PEDIATRICS Vol. 104 No. 1 Supplement July 1999, pp. 158-163

Characteristics of Families Who Attend Free Vaccine Fairs

Simon J. Hambidge, MD, PhD^*, , Sally A. Easter, MD, JD^*, Sharon Martin, RN, Paul Melinkovich, MD^*, , Jeffrey Brown, MD, MPH^*, , and Carol D. Siegel, MD, MSPH^*

From the ^* Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, and  Denver Health Medical Center, Denver, Colorado.

	ABSTRACT

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Objective.  To determine the health care resources and perceived barriers to care of families attending free vaccine fairs.

Design.  A cross-sectional survey.

Setting.  Twelve free vaccine fairs in Denver, Colorado, in 1994.

Participants.  A total of 533 consecutive parents or guardians of children receiving vaccine at the fairs.

Interventions.  None.

Measurements/Results.  Survey respondents reported that their children received regular health care through a private physician or health maintenance organization (HMO) (47%), a public clinic (20%), or a hospital-based clinic (14%); 18% had no regular site for health care. Twenty-seven percent of the families carried private insurance, although less than half of these plans covered children's vaccines: 9% were enrolled in an HMO or a preferred provider organization and 13% had Medicaid, whereas 50% had no health insurance. Families who received primary care at a private physician's office (OR: 1.7; 95% CI: 1.01-2.7) and those with no regular site for health care (OR: 2.0; 95% CI: 1.01-4.0) were more likely than those who went to a public clinic or hospital clinic to report free vaccine as the most important reason for attending a vaccine fair. Conversely, families who received well-child care at a hospital clinic were more likely to identify no appointment needed as the most important reason (OR: 2.7; 95% CI: 1.4-5.1). Families with private health insurance (OR: 2.3; 95% CI: 1.05-4.0) or no health insurance (OR: 2.3; 95% CI: 1.1-4.6) were more likely to identify free vaccine as the most important reason for attending a vaccine fair, whereas those enrolled in an HMO or preferred provider organization identified convenient time as the most important reason (OR: 3.2; 95% CI: 1.2-8.3). Families with Medicaid (OR: 3.2; 95% CI: 1.3-8.3) or with no insurance (OR: 2.1; 95% CI: 1.02-4.6) were more likely than were those with private insurance to identify no appointment needed as the most important reason for attending a vaccine fair.

Conclusions.  Most families attending free vaccine fairs have a regular source of health care. For families with private health insurance or with no health insurance, the availability of free vaccine is the major reason to bring their children to a vaccine fair, whereas for families whose insurance routinely covers the cost of childhood vaccine (HMO, Medicaid), convenience is the major determinant.  Key words:  underimmunization, free vaccine fair, barriers to childhood immunization.

Underimmunization continues to be a major public health challenge in the United States, particularly among preschool children. In this decade, many local, state, and federal programs, such as Vaccines For Children and the Childhood Immunization Initiative, have been created to address this problem. Recent figures from the Centers for Disease Control and Prevention (CDC) show that toddler immunization rates have increased substantially since the early 1990s: by 1996, 95% of 2-year-olds had received at least three doses of diphtheria and tetanus toxoids and pertussis vaccine (DTP) (up from 83% in 1992); 92% had adequate Haemophilus influenza type B vaccine (HiB) coverage (up from 28%); 91% had at least three doses of oral (live attenuated) poliovirus vaccine (OPV) or inactivated poliovirus vaccine (IPV) (up from 72%); 91% had at least one measles-containing vaccine (up from 83%); and 82% had three doses of hepatitis B vaccine (up from 8%).¹ However, the CDC and others also have reported substantial variability in toddler immunization levels among different states, as well as persistently low levels in many urban areas.^2-7

The reasons for childhood underimmunization are multifactorial and include family and parental factors, provider factors, and health care system barriers.^8,9 One approach to boost childhood immunization levels on a local level has involved mass immunization campaigns and the use of free vaccine fairs. Free vaccine fairs, although not providing other well child care or continuity of care, do provide vaccine at no cost, with no need for an appointment, very little waiting time, and (if offered at multiple sites) at convenient locations. Thus they circumvent many barriers found in the health care system. However, the motivations of families who choose to bring their children to vaccine fairs for their immunizations are unknown and are not addressed in the medical literature thus far. A better understanding of why families bring their children to vaccine fairs, as well as their perceived barriers to immunization at more conventional sites of health care, may help to define better the challenges in obtaining 90% immunization levels for all children in the country.

