Understanding the 2018 National Autism Spectrum Disorder Surveillance System (NASS) Report
- Who contributed to the report
- Where the information in the NASS report came from
- What the report says about ASD prevalence in Canada
- How epidemiological surveillance helps those with autism
- Tracking autism prevalence over time
- National variations in the autism prevalence
- Comparing Canadian ASD prevalence estimates to other countries
Six provinces and one territory contributed data to the NASS report (Newfoundland and Labrador, Nova Scotia, Prince Edward Island, New Brunswick, Quebec, British Columbia and the Yukon). The Public Health Agency of Canada will continue to work with these provinces to collect data for the NASS and will work with other provinces and territories not currently participating in the NASS to encourage them to participate.
In Canada, the NASS collects information on 5-17 year olds through education, health and social services data sources. The NASS includes ASD cases with a confirmed diagnosis. Personally identifiable information is removed before data are shared with the Public Health Agency of Canada.
The NASS reports an estimated prevalence of ASD among Canadian children and youth ages 5-17 years of 1 in 66. The estimate of 1 in 66 reported refers to children and youth and cannot be used to estimate the total number of Canadians of all ages (toddlers, preschoolers and adults) with a diagnosis of autism.
Currently, it is impossible to estimate the number of people in Canada with ASD, since it is unknown how many younger children (those less than 5) and adults (those older than 17) have ASD.
Having these data helps governments, professionals, health care providers, service providers, educators, community, stakeholders and others help meet the needs of those with the disorder. These data could promote development of programs or human resource and budgetary planning by governments.
Three provinces (Prince Edward Island, Newfoundland and Labrador and Quebec) provided information on the prevalence of autism since 2003 for children ages 5-14. In each of these provinces, prevalence has increased since 2003.
It is unknown how much of the increase in ASD prevalence is due to more awareness of the signs of autism and/or if prevalence is increasing over time. Continued monitoring and reporting will support better understanding of the patterns and rates associated with autism over time.
The national prevalence estimate is an average of the provincial and territorial prevalence and, as such, the actual prevalence in each province and territory may be higher or lower than the national average (this is expected). Provinces and territories use different methods and sources to collect their data and this may influence their estimates. For more specific information on each province or territory, please see the full report or contact them directly.
The United States uses a different way to estimate the prevalence of autism. In the U.S. data on 8 year old children with autism are captured in the Autism and Developmental Disabilities Monitoring (ADDM) Network. In 2012, the most recent year for which data are reported, records from multiple sources were reviewed from 11 different Network sites (Arkansas, Arizona, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, South Carolina, Utah and Wisconsin). Records were reviewed by a healthcare professional to determine if a child has a diagnosis of ASD and/or behaviours consistent with ASD. Despite the differences in methods between Canada and the U.S., the results from these two tracking systems are quite similar with the prevalence of ASD among 8 year olds being 1 in 63 in Canada (2015) and 1 in 68 in the US (2012).