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Progress in Improving State and Local Disease Surveillance ---United States, 2000--2005
In September 2000, states began receiving federal funding to plan and implement integrated electronic systems for disease surveillance. CDC and state and local health departments had recognized the importance of such systems and of uniform standards to improve the usefulness of public health surveillance and the timeliness of response to outbreaks of disease. Previously, state health departments received most case-report forms by mail and then entered the data into computer systems, sometimes weeks after the cases of notifiable disease had occurred, including cases that warranted immediate public health investigation or intervention. In addition, depending on the disease, only 10%--85% of cases were reported, and more than 100 different systems were used to transmit these reports from the states to CDC (CDC, unpublished data, 2005). This report summarizes progress since the initial funding in 2000 in improving state and local disease surveillance through secure, Internet-based data entry and automated electronic laboratory results (ELR) reporting. Both are components of the National Electronic Disease Surveillance System (NEDSS),* the surveillance and monitoring component of the broader Public Health Information Network (PHIN) initiative. Local, state, and national public health officials should continue to improve the timeliness and completeness of disease surveillance.
To ensure that information can be collected, exchanged, and interpreted at all levels (i.e., local, state, and national), CDC has worked with state and local health departments and clinical partners to identify data and information system standards to incorporate into NEDSS. By facilitating the identification, adoption, and implementation of standards for data content, format, transport, and security, the NEDSS project seeks to strengthen the ability of public health agencies to exchange pertinent information needed for surveillance and intervention between clinicians and public health agencies and among public health partners. State health departments have pursued these goals by developing, modifying, or commissioning their own NEDSS-compatible systems or by implementing and configuring the NEDSS Base System§ to meet their specific needs.
As of April 2005, a total of 27 state health departments and two municipal health departments (New York City and Los Angeles) were entering at least some notifiable disease data by using a secure, Internet-based system (Figure 1). Twenty-three other states were actively planning, developing, and implementing Internet-based systems. Although Internet-based data entry is frequently performed by workers in local and state health departments, in at least 13 states, data entry is also performed by private health-care providers, infection-control practitioners, and/or clinical laboratory workers, expediting availability of the data to health departments.
In addition to secure, Internet-based reporting, NEDSS supports ELR. When a test result indicates a notifiable condition, clinical diagnostic and public health laboratories with ELR transmit data from their computer systems directly to state and local health department systems. As of April 2005, a total of 26 state health departments (excluding those receiving only blood lead level results) received laboratory test results via ELR (Figure 1), and the remaining 24 states were in various stages of preparing for ELR.
The experiences of three state health departments illustrate capabilities provided through NEDSS and PHIN that have improved the practice of public health.
In late 2001, the New Jersey Department of Health and Senior Services (NJDHSS) implemented the secure, Internet-based, Communicable Disease Reporting System (CDRS). Since implementation of CDRS, the number of reported cases of notifiable diseases doubled from 14,608 in 2002 to 29,967 in 2004, and the percentage of cases entered by NJDHSS staff decreased from 67% in 2002 (and from 100% in 2001) to approximately 16% in 2004 (Figure 2). In addition, the percentage of cases entered by local health departments, hospitals, and Local Information Network and Surveillance Systems (i.e., regional public health networks) increased from approximately 11% in 2002 (and from zero in 2001) to 50% in 2004 (Figure 2), including 30% entered by health-care providers at hospitals or medical centers. During 2004, approximately 34% of the cases were reported via ELR by Laboratory Corporation of America (Burlington, North Carolina).
Before CDRS, cases of notifiable diseases might have required several months for entry of data in the NJDHSS system because of delays in reporting, postal service, and data entry. However, timeliness has improved substantially. In 2003, NJDHSS determined that cases were entered into CDRS an average of 28 days after illness onset. In 2004, that average had been reduced to 3--4 days. In addition, cases can now be updated in minutes and are available statewide to authorized persons in seconds.
In June 2004, Oklahoma implemented its secure, Internet-based disease surveillance and reporting system, Public Health Information and Disease Detection of Oklahoma. Once a case is verified by health department staff and assigned to the appropriate jurisdiction, the system supports online follow-up by local public health nurses representing all Oklahoma counties. As of June 1, 2005, a total of 164 infection-control practitioners and 210 laboratorians representing all Oklahoma hospitals and 32 physicians had registered to use the system.
Upon entry of a disease deemed urgently notifiable by state administrative law,¶ the Oklahoma system automatically sends a page, text message, and e-mail message with key details to the state epidemiologist on call. The system also informs persons reporting cases that they will be contacted within 15 minutes by that epidemiologist. Regardless of the hour, the epidemiologist can then log on to the system from any location and initiate a rapid public health response when warranted. During June 2004--May 2005, epidemiologists launched case investigations within the targeted response time of 15 minutes on 111 urgently notifiable disease reports, including 10 cases of invasive meningococcal disease, 12 cases of tularemia (endemic in Oklahoma), and one outbreak of unknown infectious disease.
In January 2003, the Pennsylvania Department of Health implemented a secure, Internet-based disease reporting system, PA-NEDSS, that incorporates online reporting** by laboratories, hospitals, and clinicians; fully integrated ELR; case management; and analysis capabilities. Submitted reports are immediately accessible by state and local health department staff.
