Map tracking points of a victim’s activity
in the 24 hours preceding a violent assault.

Gunshot injury is the leading cause of death in 10-19 year old African American males and the second leading cause of adolescent death overall. Assaultive injuries appear as the end result of a causative web of factors that include alcohol, firearms, and dangerous urban environments. Yet little is known about the epidemiology of assaultive injury from guns and other weapons among adolescents.

Researchers at the University of Pennsylvania, School of Medicine, have set out to learn whether things adolescents do and places they go are associated with whether they will be the victim of violence. The project, the Space-Time Adolescent Risk Study (STARS) is led by Douglas Wiebe and Charles Branas of the Center for Clinical Epidemiology and Biostatistics and Therese Richmond from the University of Pennsylvania School of Nursing who aim to identify key behavioral and environmental factors that put young people ages 10-19 at risk for being assaulted, thereby spearheading an innovative application of epidemiological space-time modeling.

Azavea was contracted to build the space-time activity tracking software tool to help health care professionals in interviewing adolescent victims of violent crime. STARS Travel Path is a desktop mapping application and database, and is designed to help interviewers guide adolescents injured in an assault through the process of reconstructing the series of events and encounters in the 24-hour time period preceding the assault. Using laptops with GIS data and the STARS application installed, trained interviewers work with each victim to record the victim’s verbal account of his or her activities by placing digital markers indicating the location of each significant activity, on a street map or high-resolution satellite photo.

The interviewer is able to accurately assign times and other information to the markers on a victim’s map – including the assault event – based on factors such as the victim’s mode of transportation to or from each event, speed of movement, interruptions, and other environmental factors. The interviewer also inputs key data on whether the victim was in possession of a gun or took drugs and/or alcohol at any time in the 24 hours prior to the assault. Typically 80-100 points of activity are recorded on each victim’s map. Typically 80-100 points of activity are recorded on each victim’s map. Visually mapping a verbal account of activities provides researchers with a powerful tool that aids in accurately recording complex space/time data.

“Epidemiologic research of this type – that aims to identify risk factors for injury – has typically collected data for only the time at which the injury occurred. We expect that the activities that lead up to an assault are equally important to consider. This application lets us do this by recreating adolescents’ moment-to-moment paths with a high degree of spatial and temporal accuracy. An additional plus is that the mapping interface seems to help keep participants engaged during the interview process.” – Doug Wiebe, University of Pennsylvania Center for Clinical Epidemiology and Biostatistics

The STARS activity mapping application utilizes ESRI’s ArcGIS Engine toolkit to quickly generate and display customized maps, and geocode and record points of activity. The point data and the factors related to each point are then stored in a simple database. Data gathered in the field, on hand-held computers, can be uploaded to a master database linked by X-Y coordinates to environmental data, statistically analyzed. Ultimately, it is hoped that the results of this study will help researchers understand how daily routine, social interactions, use of drugs and alcohol and possession of weapons effects an adolescent individual’s risk of being assaulted with a weapon.