The Public Health Agency of Canada (PHAC) acknowledges the efforts that are taking place across the country towards supporting those who are living with Autism Spectrum Disorder (ASD). Most of this support takes place in the health care, education and social services sectors —domains under the responsibility of provincial and territorial governments. An essential aspect in supporting these front-line efforts is developing an understanding of the magnitude and characteristics of individuals with ASD both across regions and over time. Although there are existing repositories of ASD data across the country, there are no comprehensive and comparable national level data. In response, PHAC has established the National ASD Surveillance System (NASS), with an initial focus on child and youth populations. NASS is a collaboration of federal, provincial and territorial governments, working to build a comprehensive picture of ASD in Canada. NASS will contribute evidence to help inform critical planning of programs, services and research that impact Canadians living with ASD, their families and caregivers.

Electronic reproduction. Additional authors include: Authors: Marianna Ofner, PhD, Anthony Coles, MPA, Mary Lou Decou, MSc, Minh T Do, PhD, Asako Bienek, MHA, Judy Snider, MSc and Anne-Marie Ugnat, PhD.

List of figures -- List of tables -- List of acronyms -- Foreword -- Executive summary -- Introduction -- What is Austism Spectrum Disorder (ASD)? -- What is Public Health Surveillance? -- What is the National Autism Spectrum Disorder Surveillance System (NASS)? -- How was NASS developed? -- What methodology is used to collect data? -- Who is counted? -- What information is counted? -- What data sources were used to collect data? -- National results -- What proportion of children and youth are represented in 2015 results? -- How many children and youth were identified with ASD in 2015? -- How do ASD prevalence rates differ by sex and age? -- At what age are children and youth with ASD typically diagnosed? -- How do results vary by province and territory? -- How do results compare with earlier years? -- What rates of incidence were reported for 2015? -- How do NASS results compare with results from the United States? -- Provincial and territorial results -- Newfoundland and Labrador -- Nova Scotia -- Prince Edward Island -- New Brunswick -- Quebec -- British Columbia -- Yukon -- Future directions -- Technical annex: NASS surveillance methods -- References.