A population-based study of emergency department presentations for asthma in regions of Alberta

Objective: We describe the epidemiology of asthma presentations to emergency departments (EDs) for 3 main regions in the province of Alberta. Methods: We used a comprehensive ED database to identify ED visits in Alberta from April 1999 to March 2005. We linked the visits to other provincial administrative databases to obtain all data on follow-up encounters for asthma during that period. Information extracted included demographics, regions of residence (Edmonton, Calgary or non-major urban [NMU]) timing of ED visits, and subsequent visits to non-ED settings. Data analysis included descriptive summaries and directly standardized visit rates. Results: During the 6-year study period, 93 146 patients made 199 991 ED visits for asthma. Crude rates in 2004/05 were 7.9/1000, 6.5/1000 and 15.4/1000 in the Edmonton, Calgary and NMU regions, respectively. The Edmonton and Calgary regions had consistently lower visit rates than the NMU regions. The ED visits were followed by low rates of follow-up visits in a variety of non-ED settings, at different intervals. Conclusion: Asthma is a relatively common presenting problem in Alberta EDs. This study identified relatively stable rates of presentation during the study period, and variation among regions in terms of age and sex. This study provides further understanding of the variation associated with ED presentation and indicates possible targets for specific interventions to reduce asthma-related ED visits.