Epidemiology of ASD Anthony Bailey Institute of Mental Health Chair, - - PDF document

Epidemiology of ASD

Anthony Bailey Institute of Mental Health Chair, UBC

Why conduct epidemiological studies

• Counting
• Disease distribution (age, sex, geographical,

time, associated factors)

• Severity
• Aetiology
• Costs and service planning

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Epidemiology

• Prevalence: number of individuals with a

condition in a population at a particular point in time

• Incidence: Number of individuals born with a

condition over a particular time period

• A case: a person with the defined condition
• Geographical boundary
• Age range
• Time range

ASD Epidemiology

• Virtually all studies are prevalence studies
• Vast majority of studies are of children
• Making sense of secular changes requires:
• Understanding of changes in diagnostic

criteria

• Knowledge of epidemiology of other

neurodevelopmental disorders

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Pervasive Developmental Disorders

• Autism
• Atypical autism
• Asperger’s syndrome
• PDD NOS
• Rett syndrome
• Disintegrative psychosis

DSM‐5:Neurodevelopmental Disorders

• Intellectual Disabilities
• Communication Disorders
• Autism Spectrum Disorder
• ADHD
• Specific Learning Disorder
• Motor Disorders
• Other Neurodevelopmental Disorders

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1944: Asperger

Autistic psychopathy Assumed genetic Passed from father to son

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Adults

• Redpath Center, Ontario
• 2014 Survey of adults with ASD
• 50% of adults were diagnosed after the age of

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Possible approaches

• Record review
• Survey data
• Administrative data

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THE 2018 NATIONAL AUTISM SPECTRUM DISORDER SURVEILLANCE SYSTEM (NASS) REPORT ‐ ‘MADE IN CANADA’

Ottawa, Ontario March 2018

ACKNOWLEDGEMENTS

This work was made possible through collaboration with the Public Health Agency of Canada, participating provincial and territorial governments and expert advice from the Autism Spectrum Disorder – Advisory Committee.

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PRESENTATION OVERVIEW

2018 NASS Report Highlights Reporting Products and Activities National Autism Spectrum Disorder Surveillance System (NASS)

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 Estimate how many Canadians have ASD (prevalence) and how many new cases are emerging (incidence) over time  Describe the population of Canadians with ASD and compare patterns within Canada and internationally  Increase public awareness and understanding of ASD prevalence  Inform policy and program decision making

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NASS OBJECTIVES

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TARGET AUDIENCES FOR THE NASS REPORT

 Government decision and policy makers and program officials  Individuals, families and communities living with ASD  Researchers and epidemiologists  Non government organizations, professionals and advocates  Service providers  General public

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REPORT RELEASE DATE: MARCH 29, 2018

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BACKGROUND

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Highly collaborative multi‐source and multi‐sector administrative data collection approach Based on 2015 data on children and youth aged 5–17 years Data from 7 provinces and territories (NL, NS, PEI, NB, QC, BC, YK) Data represents 40% of 5–17 year olds across Canada (88% of participating jurisdictions) Reports historical data with rising year‐over‐year prevalence trends in several jurisdictions Research questions out of scope for the NASS Report (e.g., causality and associated risk factors) Continued monitoring will support better understanding ASD rates and patterns over time

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*N.B. The previously reported rate for ASD in Canada was 1 in 94 based on the National Epidemiological Database for the Study of Autism in Canada (NEDSAC). Source: Autism Spectrum Disorder among Children and Youth in Canada 2018: A report of the National Autism Spectrum Disorder Surveillance System

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ASD PREVALENCE BY SEX, 5‐17 YEARS, 2015

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Source: Autism Spectrum Disorder among Children and Youth in Canada 2018: A report of the National Autism Spectrum Disorder Surveillance System

ASD PREVALENCE RATES IN 3 JURISDICTIONS, 5‐14 YEARS, 2003‐15

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Source: Autism Spectrum Disorder among Children and Youth in Canada 2018: A report of the National Autism Spectrum Disorder Surveillance System

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CANADA ‐ UNITED STATES COMPARISON

NASS

• 2015 data
• Monitors 5‐17 year olds
• 1 in 63 among 8 year olds

ADDM NETWORK

• 2012 data
• Monitors 8 year olds only
• 1 in 68 among 8 year olds

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Source: Autism Spectrum Disorder among Children and Youth in Canada 2018: A report of the National Autism Spectrum Disorder Surveillance System

ASD PREVALENCE RATES BY PROVINCE AND TERRITORY, 5‐17 YEARS, 2015

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Source: Autism Spectrum Disorder among Children and Youth in Canada 2018: A report of the National Autism Spectrum Disorder Surveillance System

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Sex

• Sex ratio varied from 1:3 to1:5 across

provinces

• UBC Adult clinic ~ 1:1

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