Int. J. Environ. Res. Public Health 2011, 8 261 There were benefits to the hospitals beyond the research itself. Institutionalizing tobacco use identification and documentation procedures is recommended by clinical practice guidelines [2] and through participation in this study, hospitals were able to implement this best practice. Hospitals were also able to use participation in research and implementation of a best practice in their hospital accreditation reports as a quality indicator for disease surveillance/prevention although tobacco-use identification and documentation is not a specific, nor mandatory, accreditation standard in Canada. There were limitations to this study. First, tobacco use status was self-reported by patients, it was not recorded for 11% of admissions each year, and the “twelfth” hospital in NW Ontario did not contribute data because they were not on the same Meditech electronic system as the other hospitals thereby limiting the generalizability to the entire region. However, the number of patients tracked was sufficiently large and tobacco use status was tracked over a long enough period of time that the data collected can reasonably be considered to represent the ED population for this northern region of the province rather than a sample of the population. Second, although the ED tobacco use prevalence data were similar to that of the general population of the region and remained stable over time, people who visit the ED could be different than the general population so the generalizability of the ED prevalence rates to the general population should be interpreted with caution. Finally, due to our inability to explain the dramatic drop in tobacco prevalence from 2007 to 2008 at the regional hospital, the higher prevalence rates for 2007 at the regional hospital should be interpreted with caution. The systematic tobacco use tracking and general population comparisons in this study provide a “big picture” overview that highlights the magnitude of the tobacco use problem in these northern communities and will enable those responsible for tobacco control policies, programs, research, and surveillance to assess the situation and inform decision-making. In order to allocate limited healthcare resources rationally for tobacco control, it is necessary to elucidate the economic burden of tobacco use within different segments of the population. The age-specific tobacco use prevalence in these communities is now well described for variability and the tobacco use question remains on the ED registration software as part of standard practice so tobacco use can continue to be collected and used to track trends over time. The ability to systematically track tobacco use on the ED population and the findings that revealed similar tobacco use prevalence rates between the ED and general population also highlight the possibility of using the ED for other surveillance purposes, especially in smaller communities where community-specific population data might not be available. Acknowledgements This study was made possible through funding from the Cancer Research Fund of the Thunder Bay Regional Health Sciences Foundation. I would like to acknowledge the CEOs, senior administration, and ED registration managers at the participating hospitals for their support of the project and the ED registration staff for asking the tobacco use question. My gratitude goes to Scott Sellick, PhD, for his work on the research with the hospitals and for reviewing the paper; Mary Pohjolainen and Andrew Wehrstedt for their work on the Meditech registration software; Peter Brink, PhD, for his work on the early data extractions; and, Tracy Hirvas, BSc, for setting up the SQL server, writing the database access and extraction programs, trouble-shooting, and providing the data in a form that I could analyze.