Mapping It Out: Using Atlases To Detect Patterns in Health Care, Disease, and Mortality

“In health care, geography is destiny.” So says the Dartmouth Atlas of Health Care in the United States, which describes health care utilization according to geographic patterns. Although this atlas provides data on health care delivery, other atlases present geographic patterns of data germane to the interests of internists, researchers, and epidemiologists, including incidence and prevalence of specific diseases by age and sex and death from various causes.

The value of medical atlases lies in their unique ability to provide tremendous amounts of information about the relation between disease and location in a concise, visual, easy-to-read format, primarily maps. These relations have sometimes proven critical. For example, by studying the geographical spread, investigators discovered that contaminated water was the source of the London cholera epidemic in the mid-1800s. The advent of computer graphics sparked a revolution in the development of detailed maps, thus expanding the reach and power of atlases. Maps are now capable of showing, in fine detail, geographic patterns of disease and mortality by cause, age, race, and sex.

The Web sites of the Centers for Disease Control (CDC), National Institutes of Health (NIH), and National Cancer Institute (NCI) contain massive amounts of numerical and verbal information. But wading through pages and pages of Web text can be daunting. Atlases, which are illustrative by design, display statistics that would ordinarily occupy several pages of text in one multilayered map. This layering process visually presents cross-relational data. For instance, the top layer of a multilayered map in a mortality atlas may show lung cancer rates in a specific region. The next layer may show mortality rates from lung cancer in white women in that region. The next layer may show cigarette smoking habits of white women and mortality in white women from lung cancer in that region. Additional …