immunized than those served by public health clinics; the public-private difference for ... of California, Berkeley-University of California, San Francisco, School of Medicine, Joint ... Two children at each school are randomly selected and their.
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Articles
Immunizing California's Children Effects of Current Policies on Immunization Levels MICHAEL SCHEIBER, MD, MPH, Berkeley, and NEAL HALFON, MD, MPH, Oakland, California
Data collected by the Immunization Unit of the California Department of Health Services from 1979 to 1987 were analyzed to determine the effects of changes in state policy on the immunization levels of children in California. By December 1986, 90% of all children entering kindergarten in California were adequately immunized, representing a 15% increase from 1979. Although California has shown substantial improvements, it still lags behind the national weighted average. Even with high levels of immunization at kindergarten entry, many toddlers of 7 months and 2 years old remain inadequately immunized. Children immunized solely in the private sector were more adequately immunized than those served by public health clinics; the public-private difference for infants aged 7 months was nearly twofold. (Scheiber M, Halfon N: Immunizing California's children-Effects of current policies on immunization levels. West J Med 1990 Oct; 153:400-405)
I mmunizations against infectious diseases have had a remarkable effect on the profile of childhood morbidity and mortality and, for most children, have eliminated the threat of many childhood illnesses. So important are immunization programs that levels of childhood immunizations have often served as a general indicator of the health status of a given population. Moreover, these programs have been shown to be cost-effective, with measles vaccination, for example, resulting in an estimated net savings of $5.1 billion during the first 20 years of its licensure in the United States (1963 to 1982).1 In addition, even given the problem of occasional adverse reactions to pertussis vaccinations, the ratio of overall costs to a community without a DPT [diphtheria and tetanus toxoids with pertussis vaccine] immunization program to those with a program were estimated at 5.7:1.23 Despite the remarkable progress made in immunizing children, vaccine-preventable illness continues to occur, certain segments of the child population remain underimmunized, and vaccine-related complications continue to occur. The purpose of this study is to assess current levels of immunization for children in California and to determine the effectiveness of policies aimed at improving the efficacy of immunization programs. In 1977 a federal effort was made to increase immunization levels in the United States. The goal was to raise immunization levels in American children for the common vaccine-preventable diseases to more than 90% by 1979. This goal was achieved with success in school-aged children, and two new goals for 1990 were established in December 1980 by the Public Health Service: to raise national immunization levels in toddlers to 90% by age 2 years and to raise the immunization levels of children in day-care centers and schools (grades K through 12) to 95%. Vaccine-preventable illnesses continue to plague children in the United States, however. In the time span January 1, 1978, through June 30, 1986, more than 17,000 cases
of vaccine-preventable infectious diseases were reported in the state of California alone (California Department of Health Services [CDHS] data). In 1982 and 1983, of reported pertussis cases in the US in children aged 3 months to 6 years, 68% occurred in inadequately immunized children.4 National estimates indicate that susceptibility rates to measles or rubella may be as high as 20% in our colleges and universities. There were major measles outbreaks in California in Los Angeles County in 1984, Riverside County in 1985, and San Bernardino and Sonoma counties in 1986 (CDHS data). More recently in California during a measles outbreak between April 1 and June 30, 1990, measles was reported to occur in 1,799 persons aged 16 months to 33 years. Of these cases, 70.6% occurred in persons without documented adequate immunization after 12 months of age (CDHS data). Statutory initiatives have had a major influence on the levels of immunization by mandating certain immunizations for school entry. Senate Bill 942 was passed in California in 1977 to provide a comprehensive, compulsory school immunization law. This bill clarified much of the confusion surrounding vaccine requirements for school registration and instituted uniform vaccine requirements. It repealed existing immunization laws and substituted one uniform law for all required immunizations. It also standardized school immunization records, entrance requirements, and sanctions against unimmunized students. The impact of this legislation is reflected in the incidence of selected vaccine-preventable diseases in California for 1977 and 1985, showing that this policy has brought about a decrease in the incidence of these diseases (Figure 1). Even more stringent requirements implemented in 1986 increased accountability by requiring children entering California schools or state-licensed child day-care centers to provide a written immunization record for each required vaccine dose from a health care professional, including specifying the year and month of vaccine administration.
