Findings published in the November 18, 2008 edition of the Canadian Medical Association Journal suggest that approximately 30 per cent of Canadians diagnosed with asthma may not have the disease. The question is how the diagnosis was determined in the first place and what can be done to improve diagnostic accuracy.

• Dr. Shawn Aaron, Senior Scientist, Clinical Epidemiology, Ottawa Health Research Institute, Associate Professor of Medicine, Faculty of Medicine, U of Ottawa and Staff physician, Division of Respiratory Medicine, Ottawa Hospital