Understanding the 2018 National Autism Spectrum Disorder Surveillance System report

On March 29, 2018, the Public Health Agency of Canada published the first comprehensive review of the prevalence of autism spectrum disorder (ASD) in Canada.

The report provides results on the prevalence of ASD in 2015 among Canadian children aged 5 to 17 years, based on a diagnosis. It includes breakdowns by sex and province or territory.

This page provides a summary of the report.

On this page

• Report contributors across Canada
• Information sources used in the report
• ASD prevalence among Canadian children and youth
• Differences in ASD prevalence across Canada
• Changes in ASD prevalence in Canada over time
• ASD prevalence in Canada is similar to the United States
• Tracking data can help people with ASD

Report contributors across Canada

Seven provinces and territories contributed to the report:

• Newfoundland and Labrador
• Nova Scotia
• Prince Edward Island
• New Brunswick
• Quebec
• British Columbia
• Yukon

The Public Health Agency of Canada will continue to work with the other provinces and territories to support their participation in future reports.

Information sources used in the report

The report findings only include cases with an ASD diagnosis. Information was collected from education, health and social services sources and is provided by the provinces and territories to the Public Health Agency of Canada. No individual can be identified through these data.

ASD prevalence among Canadian children and youth

Among Canadian children and youth aged 5 to 17 years, the estimated prevalence of ASD in 2015 was 1 in 66.

Note: The estimate of 1 in 66 applies to children aged 5 to 17 years only – it can’t be used to estimate to the total number of Canadians with ASD. The number of older or younger Canadians with ASD is unknown at this time.

Among children 5-17 included in the report, some were diagnosed before the age of 5. This information was included in the report to help measure at what age children were diagnosed.

Differences in ASD prevalence across Canada

The prevalence rates reported by the provinces and territories are different; some are higher and some are lower than others. Provinces and territories use different methods to collect their data and some of the differences in the rates are likely a result of these methods.

Changes in ASD prevalence in Canada over time

It is currently not known if ASD rates have increased nationally over time. Three provinces (Prince Edward Island, Newfoundland and Labrador and Quebec) provided information on the prevalence of ASD since 2003 for children and youth aged 5-14 years.

The data from those provinces shows an increase in ASD prevalence from 2003 to 2015. It is unknown at this time if increases reported by the three provinces are due to an increase in the rate of autism, and/or if it is due to better awareness of the signs of autism.

Future monitoring and reporting will allow us to track changes in ASD prevalence over time.

ASD prevalence in Canada is similar to the United States

Although the United States uses a different method to estimate the prevalence of ASD, the results are similar.

The most recent estimated rate of ASD among 8 year olds in the United States is 1 in 68 (2012). The estimated rate of ASD among 5-17 year olds in Canada is 1 in 66 (2015).

Note: The data from the United States includes cases where a child doesn’t have a diagnosis. In the US, trained clinicians review records to determine if a child has behaviours that are consistent with ASD. About 18% of the cases identified in the US in 2012 did not have an ASD diagnosis.

Tracking data can help people with ASD

Knowing the frequency of a disorder can help policy makers, health care providers, educators and others to develop programs and plans to meet the needs of people with ASD and their families. The information from the report will help inform further research on ASD.