Autism Spectrum Disorders: Findings from CDC s Latest Prevalence Report

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1 Autism Spectrum Disorders: Findings from CDC s Latest Prevalence Report Jon Baio, Ed.S. Epidemiologist National Center on Birth Defects and Developmental Disabilities Centers for Disease Control and Prevention (CDC) I have no relevant financial or nonfinancial relationships within the products or services described, reviewed, evaluated or compared in this presentation ASHA Convention Atlanta, Georgia November 16, 2012 The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention. National Center on Birth Defects and Developmental Disabilities Centers for Disease Control and Prevention

Autism spectrum disorders (ASDs) are a group of developmental disabilities characterized by impairments in social interaction and communication and by restricted, repetitive, and stereotyped patterns

2 Autism spectrum disorders (ASDs) are a group of developmental disabilities characterized by impairments in social interaction and communication and by restricted, repetitive, and stereotyped patterns of behavior Symptoms can be identified by 14 months; typically persist throughout a person's life Many people with ASDs also have difficulty learning, paying attention, or reacting to different sensations Throughout this presentation, the terms autism and autism spectrum disorders are used interchangeably, but generally exclude the CDD and Rett subtypes

3 Statistics: CDC s Autism Public Health Actions Autism and Developmental Disabilities Monitoring (ADDM) Network Studies: Population-based surveillance of autism and other developmental disabilities Evaluate trends in prevalence and characteristics of children with autism Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) Action: Study to Explore Early Development (SEED) Identify factors that may put children at risk for autism Learn the Signs. Act Early. Improve early identification of developmental delays and autism

4 How common are Autism Spectrum Disorders? Estimates of population prevalence vary widely across time and space Different case ascertainment methods National or community surveys Clinical samples or registries Record-review methodology Different case definitions Parent report of historical diagnosis Diagnostic criteria (DSM-III, III-R, IV, IV-TR, 5) Diagnostic instruments (screening checklists, observational tools) Challenges in tracking autism prevalence Complex nature of the disorders Lack of biologic markers for diagnosis

5 Early Epidemiologic/Prevalence Studies Early epidemiologic studies in the 1970s (Denmark, UK, Japan) estimated the prevalence of autism at 4-5 per 10,000 (1 in 2500) Three US studies from 1980 s and early 1990 s estimated the prevalence of autistic disorder ranging from 3 to 4 per 10,000 Other studies from outside the US in the 1990 s estimated the prevalence of Autism/ASD ranging from 1 to 6 per 1, CDC study in Brick Township, NJ estimated the prevalence of Autistic Disorder at 4 per 1,000 and the broader Autism Spectrum (ASD) at 6.7 per 1,000

Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) Ongoing, active surveillance program since 1991 Records-based surveillance Multiple sources (education, healthcare,

6 Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) Ongoing, active surveillance program since 1991 Records-based surveillance Multiple sources (education, healthcare, disability services) 5 counties of Metropolitan Atlanta ASD surveillance incorporated into MADDSP in 1998 (1996 surveillance year) because of lack of US prevalence data and increasing public concern

7 MADDSP Methods: Records-based Surveillance Identify records to review at multiple educational and health sources in the community Educational: psycho-educational assessments, special education files; range of eligibility categories in special education from public schools Health: Discharge diagnosis, billing code, or referral reason at clinics, evaluation centers, etc. Review children s evaluation records for DD indicators ( triggers ) Behavioral/physical descriptions consistent with ASD or CP Standardized test scores for ID, HL and VI Abstract information from records containing triggers

8 Autism Clinician Review Case status is determined by clinicians who review the abstracted records using a systematic coding scheme based on DSM-IV-TR diagnostic criteria.