Most counties in the country are required by law to provide required vaccinations for children free of charge. Why, when free immunizations are available, are vaccine fairs an attractive alternative for families? Vaccine fairs represent "uncoordinated care," to use a phrase first coined in the 1960s¹⁰; they provide no health maintenance and no continuity of care. Yet vaccine fairs are well attended in multiple cities around the country. In fact, the vaccine fairs that were the setting for this study were part of a coordinated effort of the National Immunization Campaign, with free vaccine being offered to children in 15 cities nationwide. In the metropolitan Denver area, at least several health fairs are held every year in which free vaccines are available for children (P. Rotharmel, BSN, personal communication, 1998). Furthermore, every major metropolitan area in the country offers some type of health fair, at least on an annual basis, at which free vaccine is available for children (J. FitzRandolph, personal communication, 1998).

The goal of this study was to describe a population of families who use free vaccine fairs as a source of childhood immunizations. In particular, we were interested in examining the other health care resources available to them and their perceived barriers to vaccination.

	METHODS

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Setting

The study was conducted in Denver, Colorado, an urban area with a population of 467 610 in the 1990 census. Between August 10, 1994, and November 5, 1994, the Metro Denver Infant Immunization Campaign (MDIIC) sponsored 12 free immunization fairs. The MDIIC is a coalition of health departments representing five metropolitan counties, local health facilities, local businesses, and the public school system. The Colorado Department of Health provided free vaccines; the National Immunization Campaign provided some federal funding for the fairs. These fairs were located in a variety of settings such as public schools, community centers, churches, health fairs, a private urban hospital, a homeless shelter, a shopping mall, and a Head Start center. The fairs were advertised on radio and television and in fliers. The number of children at each fair was between 3 and 147. Volunteers at the vaccine fairs determined each child's immunization status from parental hand-held vaccine cards; if no records were available, age-appropriate immunizations were given. In all, 595 children received a total of 1401 vaccinations. All families received written documentation of vaccines administered at the fairs.

Study Design

Descriptive, cross-sectional survey.

Study Population

Subjects were the responsible adults accompanying children to the immunization fair. Volunteers approached all families at the fairs for an interview; interviews were conducted with one respondent per family in English or Spanish.

Measurement

One of three volunteers administered the survey in face-to-face interviews. The interview took approximately 15 minutes to administer, using a structured questionnaire instrument developed by the investigators. The questionnaire consisted of 24 items that addressed basic demographic characteristics (race, language spoken at home); reasons for obtaining immunizations at the fair; usual sources of health care; perceived barriers to receiving health care; and mechanisms for paying for medical care. Several questions were based on a questionnaire instrument developed by Lieu and associates in a previous study of immunization clinics.¹¹ Response choices were read to the respondent. The questionnaire was translated into Spanish and is available on request. A pilot study of the questionnaire was conducted to test its validity before the primary study.

Data Analysis

Data entry and analysis were performed using EpiInfo software from the CDC.¹² Descriptive statistics, including frequencies and percentages, were calculated for each item on the questionnaire using the entire sample of 513 respondents. When the "n" for a given question is greater than 513, it is because some respondents answered "yes" to more than one answer in a single question. When the "n" on a given question is less than 513, it is because not all respondents answered all questions. The percentage given in the Tables was calculated using the number of respondents for each question and is rounded to the nearest whole number (thus, the percentages may not always add up to exactly 100%).

