Veterans Health Information Systems and Technology Architecture (VistA)

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Joan Breuer, Ph.D. Begin edit for this article: The history, early use statistics, and clinical applications are shown already in this orignial article. For new information: http://en.wikipedia.org/wiki/VistA By 2003, the VHA was the largest single medical system in the United States, providing care to over 4 million veterans, employing 180,000 medical personnel and operating 163 hospitals, over 800 clinics, and 135 nursing homes. About a quarter of the nation's population is potentially eligible for VA benefits and services because they are veterans, family members, or survivors of veterans. By providing electronic health records capability, VistA is thereby one of the most widely used EHRs in the world. Nearly half of all US hospitals that have a full implementation of an EMR are VA hospitals using VistA. More information on VistaA: http://www4.va.gov/VISTA_MONOGRAPH/ As of 2009, VISTA incorporates all of the benefits of DHCP as well as including the rich array of other information resources that are becoming vital to the day-to-day operations at VA medical facilities. It represents the culmination of DHCP's evolution and metamorphosis into a new, open system, client-server based environment that takes full advantage of commercial solutions, including those provided by Internet technologies. End Editing Joan Breuer


In the late 1970's, the Office of Data Management and Telecommunications (ODM&T) was given the job to computerize the VA nationwide [Brown, SH,2003]. It was developed using MUMPS (Massachusetts General Hospital Utility Multi-Programming System), or alternatively, M programming language.

Frustrated with slow systems development by the (ODM&T), which took 14 years to deploy a laboratory system to six sites, the Department of Medicine & Surgery created the Computer-Assisted System Staff (CASS) in 1977. Their Decentralized Hospital Computer Program (DHCP) included programs for administration, mental health, radiology and dietetics. They also focused on re-usability and the adherence to an active data dictionary, two characteristics that were declared in a conference in December 1982.

The ODM&T tried to shut down development, but DHCP developers continued their work. Eventually VA Administrator Robert Nimmo approved a policy giving facility directors the power to choose computer applications in 1982. A first group of 25 sites and 11 applications was in place by 1983. These were followed by up to 100 sites in year 1985 .

Performance has always been an issue and continues to be so into the future. One of the chief reasons is that data has not only risen steady as more sites and locations have joined, but the VA is required to keep all data about a patient for 75 years after the last patient visit! This is even after the patient has died. Even if a patient has been inactive, data needs to be accessible immediately for whatever a physician might need it for.

In 1995, DHCP was enshrined as a recipient of the Computerworld Smithsonian Award for best use of Information Technology in Medicine. A year later, the name VistA was officially given to the much improved system after the addition of a visual layer written using Delphi.

By 1999, multimedia online patient records were provided in VistA. Images from specialties such as cardiology, pulmonary and gastronintestinal medicine, pathology , radiology, hematology and nuclear medicine were supported.

As of 2001, it was the largest system in use in the US, with medical documentation and ordering available at every VA hospital in the country. In September 2002, 90.6% of all inpatient and outpatient pharmacy orders were entered by the provider. Today, the system is in use in hundreds of hospitals and clinics worldwide, not just in the VA Hospital System.

VistA consists of nearly 100 applications. Two relatively new applications include Computertized Patient Record System (CPRS) and Barcode Medication Administration (BCMA). A complete description and list of all applications can be found at the Vista website.

Being a system implemented somewhat uniformly across 128 sites, it is noteworthy in its site-specific flexibility. Individual user sites can adopt data dictionaries unique to that site. One important drawback of VistA is that site-specific data dictionaries prevents data summarization between sites, or on a system-wide level. Such data sharing and reporting limitations across sites can be overcome using a national dictionary acting as a cross-reference.

The VA currently runs a majority of VistA systems on InterSystems Caché. VistA can also run on GT.M, an open source database engine for Linux and Unix computers. Although initially separate releases, publicly available VistA distributions are now often bundled with the database in an integrated package. This has considerably eased installation.

"For more than 20 years, the FOIA has been used by nonprofit, commercial and foreign entities to obtain copies of the VistA source code. Through such FOIA requests, versions of VistA are in active use in Finland, Germany, Egypt and Latin America, as well as by a number of state and local health care systems in the United States. Examples of external VistA user organizations can be found in Hardhats.org (2003), Marshall (2003) and Medsphere (2003)." [West, Joel,2003]

VistA and and AHLTA of the DoD, were the first two largest US Government EHR built on standardized base of interoperability of patient records. The project objective was to develop an interface between the DoD Clinical Data Repositiry (CDR), and the VA's Health Data Repository (HDR) that support a real time bi-directional exchange of computable health data.


References

1. Brown, SH, Lincoln MJ et al. VistA - U.S. Department of Veterans Affairs national-scale HIS. International Journal of Medical Informatics. 2003; 69:135-156.

2. West, Joel and O’Mahony, Siobhán [1]. 2003