.3, 6.4, and 11 deaths per 100,000 for whites, African Americans, and Latinos, respectively, in California.3 The prevalence of HPV is highest (45%) among young women aged 20 to 24 years,4,5 and the likelihood of HPV infection is about 75% among adults aged 15 to 49 years.2 The costs of treating HPV and its related disease are estimated at or above $4 billion annually.6
Two HPV vaccines, Gardasil and Cervarix, became available in 2006 and 2009, respectively.7,8 Gardasil guards against subtypes 6, 11, 16, and 18; Cervarix guards against subtypes 16 and 18 only. Both are nearly 100% effective against precancerous lesions, with Cervarix more effective against persistent infections (nearly 100%) than Gardasil (86-89%).1,2 The vaccines are recommended for young females aged 12 to 26 years and may have some benefits for older women.9-11 Financial constraints may be a significant barrier to HPV vaccination. The vaccine, at an estimated cost of $360 for the 3-dose vaccine plus the associated administration and visit fees (estimated at $92), is too expensive without insurance coverage for most low-income families.12
Free vaccine for children may be obtained from various sources including the federally funded Vaccine for Children (VFC) program, which covers about 40% of poor children2; and the Immunization Grant Program (Section 317), which is subject to budget shortfalls.2 Vaccine manufacturers may cover uninsured adults and Medicaid may cover vaccine costs for adults.4 The scope of these forms of coverage is unknown and the underinsured may still have limited access.13
Among privately insured patients, the vaccine may not be covered or covered fully.14 In early 2008, some preferred provider organizations (PPOs) in California did not cover the vaccine.12 Lack of coverage or knowledge of coverage for the vaccine is a frequently reported reason for not vaccinating against HPV.15 Differential rates of compliance with the federal Advisory Committee on Immunization Practices by PPOs versus health maintenance organizations (HMOs) shortly after availability of the HPV vaccine, as well as higher cost-sharing requirements by PPOs, may have led to additional barriers to vaccination according to the type of private insurance coverage. Overall, high costs and inadequate coverage of the HPV vaccine are likely to lead to uneven vaccination rates among lowincome and other disadvantaged groups. Understanding the impact of financial barriers on adherence to HPV vaccination is needed to improve HPV vaccination rates and to prevent HPV infection and its disease sequelae among all eligible-age females.16
Data and Sample
We used the 2007 California Health Interview Survey (CHIS) for this study. The survey is a representative randomdial telephone survey of more than 53,600 households, including about 51,000 adults, and is conducted in English, Spanish, Mandarin, Cantonese, Korean, and Vietnamese languages to capture the great majority of non–English speaking populations. It has an overall response rate of 21.2% and has been found in multiple studies to be representative of the California population.17 The sample included all females aged 18 to 26 years (n = 1840) as well as girls aged 8 to 17 years (n = 5765) who are recommended to receive HPV vaccination. Parents of teenagers answered the CHIS vaccination questions to increase the reliability of responses and because the vaccination decision is most likely to be made by parents of minors.
Conceptual Framework, Research Questions, and Hypotheses
We used Andersen and Davidson’s conceptual framework for healthcare use.18 Based on this conceptual framework, HPV vaccination or intent to vaccinate was determined by enabling factors (insurance, income, and affordability of care), predisposing factors (eg, age, race), and need (eg, health status). Our primary interest was to assess the impact of enabling factors. Specifically, we wanted to determine how insurance, income, and affordability of care affect HPV vaccination rates and patients’ willingness to pay.
We hypothesized that rates of HPV vaccination or intent to vaccinate and willingness to pay for the vaccination are lower for individuals without insurance coverage or with PPO or fee-for-service (FFS) coverage, for some low-income populations (as measured by federal poverty level [FPL]), and for individuals who reported that care has been unaffordable (as measured by having delayed or forgone needed healthcare due to cost/no insurance in the past year). We assumed that some eligible individuals fell through the gaps despite availability of VFC and other programs. We also examined the role of enabling factors in knowledge of the HPV vaccine, hypothesizing that vaccine knowledge was lower among lower income and uninsured groups who were not targeted by vaccine manufacturers’ advertising campaigns early on.
Five different dependent variables are included in this study. Adults and parents (Figure) were asked (1) if they had heard of the HPV vaccine prior to the survey. Those who had heard of the vaccine were asked (2) if they/their daughters had received at least 1 dose of the HPV vaccine, and if so (3) whether they/their daughters had received all 3 doses. Respondents who had not heard of the vaccine were informed of the existence and intent of the vaccine and were then asked (4) if they were interested in receiving the vaccine (adults) or giving it to their daughter if a doctor recommended it. Those who were interested in receiving the vaccine were asked (5) if they were willing to pay $360 for the 3-dose vaccine.
The independent variables of interest were insurance, poverty level, and affordability, as indicated by forgone or delayed care due to cost/no insurance. Insurance coverage was defined as private HMO, private PPO, public HMO, public FFS, or uninsured. The private HMO category includes variations in HMO types including point-of-service plans and exclusive provider organizations. The private PPO category includes PPOs and FFS options; the latter is an increasingly uncommon form of insurance in California. Public HMOs may also include some exclusive provider organizations but are primarily HMOs. Public non-HMO coverage in California is an FFS form of coverage. The distinctions in form or coverage were included to account for differences in benefit levels, cost-sharing requirements, restrictions imposed on use of various services, provider networks, and provider compensation and incentives. HMOs are more likely to cover all vaccinations and have lower cost sharing but may impose authorization requirements on services, while PPOs are more likely to have higher cost sharing but fewer restrictions on use. Public FFS coverage does not include cost sharing, but provider participation in the program and subsequent access to care may be more limited.
Poverty level was indicated by FPL—less than 100%, 100% to 299%, and 300% or higher—and was used to assess the individual’s ability to pay for the associated out-of-pocket costs of HPV vaccine if insured or the full cost of the vaccine if uninsured and unable to receive free vaccination. Affordability was indicated by reports of having forgone or delayed receipt of needed medical care due to cost/no insurance in the past year and was intended to account for financial barriers to access not
captured by other variables in the models. Forgone or delayed care due to other reasons was also included in the models to control for nonfinancial reasons such as lack of time that lead individuals and parents not to obtain the HPV vaccination. All models were also controlled for predisposing factors and other potentially confounding factors. Predisposing control variables included age, race/ethnicity, education, and family status. Age was categorized as 18 to 21 and 22 to 26 years for the young adult females and 18 to 35, 36 to 55, and 56 years and older for the parents. Race and ethnicity were defined as white, Latino, Asian American, African American, and other groups. Education was dichotomized into any college education versus less. Marital and family status was defined as married, single with children, and single without children in the adult sample, and single with children versus married with children in the parent sample. We included the receipt of the flu vaccine in the past year as a measure of a health-seeking behavior. Need was controlled for with perceived health status noted as excellent, very good, or good versus fair or poor.
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