Summary of key findings

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Recent trends in upper respiratory infections, ear infections and asthma among young Canadian children

The prevalence of asthma, one of the most common chronic conditions in childhood, has declined among Canadian children aged 2 to 7 to its lowest level in more than a decade.  

The prevalence of upper respiratory infections among children aged 2 to 3 has remained constant or declined in most regions, although it has risen significantly in Quebec.  Ear infections have declined significantly in all regions. 

One factor that may have contributed to the decreased prevalence of asthma and ear infections among young children is reduced exposure to cigarette smoke. 

Daily smoking among people aged 15 or older declined steadily between 2000 and 2008.  At the same time, the percentage of children regularly exposed to tobacco smoke at home decreased.  There has also been a decline in the percentage of children aged 2 to 3 who live in households in which at least one parent is a daily smoker.

Asthma

Between 1994/1995 and 2000/2001, the percentage of children aged 2 to 7 diagnosed with asthma rose from 11.5% to 13.2%.  However, new data from the National Longitudinal Survey on Children and Youth (NLSCY) show that by 2008/2009, this figure had declined to 9.8%.   The upturn in asthma prevalence to 2000/2001 and the subsequent decrease occurred in all age groups.

Throughout the 14 years, a significantly higher percentage of boys than girls had been diagnosed with asthma, but among both sexes, asthma prevalence followed the general trend.

Previous studies have reported regional variations in the prevalence of childhood asthma, with British Columbia and the Prairie provinces having lower rates than other regions.  However, this pattern has changed markedly.

Since 2000/2001, the percentage of children aged 2 to 7 with asthma fell in the Atlantic provinces, Quebec and Ontario, but remained relatively stable in British Columbia and the Prairies.  As a result, in 2006/2007 and 2008/2009, no significant regional differences in the prevalence of asthma emerged.

Upper respiratory infections

Upper respiratory infections, including the common cold, are frequent among children, with three to eight infections a year typical.  

In 1994/1995, 26% of Canadian children aged 2 to 3 were reported by their parents as having frequent upper respiratory infections.  This percentage remained almost stable over the next 14 years: in 2008/2009, it was 23%.

The prevalence of frequent upper respiratory infections among children aged 2 to 3 was lowest in the Atlantic region, and highest in Quebec during the 14 years. 

Over this period, the prevalence of frequent upper respiratory infections fell in all regions except Quebec, where the percentage rose from 28% to 39%.

Ear infections

Otitis media (middle-ear infection or inflammation) is also common in childhood.  In 1994/1995, 67% of Canadian children aged 2 to 3 had had at least one ear infection since birth.  About 26% had had frequent ear infections, that is, four or more.

By 2008/2009, the percentage of children aged 2 to 3 who had had at least one ear infection had dropped to 50%, and the percentage who had had four or more had fallen to 13%.  Boys were more likely than girls to have had ear infections. 

Children in the Atlantic provinces and Quebec tended to have high ear infection rates, while in British Columbia, rates tended to be low.  In all regions except Quebec, the prevalence of ear infections has fallen since 1994/1995.

Full article

For more information about this article, contact Eleanor Thomas (1-613-951-3002; Eleanor.Thomas@statcan.gc.ca), Special Surveys Division, Statistics Canada.