The regional immunization registry as a public health tool for improving clinical practice and guiding immunization delivery policy

OUP accepted manuscript

Objective

Supporting public health research and the public’s situational awareness during a pandemic requires continuous dissemination of infectious disease surveillance data. Legislation, such as the Health Insurance Portability and Accountability Act of 1996 and recent state-level regulations, permits sharing deidentified person-level data; however, current deidentification approaches are limited. Namely, they are inefficient, relying on retrospective disclosure risk assessments, and do not flex with changes in infection rates or population demographics over time. In this paper, we introduce a framework to dynamically adapt deidentification for near-real time sharing of person-level surveillance data.

Materials and Methods

The framework leverages a simulation mechanism, capable of application at any geographic level, to forecast the reidentification risk of sharing the data under a wide range of generalization policies. The estimates inform weekly, prospective policy selection to maintain the proportion of records corresponding to a group size less than 11 (PK11) at or below 0.1. Fixing the policy at the start of each week facilitates timely dataset updates and supports sharing granular date information. We use August 2020 through October 2021 case data from Johns Hopkins University and the Centers for Disease Control and Prevention to demonstrate the framework’s effectiveness in maintaining the PK11 threshold of 0.01.

Results

When sharing COVID-19 county-level case data across all US counties, the framework’s approach meets the threshold for 96.2% of daily data releases, while a policy based on current deidentification techniques meets the threshold for 32.3%.

Conclusion

Periodically adapting the data publication policies preserves privacy while enhancing public health utility through timely updates and sharing epidemiologically critical features.

Improving immunization data quality in Peru and Mexico: Two case studies highlighting challenges and lessons learned

INTRODUCTION

The Global Vaccine Action Plan and the Regional Immunization Action Plan of the Americas call for countries to improve immunization data quality. Immunization information systems, particularly electronic immunization registries (EIRs), can help to facilitate program management and increase coverage. However, little is known about efforts to develop and implement such systems in low- and middle-income countries. We present the experiences of Mexico and Peru in implementing EIRs.

METHODS

We conducted case studies of an EIR in Mexico and of a population registry in Peru. Information was gathered from technical documents, stakeholder focus groups, site visits, and semi-structured interviews of national stakeholders. We organized findings into narratives that emphasized challenges and lessons learned.

RESULTS

Mexico built one of the world's first EIRs, incorporating novel features such as local-level tracking of patients; however, insufficient resources and poor data registration practices led to the system's discontinuation. Peru created an information system to improve affiliation to social programs, including the immunization program and quality of demographic data. Mexico's experience highlights lessons in failed sustainability of an EIR and a laudable effort to reform a country's information system. Peru's demonstrates that attempts to improve health and other data may strengthen health systems, including immunization data. Major challenges in information system implementation and sustainability in Peru and Mexico related to funding, clear governance structures, and resistance among health workers.

DISCUSSION

These case studies reinforce the need for countries to ensure adequate funding, plans for sustainability, and health worker capacity-building activities before implementing EIRs. They also suggest new approaches to implementation, including economic incentives for sub-national administrative levels and opportunities to link efforts to improve immunization data with other health and political priorities. More information on best practices is needed to ensure the successful adoption and sustainability of immunization registries in low- and middle-income countries.

Direct-to-adolescent text messaging for vaccine reminders: What will parents permit?

BACKGROUND

Direct-to-adolescent text messaging may be a consideration for vaccine reminders, including human papilloma virus (HPV), but no studies have explored the minimum age at which parents would allow adolescents to receive a text message.

METHODS

We distributed a survey to parents of 10-17 year olds during any office visit in two practice based research networks in South Carolina and Oklahoma. We asked about parental preference for receiving vaccine reminders for their adolescent, whether they would allow the healthcare provider to directly message their adolescent, and if so, what would be the acceptable minimum age.

RESULTS

In 546 surveys from 11 practices, parents of females were more supportive of direct-to-teen text message reminders than were parents of males, (75% v. 60%, p < .001). The median age at which parents would allow direct text messages from physicians' offices was 14 in females compared to 15 in males, p = .049. We found a correlation between the child's age and the youngest age at which parents would allow a direct text message. Of the parents who permitted a text message directly to their adolescent, most reported an allowable age higher than their adolescent's current age until the age of 15.