9 Additional Data on Characteristics Demographic Date of birth, race, sex Child and mother identifying information Educational Primary exceptionality Cognitive and adaptive functioning Clinical Diagnostic impressions Behavioral symptoms, autism tests Age of evaluations and diagnoses

10 MADDSP 1996 Autism Pilot 5 4 prevalence per 1, years 4 years 5 years 6 years 7 years 8 years 9 years 10 years Age

11 MADDSP 1996 Autism Pilot 6 Male Female prevalence per 1, White Black

12 Primary Special Education Exceptionality 9% 6% Autism 9% 41% SDD ID 14% S/L BD Other 21%

13 Expansion of CDC s DD Surveillance Programs SEC Developmental disabilities surveillance and research programs. (a) National Autism and Pervasive Developmental Disabilities Surveillance Program. (1) In general.the Secretary of Health and Human Services... acting through the Director of the Centers for Disease Control and Prevention, may make awards of grants and cooperative agreements for the collection, analysis, and reporting of data on autism and pervasive developmental disabilities... (2) Eligibility.To be eligible to receive an award under paragraph (1) an entity shall be a public or nonprofit private entity (including health departments of States and political subdivisions of States, and including universities and other educational entities).

15 Expansion of CDC s DD Surveillance Activities 1998: ASD surveillance study in Brick Township, NJ Estimated the prevalence of Autistic disorder at 4 per 1,000 and the broader Autism spectrum (ASD) at 6.7 per 1, : WV funded to implement ASD surveillance 2000: Four additional sites funded (AZ, MD, NJ, SC) 2001: Two CADDRE sites adopt ADDM methods (CO, PA) 2002: Four new sites funded (AR, FL, NC*, UT) 2003: Three new sites funded (AL, MO, WI) 2006: Ten sites funded for ADDM Phase : Three sites from Phase 1 reinstated 2010: Eleven sites funded for ADDM Phase 3

Working together to understand the magnitude and characteristics of the population of children with autism and related developmental disabilities to inform science and policy Currently there are 11

16 Working together to understand the magnitude and characteristics of the population of children with autism and related developmental disabilities to inform science and policy Currently there are 11 funded ADDM sites, plus CDC/MADDSP Autism prevalence among 8 year olds is monitored in all sites Piloting autism surveillance among 4 year olds in six sites Some sites also track Cerebral Palsy (4) and/or Intellectual Disability (7)

18 Strengths Large, population-based study of autism Multiple-source case ascertainment, including both health and special education records Record review methodology maximizes population coverage Coding scheme and systematic review of behavioral descriptions to determine case status (based on DSM-IV-TR diagnostic criteria) Information on presence of other developmental disabilities

19 Limitations No clinical validation of case status (although one study was completed in Fulton County, with PPV = 79%) Limited data on severity of autism symptoms Underascertainment of children with undocumented symptoms, children not being served in abstraction facilities, children in private schools or home-schooled (Fulton County study showed sensitivity = 60%)

20 ADDM Network Autism Prevalence Reports 2007: First reports representing 2000 & 2002 surveillance years 1 in year-old children in these communities identified with autism 2009: Second reports representing 2004 & 2006 surveillance years 1 in year-old children in these communities identified with autism Autism prevalence increased 57% between 2002 and : Most recent report representing 2008 surveillance year 14 areas in U.S. Characteristics of children identified with autism Comparisons to earlier ADDM Network surveillance years (2002 & 2006)

ADDM Network 2000-2008 Identified Prevalence of Autism Combining Data from All Sites Surveillance Year Birth Year Number of ADDM Sites Reporting 8-year-old Population Number of children identified

21 ADDM Network Identified Prevalence of Autism Combining Data from All Sites Surveillance Year Birth Year Number of ADDM Sites Reporting 8-year-old Population Number of children identified with ASDs Prevalence per 1,000 Children (Range across sites) ,761 1, ,578 2, ,335 1, ,038 2, ,093 3, ( ) 6.6 ( ) 8.0 ( ) 9.0 ( ) 11.3 ( )

22 Overview of Findings Combining data from all sites: 1 in 88 eight-year-old children identified with autism 23% increase, % increase, Identified prevalence of autism continues to rise in most ADDM Network communities Rate of increase higher in some groups Identified prevalence of autism varies widely Across sites By sex By race/ethnicity

23 Change in Identified Autism Prevalence Among ADDM Sites Identified Autism Prevalence per 1,

24 Change in Identified Autism Prevalence by Sex (*Percent change in 13 sites completing both 2002 & 2008 surveillance years) 20 *82% 18 Identified Autism Prevalence per 1, All Children Male Female *78% *63% Surveillance Year

25 Change in Identified Autism Prevalence by Race/Ethnicity (*Percent change in 13 sites completing both 2002 & 2008 surveillance years) 14 Identified Autism Prevalence per 1, All Race/Ethnicity White Black Hispanic *70% *78% *91% *110% Surveillance Year