From the University of California, Berkeley-University of California, San Francisco, School of Medicine, Joint Medical Program (Dr Scheiber), and the Center for the Vulnerable Child, Children's Hospital Medical Center of Northern California, Oakland, and the Institute for Health Policy Studies, University of California, San Francisco, School of Medicine (Dr Halfon). This work was partially supported by the James Irvine Foundation and the Harris Trust of the Institute of Governmental Studies, University of California, Berkeley. Reprint requests to Neal Halfon, MD, MPH, Center for the Vulnerable Child, Children's Hospital Oakland, 747-52nd St, Oakland, CA 94609.
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ABBREVIATIONS USED IN TEXT
CDHS = California Department of Health Services CSIR = California School Immunization Record DPT = diphtheria and tetanus toxoids and pertussis vaccine OPV = oral [attenuated] poliovirus vaccine
Before this change, guardians without written immunization records for their children had the option of filling out and signing the California School Immunization Record. This study reviews and analyzes data collected by the CDHS Immunization Unit to determine current levels of immunizations, trends in those levels of immunizations, the factors associated with those trends, and policy alternatives that could prove useful in meeting identified shortfalls. Methods Data from the CDHS Immunization Unit from 1979 to 1987 were analyzed. These data were generated from two annually state-administered surveillance systems: the Selective Review and the Kindergarten Survey. Selective Review The selective reviews are extensive surveys conducted by the Immunization Unit to review and establish the validity of data on the immunization status of children in California's schools and day-care centers.* The purpose of the reviews is to evaluate the effectiveness of the follow-up of conditionally admitted students, to verify the data obtained on the annual Kindergarten Survey (school entry data), and to conduct retrospective studies of immunization levels of children at various age checkpoints. The selective reviews are conducted at approximately 280 schools in California, which constitutes a sample size to achieve 95% confidence intervals that would allow the estimation of the percentage of unimmunized children to be in the range of 10%. Schools are randomly selected, but if that school has already participated in a previous selective re*The CDHS defines a day-care center as any facility located outside of a private home, usually with more than 12 children, and does not confine its data collection to those institutions licensed by the Department of Social Services.
n
1977
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1985
view, it is replaced by another school selected at random. The CDHS has accepted the small loss in validity generated by this selection system because of the advantage of increased quality control of record-keeping that generally results from a school's participation in a selective review. Two children at each school are randomly selected and their California School Immunization Records (CSIRs) are reviewed by CDHS staff members. Two studies were done, one in Los Angeles County and the other at the state level, that measured the accuracy of the CSIR as compared with parents' documented records. Both studies indicated that parents' written immunization records matched comparably with the CSIRs within a margin of 5% error (CDHS data). Since the initial school review in 1981. the state has added a similar review of child care centers, reviewing approximately 210 to 215 centers each year.
Kindergarten Survey Kindergarten surveys were done by schools on a voluntary basis between 1974 and 1977 and were mandated after 1978. This law requires that one employee from each school with kindergarten grades compile all the CSIRs for the kindergarten children and tally the number and percentages of children up-to-date for each of the required vaccinations. Results Immunization Levels in California School Children The kindergarten survey completed on January 22, 1987, shows that in 1986,90.12% of all children beginning kindergarten (public and private schools combined) in California had school records indicating that they had received all the immunizations required for school registration. Table 1 shows the vaccine requirements for kindergarten effective September 1986. The percentage of children who are adequately immunized at the start of kindergarten has increased about 15% since 1979 (Figure 2). Nevertheless, California still falls slightly below the national weighted average that the Centers for Disease Control report for percentages of school children who have completed all staterequired vaccinations (Figure 3). School Compliance With Official Policy As would be expected, as immunization levels rise, the total percentage of students with conditional admissions to kindergarten (those needing one or more immunizations
10.000 *
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Measles
Rubella
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Figure 1.-The graph shows the number of cases of selected vaccinepreventable illnesses in California in 1977 and 1985 (compiled from California Department of Health Services data).
1 1980
1981
1982
1983 Year
1984
1985
1986
Figure 2.-The percentage of students is shown who enter kindergarten in California meeting all legal vaccine requirements at the time of school entry, by year, from 1979 to 1986 (compiled from California Department of Health Services data).