CONCLUSION

Our study suggests that direct-to-adolescent text messaging would be allowed by parents for older adolescents. This supports an intervention aimed at older adolescents, such as for receipt of MCV4 dose #2, delayed HPV vaccine series completion and annual influenza vaccination.

Patient reminder and recall interventions to improve immunization rates

BACKGROUND

Immunization rates for children and adults are rising, but coverage levels have not reached optimal goals. As a result, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care, and large demands on primary care providers, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. One common theme across immunization programs in many nations involves the challenge of implementing a population-based approach and identifying all eligible recipients, for example the children who should receive the measles vaccine. However, this issue is gradually being addressed through the availability of immunization registries and electronic health records. A second common theme is identifying the best strategies to promote high vaccination rates. Three types of strategies have been studied: (1) patient-oriented interventions, such as patient reminder or recall, (2) provider interventions, and (3) system interventions, such as school laws. One of the most prominent intervention strategies, and perhaps best studied, involves patient reminder or recall systems. This is an update of a previously published review.

OBJECTIVES

To evaluate and compare the effectiveness of various types of patient reminder and recall interventions to improve receipt of immunizations.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and CINAHL to January 2017. We also searched grey literature and trial registers to January 2017.

SELECTION CRITERIA

We included randomized trials, controlled before and after studies, and interrupted time series evaluating immunization-focused patient reminder or recall interventions in children, adolescents, and adults who receive immunizations in any setting. We included no-intervention control groups, standard practice activities that did not include immunization patient reminder or recall, media-based activities aimed at promoting immunizations, or simple practice-based awareness campaigns. We included receipt of any immunizations as eligible outcome measures, excluding special travel immunizations. We excluded patients who were hospitalized for the duration of the study period.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane and the Cochrane Effective Practice and Organisation of Care (EPOC) Group. We present results for individual studies as relative rates using risk ratios, and risk differences for randomized trials, and as absolute changes in percentage points for controlled before-after studies. We present pooled results for randomized trials using the random-effects model.

MAIN RESULTS

The 75 included studies involved child, adolescent, and adult participants in outpatient, community-based, primary care, and other settings in 10 countries.Patient reminder or recall interventions, including telephone and autodialer calls, letters, postcards, text messages, combination of mail or telephone, or a combination of patient reminder or recall with outreach, probably improve the proportion of participants who receive immunization (risk ratio (RR) of 1.28, 95% confidence interval (CI) 1.23 to 1.35; risk difference of 8%) based on moderate certainty evidence from 55 studies with 138,625 participants.Three types of single-method reminders improve receipt of immunizations based on high certainty evidence: the use of postcards (RR 1.18, 95% CI 1.08 to 1.30; eight studies; 27,734 participants), text messages (RR 1.29, 95% CI 1.15 to 1.44; six studies; 7772 participants), and autodialer (RR 1.17, 95% CI 1.03 to 1.32; five studies; 11,947 participants). Two types of single-method reminders probably improve receipt of immunizations based on moderate certainty evidence: the use of telephone calls (RR 1.75, 95% CI 1.20 to 2.54; seven studies; 9120 participants) and letters to patients (RR 1.29, 95% CI 1.21 to 1.38; 27 studies; 81,100 participants).Based on high certainty evidence, reminders improve receipt of immunizations for childhood (RR 1.22, 95% CI 1.15 to 1.29; risk difference of 8%; 23 studies; 31,099 participants) and adolescent vaccinations (RR 1.29, 95% CI 1.17 to 1.42; risk difference of 7%; 10 studies; 30,868 participants). Reminders probably improve receipt of vaccinations for childhood influenza (RR 1.51, 95% CI 1.14 to 1.99; risk difference of 22%; five studies; 9265 participants) and adult influenza (RR 1.29, 95% CI 1.17 to 1.43; risk difference of 9%; 15 studies; 59,328 participants) based on moderate certainty evidence. They may improve receipt of vaccinations for adult pneumococcus, tetanus, hepatitis B, and other non-influenza vaccinations based on low certainty evidence although the confidence interval includes no effect of these interventions (RR 2.08, 95% CI 0.91 to 4.78; four studies; 8065 participants).

AUTHORS' CONCLUSIONS

Patient reminder and recall systems, in primary care settings, are likely to be effective at improving the proportion of the target population who receive immunizations.