26 Change in Identified Autism Prevalence by Intellectual Ability+ (*Percent change in 7 sites+ completing both 2002 & 2008 surveillance years) Identified ASD Prevalence per 1, IQ 70 IQ = IQ > 85 *93% *45% *117% Surveillance Year +Includes sites having information on intellectual ability available for at least 70% of children who met the ASD case definition

27 Change in Proportion of Children with Previously Documented Autism Classification (Combining data from 10 sites completing 2002, 2006 and 2008 surveillance years) Surveillance Year % with Previously Documented Autism Classification 72% 77% 79% Proportion of children meeting the autism surveillance case definition with a documented autism classification in their records increased over time in 7 of 10 sites completing all three surveillance years

28 Previously Documented Autism Classification ADDM Network, 2008 (Combining data from 14 sites completing 2008 surveillance year) Male 79.0% 11.8% 9.2% Female 76.0% 13.1% 10.9% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% ASD diagnosis or eligibility on record Suspicion of ASD noted No mention of ASD on record

29 Earliest Known Autism Diagnosis Median Age and Proportion by Diagnostic Subtype ADDM Network, 2008 (Combining data from 14 sites completing 2008 surveillance year) Subtype of Earliest Diagnosis: Autistic Disorder ASD/PDD Asperger Disorder Distribution of Subtypes: 44% 47% 9% Median Age of Earliest Diagnosis: 48 Months 53 Months 75 Months Distribution of subtypes did not change between (p=.71) Median age within each subtype slightly for AUT/ASD, slightly for ASP (p>.1) Evaluation records may not capture exact age/subtype of child s earliest autism diagnosis Instability of subtypes for about 20% of children (different subtypes across evaluations)

30 Earliest Known Diagnostic Subtype ADDM Network, 2008 (Combining data from 14 sites completing 2008 surveillance year) Male 44.1% 46.8% 9.1% Female 44.2% 46.7% 9.2% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Autistic Disorder ASD/PDD Asperger Disorder

31 Variation across Sites in Identified Prevalence of Autism ADDM Network, 14 Sites, 2008 Identified Autism Prevalence per 1, Health-Only Records Access Education & Health Records Access Prevalence for All Sites Combined 0

Arkansas Georgia North Carolina Arizona New Jersey Utah

+Includes sites having information on intellectual

32 Variation across Sites in Identified Prevalence of Autism ADDM Network, 7 Sites+, 2008 South Carolina Arkansas Georgia North Carolina Arizona New Jersey Utah IQ 70 Missing (no IQ data) IQ > 70 +Includes sites having information on intellectual ability available for at least 70% of children who met the ASD case definition

33 Summary of Findings Identified prevalence of autism continues to rise in most ADDM Network communities Combining data from all sites: 1 in 88 eight-year-old children identified with autism 23% increase, % increase, Rate of increase higher among Hispanic children, black children, and children without intellectual disability Identified prevalence of autism varies widely Across sites By sex By race/ethnicity

Implications of ADDM Network Findings Autism continues to be an important public

disparities in identified prevalence Across sites (methodologic: access to records /

socioeconomic status More children than ever are being identified as having autism

34 Implications of ADDM Network Findings Autism continues to be an important public health concern Better identification among certain subgroups Still concerned about disparities in identified prevalence Across sites (methodologic: access to records / geographic: access to care) Among children of minority race/ethnicity, low socioeconomic status More children than ever are being identified as having autism About 20% are not identified with autism by community providers Others are not recognized as early as they can be

35 Understanding Autism Prevalence Wide variation in prevalence estimates across time and space Changing criteria used to diagnose autism Geographic differences in diagnostic practices Changes in policy affecting availability of services Increased awareness in communities True increase in symptoms in population No single explanation; multiple factors at play

36 Moving Forward CountingAutism/ Continue ongoing surveillance to evaluate temporal trends Investigator-initiated analyses Timing and stability of diagnosis Incorporating DSM-5 criteria Socioeconomic disparities Intellectual functioning Geospatial analyses Birth characteristics Parental age Multiple births Gestational age and birthweight

