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Harnessing Geography Improves Outcomes
By Bill Davenhall, Esri Health and Human Services

This patient record application uses ArcWeb Services from within a hospital Intranet application.

Practices that minimize a patient's exposure to unnecessary risk of infection or reduce the occurrence of medication dosage errors—historically, these and similar measures have been viewed as patient safety issues for hospitals. However, the Joint Commission of Accreditation of Healthcare Organizations, the oldest and largest health care accrediting body in the United States, recently suggested that patient safety extends beyond the walls of the hospital and into the community. Experts on clinical outcomes have long recognized that geography plays a critical role in medical outcomes. This new definition of patient safety presents interesting questions and new opportunities for the application of GIS.

Patient safety and quality care do not end with patient discharge. With the highest quality of medical care, patient safety spans both time and place. By using spatial and geographic intelligence, hospitals can deliver quality health care in a new analytical framework that considers issues of lifelong patient safety.

Extending Patient Safety

Health care providers are insured against malpractice and general liability for the actions of unskilled practitioners or the effects of unsafe conditions within hospitals and clinics. Rarely has the responsibility for patient safety extended beyond facility walls.

However, does this system offer the best quality care and safety to patients and the community? A book on quality of care published in 2000 by the Institute of Medicine (IOM) of the National Academies, To Err Is Human: Building a Safer Health System, estimates that annually as many as 98,000 patients die unnecessarily in United States hospitals. Unmentioned in these statistics are the equally unnecessary deaths of hundreds of thousands of Americans with chronic conditions that could have been prevented or better managed.

Viewing patient safety outside health care facility walls requires that health organizations revisit both goals and operating procedures. This expanded definition of patient safety has the potential to profoundly affect how health care services are organized, delivered, and evaluated. Two major aspects must be reexamined—when patient safety begins and how indicators of quality care that are able to transcend time and place are defined.

Geography as Medical Destiny

The health care system strives to produce favorable and expected outcomes for patients. To provide for patient safety within the context of the larger community, health care practitioners must be able to evaluate a wide range of historical and temporal information that is both clinically relevant as well as place and time sensitive.

Major health care accreditation and oversight bodies, such as IOM, have expressed interest in redefining the geographic or spatial scope of patient safety, encouraging health care providers to consider the value of integrating internally generated health care information with externally available population health information.

The principal drivers for such a redefinition of quality care and patient safety include the impact of unintentional toxic exposures, compromised environmental conditions, unexpected situational dangers, untoward outcomes, medical misadventures (during or after clinical care), and the lack of timely logistical information for dispatching health professionals and medical supplies.

Impact of Location

Research on the impact of geography has shown long-term effects on various aspects of health and safety. The newest approach redefines location as where the patient is at all times and generates this level of patient information using technology similar to that used by court systems to track individuals with ankle and wrist bracelets. Researchers are equipping patients with GPS and devices for monitoring ambient air quality. Whether inside or outside facility walls, the ability to monitor environmental and clinical inputs has vastly improved.

Proposed research at the Loma Linda University School of Public Health, funded by the Environmental Protection Agency, provides a glimpse of these capabilities. The study will focus on the impact of ambient air quality on cardiovascular disease. Subjects will wear small devices that record the quality of the surrounding air, and their movements will also be tracked. Personal health measuring devices that can be mounted, installed, or swallowed will probably be available for use in mainstream research and clinical trials in the not too distant future.

These new strategies for health monitoring come on the heels of substantial literature that describes the impact of geographic location on health. Numerous studies demonstrate the effects limited sunlight exposure and consequent vitamin D deficiencies have on the development of cancer, diabetes, hypertension, and osteoporosis. Geographic locations far from the equator that provided limited exposure to sunlight were chosen for these studies.

The importance of place in medicine is becoming increasingly better understood. The seminal work of Dr. John Wennberg has demonstrated that geography alone is a good predictor of medical outcomes. A physician–researcher at Dartmouth Medical School, Wennberg has demonstrated that when all clinical and demographic factors are held constant, geography can explain the observed differences in both outcomes and correct diagnoses.

When Does Patient Safety and Quality Care Begin?

Defining when patient safety and quality care begin helps determine what type of data should be collected and how patients should be monitored as well as the type of information system needed for organizing and analyzing this data. Currently, most health care providers create artificial boundaries that constrain exposure to potential risks and liabilities.

Consider the situation of a person who enters the hospital with a life-threatening disorder. While under hospital care, his blood pressure and temperature are routinely monitored. After being discharged, and carefully helped to a car, that same patient arrives home and must climb two flights of stairs every day unassisted. No one takes his blood pressure or temperature for weeks. When did quality care and patient safety begin? When did it end?

The terms patient safety and quality of care are used with the assumption that when a person becomes a patient is straightforward and can be determined exactly. In the previous scenario, when did the man become a patient? When did he cease to be one?

It becomes apparent that becoming a patient represents a continuum rather than an event. The health care system currently defines a patient's use of the health care system in terms of individual events. This perspective is reflected in the industry's terminology. Interactions with hospitals and doctors are described as encounters, events, admissions, or discharges.

Health care providers view these transactions as separate events or, at most, events related to an episode of care. From the patient's perspective, it is difficult to say when the concept of quality of care and patient safety begins or ends. Conversely, patients see quality care, or the lack of it, as a series of related events along a continuum.

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