To assess statistically significant associations, Cornfield ORs and 95% CIs were calculated.

	RESULTS

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Study Population

Table 1 shows the demographics and health insurance status of the study population. Among 533 consecutive parents/guardians of children attending the vaccine fairs, 513 completed the questionnaire, 1 refused, and 19 were unable to participate because of a language barrier, for an overall response rate of 96.2%. The racial composition of the study population was similar to that of Denver, which, in the 1990 census, had a population that was 12% African-American, 61% white (not of Hispanic origin), and 23% of Hispanic origin. Twenty-five percent of the families were enrolled in at least one federal entitlement program (Aid to Families with Dependent Children, Supplemental Security Income, or the Special Supplemental food Program for Women, Infants, and Children). Of those families who had private insurance, 49% stated that their insurance did not cover children's vaccines, and another 19% did not know whether their insurance covered vaccines (data not shown). Seventy-four percent of the children brought to the vaccine fairs were younger than 6 years of age; 61% lived within the city or county of Denver, whereas most of the remainder lived in surrounding suburbs or rural areas; and 5 children came from small mountain towns elsewhere in Colorado. By parental report, 93% of the children were citizens of the United States (data not shown).

Immunization Status

Volunteers assessed the immunization status of children attending the vaccine fairs based on parent-held immunization cards (brought to the fairs by >62% of the families) or parental recall. Seventy-six percent of the children were not up to date with their vaccines; 23% had unknown immunization status; and 7 children were up to date and did not require any vaccine (data not shown). If their immunization status was unknown, children received age-appropriate vaccines. After the vaccine fairs, 107 children (21% of the study population) remained underimmunized and were informed that they needed additional immunizations.

Health Care Sources

Figure 1 depicts the health care sources of the families attending the free vaccine fairs. For well-child care, greater than 20% of respondents lacked a regular source of primary care; 47% utilized a private physician or health maintenance organization (HMO), 20% used a public primary care clinic, and 14% used a hospital-based clinic (defined as a primary care clinic based in either a public or a private hospital). The remaining few children had received well-child care from other sources (for example, in Mexico and through the military). Seventy-seven percent of the children who were brought to the vaccine fairs had undergone a "regular check-up" within the past year, based on parental recall (data not shown). For sick care, the distribution of health care sources was similar to that for well-child care, except that 4% of the study population used an emergency department. As for well-child care, fewer than 20% of the families had no regular site for care when their child was sick.

View larger version (27K): [in this window] [in a new window]   Fig. 1.   Health care sources, for well-child care and sick child care, for families attending free vaccine fairs (N = 510).

Sources of previous immunizations were identified by 499 respondents (data not shown). The most frequent site for previous immunizations was the private doctor's office (35%). Public clinics or health centers (23%), public immunization clinics (20%), and hospital-based clinics (14%) also were heavily utilized. Eighteen children (3%) had received no previous immunizations, whereas 28 (5%) had received immunizations at other sources (for example, from the county health nurse; through the military; and abroad in Mexico, Puerto Rico, Honduras, Japan, and Korea).

Barriers to Immunization

When asked what was the primary difficulty in receiving vaccine at the child's usual site of medical care (Table 2), the most frequent response was cost (42%). Other important barriers included waiting time for the appointment (22%), limited clinic hours (8%), and inconvenient location (3%). Other obstacles to receiving vaccine at the child's site of primary care included long waiting times in the office, vaccines not being given in the office, and dissatisfaction with the primary care physician (one respondent).

When families were asked what reasons were important in encouraging them to bring their children to the vaccine fair, free vaccine (83%), convenient time (84%), convenient location (72%), and availability of vaccine without an appointment (89%) were the most frequent responses. Other reasons included, "It needs to be done" and "Immunizations are important for kids." When asked to identify the single most important reason for coming to the vaccine fair, 49% of families cited the availability of free vaccine, whereas 20% cited the fact that no appointment was necessary, 15% cited convenient time, and 7% cited convenient location (Table 3).

