TORONTO — One-third of Canadian adults who have been told they have asthma may have been wrongly diagnosed by their doctor, according to a new study that reveals serious problems with the way the disease is identified and treated in Canada.
The findings, being published Tuesday in the Canadian Medical Association Journal, suggest thousands may needlessly be taking medications that could have life-altering side effects and major costs.
"There's a lot of drugs being consumed and paid for that really are not likely to have any therapeutic role for these patients," said Shawn Aaron, head of the respirology division at the University of Ottawa and lead author of the study. "If this study is true, and I have no reason to believe it's not, there are 30 per cent of people walking around in Canada who believe they have asthma, whose physicians have told them they have asthma, who don't [have asthma]."
About 8.3 per cent of Canadians aged 12 and older were identified as having asthma in 2005, according to Statistics Canada. In 2007, 3.4 million prescriptions were issued for the top five asthma medications, at a cost of nearly $329-million, according to IMS Health Canada, a company that tracks the pharmaceutical industry.
