Improved diagnostic validity of the ADOS revised algorithms: a replication study in an independent sample

Gender Differences: Confirmatory Factor Analysis of the ADOS-II

PURPOSE

Recent research has suggested that autism may present differently in girls compared to boys, encouraging the exploration of a sex-differential diagnostic criteria. Gender differences in diagnostic assessments have been shown on the ADOS-II, such that, on average, females score significantly lower than males on all scales and are less likely to show atypicality on most items related to social communicative difficulties. Yet, gender differences in the latent structure of instruments like the ADOS-II have not been examined systematically.

METHODS

As such, this secondary data analysis examined 4,100 youth diagnosed with autism (Mage = 9.9, 813 female & 3287 male) examined item response trends by gender on the ADOS-II Module 3.

RESULTS

Multi-Group Confirmatory Factor Analysis results show that the factor loadings of four ADOS-II items differ across the genders. One SCD item and one RRB item are strongly related to the latent factor in the female group, while two RRB items have larger factor loadings in the male group.

CONCLUSION

The assumption of an identical latent factor structure for the ADOS-II Module 3 for males and females might not be justifiable. Possible diagnostic implications are discussed.

Autism spectrum disorder in ICD-11-a critical reflection of its possible impact on clinical practice and research

This perspective article compares and contrasts the conceptualization of Autism Spectrum Disorder (ASD) in ICD-11 and DSM-5. By guiding the user through the ICD-11 text, it is argued that, in contrast to DSM-5, ICD-11 allows a high variety in symptom combinations, which results in an operationalization of ASD that is in favor of an extreme diverse picture, yet possibly at the expense of precision, including unforeseeable effects on clinical practice, care, and research. The clinical utility is questionable as this conceptualization can hardly be differentiated from other mental disorders and autism-like traits. It moves away from an observable, behavioral, and neurodevelopmental disorder to a disorder of inner experience that can hardly be measured objectively. It contains many vague and subjective concepts that lead to non-falsifiable diagnoses. This bears a large danger of false positive diagnoses, of further increased prevalence rates, limitations of access to ASD-specific services and of increasing the non-specificity of treatments. For research, the hypothesis is that the specificity of ASD will be reduced and this will additional increase the already high heterogeneity with the effect that replication of studies will be hampered. This could limit our understanding of etiology and biological pathways of ASD and bears the risk that precision medicine, i.e., a targeted approach for individual treatment strategies based on precise diagnostic markers, is more far from becoming reality. Thus, a more precise, quantitative description and more objective measurement of symptoms are suggested that define the clinical ASD phenotype. Identification of core ASD subtypes/endophenotypes and a precise description of symptoms is the necessary next step to advance diagnostic classification systems. Therefore, employing a more finely grained, objective, clinical symptom characterization which is more relatable to neurobehavioral concepts is of central significance.

Replication study for ADOS-2 cut-offs to assist evaluation of autism spectrum disorder

The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) has been widely used for ASD assessment. While prior studies investigated sensitivity and specificity of ADOS-2 Modules 1-3, there has been limited research addressing algorithm cut-off scores to optimize ADOS-2 classification. The goal of this study was to assess algorithm cut-off scores for diagnosing ASD with Modules 1-3, and to evaluate alignment of the ADOS-2 classification with the best estimate clinical diagnosis. Participants included 3144 children aged 31 months or older who received ADOS-2 Modules 1-3, as well as the best estimate clinical diagnosis. Five classification statistics were reported for each module: sensitivity, specificity, positive predictive value, negative predictive value, and accuracy (i.e., Receiver Operator Classification Statistic), and these statistics were calculated for the optimal cut-off score. Frequency tables were used to compare ADOS-2 classification and the best estimate clinical diagnosis. Half of the sample received Module 3, 21% received Module 2, and 29% received Module 1. The overall prevalence of ASD was 60%; the male-to-female ratio was 4:1, and half of the sample was non-White. Across all modules, the autism spectrum cut-off score from the ADOS-2 manual resulted in high sensitivity (95%+) and low specificity (63%-73%). The autism cut-off score resulted in better specificity (76%-86%) with favorable sensitivity (81%-94%). The optimal cut-off scores for all modules based on the current sample were within the autism spectrum classification range except Module 2 Algorithm 2. In the No ASD group, 29% had false positives (ADOS-2 autism spectrum classification or autism classification). The ADOS-2 autism spectrum classification did not indicate directionality for diagnostic outcome (ASD 56% vs. No ASD 44%). While cut-off scores of ADOS-2 Modules 1-3 in the manual yielded good clinical utility in ASD assessment, false positives and low predictability of the autism spectrum classification remain challenging for clinicians.

Diagnostic validity of Autism Diagnostic Observation Schedule, second edition (K-ADOS-2) in the Korean population

Background

Although the Korean version of the Autism Diagnostic Observation Schedule-2 (K-ADOS‐2) is widely being used to diagnose autism spectrum disorder (ASD) in South Korea, no previous study has examined the validity and reliability of all modules of K-ADOS-2 across a wide age range, particularly older children, adolescents, and adults.

