Progress in Immunization Information Systems — United States, 2010
Immunization information systems (IIS) are confidential, computerized, population-based systems that collect and consolidate vaccination data from vaccination providers and provide important tools for designing and sustaining effective immunization strategies at the provider and immunization program levels (1). These tools include clinical decision support, vaccination coverage reports, interoperability with electronic health record systems, vaccine inventory management, and the ability to generate reminder and recall messages. In 2010, based on strong evidence of effectiveness, the Task Force on Community Preventive Services recommended IIS use as a means of increasing vaccination rates (2). A Healthy People 2020 target (IID-18) is to increase to 95% the proportion of children aged <6 years whose immunization records are in fully operational, population-based IIS (3). To monitor progress toward program goals, CDC annually surveys 56 immunization program grantees (50 states, five cities, and the District of Columbia) using the IIS Annual Report (IISAR). Results from the 2010 IISAR (completed by 54 grantees) indicate that 82% (18.8 million) of U.S. children aged <6 years participated in IIS, as defined by having at least two recorded vaccinations, an increase from 78% (18.0 million) in 2009 (1). Among 52 grantees who responded to questions about the Vaccine Tracking System (VTrckS), CDC's new national vaccine ordering and inventory management system for publicly purchased vaccine, 38 (73%) indicated their intention to use the IIS in their state or city to interface with VTrckS. Use of IIS to interface with VTrckS might provide additional incentive for vaccination providers to participate in IIS and enhance IIS utility by supporting efficient and effective methods for providers to order vaccine and track inventory and by promoting greater accountability of publicly purchased vaccine.
Of 56 immunization program grantees (50 states, five cities,* and the District of Columbia), 2010 IISAR data† were available for 54 grantees (Massachusetts was excluded because of an incomplete report and New Hampshire was not eligible because it did not have an IIS in 2010). The self-administered survey asked about child, adolescent, and adult participation in IIS, vaccination coverage for these groups, provider participation in IIS, and IIS functionality (e.g., interoperability with electronic health records, data quality, vaccine inventory management, and use of IIS data).
Child participation was defined as having two or more vaccinations documented in an IIS. Participation was calculated by dividing the number of children aged <6 years in an IIS meeting this criteria by the 2010 U.S. Census estimate for the number of children in this age group in that grantee's geographic area. Demographic data in IIS are obtained from birth certificates and birth hospital records, which often also contain records of the birth dose of hepatitis B vaccine. Defining participation in an IIS as having ≥2 recorded doses ensures that the child received at least one vaccination from a provider who participates in an IIS. Nationally, 18.8 million U.S. children aged <6 years (82%) participated in an IIS in 2010. Child participation in IIS has increased steadily, from 63% in 2006§ to 82% in 2010, with an average 4.8 percentage point increase each year. Of the 54 grantees with available data in 2010, 24 (44%) reported that >95% of children aged <6 years in their geographic area participated in their IIS. An additional 14 (26%) grantees reported child participation rates ranging from 80% to 94% (Figure 1).
Provider Site Participation
Vaccination provider sites enroll in IIS to share vaccination data and to use IIS functions and features that support vaccine delivery. In the 2010 IISAR, sites were considered to participate in IIS if they submitted data to the IIS in their state or city in the previous six months (i.e., from July 1 through December 31, 2010), indicating recent submissions. Data were collected separately for public and private provider sites. In 2010, a total of 11,536 public and 36,512 private provider sites participated in IIS. Provider site participation rates were not calculated because the number of vaccination providers in the United States is not known. From 2006 through 2010, 49 grantees (excluding Alaska, Georgia, Hawaii, Kentucky, Massachusetts, New Hampshire, and South Carolina) reported data each year. Among grantees with available data, the number of participating public provider sites increased from a low of 6,745 in 2006 to a high of 11,536 in 2010; private provider site participation also increased annually during the period, from 27,894 to 36,512 (Figure 2). Although the number of public and private provider sites that participated in IIS increased from 2006 to 2010, these counts lagged behind the number enrolled each year (40,075 enrolled provider sites in 2006; 88,061 enrolled provider sites in 2010). The substantial increase in enrolled public and private provider sites in 2010 likely represents response to the 2009 influenza A (H1N1) pandemic; most immunization programs required providers to enroll in the IIS in their state or city to obtain influenza A (H1N1)pdm09 vaccine.
