A Replication of the Autism Diagnostic Observation Schedule (ADOS) Revised Algorithms

Abstract

Objective-To replicate the factor structure and predictive validity of revised Autism Diagnostic Observation Schedule algorithms in an independent dataset (N = 1,282).Method-Algorithm revisions were replicated using data from children ages 18 months to 16 years collected at 11 North American sites participating in the Collaborative Programs for Excellence in Autism and the Studies to Advance Autism Research and Treatment.Results-Sensitivities and specificities approximated or exceeded those of the old algorithms except for young children with phrase speech and a clinical diagnosis of pervasive developmental disorders not otherwise specified.Conclusions-Revised algorithms increase comparability between modules and improve the predictive validity of the Autism Diagnostic Observation Schedule for autism cases compared to the original algorithms. Particular attention was paid to the factor structure and predictive validity of the revised algorithms in this large independent dataset. NIH Public AccessThe ADOS is a semistructured, standardized assessment designed for use with individuals referred for possible autism spectrum disorders (ASDs). Four ADOS modules accommodate various developmental and language levels. In each, a protocol of activities or social presses is administered in approximately 45 minutes, and then items are scored on a 4-point scale, with 0 indicating "no abnormality of type specified" and 3 indicating "moderate to severe abnormality." To receive an ADOS classification of autism or ASD, an individual's scores on the original diagnostic algorithms must meet separate cutoffs in the Communication and Social domains, and a summation of the two. If any or all of these thresholds are not met, then a nonspectrum classification is assigned. Item scores of 2 and 3 are collapsed in the algorithms to reduce the impact of individual items.ADOS algorithm revisions were prompted by questions of effects of impairment level on current totals. Gotham and colleagues 1 noted that module 1 totals in the Michigan 2007 sample exhibited a restricted range due to scoring communication items in nonverbal children. Joseph and colleagues 3 reported correlations between ADOS social domain totals and level of cognitive impairment for preschool children. De Bildt and colleagues 4 found that ADOS classifications appeared to be least valid for children with mild, compared to moderate or profound, mental retardation. Thus, algorithm revisions were undertaken to improve sensitivity and specificity while possibly reducing age and IQ effects of the ADOS.Another goal of the Michigan 2007 revisions was to modify the existing ADOS domain structure of distinct domains and cutoffs for Social and Communication items, based on several studies that found a single factor best described social and communication domain items.5 -7 In response to findings that observation of repetitive behaviors may make an independent contribution to diagnostic stability, 8 restricted, repetitive behavior (RRB) items were included in the total to which...

Social Interaction Style of Children and Adolescents with High-Functioning Autism Spectrum Disorder

“…Hence, our findings might not fully generalize to children and adolescents with more severe forms of ASD. Earlier studies have already shown a relatively poor sensitivity of the ADOS (ranging from .49 to .80) in classifying individuals with PDD-NOS (Bastiaansen et al 2010;Gotham et al 2008). However, it should also be noted that in the current study the distribution of clinical diagnoses (autism, syndrome of Asperger, PDD-NOS) was not significantly different for participants scoring above or below the ADOS cutoff for an ASD.…”

“…Despite the extensive diagnostic procedures, only thirtyseven percent of the participants (n = 57) received a total score on the ADOS at or above the cutoff point for ASD (C7). Earlier studies have already shown a relatively poor sensitivity of the ADOS (ranging from .49 to .80) in classifying individuals with PDD-NOS (Bastiaansen et al 2010;Gotham et al 2008). Therefore, all statistical analyses were repeated to check whether results differed between individuals scoring below or at/above the ADOS cutoff point.…”

Computational prosodic markers for autism

“…To confirm, however, whether a child indeed met diagnostic classification criteria for the ASD group, each child was further evaluated. The decision to classify a child in the ASD group was based on: (i) results on the revised algorithm of the ADOS (Lord et al, 2000; Gotham, Risi, Dawson, Tager-Flusberg, Joseph, Carter, et al, 2008), administered and scored by trained, certified clinicians; (ii) results on The Social Communication Questionnaire (SCQ; Berument, Rutter, Lord, Pickles, & Bailey,1999), a parent-report measure; and (iii) results of a consensus clinical diagnosis made by a multidisciplinary team in accord with DSM-IV criteria (American Psychiatric Association, 2002). In all cases, a diagnosis of ASD was supported by ADOS scores at or above cutoffs for PDD-NOS and by the consensus clinical diagnosis.…”

Evidence for autism spectrum disorder in Jacobsen syndrome: identification of a candidate gene in distal 11q

“…Using a clinical best estimate diagnostic approach following criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, 25 and following a method used in previous published research studies that includes clinical judgment, 23,26,27 each case was classified as ASD or non-ASD.…”