Int. J. Environ. Res. Public Health 2011, 8 256 The researchers worked with the regional hospital’s information services (IS) department to add the question to the electronic admitting records of all participating hospitals and to “turn on” the question at each hospital only after the admitting staff had been trained. For quality control, the question was added as a no-by-pass field, and reasons for incomplete data were added as options for the question (not asked, not able [to answer], and refused) so they could be tracked. The Meditech admitting databases for all of the participating hospitals were connected to the regional hospital’s system through a shared licensing agreement which simplified and centralized the process. The admitting staff received brief training from the PI that covered their role in asking the tobacco-use question and details about the question—where to find it in Meditech, how to ask and answer the question, the fact that the system had been set so that the question could not be by-passed, how to answer patients’ questions about being asked the question, and how the responses from the question would be used to determine tobacco use prevalence so that in turn, the magnitude of the need for providing patient services for tobacco cessation could be determined. Posters were placed in the admitting areas that explained the study. All patients visiting the ED in the participating hospitals were registered by admitting clerks as part of standard practice. Admitting clerks were instructed to ask all patients 18+ years about their tobacco use status. Scheduled visits such as dressing changes and IV anti-biotic administration were not eligible nor were appointments for laboratory work or other technical services that were not emergency visits. Data were extracted from all hospitals’ Meditech database by a program written by the regional hospital’s IS department, and made available to the researchers through a SQL server purchased for the study. 2.4. Primary Outcomes The primary outcomes were proportion of patients screened for tobacco use, overall 30-day point prevalence tobacco use, tobacco prevalence stratified by age category, and age-stratified tobacco prevalence for ED patients compared to regional, provincial, and national prevalence in the general population. 2.5. Statistical Analyses Data were cleaned to exclude patients <18 years of age and non-emergent visits as per the eligibility criteria (e.g., dressing changes, IV medications, lab visits, etc.). Tobacco prevalence was calculated separately for each year of data collection (January–December 2007–2010) using frequency counts. Each individual patient was counted only once per year using the first admission for the year; all other visits were excluded to maintain independence of data. Age categories for the main tobacco use prevalence outcomes were based on the 5-year age categories used by Statistics Canada for population census data [10]. Larger age categories were used for comparisons with the general population based on age categories for which regional, provincial, and national smoking prevalence data were available. Patients 18 and 19 years of age were excluded from the provincial and regional population comparisons because general population smoking prevalence data combine 18–19 year olds with younger ages (12–15 years) and the current study did not collect data on patients <18 years. For the regional comparisons, the communities of Atikokan, Fort Frances, Red Lake, Sioux Lookout, and