Vaccine Inventory and Management
In 2010, CDC developed VTrckS,¶ a vaccine tracking system to facilitate vaccine ordering, inventory management, and related processes for publicly purchased vaccine. Vaccination providers can report inventory and order vaccine in three ways: 1) providers can access VTrckS directly through a web service, 2) immunization program grantees can manually enter vaccine orders and inventory into the VTrckS web service on behalf of providers, and 3) providers can enter vaccine orders and inventory into an IIS, which interfaces with VTrckS through a file upload. Immunization program grantees can select one or more options for vaccination providers in their jurisdiction. In the 2010 IISAR, 38 (73%) of the 52 grantees that responded to VTrckS questions indicated their intention to use their IIS to interface with VTrckS. Among those 38 grantees, 32 (84%) planned to implement this functionality within 12 months. Of the 14 grantees not intending to use their IIS to interface with VTrckS, 11 (79%) planned to manually enter vaccine orders into VTrckS on behalf of providers and eight (57%) planned to allow providers to access VTrckS directly.
Janet Fath, PhD, Terence W. Ng, MPH, Laura J. Pabst, MPH, Immunization Services Div, National Center for Immunization and Respiratory Diseases, CDC. Corresponding contributor: Laura J. Pabst, email@example.com, 404-639-6082.
Data from the IISARs demonstrate that increases in child and provider site participation in IIS have been achieved in recent years. However, challenges to meeting the Healthy People 2020 objective and other program goals remain. Because IIS rely on providers to submit vaccination data to the system, ensuring that immunization programs identify, recruit, and train all vaccination providers in their jurisdictions to participate in IIS is essential.
One of several challenges to achieving those goals is that no master list or database of U.S. vaccination provider sites exists. Provider sites begin and cease operations often, making it difficult for immunization programs to ensure that all vaccination provider sites in a state or city have been identified and enrolled. Immunization programs use multiple resources to identify all vaccination providers in their jurisdictions. However, systematic solutions to this challenge that can be applied across all grantees in the United States are not yet available. The population of providers currently enrolled in IIS likely does not represent all vaccination providers in the United States. This, in addition to the gap between enrolled and participating provider sites in IIS from 2006–2010, suggests that additional progress can be made. Another challenge is that, although several states and cities have legal mandates requiring some or all vaccination providers to report vaccinations to the IIS, these mandates are difficult to enforce.
The 2009 influenza A (H1N1) pandemic highlighted another challenge in measuring provider site participation in IIS. Most immunization programs required providers who wished to obtain influenza A (H1N1)pdm09 vaccine to enroll in the IIS. Because of the high public demand for vaccine and the need for diverse health-care providers to offer the vaccine to persons, many providers who do not typically engage in routine vaccination activities enrolled in IIS. Some of these providers ultimately did not order and administer influenza A (H1N1)pdm09 vaccine. Those who did might have administered influenza vaccine only during the first half of 2010, during the national response to the pandemic. After August 2010, when the pandemic was determined to have ended, those providers likely did not administer or report influenza A (H1N1)pdm09 vaccine doses during the rest of the year, when provider site participation was measured. This might have resulted in a substantial increase in the number of provider sites enrolled in IIS, without a corresponding increase in the number of participating provider sites. Thus, tracking provider site participation rates, rather than counts, can lead to misinterpretations of IIS achievements.
To encourage participation among routine vaccinators, IIS offer many tools to benefit providers (e.g., vaccine forecasting, reminder and recall messaging, and provider assessment and feedback). The recent inclusion of vaccine inventory and management tools in IIS might further support vaccination providers and encourage participation in IIS.
In 2010, CDC introduced VTrckS, which replaced several older systems at CDC. VTrckS is designed to enhance internal controls and help standardize and improve processes for contract management and reconciliation, vaccine ordering, and inventory tracking. Before VTrckS became available, some IIS grantees had added, or were in the process of adding, vaccine ordering components to their IIS. To support these grantees and others who planned to add similar components to their IIS, CDC developed software capabilities, referred to as the VTrckS ExIS interface, to facilitate sharing data between other vaccine inventory systems (e.g., IIS) and VTrckS. Grantees that choose to use the VTrckS ExIS interface are not required to use their IIS; grantees may choose instead to use another external system for that function. However, the majority of immunization program grantees have indicated that they plan to use their IIS. Providers benefit by this approach because they can access a single system (the IIS) to order publicly funded vaccines and to otherwise participate in the state's immunization program. In 2010, the ExIS interface was successfully pilot tested with two IIS, which were included among the 38 that indicated interest in using the interface. Since completion of the 2010 IISAR and the ExIS pilot, three additional grantees committed to using their IIS to interface with VTrckS, for a total of 41 of 56 grantees. Deployment is scheduled to occur between May 2012 and May 2013.
