Problem/Condition: Autism spectrum disorder (ASD). Period Covered: 2016. Description of System: The Autism and Developmental Disabilities Monitoring (ADDM) Network is an active surveillance program that provides estimates of the prevalence of ASD among children aged 8 years whose parents or guardians live in 11 ADDM Network sites in the United States

Problem/Condition Autism spectrum disorder (ASD). Period Covered 2018. Description of System The Autism and Developmental Disabilities Monitoring (ADDM) Network conducts active surveillance of ASD. This report focuses on the prevalence and characteristics of ASD among children aged 8 years in 2018 whose parents or guardians lived in 11 ADDM Network sites in the United States (Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah, and Wisconsin). To ascertain ASD among children aged 8 years, ADDM Network staff review and abstract developmental evaluations and records from community medical and educational service providers. In 2018, children met the case definition if their records documented 1) an ASD diagnostic statement in an evaluation (diagnosis), 2) a special education classification of ASD (eligibility), or 3) an ASD International Classification of Diseases (ICD) code. Results For 2018, across all 11 ADDM sites, ASD prevalence per 1,000 children aged 8 years ranged from 16.5 in Missouri to 38.9 in California. The overall ASD prevalence was 23.0 per 1,000 (one in 44) children aged 8 years, and ASD was 4.2 times as prevalent among boys as among girls. Overall ASD prevalence was similar across racial and ethnic groups, except American Indian/Alaska Native children had higher ASD prevalence than non-Hispanic White (White) children (29.0 versus 21.2 per 1,000 children aged 8 years). At multiple sites, Hispanic children had lower ASD prevalence than White children (Arizona, Arkansas, Georgia, and Utah), and non-Hispanic Black (Black) children (Georgia and Minnesota). The associations between ASD prevalence and neighborhood-level median household income varied by site. Among the 5,058 children who met the ASD case definition, 75.8% had a diagnostic statement of ASD in an evaluation, 18.8% had an ASD special education classification or eligibility and no ASD diagnostic statement, and 5.4% had an ASD ICD code only. ASD prevalence per 1,000 children aged 8 years that was based exclusively on documented ASD diagnostic statements was 17.4 overall (range: 11.2 in Maryland to 29.9 in California). The median age of earliest known ASD diagnosis ranged from 36 months in California to 63 months in Minnesota. Among the 3,007 children with ASD and data on cognitive ability, 35.2% were classified as having an intelligence quotient (IQ) score ≤70. The percentages of children with ASD with IQ scores ≤70 were 49.8%, 33.1%, and 29.7% among Black, Hispanic, and White children, respectively. Overall, children with ASD and IQ scores ≤70 had earlier median ages of ASD diagnosis than children with ASD and IQ scores >70 (44 versus 53 months). Interpretation In 2018, one in 44 children aged 8 years was estimated to have ASD, and prevalence and median age of identification varied widely across sites. Whereas overall ASD prevalence was similar by race a...

The Autism Diagnostic Observation Schedule (ADOS; Lord et al., 2000) is widely accepted as a "gold standard" diagnostic instrument, but it is of restricted utility with very young children. The purpose of the current project was to modify the ADOS for use in children under 30 months of age. A modified ADOS, the ADOS Toddler Module (or Module T), was used in 360 evaluations. Participants included 182 children with best estimate diagnoses of ASD, non-spectrum developmental delay or typical development. A final set of protocol and algorithm items was selected based on their ability to discriminate the diagnostic groups. The traditional algorithm "cutoffs" approach yielded high sensitivity and specificity, and a new range of concern approach was proposed.Keywords autism spectrum disorders; diagnosis; ADOS; infants; toddlers Almost ten years ago, the standardization of a revised Autism Diagnostic Observation Schedule (ADOS), a semi-structured assessment for the diagnosis of autism spectrum disorders (ASD) (Lord, Rutter, DiLavore & Risi, 1999) was described. The ADOS has gradually become an integral part of many research and clinical protocols of children suspected of having an autism spectrum disorder (ASD). Due to the growing understanding of symptoms in the first two years of life and the desire of researchers and clinicians to have standardized instruments for use with infants and young toddlers, there is a need for diagnostic tools that are appropriate for very young children. This paper presents a new Toddler Module of the ADOS. The Toddler Module retains the original spirit and many of the original tasks of the ADOS, but is intended for use in children under 30 months of age who have nonverbal mental ages of at least 12 months. The scope of this report is to provide a summary of the new measure, the procedures used to develop it, a description of the standardization sample and relevant psychometrics.In introducing this new module, it is valuable to review the structure of the previously published ADOS. The ADOS evaluates social interaction, communication and play through a series of planned "presses" (Lord et al., 1989) in the context of a naturalistic social interaction. Some of the presses are intended to offer a high level of structure for the participant, while others are intended to provide less structure. All presses, however, afford contexts for both initiations and responses, which are then coded in a standardized manner. An algorithm, which sums the scores of particular items from the measure, yields a classification indicative of autism, ASD or nonspectrum conditions. This classification can then be used by a clinician or researcher as one part of a comprehensive diagnostic process.The first ADOS was introduced in the late 1980s and was intended for children who had a spoken language age equivalent of at least 36 months. A revision was published in 2000 that reflected the need for the measure to be applicable to a wider range of chronological and developmental ages. The 2000 version provided f...

Context Clinical best estimate diagnoses of specific autism spectrum disorders (autistic disorder, pervasive developmental disorder-not otherwise specified, Asperger’s disorder) have been used as the diagnostic gold standard, even when information from standardized instruments is available. Objective To determine if the relationships between behavioral phenotypes and clinical diagnoses of different autism spectrum disorders vary across 12 university-based sites. Design Multi-site observational study collecting clinical phenotype data (diagnostic, developmental and demographic) for genetic research. Classification trees were employed to identify characteristics that predicted diagnosis across and within sites. Setting Participants were recruited through 12 university-based autism service providers into a genetic study of autism. Participants 2102 probands (1814 males) between 4 and 18 years of age (M age=8.93, SD=3.5 years) who met autism spectrum criteria on the Autism Diagnostic Interview–Revised and Autism Diagnostic Observation Schedule and had a clinical diagnosis of an autism spectrum disorder. Main Outcome Measures Best estimate clinical diagnoses predicted by standardized scores from diagnostic, cognitive, and behavioral measures. Results Though distributions of scores on standardized measures were similar across sites, significant site differences emerged in best estimate clinical diagnoses of specific autism spectrum disorders. Relationships between clinical diagnoses and standardized scores, particularly verbal IQ, language level and core diagnostic features, varied across sites in weighting of information and cut-offs. Conclusions Clinical distinctions among categorical diagnostic subtypes of autism spectrum disorders were not reliable even across sites with well-documented fidelity using standardized diagnostic instruments. Results support the move from existing sub-groupings of autism spectrum disorders to dimensional descriptions of core features of social affect and fixated, repetitive behaviors, together with characteristics such as language level and cognitive function.