Method

Data from 2,158 participants were included (mean age = 79.7 months; 73.6% male): 1473 participants with ASD and 685 participants without ASD (Toddler Module, n = 289; Module 1, n = 642; Module 2 n = 574; Module 3 n = 411; Module 4, n = 242). Participants completed a battery of tests, including the K-ADOS or K-ADOS-2 and other existing diagnostic instruments. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve, positive predictive value (PPV), negative predictive value (NPV), Cohen’s kappa (k), and agreement with existing diagnostic instruments were computed. Cronbach’s α values were also calculated.

Results

All developmental cells of the K-ADOS-2 showed sufficient ranges of sensitivity 85.4–100.0%; specificity, 80.4–96.8%; area under the ROC curve, .90-.97; PPV, 77.8–99.3%; NPV, 80.6–100.0%; and k values, .83–.92. The kappa agreements of developmental cells with existing diagnostic instruments ranged from .20 to .90. Cronbach’s α values ranged from .82 to .91 across all developmental cells.

Limitation

The best-estimate clinical diagnoses made in this study were not independent of the K-ADOS-2 scores. Some modules did not include balanced numbers of participants in terms of gender and diagnostic status.

Conclusion

The K-ADOS-2 is a valid and reliable instrument in diagnosing ASD in South Korea. Future studies exploring the effectiveness of the K-ADOS-2 in capturing restricted, repetitive behaviors and differentiating ASD from other developmental disabilities are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00506-5.

Play in Relation to Autism Traits in Young Children at Elevated Likelihood for Autism Spectrum Disorder

Play of younger siblings of children with autism spectrum disorder (ASD) (siblings; n = 44), very preterm children (preterms; n = 44), and children at typical likelihood for ASD (n = 36) was observed at 24 months. Children with ASD and atypical development engaged less in spontaneous (pre-)symbolic play than typically developing children. Total duration of spontaneous and elicited (pre-)symbolic play was associated with later ASD traits in siblings. However, no association between most play variables and ASD traits was found in preterms. This suggests possible different ASD-trajectories between siblings and preterms. Thus, spontaneous (pre-)symbolic play may be indicative of developmental challenges across several populations, and results highlight the need to move beyond studying only siblings in order to broaden our understanding of ASD.

Joint attention and intelligence in children with autism spectrum disorder without severe intellectual disability

In children with autism spectrum disorder (ASD), joint attention is regarded as a predictor of language function, social skills, communication, adaptive function, and intelligence. However, existing information about the association between joint attention and intelligence is limited. Most such studies have examined children with low intelligence. For this study, we investigated whether joint attention is related to intelligence in young children with autism spectrum disorder (ASD) without severe intellectual disability. We analyzed 113 children with ASD aged 40–98 months. Their Kaufman Assessment Battery (K‐ABC) Mental Processing Index (MPI) scores are 60 and more (mean 93.4). We evaluated their intelligence using K‐ABC and evaluated their joint attention using ADOS‐2. After we performed simple regression analyses using K‐ABC MPI and its nine subscales as dependent variables, using joint attention as the independent variable, we identified joint attention as a positive predictor of the MPI and its two subscales. From this result, we conclude that joint attention is related to intelligence in young children with ASD without severe intellectual disability. This result suggests a beneficial effect of early intervention targeting joint attention for children with ASD.

Autism spectrum disorder screening in Chinese-language preschools

This study examined the reliability and validity of the 13-item Classroom Observation Scale as used by teachers and non-clinically trained observers to identify children who more likely than their peers to have autism spectrum disorder in less-resourced preschools. A total of 534 children (ages 2;10 to 4;5, Mean = 3;8) from nine Chinese-language preschools serving families from lower-middle to middle socioeconomic backgrounds in Hong Kong were observed in their first preschool year using the Classroom Observation Scale. The 75 screen-positive children and 55 randomly selected typically developing peers were clinically assessed for autism spectrum disorder 1 year later. The Classroom Observation Scale as used by teachers and non-clinically trained researchers helped to identify preschoolers who were later diagnosed with autism spectrum disorder with odds ratios of 3.11 and 8.66, respectively. This study provided further evidence on the versatility and ecological validity of the Classroom Observation Scale for use by preschool teachers and observers with little or no clinical training in the early identification of children with autism spectrum disorder in community settings.