The findings in this report are subject to at least three limitations. First, although CDC provides guidance to grantees to validate IISAR responses, data are self-reported and self-validated, which might overestimate or underestimate participation rates. Second, because some of the 56 grantees did not report data during the period studied, nationwide child and provider site participation estimates might be underestimated. Finally, the full universe of vaccination providers in the United States is not known, thus limiting accurate assessment of provider site participation. The mass enrollment of provider sites during the 2009 influenza A (H1N1) pandemic biased participation rates in 2010 and limited the assessment of trends.
VTrckS was designed to modernize the vaccine ordering and management process. Use of IIS to interface with VTrckS allows grantees to manage vaccine ordering and distribution at the local level, submit data to the national system, and maintain control of their processes and communications with providers. Providers save time by logging on to a single system to report vaccinations, review patient vaccine histories, track inventory, order vaccines, and use other IIS functions and features. The success of these efforts reinforces the benefits of IIS for immunization programs and vaccination providers. Use of IIS to interface with VTrckS might provide an additional incentive for vaccination providers to participate in IIS. The interface with VTrckS might further enhance the utility of IIS by supporting efficient and effective methods for providers to order vaccine and track inventory and by promoting greater accountability for publicly purchased vaccine.
- CDC. Progress in immunization information systems—United States, 2009. MMWR 2011;60:10–2.
- Community Preventive Services Task Force. Universally recommended vaccinations: immunization information systems. In: The guide to community preventive services. Atlanta, GA: US Department of Health and Human Services, CDC; 2010. Available at http://www.thecommunityguide.org/vaccines/universally/imminfosystems.html. Accessed February 9, 2012.
- US Department of Health and Human Services. Healthy people 2020. Washington, DC: US Department of Health and Human Services; 2010. Available at http://healthypeople.gov/2020/topicsobjectives2020/objectiveslist.aspx?topicid=23. Accessed February 9, 2012.
* Chicago, Illinois; Houston, Texas; New York, New York; Philadelphia, Pennsylvania; and San Antonio, Texas.
† Additional information available at http://www.cdc.gov/vaccines/programs/iis/annual-report-iisar/index.html.
§ An error was identified in previously published 2006–2009 child participation rates. Data have been corrected in this report.
¶ Additional information available at http://www.cdc.gov/vaccines/programs/vtrcks.
What is already known on this topic?
In 2006, a total of 34,639 vaccination provider sites participated in immunization information systems (IIS). In 2009, 78% of all U.S. children aged <6 years (18.0 million) participated in IIS.
What is added by this report?
In 2010, the number of vaccination provider sites participating in IIS increased to 48,048, and 82% of all U.S. children aged <6 years (18.8 million) participated in IIS. Among immunization program grantees, 73% reported that they intended to use their IIS to interface with the Vaccine Tracking System (VTrckS), CDC's new vaccine ordering and inventory management system for publicly purchased vaccine; the remaining grantees intended to access VTrckS directly.
What are the implications for public health practice?
Use of IIS to interface with VTrckS might provide an additional incentive for vaccine providers to participate in IIS and further enhance the utility of IIS by supporting efficient and effective methods for providers to order vaccine and track inventory and by promoting greater accountability of publicly purchased vaccine.
Abbreviations: NYC = New York City; DC = District of Columbia.
* Defined as having two or more vaccinations recorded in the IIS.
† Chicago, Illinois; Houston, Texas; New York, New York; Philadelphia, Pennsylvania; and San Antonio, Texas.
Alternate Text: The figure shows the percentage of children aged <6 years participating in an immunization information system (IIS), in five cities in the United States, and the District of Columbia during 2010. Nationally, 18.8 million U.S. children aged <6 years (82%) participated in an IIS in 2010. Child participation in IIS has increased steadily, from 63% in 2006 to 82% in 2010, with an average 4.8 percentage point increase each year. Of the 54 grantees with available data in 2010, 24 (44%) reported that >95% of children aged <6 years in their geographic area par¬ticipated in their IIS. An additional 14 (26%) grantees reported child participation rates ranging from 80% to 94%.
* Defined as having submitted data to the IIS in the last 6 months.
Alternate Text: The figure above shows the number of public and private vaccination provider sites enrolled and participating in an immunization information system, by year, in the United States during 2006-2010. From 2006 through 2010, 49 grantees (excluding Alaska, Georgia, Hawaii, Kentucky, Massachusetts, New Hampshire, and South Carolina) reported data each year. Among grantees with available data, the number of participating public provider sites increased from a low of 6,745 in 2006 to a high of 11,536 in 2010; private provider site participation also increased annually during the period, from 27,894 to 36,512.
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