According to the Ontario Asthma Surveillance Information System (OASIS), in 2011, nearly 80,000 Simcoe Muskoka residents were living with asthma. The 2011 age-standardized asthma prevalence rate in Simcoe Muskoka of 15.82 per 100 (15.71, 15.94) was marginally higher than provincial age-standardized prevalence rate of 15.28 per 100 (15.24, 15.29).
There was a significant increasing trend in asthma prevalence in both Simcoe Muskoka and Ontario as a whole from 1996 to 2011, with an average annual increase of approximately four per cent per year. The Simcoe Muskoka prevalence rates have been above the provincial rates since 2004.
In Simcoe Muskoka between 1996 and 2011, the age-standardized asthma prevalence was higher among females when compared with males for the entire period. Both the male and female age-standardized asthma prevalence rates in Simcoe Muskoka demonstrated a similar upward trend as did the overall prevalence rates for Simcoe Muskoka.
Between 1996 and 2011 in Simcoe Muskoka, asthma prevalence rates increased for all ages, other than children under 10 years of age. The largest increases in prevalence rates were observed for youth between 10 and 19 years of age and young adults between 20 and 29 years of age.
In 2011, asthma prevalence rates were highest among older children and teens (10-19 years) with more than one-in-five living with asthma. These rates were more than double the rates for young children less than five years of age and adults 40 years of age and older. The provincial age-specific asthma prevalence rates were higher than the Simcoe Muskoka rates for children and youth under 20 years of age and for seniors 60 years of age and older. The Simcoe Muskoka age-specific prevalence rates were higher than the provincial rates for adults between 20 and 49 years of age.
According to the Canadian Community Health Survey (CCHS), from 2009 to 2014, the self-reported prevalence of asthma among the Simcoe Muskoka population 12 years and older was 9% (8.0%, 10.6%) compared with 8% (7.7%, 8.3%) for the province as a whole. Asthma prevalence is highest among those living in households in the bottom 20 per cent of income.
The rate of new asthma cases (also called the incidence rate) provides a measure of the risk of developing asthma over a given period of time. This is different from the asthma prevalence rates presented above, which provide a measure of how wide spread asthma is over a given period of time.
In 2011, the age-standardized incidence rate of asthma in Simcoe Muskoka for all ages and both sexes was 3.86 (3.67, 4.04) per 1,000 population. This was significantly lower than the Ontario asthma incidence rate of 4.99 (4.94, 5.03) per 1,000.
The asthma incidence rates in Simcoe Muskoka declined significantly between the 1996 and 2011, with an annual percentage decrease of approximately six per cent per year. There was a similar, but less pronounced, decline in the Ontario asthma incidence rates over the same time period of approximately four per cent per year.
In Simcoe Muskoka between 1996 and 2011, the age-standardized asthma incident rates for both males and females demonstrated a similar downward trend as did the overall rates for Simcoe Muskoka. The female incidence rates were consistently higher than the male rates up until 2004; however, between 2004 and 2011 the male and female rates were not significantly different from each other.
In 2011 in Simcoe Muskoka, asthma incidence was highest among young children, with 22 new asthma cases diagnosed per 1,000 children under the age of five. This drops to 8 cases per 1,000 among five to nine year-old children and 4 cases per 1,000 for 10 to 14 year-old children. After 14 years of age, the incidence rates range from 1 to 3 new cases per 1,000 for all age groups. The 2011 age-specific asthma incidence rates for Ontario as a whole were significantly higher than the Simcoe Muskoka rates for children under 10 years of age and adults between 20 and 69 years of age.
Between 1996 and 2011 in Simcoe Muskoka, asthma incidence rates decreased for all age groups. The largest decreases in incidence were observed between 2005 and 2008, particularly among young children under the age of five. This steep drop in asthma incidence between 2005 and 2008 corresponds with an improvement in air quality over the same time period as measured by the Air Quality Health Index at the Barrie monitoring station.