Autism spectrum disorder screening in preschools

LAY ABSTRACT

With professional training and regular opportunities to observe children interacting with their peers, preschool teachers are in a good position to notice children's autism spectrum disorder symptomatology. Yet even when a preschool teacher suspects that a child may have autism spectrum disorder, fear of false alarm may hold the teacher back from alerting the parents, let alone suggesting them to consider clinical assessment for the child. A valid and convenient screening tool can help preschool teachers make more informed and hence more confident judgment. We set out to develop a screening tool that capitalizes on peer interaction as a naturalistic "stress test" to identify children more likely than their peers to have autism spectrum disorder. A total of 304 3- to 4-year-olds were observed at school with an 84-item preliminary checklist; data-driven item reduction yielded a 13-item Classroom Observation Scale. The Classroom Observation Scale scores correlated significantly with Autism Diagnostic Observation Schedule-2 scores. To validate the scale, another 322 2- to 4-year-olds were screened using the Classroom Observation Scale. The screen-positive children and randomly selected typically developing peers were assessed for autism spectrum disorder 1.5 years later. The Classroom Observation Scale as used by teachers and researchers near preschool onset predicted autism spectrum disorder diagnoses 1.5 years later. This user-friendly 13-item Classroom Observation Scale enables teachers and healthcare workers with little or no clinical training to identify, with reliable and valid results, preschoolers more likely than their peers to have autism spectrum disorder.

Systematic Review and Meta-Analysis of the Clinical Utility of the ADOS-2 and the ADI-R in Diagnosing Autism Spectrum Disorders in Children

The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) and the Autism Diagnostic Interview, Revised (ADI-R) have high accuracy as diagnostic instruments in research settings, while evidence of accuracy in clinical settings is less robust. This meta-analysis focused on efficacy of these measures in research versus clinical settings. Articles (n = 22) were analyzed using a hierarchical summary receiver operating characteristics (HSROC) model. ADOS-2 performance was stronger than the ADI-R. ADOS-2 sensitivity and specificity ranged from .89-.92 and .81-.85, respectively. ADOS-2 accuracy in research compared with clinical settings was mixed. ADI-R sensitivity and specificity were .75 and .82, respectively, with higher specificity in research samples (Research = .85, Clinical = .72). A small number of clinical studies were identified, indicating ongoing need for investigation outside research settings.

Utility of the Autism Diagnostic Observation Schedule and the Brief Observation of Social and Communication Change for Measuring Outcomes for a Parent-Mediated Early Autism Intervention

Measuring outcomes for autistic children following social communication interventions is an ongoing challenge given the heterogeneous changes, which can be subtle. We tested and compared the overall and item-level intervention effects of the Brief Observation of Social Communication Change (BOSCC), Autism Diagnostic Observation Schedule (ADOS-2) algorithm, and ADOS-2 Calibrated Severity Scores (CSS) with autistic children aged 2-5 years from the Preschool Autism Communication Trial (PACT). The BOSCC was applied to Module 1 ADOS assessments (ADOS-BOSCC). Among the 117 children using single or no words (Module 1), the ADOS-BOSCC, ADOS algorithm, and ADOS CSS each detected small non-significant intervention effects. However, on the ADOS algorithm, there was a medium significant intervention effect for children with "few to no words" at baseline, while children with "some words" showed little intervention effect. For the full PACT sample (including ADOS Module 2, total n=152), ADOS metrics evidenced significant small (CSS) and medium (algorithm) overall intervention effects. None of the Module 1 item-level intervention effects reached significance, with largest changes observed for Gesture (ADOS-BOSCC and ADOS), Facial Expressions (ADOS), and Intonation (ADOS). Significant ADOS Module 2 item-level effects were observed for Mannerisms and Repetitive Interests and Stereotyped Behaviors. Despite strong psychometric properties, the ADOS-BOSCC was not more sensitive to behavioral changes than the ADOS among Module 1 children. Our results suggest the ADOS can be a sensitive outcome measure. Item-level intervention effect plots have the potential to indicate intervention "signatures of change," a concept that may be useful in future trials and systematic reviews. LAY SUMMARY: This study compares two outcome measures in a parent-mediated therapy. Neither was clearly better or worse than the other; however, the Autism Diagnostic Observation Schedule produced somewhat clearer evidence than the Brief Observation of Social Communication Change of improvement among children who had use of "few to no" words at the start. We explore which particular behaviors are associated with greater improvement. These findings can inform researchers when they consider how best to explore the impact of their intervention.

Autism Spectrum Disorder Symptoms are Associated with Connectivity Between Large-Scale Neural Networks and Brain Regions Involved in Social Processing

The neurobiology of autism spectrum disorder remains poorly understood. The present study addresses this knowledge gap by examining the relationship between functional brain connectivity and Autism Diagnostic Observation Schedule (ADOS) scores using publicly available data from the Autism Brain Imaging Data Exchange (ABIDE) database (N = 107). This relationship was tested across all brain voxels, without a priori assumptions, using a novel statistical approach. ADOS scores were primarily associated with decreased connectivity to right temporoparietal junction, right anterior insula, and left fusiform gyrus (p < 0.05, corrected). Seven large-scale brain networks influenced these associations. Findings largely encompassed brain regions involved in processing socially relevant information, highlighting the importance of these processes in autism spectrum disorder.