IMMUNIZATION IN CALIFORNIA
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IMMUNIZATION
IN
TABLE l.-School Entry Vaccine Requirements for the State of Califomia, Effective September 1986 Minimum Doses Required
Vaccine
1 Polio (trivalent OPV) .................................. 3Diphtheria, tetanus, and pertussis (DTP) Age 6 yr or younger-pertussis required 1 DTP or any combination of DTP with DT or Td .............................. 4, but... Age 7 yr or older-pertussis not required 1 3, but... Td, DT, or DTP or any combination ., 1 each, but ... 1 Measles, rubella, mumpst Can be given separately or together
Additional Dose Requirements
more dose if last was before 2nd birthday
more dose if last was before 2nd birthday more Td dose if last was before 2nd birthday more dose of any given before the first birthday
DT - diphtheria and tetanus toxoids, adsorbed, pediatric; Td - adult tetanus toxoid (full dose) and diphtheria toxoid (reduced dose)
'if inactivated poliovirus (IPV) or a combination of oral, attenuated poliovirus (OPV) and IPV was given, at least 4 doses are required. One more dose is required ifthe last dose was given before the second birthday. tMumps immunization is not required for pupils 7 years of age and older.
who were allowed to attend classes for the grace period) has been declining (Figure 4). The 1987 Selective Review indicated that 85% of public kindergartens and 75% of private kindergartens were strictly and completely enforcing the new school entry regulations at the time of the survey. In the day-care centers, the new regulations are being enforced by 88.5% of Head Start programs, 74.3% of public day-care centers, and 64.1% of private day-care centers. Between the kindergarten surveys, compiled at the time school starts, and the selective reviews conducted six months later, the schools have time to enforce the regulations and ensure that all conditionally admitted students receive the immunizations they are missing. Private schools and public schools have different rates of compliance to the requirements. Public schools more rigorously follow up on conditionally admitted students (Figure 5). * California NNational Weighted Average
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Figure 4.-The percentage of students is shown who entered kindergarten in California by year from 1979 to 1986 whose vaccine status was classified as conditional at the time of school entry (compiled from California Department of Health Services data).
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Figure 3.-The percentage of students is shown who enter kindergarten in California meeting all legal vaccine requirements at time of school entry compared with the national weighted average by year for 1982, 1983, and 1986 (compiled from data from the California Department of Health Services and the Centers for Disease Control).
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-10 Year Figure 5.-The percentage change is shown for the number of students with conditional vaccine status between school entry and selective review in public and private schools in California by year, from 1981 to 1986 (compiled from California Department of Health Services data).
THE WESTERN JOURNAL OF MEDICINE * OCTOBER 1990 *
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Underimmunized Segments of the Population By retrospectively examining individual immunization records during the selective reviews, we were able to estimate immunization levels for groups of children at different ages before school entry. Children aged 2 years and 7month-old children are particularly underimmunized segments of the California population. While the percentage of these children who are adequately immunized has been increasing with time (Figure 6), the immunization levels for these two groups are both considerably lower (P < .001) than the levels for 1-year-olds and kindergartners. During the 1987 selective school review, the California Immunization Unit conducted a special retrospective survey to identify the source of immunization of California children and to compare school immunization records with parental records kept at home. Based on the school immunization records and parental responses, children in the survey were immunized by the following types of medical provider: private physician, 67.2%; public clinic, 15.6%; public and private combination, 16.7%; and military, 0.5%. Further analysis revealed that health maintenance organizations are the sole medical source for 10.2% of the children, and another 7% used a combination of health maintenance organizations and other providers to obtain their immunizations.5 At each age checkpoint, children who received their immunizations solely in the private sector were more adequately immunized than children served by public health clinics (Figure 7).5 At certain ages, the discrepancy is significant. For instance, at 7 months of age only 32% of children
95
85
4
using public clinics were adequately immunized, whereas 63% of those using private physicians were up-to-date. Discussion The data presented here show that while immunization levels in California children are still slightly below the national average, they are improving. Recent legislative changes in California have clarified vaccine requirements and public health implementation at the school level. Public schools are complying with the new regulations to a greater extent than are private schools and have a lower percentage of students with conditional vaccine status at the time of both the kindergarten survey and the selective reviews. Young children, especially 7-month-old and 2-year-old children, have disturbingly low immunization levels. Furthermore, this "toddler gap" is nearly twice as great for children dependent on public clinics for their vaccinations as for children who receive their immunizations in the private sector. As immunization levels increase in California, they are approaching the national average. Several considerations may explain California's apparent shortcomings. Vaccine requirements in California are more rigorous than in many other states. For instance, during the 1985-1986 school year, vaccination against mumps, required for grades K through 12 in California, was not required for any grade in 17 states and was required of new entrants only or only for grades K through 6 or lower in 17 states. Also, most states report kindergartners with a total of four doses of DTP and three doses of oral, attenuated poliovirus vaccine (OPV) as adequately immunized, whereas California reports these children as inadequately immunized if all doses were received before the second birthday. Furthermore, the new California laws require stricter documentation than other states for counting a child's immunizations up-to-date. Part of the real gap between California's and the national coverage may be explained by the sheer magnitude of the responsibilities facing California public health professionals. California is responsible for immunizing a large population of children, many of whom are immigrants. Approximately 433,334 infants are born each year in California, a figure that represents about an eighth of the children
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Figure 6.-The graph shows the percentage of California children whose vaccine antigens are all up-to-date, by age group and year from 1982 to 1986 (compiled from California Department of Health Services data).