37 More Than Just A Number Provides a more complete picture of autism Informs early identification efforts CDC s Autism Tracking Helps identify potential risk factors Guides our research and the research of other scientists

38 Acknowledgments Martha Wingate, DrPH, Beverly Mulvihill, PhD, University of Alabama at Birmingham; Russell S. Kirby, PhD, University of South Florida, Tampa; Sydney Pettygrove, PhD, Chris Cunniff, MD, F. John Meaney, PhD, University of Arizona, Tucson; Eldon Schulz, MD, University of Arkansas for Medical Sciences, Little Rock; Lisa Miller, MD, Colorado Department of Public Health and Environment, Denver; Cordelia Robinson, PhD, University of Colorado at Denver and Health Sciences Center; Gina Quintana, Colorado Department of Education, Denver; Marygrace Yale Kaiser, PhD, University of Miami, Coral Gables, Florida; Li-Ching Lee, PhD, Johns Hopkins University, Rebecca Landa, PhD, Kennedy Krieger Institute, Baltimore, Maryland; Craig Newschaffer, PhD, Drexel University, Philadelphia, Pennsylvania; John Constantino, MD, Robert Fitzgerald, MPH, Washington University in St. Louis, Missouri; Walter Zahorodny, PhD, University of Medicine and Dentistry of New Jersey, Newark; Julie Daniels, PhD, University of North Carolina, Chapel Hill; Ellen Giarelli, EdD, Drexel University, Philadelphia, Pennsylvania; Jennifer Pinto-Martin, PhD, University of Pennsylvania; Susan E. Levy, MD, The Children s Hospital of Philadelphia, Pennsylvania; Joyce Nicholas, PhD, Jane Charles, MD, Medical University of South Carolina, Charleston; Judith Zimmerman, PhD, University of Utah, Salt Lake City; Matthew J. Maenner, PhD, Maureen Durkin, PhD, DrPH, University of Wisconsin, Madison; Catherine Rice, PhD, Jon Baio, EdS, Kim Van Naarden Braun, PhD, Keydra Phillips, MPH, Nancy Doernberg, Marshalyn Yeargin- Allsopp, MD, Division of Birth Defects and Developmental Disabilities, National Center on Birth Defects and Developmental Disabilities, CDC. Data collection was coordinated at each site by ADDM Network project coordinators: Anita Washington, MPH, Yasmeen Williams, MPH, Kwin Jolly, MS, Research Triangle Institute, Atlanta, Georgia; Neva Garner, University of Alabama at Birmingham; Kristen Clancy Mancilla, University of Arizona, Tucson; Allison Hudson, University of Arkansas for Medical Sciences, Little Rock; Andria Ratchford, MSPH, Colorado Department of Public Health and Environment, Denver; Yolanda Castillo, MBA, Colorado Department of Education, Denver; Claudia Rojas, Yanin Hernandez, University of Miami, Coral Gables, Florida; Kara Humes, Rebecca Harrington, MPH, Johns Hopkins University, Baltimore, Maryland; Rob Fitzgerald, MPH, Washington University in St. Louis, Missouri; Josephine Shenouda, MS, University of Medicine and Dentistry of New Jersey, Newark; Paula Bell, University of North Carolina, Chapel Hill; Rachel Reis, University of Pennsylvania, Philadelphia; Lydia King, PhD, Medical University of South Carolina, Charleston; Amanda Bakian, PhD, Amy Henderson, University of Utah, Salt Lake City; Carrie Arneson, MS, University of Wisconsin, Madison; Susan Graham Schwartz, MSPH, CDC. Additional assistance was provided by project staff including data abstractors, clinician reviewers, epidemiologists, and data management/programming support. Ongoing ADDM Network support was provided by Joanne Wojcik, Victoria Wright, National Center on Birth Defects and Developmental Disabilities, CDC, Rita Lance, Northrop Grumman, contractor to CDC.

39 Community Report on Autism To download a copy of the Community Report, please visit

Autism Spectrum Disorder (ASD) Surveillance Year 2010 Findings

Arkansas Autism and Developmental Disabilities Monitoring (AR ADDM) Program Autism Spectrum Disorder (ASD) Surveillance Year 2010 Findings & Comparison with Arkansas 2002 Baseline Prevalence Study Eldon