Description of Criterion Validity of the Autism Spectrum Rating Scales 6-18 Parent Report: Initial Exploration in a Large Community Sample

Research regarding psychometric properties of autism spectrum disorder questionnaires is lacking. This study explored the criterion validity of the ASRS 6-18 parent report (ASRS-6-18-P) in a large, well-characterized, real-world clinical sample of 422 children ([Formula: see text] autism [AUT] n = 139; non-autism [NOT] n = 283) evaluated with the Autism Diagnostic Observation Schedule-2, a gold-standard measure. Significant mean differences were observed for DSM-5, social, and unusual behaviors. Total, DSM-5, social, and unusual behaviors demonstrated significant correlations with ADOS-2 comparison scores (modules 1-3), but not with module 4 (raw) scores. DSM-5 and Unusual Behaviors demonstrated significant but poor AUCs (0.60). Findings with/without covariates (IQ/age) were overall similar. Sensitivity and specificity could not be optimized. The suggested cutpoint (T-score = 60) demonstrated unacceptably high false positive rates (> 76.33%). While findings suggest limited diagnostic utility of the ASRS-6-18-P, the sample's complex psychiatric presentation and measurement error inherent in cutoff score application should be considered when generalizing results. Further research is recommended.

Preliminary evidence of the validity process of the Autism Diagnostic Observation Schedule (ADOS): translation, cross-cultural adaptation and semantic equivalence of the Brazilian Portuguese version

OBJECTIVES

To translate and back-translate the Autism Diagnostic Observation Schedule (ADOS) into Brazilian Portuguese, to assess its cross-cultural semantic equivalence, and to verify indicators of quality of the final version by analyzing the inter-rater reliability of the ADOS scores.

METHODS

This study had three stages: 1) translation and back-translation; 2) semantic equivalence analysis; and 3) pre-test to verify the agreement between mental health specialists and an ADOS senior examiner regarding the scoring procedure. Authorization to translate and carry out the cultural adaptation of the instrument was first obtained from the Western Psychological Services, publishers of the instrument.

RESULTS

The main preliminary results pointed to good equivalence between the original English version and the final version and the Brazilian version following the cultural adaptation process. Some semantic differences were found between the original version and the back-translation into English, but they did not interfere with the first translation into Portuguese or into the final version. One of the limitations of the study was the small sample size; for that reason, the inter-rater reliability of the ADOS scores between the specialists and the senior examiner using the kappa coefficient was adequate for 7 out of 10 areas.

CONCLUSIONS

We conclude that the creation of an official Brazilian version of ADOS will help to strengthen clinical and scientific research into ASD, and deter the use of other unauthorized versions of ADOS in the country.

Student-teacher relationships of children with autism spectrum disorder: Distinct contributions of language domains

BACKGROUND AND AIMS

High quality student-teacher relationships (STR) are important for children's academic and social development. We explore how individual child language domains (semantics, syntax, pragmatics), teacher years of experience, and classroom placement (general or special education) relate to STR quality for children with autism spectrum disorder (ASD) across the school year.

METHODS AND PROCEDURES

191 children with ASD (Mage = 5.6 years) completed a standardized language assessment and their teachers reported on STR quality twice during the school year.

OUTCOME AND RESULTS

Pragmatics, but not semantics or syntax, had a direct effect on student-teacher closeness. The association between semantics and closeness was moderated by classroom type; for students with low semantics, teacher-reported closeness was lower in general versus special education. Teachers in special versus general education classrooms reported closer relationships. More experienced teachers reported closer and less conflictual relationships. None of the three language domains were associated with student-teacher conflict.

CONCLUSIONS AND IMPLICATIONS

Pragmatic and semantic language skills were associated with closer relationships. Language-focused therapies may be effective in carrying over to impact STR quality. Given the stability in relationship quality, targeted interventions should be delivered to teachers at the beginning of the school year to support positive relationship development.

Exploring diagnostic validity of the autism diagnostic observation schedule-2 in South Korean toddlers and preschoolers

This study aims to provide the initial validity of the Autism Diagnostic Observation Schedule-2 (ADOS-2) Toddler Module and Module 1-2 for South Korean toddlers and preschoolers. Based on 143 children, the ASD group (n = 68) showed significantly higher ADOS-2 item and algorithm total scores as well as social affect and repetitive and restricted behaviors domain scores compared with children with nonspectrum (NS; n = 42) disorders and typically developing (TD; n = 33) children. Using lower algorithm cutoffs, sensitivities were excellent for the ASD versus NS/TD comparisons, ranging from 94% to 100% across different Modules. Specificities varied more, ranging from 82% to 100%. Internal consistency was strong with high item-total correlations (r of 0.6-0.9) and Cronbach's Alphas (all above 0.7). Results demonstrated promising, initial evidence for the validity of the ADOS-2 for South Korean toddlers and preschoolers from 1 to 4 years of age. The ADOS-2 could be implemented, with minimal adaptations, in research and clinical settings in South Korea. This study is one of the first steps toward validating the ADOS-2 in other Eastern countries that are in great need for a valid instrument for the detection of ASD. Autism Res 2019, 12: 1356-1366. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Results of this study demonstrated promising, initial evidence for the validity of a gold standard measure for the diagnosis of autism, the Autism Diagnostic Observation Schedule-2 (ADOS-2), for South Korean toddlers and preschoolers. The ADOS-2 could be implemented, with minimal adaptations, in research and clinical settings in South Korea. This study is one of the first steps toward validating the ADOS-2 in other Eastern countries that are in great need of a valid instrument for the detection of ASD.

