Since the 1970s, there have been substantial increases in asthma prevalence in children of industrialized and non-industrialized countries.¹

Statistics Canada confirmed a four-fold increase in childhood asthma over a 20-year period between 1978/79 and 1994/95.¹

While some of this increase might be due to over-diagnosis, a number of international studies indicate a definite increase, with changes in the environment potentially contributing to this increase.¹

According to the Canadian Chronic Disease Surveillance System, asthma prevalence in young children has been steadily declining since 2000 with 6.2% of children aged 1 to 4 having asthma in 2011/2012 compared to 10% in 2000/2001.

¹Millar WJ, Hill GB. Childhood asthma. Health Reports (Statistics Canada, catalogue 82-003) 1998; 10(3): 9-21. http://www.statcan.gc.ca/pub/82-003-x/1998003/article/4137-eng.pdf– accessed March 15, 2017.