12 17 7 Age Checkpoint, Months
24
Figure 7.-The graph shows the percentage of children adequately immunized by source of immunizations at different age checkpoints. Data are from the California retrospective survey of kindergarten children, spring 1987, based on 188 (93%) school records and parental responses (California Department of Health Services data).
404
born in the United States and more than the combination of births occurring annually in 19 states and the District of Columbia (California Department of Finance, Population Research Unit, Sacramento, July 1, 1985). The new school entry regulations seem to be having some effect on the immunization levels of school children. In the years 1979 and 1986, the largest yearly increases occurred in immunization levels and coincided with the passage of Senate Bill 942 and the most recent legislative changes. The 1986 data also represented the biggest yearly decrease during the eight-year period 1979 to 1986 in the percentage of children starting school whose immunizations were not up-to-date for all antigens. It is anticipated that when the data become available, the fall in conditional admissions will be seen to have been even more dramatic for the school year beginning September 1987 because a considerable number of children had already registered for the 1986-1987 school year by the time the new regulations went into effect in March 1986. While the 1986 amendments, as indicated, did manage to decrease the number of students conditionally admitted, the new regulations did not have a large impact on the follow-up of those students who were illegally or mistakenly admitted. The increase in the number of students in public schools whose immunization status was classified as conditional at selective review can occur by either of two means: through the discovery at the selective review that children who the school had admitted as up-to-date were really misclassified and were missing one or more immunizations, or through admitting more students on a conditional basis. The Immunization Unit of the CDHS finds that the misclassification of children's immunization status at the initial school survey may be a likely cause for the increase. Selective reviews show that many students who had received measles, mumps, and rubella vaccinations before their first birthday or all of their DPT/DT[diphtheria and tetanus toxoids]/OPV immunizations before their second birthday were mistakenly classified as unconditional. This is a reassuring finding because most of these children are not totally lacking immunity. Rather, the boosters provide future protection against waning immunity or remove the small probability that the first series of shots did not provide adequate immunity. Financial incentives may help to explain some of the differences noted in the data between public and private schools. The fact that private schools and day-care centers are less strictly enforcing the new vaccine laws than are public schools may reflect the fact that private institutions more completely depend on full enrollment for continued viability. The toddler gap in immunizations has been a major health problem in California. Its consequences are illustrated by a sampling of disease statistics. In 1979 in California, there were 122 reported cases of pertussis. Of these cases, 92 (75%) occurred in children younger than 5 years. Infants younger than 1 year represented 54% of cases.6 In 1980 California had 147 reported pertussis cases, 78% of which occurred in children younger than 5 and 54% in infants younger than 1.7 California had 9,477 measles cases reported in 1977, 18% of which occurred in children younger than 5 years.8 For inadequately immunized toddlers, the disparity between those children receiving their immunizations from private physicians and those immunized in the public clinics is striking. Similar discrepancies have been documented in other states and have been likened to outbreaks of mea-
IMMUNIZATION IN CALIFORNIA
sles in public-sector immunized children.9 Children cared for in public clinics include those covered by Medi-Cal (California's Medicaid) and those children presumed to have no health insurance. In 1986, despite the fact that California has one of the most generous state Medicaid systems, 23 % of children in California had no public or private insurance coverage. This situation is especially tragic when California's version of the federal Early Periodic Screening, Diagnosis and Treatment Program-the Child Health and Disability Prevention Program-provides a financial mechanism for all children 29 months of age or younger who live in families with incomes as high as 200% of the poverty level to receive proper immunizations and health care maintenance services. Yet, the program currently reaches less than 30% of those eligible.10 Why does the great discrepancy between the public and private sectors exist, and why is the Child Health and Disability Prevention Program so underused? Children from low-income families who use public clinics for immunizations and health care frequently encounter numerous barriers to health care access. Many public clinics have episodic and irregular hours, long waiting times, insufficient outreach, and poor monitoring. For many of the immigrant families using public clinics, even a small degree of official government contact can be inhibiting. For other families living in poverty, or near poverty, other events and demands can outweigh the timely completion of immunization schedules. In 1986 the CDHS implemented programs to try to reduce this toddler gap and ensure that 90% or more of the children born in California each year are up-to-date for all antigens by age 2. These programs included increased emphasis on hospital-based education for new mothers, involving the Women, Infants, and Children Supplemental Food Program and other organizations to include immunization as a criterion for receiving other infant and toddler care and improving education by health care providers with such items as the "Date Next Immunization Due" stickers for the outside jackets of a child's immunization record. Also, the expansion of eligibility for the Child Health and Disability Prevention Program in recent years has been specifically targeted at children up to age 29 months, thereby possibly addressing the specific immunization needs of infants and toddlers.