Sensitivity and Specificity of the ADOS-2 Algorithm in a Large German Sample

The aim of the present study was to establish diagnostic validity of the new algorithm of the Autism Diagnostic Observation Scale, the ADOS-2, to differentiate between ASD and other clinically relevant psychiatric and developmental disorders in a large German sample. Validity of ADOS and ADOS-2 diagnostic algorithms was established in 826 individuals (n = 455 autism, n = 216 autism spectrum, n = 155 non-ASD patients) by receiver operating curves. Confidence intervals overlapped largely for ADOS and ADOS-2 algorithms, confirming diagnostic validity of both algorithms. Adding information of the Social Communication Questionnaire and the Social Responsiveness Scale resulted in slightly improved classification rates for autism in Module 4. We thus replicated previous findings of the diagnostic validity of the ADOS-2 algorithms.

Autism: One or many spectrums?

Our conceptualisation of autism spectrum disorder has changed over time, with recent classifications reflecting a heterogeneous clinical presentation now regularly encountered in routine general paediatric practice. As the prevalence of autism and associated demands for services have increased so has research into understanding the cause and trials aimed at providing best care and intervention. However, the heterogeneity of autism has meant that no single aetiology can account for all differences in presentation, and not all children benefit from broad-based interventions. Now is the time to rethink how best to understand individual differences in order to focus research efforts and take steps towards more sophisticated strategies that go beyond the behaviours we look for when making an autism diagnosis. We suggest adopting a dimensional approach to autism assessment, with the consideration of eight spectrums of abilities, ways of thinking and behaviour. This eight-spectrum approach will assist clinicians to consider each individual's strengths and needs and personalise interventions and support accordingly. Profiling individual skills across these dimensions may also provide researchers with a greater capacity to link causal pathways with specific phenotypes, which is needed to develop precision medicine for autism.

Diagnostic accuracy of the ADOS and ADOS-2 in clinical practice

The Autism Diagnostic Observation Schedule is a semi-structured, standardized assessment tool for individuals with suspected autism spectrum disorders (ASD) and is deemed to be part of the gold standard for diagnostic evaluation. Good diagnostic accuracy and interpersonal objectivity have been demonstrated for the ADOS in research setting. The question arises whether this is also true for daily clinical practice and whether diagnostic accuracy depends on specialized experience in the diagnostic evaluation. The present study explores the diagnostic accuracy of the original and the revised version of the ADOS for Modules 1 through 4. Thus, seven cases of ADOS executions were recorded and coded by a group of experts of specialized outpatient clinics for ASD. In an extensive consensus process, including video analysis of every minute of the ADOS executions, a "gold standard" coding for every case was defined. The videos of the ADOS administration were presented to a large group of clinicians (from daily clinical routine care) and their codings (n = 189) were obtained and analysed. Variance of coding and congruence with the expert coding were determined. High variance was found in the codings. The accuracy of the coding depends on the experience of the coder with the ADOS as well as on characteristics of the cases and the quality of the administration of the ADOS. Specialization in the diagnostic of ASD has to be claimed. Specialized outpatient clinics for ASD are required which guarantee a qualified diagnostic/differential diagnostic and case management with the aim of demand-oriented supply of individual cases.

Diagnostic tests for autism spectrum disorder (ASD) in preschool children

BACKGROUND

Autism spectrum disorder (ASD) is a behaviourally diagnosed condition. It is defined by impairments in social communication or the presence of restricted or repetitive behaviours, or both. Diagnosis is made according to existing classification systems. In recent years, especially following publication of the Diagnostic and Statistical Manual of Mental Disorders - Fifth Edition (DSM-5; APA 2013), children are given the diagnosis of ASD, rather than subclassifications of the spectrum such as autistic disorder, Asperger syndrome, or pervasive developmental disorder - not otherwise specified. Tests to diagnose ASD have been developed using parent or carer interview, child observation, or a combination of both.

OBJECTIVES

Primary objectives1. To identify which diagnostic tools, including updated versions, most accurately diagnose ASD in preschool children when compared with multi-disciplinary team clinical judgement.2. To identify how the best of the interview tools compare with CARS, then how CARS compares with ADOS.a. Which ASD diagnostic tool - among ADOS, ADI-R, CARS, DISCO, GARS, and 3di - has the best diagnostic test accuracy?b. Is the diagnostic test accuracy of any one test sufficient for that test to be suitable as a sole assessment tool for preschool children?c. Is there any combination of tests that, if offered in sequence, would provide suitable diagnostic test accuracy and enhance test efficiency?d. If data are available, does the combination of an interview tool with a structured observation test have better diagnostic test accuracy (i.e. fewer false-positives and fewer false-negatives) than either test alone?As only one interview tool was identified, we modified the first three aims to a single aim (Differences between protocol and review): This Review evaluated diagnostic tests in terms of sensitivity and specificity. Specificity is the most important factor for diagnosis; however, both sensitivity and specificity are of interest in this Review because there is an inherent trade-off between these two factors.Secondary objectives1. To determine whether any diagnostic test has greater diagnostic test accuracy for age-specific subgroups within the preschool age range.