Associations Between Usual Sources of Health Care and Reasons for Attending Vaccine Fairs

Table 4 depicts the associations between a family's usual source of health care and the most important reason for coming to the vaccine fairs. Families with a usual source of well-child care at a private physician's office were more likely than were those who took their children to a public clinic to identify free vaccine as the most important reason for attending the fairs (OR: 1.7; 95% CI: 1.01-2.7), as were families without a regular site for medical care for their children (those children without a medical home, OR: 2.0; 95% CI: 1.01-4.0). In contrast, those families who took their children to a hospital clinic for their well-child care were more likely than were those who went to a private physician to identify "no appointment needed" as the most important reason for coming to the fairs (OR: 2.7; 95% CI: 1.4-5.1). Families who took their children to a public clinic regularly also showed a trend toward identifying not having to make an appointment as the most important reason, compared with those who went to a private physician (OR: 1.7; 95% CI: 0.9-3.2).

Associations Between Health Insurance Coverage and Reasons for Attending Vaccine Fairs

In addition, there were associations between the type of health insurance that families had and the primary reason they came to vaccine fairs (Table 5). Families with private insurance or no insurance were more likely than were those with Medicaid to feel that free vaccine was the single most important reason (OR: 2.3; 95% CI: 1.05-4.9 and OR: 2.3; 95% CI: 1.1-4.6, respectively). Families with HMO or PPO insurance, in contrast to private fee-for-service insurance, did not identify free vaccine as a significant reason for coming to the fairs. However, families with HMO or PPO coverage did, when compared with families with no insurance, feel that convenient time was the most important reason for attending the fairs (OR: 3.2; 95% CI: 1.2-8.3).

Families with Medicaid and families without health insurance were more likely than were those with private insurance to feel that not having to make an appointment was the primary reason for coming to the vaccine fairs (OR: 3.2; 95% CI: 1.3-8.3 for Medicaid and OR: 2.1; 95% CI: 1.02-4.6 for no insurance). Families with HMO or PPO coverage showed a trend toward identifying with those with private fee-for-service insurance.

Associations Between Usual Sources of Health Care and Perceived Barriers to Vaccination

We were interested in why families did not go to their children's usual site of health care, their medical home, for vaccinations. Again, there were significant associations between where the children usually went for health care and the family's perception of barriers to vaccination at that site (Table 6). Thus, families who took their children to a private physician (whether in a traditional private practice or in an HMO setting), as well as families who went to a hospital clinic, were more likely than were those who went to a public clinic to identify cost as the primary barrier to obtaining vaccine from their usual physician (OR: 3.9; 95% CI: 2.2-7.1 for private medical home and OR: 2.4; 95% CI: 1.1-5.0 for hospital clinics). In contrast, those families who took their children to a public clinic or to a hospital clinic were more likely than were those with a private physician to feel that the waiting time for an appointment was the primary barrier to childhood vaccination there (OR: 2.6; 95% CI: 1.5-4.6 for public clinics and OR: 2.5; 95% CI: 1.3-4.7 for hospital clinics). In addition, when compared with those with a private primary source of care, families who went to a public clinic were more likely to identify limited clinic hours as the primary deterrent to getting childhood vaccines there (OR: 4.3; 95% CI: 1.6-11.9).

	DISCUSSION

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Although free vaccine fairs have become a commonplace event in large cities around the country, no information exists in the medical literature regarding families who bring their children to these fairs. We found that the vast majority of families who came to the vaccine fairs in our study identified a source of regular medical care for their children. For those families with private insurance or with no insurance, the primary reason for coming to the vaccine fair tended to be cost-sensitive. For those families with primary medical care in the public sector, the primary reason tended to be convenience-sensitive.