Policy Implications Efforts must be strengthened and continued in order to raise toddler immunization levels to an acceptable level. One way of effecting increased levels of immunization in toddlers would be through health education efforts. A successful media campaign could alert parents to the danger of vaccine-preventable infectious diseases. Such an effort was successful in Great Britain at the height of a pertussis epidemic in 1982 and has been a major strategic intervention of other successful preventive health programs. Extensive national campaigns have produced positive public health behavioral changes in many areas, such as smoking cessation and dental hygiene."1'"2 Even longer term increases in immunization levels might be achieved by including vaccine information sessions in health education programs at the school level or by including vaccine education in prenatal programs. Educational efforts must be coupled with improved outreach and access. California's Child Health and Disability Prevention Program is the best mechanism for providing access to needed preventive health services including im-
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munizations. Because of fiscal constraints, this program currently reaches only a fraction of those children eligible for services. Additional funds provided by California State Proposition 99, the cigarette tax, will be allocated to the program in 1989-1990. It is hoped that the infusion of additional funds will provide the means to increase access for uninsured and underinsured children and improve the rates of immunization. REFERENCES
1. Bloch AB, Orenstein WA, Stetler HC, et al: Health impact of measles vaccination in the United States. Pediatrics 1985; 76:524-532 2. Hinman AR, Koplan JP: Pertussis and pertussis vaccine: Reanalysis of benefits, risks, and costs. JAMA 1984; 251:3109-3113 3. Koplan JP, Schoenbaum SC, Weinstein MC, et al: Pertussis vaccine-An analysis of benefits, risks, and costs. N Engl J Med 1979; 301:906-911
4. Centers for Disease Control (CDC): Pertussis: United States, 1982 and 1983. MMWR 1984; 33:573-575 5. Immunization Update. Sacramento, California Department of Health Services, 1987 6. CDC: Annual summary 1980: Reported morbidity and mortality in the United States. MMWR 1981; 28:61 7. CDC: Annual summary 1981: Reported morbidity and mortality in the United States. MMWR 1982; 29:62 8. CDC: Annual summary 1977: Reported morbidity and mortality in the United States. MMWR 1978; 26:10-23 9. Hutchins S, Escolan J, Markowitz L, et al: Measles outbreak among unvaccinated preschool-aged children: Opportunities missed by health care providers to administer measles vaccine, Pediatrics 1989; 83:369-374 10. Halfon N, Jameson W, Brindis C, et al: Health conditions of children in California, chap 8, In Policy Analysis in California Education. Berkeley, University of California, School of Education, 1989 11. Flay BR: Mass media and smoking cessation: A critical review. Am J Public Health 1987; 77:153-160 12. Schou L: Use of mass-media and active involvement in a national dental health campaign in Scotland. Community Dent Oral Epidemiol 1987; 15:14-18
Exploratory Surgery Even asleep you feel the cutting edge. A fissure lengthens, swallows boulders, uprooted trees, the cavernous white of deeply buried bone. Oddly angled buildings work exposes
into your dreams; trucks roll across the rubble of the bed. You rise, toppling cabinets, sinks, the pillars of ancient tombs. Lightheaded still, your shaking goes on and on. Meat spoils in the aftermath. Crumbled walls prevent your body from being
recovered. In time the bleeding stops. Eventually the ground re-seeds. Water mains are clamped,
even
tucked back into place. One day you dress. Pansies bloom. Your face
is mapped with hairline cracks. You examine yourself for scars. MARILEE RICHARDS Alameda, California