SEARCH METHODS

In July 2016, we searched CENTRAL, MEDLINE, Embase, PsycINFO, 10 other databases, and the reference lists of all included publications.

SELECTION CRITERIA

Publications had to: 1. report diagnostic test accuracy for any of the following six included diagnostic tools: Autism Diagnostic Interview - Revised (ADI-R), Gilliam Autism Rating Scale (GARS), Diagnostic Interview for Social and Communication Disorder (DISCO), Developmental, Dimensional, and Diagnostic Interview (3di), Autism Diagnostic Observation Schedule - Generic (ADOS), and Childhood Autism Rating Scale (CARS); 2. include children of preschool age (under six years of age) suspected of having an ASD; and 3. have a multi-disciplinary assessment, or similar, as the reference standard.Eligible studies included cohort, cross-sectional, randomised test accuracy, and case-control studies. The target condition was ASD.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all studies for inclusion and extracted data using standardised forms. A third review author settled disagreements. We assessed methodological quality using the QUADAS-2 instrument (Quality Assessment of Studies of Diagnostic Accuracy - Revised). We conducted separate univariate random-effects logistical regressions for sensitivity and specificity for CARS and ADI-R. We conducted meta-analyses of pairs of sensitivity and specificity using bivariate random-effects methods for ADOS.

MAIN RESULTS

In this Review, we included 21 sets of analyses reporting different tools or cohorts of children from 13 publications, many with high risk of bias or potential conflicts of interest or a combination of both. Overall, the prevalence of ASD for children in the included analyses was 74%.For versions and modules of ADOS, there were 12 analyses with 1625 children. Sensitivity of ADOS ranged from 0.76 to 0.98, and specificity ranged from 0.20 to 1.00. The summary sensitivity was 0.94 (95% confidence interval (CI) 0.89 to 0.97), and the summary specificity was 0.80 (95% CI 0.68 to 0.88).For CARS, there were four analyses with 641 children. Sensitivity of CARS ranged from 0.66 to 0.89, and specificity ranged from 0.21 to 1.00. The summary sensitivity for CARS was 0.80 (95% CI 0.61 to 0.91), and the summary specificity was 0.88 (95% CI 0.64 to 0.96).For ADI-R, there were five analyses with 634 children. Sensitivity for ADI-R ranged from 0.19 to 0.75, and specificity ranged from 0.63 to 1.00. The summary sensitivity for the ADI-R was 0.52 (95% CI 0.32 to 0.71), and the summary specificity was 0.84 (95% CI 0.61 to 0.95).Studies that compared tests were few and too small to allow clear conclusions.In two studies that included analyses for both ADI-R and ADOS, tests scored similarly for sensitivity, but ADOS scored higher for specificity. In two studies that included analyses for ADI-R, ADOS, and CARS, ADOS had the highest sensitivity and CARS the highest specificity.In one study that explored individual and additive sensitivity and specificity of ADOS and ADI-R, combining the two tests did not increase the sensitivity nor the specificity of ADOS used alone.Performance for all tests was lower when we excluded studies at high risk of bias.

AUTHORS' CONCLUSIONS

We observed substantial variation in sensitivity and specificity of all tests, which was likely attributable to methodological differences and variations in the clinical characteristics of populations recruited.When we compared summary statistics for ADOS, CARS, and ADI-R, we found that ADOS was most sensitive. All tools performed similarly for specificity. In lower prevalence populations, the risk of falsely identifying children who do not have ASD would be higher.Now available are new versions of tools that require diagnostic test accuracy assessment, ideally in clinically relevant situations, with methods at low risk of bias and in children of varying abilities.

Investigating Mirror System (MS) Activity in Adults with ASD When Inferring Others' Intentions Using Both TMS and EEG

ASD is associated with mentalizing deficits that may correspond with atypical mirror system (MS) activation. We investigated MS activity in adults with and without ASD when inferring others' intentions using TMS-induced motor evoked potentials (MEPs) and mu suppression measured by EEG. Autistic traits were measured for all participants. Our EEG data show, high levels of autistic traits predicted reduced right mu (8-10 Hz) suppression when mentalizing. Higher left mu (8-10 Hz) suppression was associated with superior mentalizing performances. Eye-tracking and TMS data showed no differences associated with autistic traits. Our data suggest ASD is associated with reduced right MS activity when mentalizing, TMS-induced MEPs and mu suppression measure different aspects of MS functioning and the MS is directly involved in inferring intentions.