Childhood underimmunization has been shown to be a problem even in settings where cost is not a factor such as in HMOs that provide vaccine coverage,^13,14 through the military,^15,16 and at public health clinics.¹⁷ Indeed, missed opportunities on the part of physicians^5,1418-21; organizational barriers in the health care delivery system (lack of evening or weekend hours for working parents, vaccine administration fees, long waiting times for appointments, etc)^822-24; and parental characteristics (poverty, family size, birth order, maternal age, parental age, and parental misperceptions regarding immunizations)^8,925-29 have all been shown to contribute to childhood underimmunization. One recent study found a dose-response relationship between parent-reported problems accessing child health services and underimmunization.³⁰

However, cost remains a significant barrier to adequate childhood vaccine coverage, especially for uninsured families that do not qualify for entitlement programs and for families whose insurance does not cover childhood vaccines. It is estimated that at least 13% (8.4 million) of children in the United States are uninsured³¹; an equally large number may be underinsured and have no coverage for immunizations, despite the recent increase in federal funding for children's health insurance programs. Studies of families at public immunization clinics have shown that cost is the major reason that families give for obtaining vaccine at a public clinic rather than at their usual site of health care.^11,29

In our study, families identified cost as the single most important reason for bringing their children to a vaccine fair. This reason was especially important for families with no health insurance and for those families with private medical insurance. For families with Medicaid and HMO insurance, however, convenience (ie, no appointment needed or convenient time) was the most important reason for coming to a vaccine fair.

Several limitations pertain to these findings. First, this study addressed only those families who were motivated to bring their children to a free vaccine fair and thus did not include those children whose parental factors place them at even higher risk for underimmunization (ie, chaotic home environments, lack of transportation, lack of parental knowledge about immunizations). Second, up to one third of the immunization histories of children were based on parental recall, introducing a proven inaccuracy³² into our vaccine histories. However, immunization status of the study population was not a primary focus of this study. In addition, not all parents or guardians answered all the questions in the study; only 386 responded the question regarding health insurance. The most likely explanation for this underreporting is that the parent/guardian who brought the child to the health fair did not know the insurance status of the child, thus potentially introducing bias into the analysis. Finally, 5 years have elapsed since the vaccine fairs, the basis of this study, were held. In that time, new local, state, and federal policies impacting children's immunizations have been implemented (most notably the Title XXI State Children's Health Insurance Program, or SCHIP), and a trend toward more managed care has continued. Our results would suggest that there is an ongoing need for initiatives such as Title XXI to overcome the financial barriers that remain as an obstacle to achieving adequate childhood immunization levels.

Despite all efforts to reduce barriers to immunization and despite improvements in childhood immunization rates in this decade,^1,2 this country will likely not meet its goal of achieving 90% childhood immunization levels by the year 2000. Vaccine fairs may be needed to help fill in the gaps of the vaccine safety net. It may be in the best interest of public health officials to continue sponsoring these fairs despite their lack of coordination with sites of primary medical care. It is analogous to vaccinating seniors against influenza in shopping centers: vaccinate whenever and wherever possible.

	ACKNOWLEDGMENT

We thank Paula Dennon and Noal Makowsky for their assistance in data collection; Art Davidson for help with the data analysis; and John Steiner for critical reading of the manuscript.

	FOOTNOTES

This paper was originally presented in part as Abstract #254 at the Ambulatory Pediatric Association annual scientific meeting; May 1-5, 1998; New Orleans, LA.

Received for publication Dec 26, 1998; accepted Mar 9, 1999.

Address correspondence to Simon J. Hambidge, MD, PhD, Box 0132, Denver Health Medical Center, Pediatric Clinic, 777 Bannock St, Denver, CO 80204. E-mail: shambidg{at}dhha.org

	ABBREVIATIONS

CDC, Centers for Disease Control and Prevention; DTP, diphtheria and tetanus toxoids and pertussis vaccine; HiB, Haemophilus influenza type B vaccine; OPV, oral (live attenuated) poliovirus vaccine; IPV, inactivated poliovirus vaccine; MDIIC, Metro Denver Infant Immunization Campaign; HMO, health maintenance organization.

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