Immunization information systems to increase vaccination rates: a community guide systematic review

CONTEXT

Immunizations are the most effective way to reduce incidence of vaccine-preventable diseases. Immunization information systems (IISs) are confidential, population-based, computerized databases that record all vaccination doses administered by participating providers to people residing within a given geopolitical area. They facilitate consolidation of vaccination histories for use by health care providers in determining appropriate client vaccinations. Immunization information systems also provide aggregate data on immunizations for use in monitoring coverage and program operations and to guide public health action.

EVIDENCE ACQUISITION

Methods for conducting systematic reviews for the Guide to Community Preventive Services were used to assess the effectiveness of IISs. Reviewed evidence examined changes in vaccination rates in client populations or described expanded IIS capabilities related to improving vaccinations. The literature search identified 108 published articles and 132 conference abstracts describing or evaluating the use of IISs in different assessment categories.

EVIDENCE SYNTHESIS

Studies described or evaluated IIS capabilities to (1) create or support effective interventions to increase vaccination rates, such as client reminder and recall, provider assessment and feedback, and provider reminders; (2) determine client vaccination status to inform decisions by clinicians, health care systems, and schools; (3) guide public health responses to outbreaks of vaccine-preventable disease; (4) inform assessments of vaccination coverage, missed vaccination opportunities, invalid dose administration, and disparities; and (5) facilitate vaccine management and accountability.

CONCLUSIONS

Findings from 240 articles and abstracts demonstrate IIS capabilities and actions in increasing vaccination rates with the goal of reducing vaccine-preventable disease.

Immunization Data Exchange With Electronic Health Records

OBJECTIVE

To assess the impact of exchange of immunization information between an immunization information system (IIS) and an electronic health record on up-to-date rates, overimmunization, and immunization record completeness for low-income, urban children and adolescents.

METHODS

The New York City Department of Health maintains a population-based IIS, the Citywide Immunization Registry (CIR). Five community clinics in New York City implemented direct linkage of immunization data from the CIR to their local electronic health record. We compared immunization status and overimmunization in children and adolescents 19 to 35 month, 7 to 10 year, and 13 to 17 year-olds with provider visits in the 6-month period before data exchange implementation (2009; n = 6452) versus 6-months post-implementation (2010; n = 6124). We also assessed immunization record completeness with and without addition of CIR data for 8548 children and adolescents with visits in 2012-2013.

RESULTS

Up-to-date status increased from before to after implementation from 75.0% to 81.6% (absolute difference, 6.6%; 95% confidence interval [CI], 5.2% to 8.1%) and was significant for all age groups. The percentage overimmunized decreased from 8.8% to 4.7% (absolute difference, -4.1%; 95% CI, -7.8% to -0.3%) and was significant for adolescents (16.4% vs 1.2%; absolute difference, -15.2%; 95% CI, -26.7 to -3.6). Up-to-date status for those seen in 2012 to 2013 was higher when IIS data were added (74.6% vs 59.5%).

CONCLUSIONS

This study demonstrates that data exchange can improve child and adolescent immunization status. Development of the technology to support such exchange and continued focus on local, state, and federal policies to support such exchanges are needed.

Urban and Rural Differences in Parental Attitudes About Influenza Vaccination and Vaccine Delivery Models

OBJECTIVES

To assess and compare among parents of healthy children in urban and rural areas: (1) reported influenza vaccination status; (2) attitudes regarding influenza vaccination; and (3) attitudes about collaborative models for influenza vaccination delivery involving practices and public health departments.

METHODS

A mail survey to random samples of parents from 2 urban and 2 rural private practices in Colorado from April 2012 to June 2012.

RESULTS

The response rate was 58% (288/500). In the prior season, 63% of urban and 41% of rural parents reported their child received influenza vaccination (P < .001). No differences in attitudes about influenza infection or vaccination between urban and rural parents were found, with 75% of urban and 73% of rural parents agreeing their child should receive an influenza vaccine every year (P = .71). High proportions reported willingness to participate in a collaborative clinic in a community setting (59% urban, 70% rural, P = .05) or at their child's provider (73% urban, 73% rural, P = .99) with public health department assisting. Fewer (36% urban, 53% rural, P < .01) were likely to go to the public health department if referred by their provider. Rural parents were more willing for their child to receive vaccination outside of their provider's office (70% vs. 55%, P = .01).