Abilities to Explicitly and Implicitly Infer Intentions from Actions in Adults with Autism Spectrum Disorder

Previous research suggests that Autism Spectrum Disorder (ASD) might be associated with impairments on implicit but not explicit mentalizing tasks. However, such comparisons are made difficult by the heterogeneity of stimuli and the techniques used to measure mentalizing capabilities. We tested the abilities of 34 individuals (17 with ASD) to derive intentions from others' actions during both explicit and implicit tasks and tracked their eye-movements. Adults with ASD displayed explicit but not implicit mentalizing deficits. Adults with ASD displayed typical fixation patterns during both implicit and explicit tasks. These results illustrate an explicit mentalizing deficit in adults with ASD, which cannot be attributed to differences in fixation patterns.

Adaptation and Validation of the ADOS-2, Polish Version

Autism Diagnostic Observation Schedule (ADOS) is one of the most popular instruments used world-widely in the diagnosis of autism spectrum disorders (ASD). Unfortunately, there are only a few studies of the psychometric properties of non-English language versions of this instrument and none of the adaptation of its second edition (ADOS-2). The objective of this study was to verify the psychometric properties of the Polish version of the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2-PL). The authors recruited 401 participants: 193 with ASDs (ASD group) and 78 with non-spectrum disorders, plus 130 typically developing participants (control group). ADOS-2-PL was found to have high interrater reliability, internal consistency and test-retest reliability. Confirmatory factor analysis confirmed a good fit of the Polish data to the two-factor model of ADOS-2. As no significant differences were found between participants with childhood autism and other ASDs, only one cut-off was established for Modules 1-4. The sensitivity, specificity and positive predictive value of ADOS-2-PL are high: sensitivity was over 90% (only for the "Older with some words" algorithm in the Toddler Module the sensitivity was 71% and "Aged 5 years or older" algorithm in Module 2 sensitivity was 84%), specificity was above 80% (with the exception of the Module 4 and Module 2 "Aged 5 years or older" algorithm where it was above 70%). The results support the use of ADOS-2-PL in clinical practice and scientific research. To the best of our knowledge, there have been no reports to date about adaptations of ADOS-2 and the psychometric properties of non-English language versions. As such, this constitutes the first attempt at adapting ADOS-2, and its results could be of interest for researchers outside of Poland.

Genetic Testing for Autism Spectrum Disorder is Lacking Evidence of Cost-effectiveness. A Systematic Review

BACKGROUND

Autism Spectrum Disorder (ASD) is a highly heritable neural development disorder characterized by social impairment. The earlier the diagnosis is made, the higher are the chances of obtaining relief of symptoms. A very early diagnosis uses molecular genetic tests, which are also offered commercially.

OBJECTIVE

Systematic review of the economic impact of genetic tests in ASD.

METHODS

We performed a systematic search of databases Pubmed, Medline, Cochrane, Econlit and the NHS Center for Reviews and Dissemination for articles in English and German from January 1, 2000 to December 31, 2015. Original articles published in peer-reviewed journals were screened in a two-step process. First, we focused our search on economic evaluations of genetic tests for ASD. Second, we searched for any economic evaluation (EE) of genetic tests.

RESULTS

We identified 185 EE of genetic tests for various diseases. However, not a single EE of genetic tests has been found for ASD. The outcomes used in the EE of the genetic tests were heterogeneous, and results were generally not comparable.

CONCLUSION

There is no evidence for cost-effectiveness of any genetic diagnostic test for ASD, although such genetic tests are available commercially. Cost-effectiveness analyses for genetic diagnostic tests for ASD are urgently required. There is a clear lack in research for EE of genetic tests.

Zur Validität der deutschen Fassung der ADOS-2 unter Berücksichtigung von Geschlechtseffekten

Zusammenfassung. Fragestellung: Die deutschsprachige Version der Diagnostischen Beobachtungsskala für Autistische Störungen – 2 (ADOS-2) ist eine Revision der standardisierten Verhaltensbeobachtung für Personen mit dem Verdacht auf Vorliegen einer Autismus-Spektrum-Störung (ASS). Die Studie untersucht die diagnostische Güte der originalen und revidierten Algorithmen für die Module 1 bis 3. Methodik: An einer großen Inanspruchnahmepopulation (N = 1080, Alter 1.7–20.5 Jahre) wurde die Unterscheidungsfähigkeit der ADOS-2 zu relevanten Differenzialdiagnosen untersucht. Außerdem wurden Vergleiche bezüglich der diagnostischen Güte für beide Geschlechter getrennt vorgenommen. Ergebnisse: Der revidierte Algorithmus weist eine verbesserte Sensitivität (84.9 %) bei jedoch leicht reduzierter Spezifität (85.7 %) auf. Verbesserungen der ADOS-2 betreffen vor allem Fälle von frühkindlichem Autismus und die korrekte Klassifizierung von Mädchen. Der Einschluss von repetitiven, stereotypen Verhaltensweisen in den Algorithmus erhöht die korrekte Klassifikation in den Modulen 2 und 3. Für jüngere Kinder im Modul 1 ist dies jedoch nicht der Fall. Es zeigt sich darüber hinaus eine geringere Differenzierungsfähigkeit zu internalisierenden Störungen und Störungen des Sozialverhaltens. Schlussfolgerungen: Eine gute diagnostische Güte der ADOS-2 wurde vor allem für Kinder mit durchschnittlichen kognitiven Fähigkeiten gefunden. Die Ergebnisse sprechen für eine gute Anwendbarkeit der ADOS-2 für klinische Populationen. Voraussetzung ist jedoch eine sorgfältige und breite Diagnostik durch erfahrene Untersucher.

