Where Have You Been? Using GIS to Analyze Residential History and Health Care

By Troy Lambert



A young man from Central California is diagnosed with prostate cancer. Because of how young he is, the diagnosis did not come until he was already displaying symptoms of the disease. This man’s story ended well, and the cancer is currently in remission. The reality of the situation is rarely so kind, and one study shows women from the same area are more vulnerable to breast cancer. But why? What environmental causes could there be?

When looking beyond a simple medical diagnosis for a cause, a health care professional looks at genetics, lifestyle, and environment. When you enter a doctor’s office, you usually have a stack of forms to fill out regarding the first two: a family history, and questions about height, weight, and whether you smoke, drink, and exercise regularly.

But when is the last time you filled out a residential history as part of the intake process? Unless you have a rare or unusual condition, the answer is probably never. In the three pronged query for determining the cause of a condition, the last, and perhaps the most vital, is often neglected. Not to mention the other side of the coin: prevention.


What if the young man’s doctor had known he’d lived in an area where males were often at risk for prostate cancer, and so recommended early testing? What if he knew about a woman’s exposure to certain chemicals thought to be related to higher rates of breast cancer? Early testing would not only be highly recommended, it could be seen as vital.

So what’s the problem? And how can GIS help? The reasons are plenty, but there is an increasing movement to include location data in medical records. The question involves more about how to make such information universal and accessible than anything else.

Big Data and GIS
There is a lot of talk about GIS and big data, almost to the point where the very phrase has become a buzzword. It’s not that data isn’t available, it’s a matter of finding the needle in the haystack while at the same time realizing the haystack keeps getting bigger.

GIS can help, by tying data to location, and recording relevant relationships. However, with all the other data already in Electronic Medical Records (EMR), adding residential history could be challenging, and correlating it with other location data even more so. But there are potential answers.

The CDC and GIS
The CDC has a national map for incidents of Heart Disease, and they do have a mapping department that is working on gathering and georeferencing more data. The CDC certainly serves as a great repository for this kind of data, but to make it truly effective, more studies need to be done and more data gathered. The depth and breadth of these studies is often hindered by a common missing element: funding.

HEART DISEASE MAP, CREDIT: CDC GIS

California gathers data through the Pesticide Use Reporting system, and other states will soon follow. As pesticide use may potentially correlate to increased risk of prostate and breast cancer. Such data on a wider scale could assist medical professionals in advocating for early testing in some patients.

MAP OF PESTICIDE USE IN CALIFORNIA, 1999. CREDIT: PESTICIDE ACTION NETWORK

Centralizing this data and making it available to medical professionals is a step in the right direction, and the CDC already has data from Pennsylvania, Iowa, and city specific data from Philadelphia on several health topics. data about unhealthy days in adults, and incidence of AIDS nationwide from 2004.

Health Risk Maps
What if such data could be used to predict potential incidents of cancer and other diseases, or risk, rather than to create maps of after the fact statistics? What if potential causes could be mapped, and correlated with a patient’s residential history?

STATE CANCER PROFILES. CREDIT: NATIONAL CANCER INSTITUTE

There is a map that tracks incidence and lets the user filter by age, race, and sex. The same map, created by the National Cancer Institute and the CDC, does have some screening and risk factor data, including diet and exercise, smoking, and others. Expanding this map with additional data may be one solution.

As computers and programs advance, and it becomes easier for them to handle huge sets of data, as more data is gathered, and as the use of that data gains traction in routine healthcare evaluations, the power of GIS can be leveraged to greatly influence healthcare as we know it.

Source: GIS Lounge - Maps and GIS