CONCLUSIONS

While attitudes regarding influenza vaccination were similar, rural children were much less likely to have received vaccination. Most parents were amenable to collaborative models of influenza vaccination delivery, but rural parents were more comfortable with influenza vaccination outside their provider's office, suggesting that other venues for influenza vaccination in rural settings should be promoted.

Childhood vaccination coverage rates among military dependents in the United States

BACKGROUND AND OBJECTIVES

The Military Health System provides universal coverage of all recommended childhood vaccinations. Few studies have examined the effect that being insured by the Military Health System has on childhood vaccination coverage. The purpose of this study was to compare the coverage of the universally recommended vaccines among military dependents versus other insured and uninsured children using a nationwide sample of children.

METHODS

The National Immunization Survey is a multistage, random-digit dialing survey designed to measure vaccination coverage estimates of US children aged 19 to 35 months old. Data from 2007 through 2012 were combined to permit comparison of vaccination coverage among military dependent and all other children.

RESULTS

Among military dependents, 28.0% of children aged 19 to 35 months were not up to date on the 4:3:1:3:3:1 vaccination series excluding Haemophilus influenzae type b vaccine compared with 21.1% of all other children (odds ratio: 1.4; 95% confidence interval: 1.2-1.6). After controlling for sociodemographic characteristics, compared with all other US children, military dependent children were more likely to be incompletely vaccinated (odds ratio: 1.3; 95% confidence interval: 1.1-1.5).

CONCLUSIONS

Lower vaccination coverage rates among US military dependent children might be due to this population being highly mobile. However, the lack of a military-wide childhood immunization registry and incomplete documentation of vaccinations could contribute to the lower vaccination coverage rates seen in this study. These results suggest the need for further investigation to evaluate vaccination coverage of children with complete ascertainment of vaccination history, and if lower immunization rates are verified, assessment of reasons for lower vaccination coverage rates among military dependent children.

Vaccine hesitancy among parents of adolescents and its association with vaccine uptake

BACKGROUND

Addressing parental vaccine hesitancy may increase adolescent vaccination acceptance. However, no validated measure exists to identify parents hesitant toward adolescent vaccines.

OBJECTIVE

To determine if a modified version of the Parent Attitudes about Childhood Vaccines (PACV) survey, a previously validated tool to identify parental hesitancy toward vaccines in infants, predicts adolescent vaccine uptake at office visits.

METHODS

We modified the PACV for use in the adolescent setting and distributed it to a convenience sample of parents of adolescents aged 11 to 17 presenting for care at a diverse group of six pediatric practices in Oklahoma and South Carolina. We determined the vaccination status of the parents' adolescents for 3 vaccines (Tetanus-diphtheria-acellular pertussis [Tdap], meningococcal conjugate [MCV4], and human papillomavirus [HPV] vaccines). We used Fisher's exact tests to compare vaccination status with each survey item and with an overall general hesitancy scale that we constructed.

RESULTS

We analyzed 363 surveys. At the time of the visit, vaccination coverage was 84% for Tdap, 73% for MCV, and 45% for any dose of HPV. Thirty-nine percent of parents expressed concern about vaccine efficacy and 41% expressed concern about side effects. Forty-five percent of parents disagreed with the statement that "teens can get all of the vaccines that are due at a single visit." Two individual items were associated with not receiving a dose of HPV vaccine that was due. The overall modified PACV score failed to predict adolescent vaccine uptake at an office visit.

CONCLUSION

Several individual items were associated with vaccine uptake. The cumulative modified PACV, a general measure of vaccine hesitancy, was not associated with vaccination status despite illuminating parental hesitancy. We need to better understand vaccine-specific concerns for the adolescent population.

An education in contrast: state-by-state assessment of school immunization records requirements

OBJECTIVES

We reviewed the complexities of school-related immunization policies, their relation to immunization information systems (IIS) and immunization registries, and the historical context to better understand this convoluted policy system.

METHODS

We used legal databases (Lexis-Nexis and Westlaw) to identify school immunization records policies for 50 states, 5 cities, and the District of Columbia (Centers for Disease Control and Prevention "grantees"). The original search took place from May to September 2010 (cross-referenced in July 2013 with the list on http://www.immunize.org/laws ). We describe the requirements, agreement with IIS policies, and penalties for policy violations.

