A Case-Control Study of Adolescents' Daily Activities and Their Risk To Be Assaulted

Gunshot injury, the second leading cause of death among U.S. adolescents (10-19 years old), appears to be the end result of a causative web of factors including alcohol, weapons, and dangerous urban environments.  We are conducting a population-based case-control study in the City of Philadelphia, Pennsylvania, to investigate how the nature and whereabouts of adolescents’ daily activities relate to the likelihood of being assaulted.  Case subjects are assault victims who were injured 1) by gunshot or 2) with a non-gun weapon who are recruited from a hospital emergency department.  Healthy (ie, not injured) controls are recruited from households in the surrounding community using random digit dial.  Each subject is interviewed using portable, computerized mapping technology, to create a dynamic graphic that provides a minute-by-minute record of how, when, where, and with whom the subject spent time over the course of the past 24 hours as he or she walked or otherwise traveled from location to location and activity to activity.  Cases refer to the 24-hours preceding the shooting; controls refer to a recent 24-hour period designated at random.  Each subject also reports their activities including use of alcohol and weapons at each point through that day.  Afterward, characteristics of streets, buildings, and neighborhood populations are linked to each point along subjects’ space-time activity paths.  The data are analyzed using multivariate regression methods.  In particular, we are testing the hypothesis that time spent in proximity to alcohol outlets poses a risk to be assaulted.  The ultimate goal is to inform communities of place-based risk factors and to identify opportunities to make communities safer.  Implications of the methodologic approaches to this innovative space-time analysis will be presented.