Special Project We Are Working On
Susan G. Komen for the Cure® Shortest Path Finder Project
Summary:
NAACCR received a Komen for the Cure (Komen) 3 year, $300,000 grant in October of 2007. We have partnered with experts in geographic information system (GIS) technology from the GIS Research Lab of the Department of Geography at the University of Southern California and members of the NAACCR GIS Committee to develop a software package, the “Road Network Distance Application,” that will process batches of patient records supplied by population based cancer registries in the United States and Canada. This application will output multiple measures of driving time and distance travel by car between the patient’s residence and the health care facilities visited for cancer diagnosis and treatment. In short, this project will investigate whether a patient’s travel time and distance to obtain his or her cancer screening and treatment has an effect on outcomes such as stage at diagnosis.
Please visit this site for additional information regarding the “Road Network Distance Application.” We will post updates and new developments as the project progresses.
Project Partners
We would like to thank Komen for their support and award of the grant. NAACCR would also like to thank our newest partners, NAVTEQ and GIS Solutions, Inc. (Springfield, Illinois) for their kind donation of the data. This project would not be possible without their expertise and data file. Please visit their Web sites for additional information regarding their products and expertise. Additionally, we thank the members of the NAACCR GIS Committee who continue to lend their expertise to make this project a success.
Additional Information:
Cancer is the second leading cause of death among Americans and responsible for one of every four deaths in the United States. Cancer registries collect information about the incidence of cancer, the anatomic sites and types of cancer, the extent of disease at the time of diagnosis, and the kinds of treatment that patients receive. Data collected by cancer registries enable public health professionals to better understand and address cancer burden and contribute to cancer control efforts. One of the goals of a successful cancer control program is ensuring that effective screening tests and treatment services are available and accessible.
Numerous studies have found that distances between patient address and health care facilities can impact how and even what type of care is received (Johnston et al. 2001, Dejardin et al. 2005, Yabroff et al. 2005). Comparatively few studies, however, have incorporated information about actual travel distance or travel time, because of the difficulty and complexity of acquiring this information. Although straight-line distances and actual travel distances tend to be highly correlated (Phibbs and Luft 1995), this is less true in rural areas with sparse road networks and where there are physical barriers such as mountains and rivers. Examples of studies using travel distance or travel time include a study by Lovett et al. (2002) in which both car and bus travel time were investigated and rural areas with poor accessibility were identified. Christie and Fone (2003) used travel distance to consider the impact of various health care centralization scenarios, finding that although centralization reduces overall access, the effect on different population subgroups was highly variable. A study in northern British Columbia compared straight-line distance and actual travel distance and found that actual travel distance identified more areas of low access and did so with higher precision (McGregor et al. 2005). In an unpublished study, researchers at the Nova Scotia Cancer Registry found that residents were less likely to receive palliative radiation the further they lived from the nearer of the province's two cancer centers, with GIS-derived estimates of driving time serving as better predictors than straight-line distance measures.
NAACCR’s first attempt in helping researchers interested in transportation and travel barriers to access quality cancer care was to develop a distance calculator program for registries using the Great Circle Distance method of estimating the distance between the residence of cancer patients and up to five different facilities used in the course of cancer diagnosis and treatment (NAACCR 2005). The great circle distance is the shortest distance between any two points on the surface of the earth measured along a path on the surface of the earth. We hope to replace this tool with more accurate driving time and distance measures that calculate the shortest route using a road network.
Travelers have found useful resources on the Internet, such as Yahoo! ® maps or MapQuest ®, as examples, to provide free travel directions and duration on an interactive, trip-by-trip basis. The user can select routes based on certain criteria, such as the avoidance of highways or toll roads. Consumers have also been able to purchase global positioning systems (GPS) for creating more personalized and complicated routing of travel based on specific parameters that are input into a software program. The maps and technology, however, are proprietary and only available in an interactive environment. To be useful to research, travel distance and time must be able to be computed for batches of records simultaneously, and with consideration of multiple options that are outputted concurrently. Such a program could be a valuable asset to cancer registries, cancer researchers, health care services analysts, and those interested in identifying and alleviating disparities in access to quality cancer care, with travel distance and travel time important access parameters.