RESULTS

We found a complex web of public health, medical, and education-directed policies, which complicates immunization data sharing. Most (79%) require records of immunizations for children to attend school or for a child-care institution licensure, but only a few (11%) require coordination between IIS and schools or child-care facilities.

CONCLUSIONS

To realize the full benefit of IIS investment, including improved immunization and school health program efficiencies, IIS and school immunization records policies must be better coordinated. States with well-integrated policies may serve as models for effective harmonization.

Age-specific strategies for immunization reminders and recalls: a registry-based randomized trial

BACKGROUND

Although previous studies have found reminder/recall to be effective in increasing immunization rates, little guidance exists regarding the specific ages at which it is optimal to send reminder/recall notices.

PURPOSE

To assess the relative effectiveness of centralized reminder/recall strategies targeting age-specific vaccination milestones among children in urban areas during June 2008-June 2009.

METHODS

Three reminder/recall strategies used capabilities of the Michigan Care Improvement Registry (MCIR), a statewide immunization information system: a 7-month recall strategy, a 12-month reminder strategy, and a 19-month recall strategy. Eligible children were randomized to notification (intervention) or no notification groups (control). Primary study outcomes included MCIR-recorded immunization activity (administration of ≥1 new dose, entry of ≥1 historic dose, entry of immunization waiver) within 60 days following each notification cycle.

RESULTS

A total of 10,175 children were included: 2,072 for the 7-month recall, 3,502 for the 12-month reminder, and 4,601 for the 19-month recall. Immunization activity was similar between notification versus no notification groups at both 7 and 12 months. Significantly more 19-month-old children in the recall group (26%) had immunization activity compared to their counterparts who did not receive a recall notification (19%).

CONCLUSIONS

Although recall notifications can positively affect immunization activity, the effect may vary by targeted age group. Many 7- and 12-month-olds had immunization activity following reminder/recall; however, levels of activity were similar irrespective of notification, suggesting that these groups were likely to receive medical care or immunization services without prompting.

Factors associated with continued adherence to influenza vaccination in the elderly

OBJECTIVE

We aimed to analyze the factors influencing continued adherence to influenza vaccination in elderly persons vaccinated in the preceding season.

METHODS

Using a population-based vaccination registry, we evaluated the proportion of persons vaccinated against influenza in Navarre, Spain, in the 2010-11 season among non-institutionalized persons aged 65 years or over who had been vaccinated in the 2009-10 season. Logistic regression was used to analyze the influence of sociodemographic, clinical and health care factors.

RESULTS

Of the 64,245 persons vaccinated against influenza in the 2009-10 season, 87% were vaccinated in the 2010-11 season. Continued adherence to vaccination increased with the number of physician visits per year. It was lower in women, in the 65-69 and ≥ 95 year age-groups, in those hospitalized or diagnosed with any major chronic condition in the previous year, and in persons with hematological cancer or dementia. Health districts and physicians with higher coverage in the previous season continued to have higher adherence in the following season.

CONCLUSIONS

People vaccinated against influenza in one season tend to be vaccinated in the following one. Sociodemographic, clinical and health care factors have a moderate effect on the continuity of vaccination, with the most important factor being the treating physician.

Childhood immunization policies and the prevention of communicable disease

CME Educational Objectives

1.

Review the process through which vaccines are licensed and recommendations are developed for routine use.

2.

Discuss immunization coverage rates.

3.

Review possible strategies to improve immunization coverage rates.

The use of immunization registry-based data in vaccine effectiveness studies

Vaccine effectiveness (VE) studies provide a measure of population-based vaccine performance by combining immunization history data with rates of disease incidence. This review assessed the feasibility of using electronic immunization registry data sources in VE studies. Electronic databases were searched through January 31, 2010. Out of 17 studies, only one paper assessed data accuracy (71%), and three papers assessed population coverage of the registry (estimates ranged from 25% to 90%). This review shows that registry-based data sources can be used to conduct VE studies in a variety of settings and populations. However, we found little information regarding the quality of this data source in VE studies and future evaluations should investigate their reliability, accuracy, and potential bias.

