Prior to September 2001, RODS received data only from hospitals associated with the UPMC Health System, and efforts to recruit other hospitals met with resistance. After the terrorist attacks (including anthrax) in the Fall of 2001, other hospitals agreed to participate. Although data in this project are de-identified, certain information such as the number of ED visits by zip code were considered proprietary information by some health systems. Health Insurance Portability and Accountability Act (HIPAA) concerns also were very prominent in the discussions. Data-sharing agreements were executed with every participating health system that addressed these concerns. As an additional precaution, all RODS project members meet annually with University of Pittsburgh council to review obligations and are required to sign an agreement every year stating that they understand the terms of the data-sharing agreements and agree to abide by the terms. RODS began as a research project at the University of Pittsburgh in 1999 and has functioned with IRB approvals since that time.