432. A Near-Real-Time Method for Discovering Healthcare Worker Social Networks via Wireless Devices
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: To understand how infectious diseases spread in a clinical setting, one must understand the movements and interactions of workers and patients. In outbreak settings, contacts between people are retrospectively studied by interviewing healthcare workers and/or examining patient assignment records. We have developed a wireless method for tracking social interactions in near real time, and quickly generating social networks that can be used for infection-control purposes.
Methods: Small (pager-sized) non-RFID active badges are worn by healthcare workers and patients. The badges communicate with each other in a wireless fashion; from these data we can infer proximity of individuals to each other and we can also infer approximate duration of contact.

Results: In the accompanying graph, we plot the social network in a simulated clinical setting (an infectious disease clinic after hours) using healthcare workers and volunteers. We compared data collected from our badges with data collected by direct observation (i.e., ground truth). The sensitivity for detecting proximity (within 6 feet for as little as 30 seconds) was 0.89, with a specificity of 0.87. The sensitivity increases as contact time increases. The contacts captured and displayed in the graph below ranged from 25 to 124 seconds.
Conclusion: We have a novel, practical, and inexpensive way to quickly measure and graph social networks in healthcare settings. Unlike RFID approaches, our system does not rely on the installation of expensive infrastructure and can be deployed quickly (within minutes). The system can help reveal the dynamics of infectious disease transmission, as well as provide near-real-time contact tracing in outbreak settings.
Donald Curtis, MCS1, Jason Fries, BS1, Ted Herman, PhD1, Christopher Hlady, BS1, Sriram Pemmaraju, PhD2, Philip M. Polgreen, MD1, Alberto Segre, PhD1, Monica Severson, BA1 and  C. S. Hlady, None..
D. E. Curtis, None..
M. A. Severson, None..
J. A. Fries, None..
S. V. Pemmaraju, None..
A. M. Segre, None..
T. Herman, None..
P. M. Polgreen, None., (1)University of Iowa, Iowa City, IA, (2)University of Iowa, I, IA