Addressing adolescent immunization disparities: a retrospective analysis of school-based health center immunization delivery

OBJECTIVES

We compared completion rates for adolescent immunization series administered at school-based health centers (SBHCs) to completion rates for series administered at community health centers (CHCs) within a single integrated delivery system.

METHODS

We performed a retrospective analysis of data from an immunization registry for patients aged 12-18 years. Patients were assigned to either an SBHC or a CHC during the study interval based on utilization. We used bivariate analysis to compare immunization series completion rates between the 2 groups and multivariate analysis to compare risk factors for underimmunization. We performed subanalyses by ages 12-15 years versus ages 16-18 years for human papillomavirus (HPV) and for the combination of HPV; tetanus, diptheria, and pertussis (Tdap); and tetravalent meningococcus virus.

RESULTS

SBHC users had significantly higher completion rates (P<.001) for hepatitis B, Tdap, inactivated poliovirus, varicella, measles/mumps/rubella, and HPV for ages 16-18 years, and for the combination of HPV, Tdap, and MCV4 for ages 16-18 years. CHC users had higher completion rates for tetanus and diphtheria.

CONCLUSIONS

SBHCs had higher completion rates than did CHCs for immunization series among those aged 12-18 years, despite serving a population with limited insurance coverage.

Effectiveness of a community coalition for improving child vaccination rates in New York City

We used a retrospective, matching, birth cohort design to evaluate a comprehensive, coalition-led childhood immunization program of outreach, education, and reminders in a Latino, urban community. After we controlled for Latino ethnicity and Medicaid, we found that children enrolled in the program were 53% more likely to be up-to-date (adjusted odds ratio = 1.53; 95% confidence interval = 1.33, 1.75) and to receive timely immunizations than were children in the control group (t = 3.91). The coalition-led, community-based immunization program was effective in improving on-time childhood immunization coverage.

Delivering adolescent vaccinations in the medical home: a new era?

BACKGROUND

Medical homes are health care settings that offer continuous, comprehensive, accessible primary care; these settings generally involve pediatric and family physician practices or community health centers but can also involve gynecologists or internists.

OBJECTIVES

In this article, we review available evidence on the role of the medical home in optimizing adolescent immunization delivery, particularly with respect to health care utilization patterns and barriers to vaccinations in medical homes, and solutions.

METHODS

We conducted a systematic review of the existing immunization and adolescent literature and used a Delphi process to solicit opinions from content experts across the United States.

RESULTS

Most adolescents across the United States do have a medical home, and many pay a health care visit to their medical home within any given year. Barriers exist in regards to the receipt of adolescent immunizations, and they are related to the adolescent/family, health care provider, and health care system. Although few studies have evaluated adolescent vaccination delivery, many strategies recommended for childhood or adult vaccinations should be effective for adolescent vaccination delivery as well. These strategies include education of health care providers and adolescents/parents; having appropriate health insurance coverage; tracking and reminder/recall of adolescents who need vaccination; practice-level interventions to ensure that needed vaccinations are provided to eligible adolescents at the time of any health care visit; practice-level audits to measure vaccination coverage; and linkages across health care sites to exchange information about needed vaccinations. Medical homes should perform a quality improvement project to improve their delivery of adolescent vaccinations. Because many adolescents use a variety of health care sites, it is critical to effectively transfer vaccination information across health care settings to identify adolescents who are eligible for vaccinations and to encourage receipt of comprehensive preventive.

CONCLUSIONS

Medical homes are integral to both the delivery of adolescent immunizations and comprehensive adolescent preventive health care. Many strategies recommended for childhood and adult vaccinations should work for adolescent vaccinations and should be evaluated and implemented if they are successful. By incorporating evidence-based strategies and coordinating effectively with other health care sites used by adolescents, medical homes will be the pivotal settings for the delivery of adolescent vaccinations.

Adolescent immunizations: policies to provide a shot in the arm for adolescents

With multiple vaccines for adolescents recently recommended and in various stages of development, the issue of how to effectively deliver immunizations to this age group has become increasingly important. This manuscript addresses some of the primary barriers and potential public health solutions to providing vaccinations effectively to adolescents. The foreseen complexities associated with each potential solution will be noted throughout; there remain potentially unforeseen ramifications as well.

