255846 A Pilot Study of GPS Technology in Tracking Homeless Adults

Wednesday, October 31, 2012

Sarah Wohlford, MS , The University of Texas Southwestern Medical Center, Dallas, TX
Carol North, MD MPE , VA North Texas Health Care System, The University of Texas Southwestern Medical Center, Dallas, TX
David Pollio, PhD , School of Social Work, University of Alabama, Tuscaloosa, AL
Introduction: To date, geospatial studies of homeless populations have been limited to self-report data, calculation of distances from agency data, and non-continuous tracking through cell phone technology. These methods fail to capture movement patterns with sufficient continuity and precision to maximally inform effective service placement. The purpose of this study was to examine the feasibility of using GPS technology in a difficult-to-follow population.

Methods: Twenty homeless individuals selected from a homeless day center each carried a GPS tracking device to record their movements for one day. Participants completed a demographic questionnaire and pre-tracking and post-tracking surveys about planned and reported travels. GPS data were downloaded and exported for the creation of Google Earth spatial travel maps and to create an ArcView 9.3 database.

Results: After achieving successful deployment, 80% completion was obtained. Travel distances varied (.05-36 miles), on foot and by motor vehicle. No tracking devices were lost during deployment, although one was water-damaged in a shower. Challenges in conducting the study included battery problems (power, theft), signal loss, lengthy initial calibrations (up to 15 minutes), drift of satellite anchors to positions, and difficulties re-engaging with participants post deployment.

Conclusions: This study demonstrated the feasibility of using GPS technology to track continuous movements of the difficult-to-track homeless population. This work has clarified the need to integrate GPS and self-report data to maximize the precision of geospatial data. This study demonstrated the potential for GPS technology to improve service access and identify geospatial barriers to care beyond currently available methodologies.

Learning Areas:
Assessment of individual and community needs for health education
Environmental health sciences
Program planning
Provision of health care to the public
Public health or related research
Social and behavioral sciences

Learning Objectives:
1. Describe the challenges of using GPS technology to measure daily activities for homeless adults. 2. Describe the potential use of GPS data in identifying service barriers and improving service effectiveness.

Keywords: Geographic Information Systems, Homelessness

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I conceptualized initial research, participated in collection and analysis, and coauthored abstract and paper
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.