As of February 2005, a total of 549 public health staff members, 381 hospitals and clinics, 223 laboratories, and 564 physicians were registered with the system. In addition, 42 high-volume laboratories were submitting reports through ELR. Approximately 20,000 reports are submitted each month through PA-NEDSS; 67% of reports are received via ELR, 24% via online laboratory reporting, 8% via online hospital reporting, and 1% via other sources.
During a hepatitis A outbreak with 601 cases in 2003, all public health workers in the affected region of the state were needed to staff clinics and administer immune globulin to exposed persons to prevent further transmission of disease. Investigation of cases newly reported by PA-NEDSS were assigned to public health staff in unaffected regions, allowing local staff to focus on prevention of cases while ensuring that new cases were investigated promptly. Since the outbreak, certain areas of the state have extended that use of PA-NEDSS to balance the routine workload among counties.
Reported by: State health departments. CDC.
The transition to integrated electronic systems from paper-based systems for disease surveillance has made substantial strides in recent years. As of April 2005, a total of 27 states were using secure, Internet-based systems for entry of notifiable disease reports, and 26 received laboratory test results automatically through ELR. When clinicians, laboratories, or local health department investigators enter data securely over the Internet, that information can be available to state or local health departments immediately, avoiding delays caused by mailing forms or backlogs in data-entry processing at health departments.
Surveillance of communicable diseases focuses on ELR because a large proportion of cases can be identified from laboratory test results; diagnostic laboratories are also key surveillance partners for chronic and environmentally related disease surveillance (e.g., for blood lead level testing). ELR facilitated by NEDSS provides faster and more complete reporting of laboratory test results. Use of ELR has increased the number of cases reported to health departments by two- to threefold and has improved the timeliness of reporting by at least 3.8 days (1). ELR infrastructure also can be used to integrate public health laboratory and epidemiologic investigations. Ongoing efforts to ensure availability of PHIN-compliant laboratory information systems will equip state and local public health laboratories for standards-based exchange of information and further strengthen public health surveillance and response.
Although many states are using the Internet for ELR, challenges remain to achieving national proficiency at standards-based, secure information exchange. In its "business case" for a nationwide health information network, the Center for Information Technology Leadership (CITL) (Partners HealthCare System, Boston, Massachusetts) has defined a four-level taxonomy for health information exchange (2). The highest level, Level 4 (machine integrable information exchange), requires adherence to the structured messages and standardized data content provided by NEDSS and PHIN. However, multiple states still use different electronic formats and nonstandard content for ELR, corresponding to CITL Level 3 (machine organizable data systems). According to the CITL model, although implementation of Level 3 systems can enhance information exchange, cost savings occur only with implementation of Level 4 systems (2).
This first phase of ELR is providing state health departments with results from large multijurisdictional laboratories and from certain state public health laboratories. The next phase will require broadening of reporting from the large multijurisdictional laboratories and enabling exchange of results with other laboratories, including large hospital and local laboratories. However, many of these facilities use proprietary information systems and local (i.e., nonstandard) coding systems that would require multiple custom interfaces to enable automated exchange of results. CDC is working with national partners to identify possible solutions.
Using standards and systems to enhance the exchange of information between the clinical sector and public health is a principal goal of NEDSS and PHIN. The ELR enhancements have required detailed specifications for the format, data elements, and standard codes for ELR messages by using the Health Level Seven (version 2.3) standard message format and standard, controlled vocabularies for test names (LOINC®§§) and test results (SNOMED®¶¶). In addition, PHIN specifies the standards for secure transmission of these messages over the Internet; to meet these standards, CDC has provided the PHIN Messaging System*** for use by public and private partners. Successful ELR reporting provides experience with secure, standards-based, interoperable data exchange, relevant for public health agencies and also for their partners in clinical medicine.
The examples in this report demonstrate the impact NEDSS has had on disease surveillance and deployment of public health staff and resources. Use of secure, Internet-based systems enables public health response 24 hours a day, 7 days a week. State health departments have used these systems to manage workloads and increase capacity during outbreaks and to help improve the nation's ability to detect and respond to disease threats.
* Available at http://www.cdc.gov/nedss.
Available at http://www.cdc.gov/phin.
§ The NEDSS Base System was developed by CDC and partners to meet state and program area disease surveillance and analysis needs, while providing a secure, accurate, and efficient means for collecting and processing data.
¶ Oklahoma Administrative Code 310:515-1-3.
** Online laboratory reporting means laboratory staff members enter data into an Internet form, in contrast to ELR, in which the laboratory computer system automatically sends an electronic message to the state health department system.
Health Level Seven is one of several health-care standards developing organizations accredited by the American National Standards Institute. Available at http://www.hl7.org.
§§ Logical Observation Identifiers Names and Codes. The database and supporting documentation are maintained by The Regenstrief Institute (Indianapolis, Indiana). Available at http://www.regenstrief.org/loinc.
¶¶ Systematized Nomenclature of Medicine of the College of American Pathologists. Available at http://www.snomed.org.
*** Available at http://www.cdc.gov/phin/software-solutions/phinms.
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Date last reviewed: 8/24/2005