The success of an immunization information system in the wake of Hurricane Katrina

Within days after Hurricane Katrina in September 2005, the Houston-Harris County Immunization Registry was connected to the Louisiana Immunization Network for Kids Statewide. This linkage provided immediate access to the immunization records of children who were forced to evacuate the New Orleans, Louisiana, area. One year later, >18,900 immunization records have been found, representing an estimated cost savings of more than $1.6 million for vaccine alone and $3.04 million for vaccine plus administration fees. This experience demonstrated the vital and previously unrecognized functionality of immunization information systems in a public health emergency. Here we describe the Houston-Harris County Immunization Registry's experience after Hurricane Katrina in terms of maximizing the use of immunization information systems and the implications of this experience for patients, providers, and public health for future disaster-preparedness planning.

Measles immunization coverage determined by serology and immunization record from children in two Chicago communities

OBJECTIVES

We compared the prevalence of measles immunization determined by serology with the prevalence of measles immunization determined by immunization records, and identified factors predictive of measles immunization among a sample of children from two Chicago communities.

METHODS

We collected demographic information and blood specimens from a sample of children aged 12-71 months in two Chicago communities at risk for low measles immunization coverage levels. We collected immunization information from provider records, parent-held records, and the statewide immunization registry. We compared evidence of immunization determined by serology with evidence of immunization from these three sources of immunization records.

RESULTS

The sample of children from the two communities had serologic measles immunity levels of 85% and 90%. Significantly fewer children had evidence of immunization by record in both communities (45% and 63%, respectively).

CONCLUSIONS

Immunization coverage levels determined using immunization records were significantly lower than immunization coverage determined using serology. A fully populated immunization registry used by all immunization providers could prevent the problems of record loss and scatter.

Individually Significant Risk Factors Do Not Provide an Accurate Clinical Prediction Rule for Infant Underimmunization in One Disadvantaged Urban Area

OBJECTIVE

To define a clinical prediction rule for underimmunization in children of low socioeconomic status.

METHODS

We assessed a cohort of 1160 infants born from July 1998 through June 1999 at an urban safety net hospital that received primary care at 4 community health centers. The main outcome measure was up-to-date status with the 3:2:2:2 infant vaccine series at 12 months of age.

RESULTS

Latino infants (n = 959, 83% of cohort) had immunization rates of 74%, at least 18% higher than any other racial/ethnic group. Multivariate logistic regression demonstrated the following independent associations (relative risk, 95% confidence interval) for inadequate immunization: non-Latino ethnicity (1.7, 1.4-2.0), maternal smoking (1.3, 1.1-1.7), no health insurance (1.9, 1.4-2.3), late prenatal care (1.9, 1.5-2.3), no pediatric chronic condition (2.1, 1.2-3.1), and no intent to breast-feed (1.3, 1.1-1.6). However, the index of concordance (c-index) for this model was only 0.69. Neither excluding infants who left the health care system nor accounting for infants who were "late starters" for their first vaccines improved the predictive accuracy of the model.

CONCLUSIONS

In this predominantly Latino population of low socioeconomic status, Latino infants have higher immunization rates than other infants. However, we were unable to develop a model to reliably predict which infants in this population were underimmunized. Models to predict underimmunization should be tested in other settings. In this population, interventions to improve immunization rates must be targeted at all children without respect to individual risk factors.

Influenza among healthy young children: changes in parental attitudes and predictors of immunization during the 2003 to 2004 influenza season

BACKGROUND

In Colorado, the 2003 to 2004 influenza season was unusually early and severe and received substantial media attention.

OBJECTIVES

Among parents of healthy young children, to determine how parental knowledge and attitudes regarding influenza infection and immunization changed during the 2003 to 2004 influenza season and to identify factors predictive of influenza immunization.

METHODS

The study was conducted in 5 metropolitan Denver pediatric practices. A total of 839 healthy children age 6 to 21 months and their parents were randomly selected for participation. Parents were surveyed by telephone before (August 18 to October 7, 2003) and after (March 31 to June 10, 2004) the influenza season.

