Tracking Trends in Health Care with GIS
By Elisabeth Dowling Root and Caroline Steinberg, The Lewin Group

For the past several years, The Lewin Group has assisted the American Hospital Association (AHA) in tracking and analyzing important and emerging trends in the hospital and health care field. The AHA is a national organization that represents and serves hospitals and health care networks and their patients and communities. Through the organization's advocacy efforts, the AHA ensures that members' viewpoints are heard and addressed in national health policy development, legislative and regulatory debates, and judicial matters.

At the center of this effort is a series of quarterly reports called TrendWatch that are researched and produced by Lewin. The findings illustrated in TrendWatch reports are derived from independent research and Lewin's analysis of the AHA's Annual Hospital Survey data. This high level analysis is provided to assist hospital CEOs and regional planners in gaining a better understanding of the issues surrounding important and emerging trends in the hospital and health care field. Each edition of TrendWatch addresses a specific current issue affecting hospitals.

For example, the June 2000 issue of TrendWatch focused on the safety net and the widening disparity between the funding for the uninsured and the need for charity care. The March 2001 issue explored the growing need for and decreasing number of hospital emergency departments in the United States. TrendWatch is oriented toward policy issues and each topic feeds into the AHA's advocacy agenda for the year.

The AHA and Lewin carefully pick each topic in order to ensure that data is available to analyze the topic. However, as a research and consulting organization, Lewin does not advocate for or endorse positions on specific policy issues. Lewin provides objective and independent research on topics of interest. After analyzing data from AHA's annual hospital surveys and integrating this data with other publicly available information, Lewin tracks, projects, and disseminates information on trends through quarterly reports and special analyses. Other data sources include the HCFA National Spending Survey, National Hospital Ambulatory Medical Care Survey (NHAMCS), National Health Interview Survey, and census data.

Recently, Lewin has begun using GIS to address questions related to utilization, service delivery, and workforce development. GIS allows Lewin to examine data in a spatial context which often reveals relationships that would not have been noticeable when examining tabular data. GIS is a valuable hypothesis-building tool that allows analysts to theorize as to why spatial relationships between hospitals, service areas, and underserved populations exist. The following examples illustrate how GIS was used to examine data for the June 2000 issue of TrendWatch.

Essential Access-Broadening the Safety Net

Millions of Americans have limited access to basic health care services. The June 2000 issue of TrendWatch explored the state of the "safety net" in America and expanded this topic to include a discussion of "essential access." Many people believe that the safety net addresses the health care needs of the underinsured and the uninsured. However, according to a recent report published by the Institute of Medicine, "America's safety net is neither secure nor uniform. Rather, it varies greatly from state to state and from community to community, depending on the number of uninsured people, the local health care market, the breadth and depth of Medicaid and other programs directed at the poor and uninsured populations, as well as the general political and economic environment."

In fact, the safety net may be too narrow a concept to adequately explore the provision of essential access--a concept that is based on the services delivered, rather than on the characteristics of the facility. Essential access is defined by the community of individuals who rely on those services and by the infrastructure required to meet their needs. It is also linked closely to the special characteristics and needs of a particular community's culture, language, and socioeconomic status.

While traditional funding for these services is decreasing, the demand for them continues to increase as the number of uninsured grows. The number of uninsured has increased at a rate of roughly 10 million persons every decade. At this rate, based on Lewin Group analysis of census data, the number of uninsured will grow to about 54 million persons by 2007 or approximately 19.1 percent of the population.

Maps for the June 2000 edition of TrendWatch were created using ArcView 3.2 and data taken from the AHA Annual Hospital Survey, the Bureau of the Census, and the Bureau of Primary Health Care at the Human Resources and Services Administration. For maps that included census data, a dBASE file was created in which the population data for each area was assigned to the appropriate FIPS Code. The dBASE file was then added to an ArcView 3.2 project and joined to the shapefile using the area type field. Each hospital in the AHA data file had already been assigned a latitude and longitude so no geocoding was necessary.

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