RESULTS

Among 828 eligible parents, 472 (57%) completed the preseason survey; 316 (67%) of these parents subsequently completed the postseason survey. All analyses were performed for the 316 subjects who completed both preseason and postseason surveys. Compared with their attitudes before the influenza season, 48% of parents interviewed after the season viewed their child as more susceptible to influenza, 58% viewed influenza infections as more severe, and 66% perceived fewer risks associated with influenza vaccine. Ninety-five percent of parents reported hearing in the media about Colorado's influenza outbreak, and having heard about the outbreak in the media was associated with viewing influenza infections as more severe. A total of 258 parents (82%) immunized their child against influenza. In multivariate analyses, positive predictors of immunization included a physician recommendation for immunization and a preseason to postseason increase in the perception that immunization was the social norm. Negative predictors of immunization included high perceived barriers to immunization, less parental education, and preseason intention not to immunize.

CONCLUSIONS

Parent attitudes about influenza infection and immunization changed substantially during the 2003 to 2004 influenza season, with changes favoring increased parental acceptance of influenza vaccination for young children. During an intensively publicized influenza outbreak, a physician recommendation of vaccination was an important predictor of influenza immunization.

Patient reminder and patient recall systems to improve immunization rates

BACKGROUND

Immunization rates for children and adults are rising, but coverage levels have not reached optimal goals. As a result of low immunization rates, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care and large demands on primary care physicians, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. A common theme across immunization programs in all nations involves the challenge of determining the denominator of eligible recipients (e.g. all children who should receive the measles vaccine) and identifying the best strategy to ensure high vaccination rates. Strategies have focused on patient-oriented interventions (e.g., patient reminders), provider interventions and system interventions. One intervention strategy involves patient reminder and recall systems.

OBJECTIVES

To assess the effectiveness of patient reminder and recall systems in improving immunization rates and compare the effects of various types of reminders in different settings or patient populations.

SEARCH STRATEGY

A systematic search was performed for the initial review using MEDLINE (1966-1998) and four other bibliographic databases: EMBASE, PsychINFO, Sociological Abstracts, and CAB Abstracts. Authors also performed a search of The Effective Practice and Organisation of Care (EPOC) register in April 2001 to update the review. Two authors reviewed the lists of titles and abstracts and used the inclusion criteria to mark potentially relevant articles for full review. The reference lists of all relevant articles and reviews were back searched for additional studies. Publications of abstracts, proceedings from scientific meetings and files of study collaborators were also searched for references. In December 2004 the EPOC register was searched to identify relevant articles to update the review.

SELECTION CRITERIA

STUDY DESIGN

Randomized controlled trials (RCT), controlled before and after studies (CBA) and interrupted time series (ITS) studies written in English.

TYPES OF PARTICIPANTS

Health care personnel who deliver immunizations and children (birth to 18 years) or adults (18 years and up) who receive immunizations in any setting.

TYPES OF INTERVENTIONS

Any intervention that falls within the EPOC scope (See Group Details) and that includes patient reminder or recall systems, or both, in at least one arm of the study.

TYPES OF OUTCOME MEASURES

Immunization rates or the proportion of the target population up-to-date on recommended immunizations. Outcomes were acceptable for either individual vaccinations (e.g. influenza vaccination) or standard combinations of recommended vaccinations (e.g. all recommended vaccinations by a specific date or age).

DATA COLLECTION AND ANALYSIS

DATA COLLECTION

Each study was read independently by two reviewers. Disagreements between reviewers were resolved by a formal reconciliation process to achieve consensus.

ANALYSIS

Results are presented for individual studies as relative rates for randomized controlled trials and as absolute changes in percentage points for controlled before and after studies. Pooled results for RCTs only were presented using the random effects model.

MAIN RESULTS

Five new studies were added for this update. Increases in immunization rates due to reminders were in the range of 1 to 20 percentage points. Reminders were effective for childhood vaccinations (OR = 1.45, 95% CI =1.28, 1.66), childhood influenza vaccinations (OR = 2.87, 95% CI = 1.65, 4.98), adult pneumococcus, tetanus, and Hepatitis B (OR = 2.19, 95% CI = 1.21, 3.99), and adult influenza vaccinations (OR = 1.66, 95% CI = 1.31, 2.09). All types of reminders were effective (postcards, letters, telephone or autodialer calls), with telephone being the most effective but most costly.

AUTHORS' CONCLUSIONS

Patient reminder and recall systems in primary care settings are effective in improving immunization rates within developed countries.