Schlüsselwörter: ADOS, Diagnostik von Autismus-Spektrum-Störungen, Sensitivität, Spezifität

Comparative Validity of DSM-IV and Alternative Empirically Derived Approaches for the Assessment of ADHD

OBJECTIVE

To identify ADHD symptoms that are most highly predictive of ADHD diagnostic status and compare them against Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) algorithms in predictions of functional impairment.

METHOD

Parent and teacher ratings of ADHD were obtained from an ethnically diverse (46% non-White) sample of 151 five- to ten-year-old children (27% female) with ( n = 76) and without ( n = 75) DSM-IV ADHD. We calculated total predictive values to estimate how ratings of each ADHD symptom predicted ADHD diagnostic status based on a structured parent diagnostic interview. Optimal symptom thresholds (i.e., not at all, just a little, pretty much, very much) for predicting ADHD caseness differed for inattention and hyperactivity and parents versus teachers. Algorithms consisting of highly predictive symptoms were then created and compared against DSM-IV-based algorithms to predict independent measures of functional impairment.

RESULTS

Several empirically derived symptom algorithms were more strongly associated with functional impairment than DSM-IV-based algorithms.

CONCLUSION

These preliminary findings suggest that alternative methods to aggregating ADHD symptoms may improve predictions of impairment.

Cognitive and adaptive correlates of an ADOS-derived joint attention composite

Joint attention skills have been shown to predict language outcomes in children with autism spectrum disorder (ASD). Less is known about the relationship between joint attention (JA) abilities in children with ASD and cognitive and adaptive abilities. In the current study, a subset of items from the Autism Diagnostic Observation Schedule (ADOS), designed to quantify JA abilities, were used to investigate social attention among an unusually large cross-sectional sample of children with ASD (n = 1061). An examination of the association between JA and a range of functional correlates (cognitive and adaptive) revealed JA was significantly related to verbal (VIQ) and non-verbal (NVIQ) cognitive ability as well as all domains of adaptive functioning (socialization, communication, and daily living skills). Additional analyses examined the degree to which the relation between adaptive abilities (socialization, communication, and daily living skills) and JA was maintained after taking into account the potentially mediating role of verbal and nonverbal cognitive ability. Results revealed that VIQ fully mediated the relation between JA and adaptive functioning, whereas the relation between these adaptive variables and JA was only partially mediated by NVIQ. Moderation analyses were also conducted to examine how verbal and non-verbal cognitive ability and gender impacted the relation between JA and adaptive functioning. In line with research showing a relation between language and JA, this indicates that while JA is significantly related to functional outcomes, this appears to be mediated specifically through a verbal cognitive pathway.

The objectivity of the Autism Diagnostic Observation Schedule (ADOS) in naturalistic clinical settings

The Autism Diagnostic Observation Schedule (ADOS) is a first-choice diagnostic tool in autism spectrum disorder (ASD). Excellent interpersonal objectivity (interrater reliability) has been demonstrated for the ADOS under optimal conditions, i.e., within groups of highly trained "research reliable" examiners in research setting. We investigated the spontaneous interrater reliability among clinically trained ADOS users across multiple sites in clinical routine. Forty videotaped administrations of the ADOS modules 1-4 were rated by five different raters each from a pool of in total 15 raters affiliated to 13 different clinical sites. G(q,k) coefficients (analogous to intraclass correlations), kappas (ĸ) and percent agreement (PA) were calculated. The median interrater reliability for items across the four modules was G(q,k) = .74-.83, with the single ADOS items ranging from .23 to .94. G(q,k) for total scores was .85-.92. For diagnostic classification (ASD/non-spectrum), PA was 64-82 % and Fleiss' ĸ .19-.55. Objectivity was lower for pervasive developmental disorder not otherwise specified and non-spectrum diagnoses as compared to autism. Interrater reliabilities of the ADOS items and domain totals among clinical users across multiple sites were in the same range as previously reported for research reliable users, while the one for diagnostic classification was lower. Differences in sample characteristics, rater skills and statistics compared with previous studies are discussed. Findings endorse the objectivity of the ADOS in naturalistic clinical settings, but also pinpoint its limitations and the need and value of adequate and continuous rater training.

Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers: Application in a Non-US Sample of 1,104 Children

The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, J Autism Dev Disord 42(1):82-93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of the algorithms. The diagnostic validity was lower, with satisfactorily high specificities but moderate sensitivities. Young children with clinical ASD and lower language ability were largely in the mild-to-moderate or moderate-to-severe concern ranges of the ADI-R, nearly half of the older and phrase speech ASD-group fell into the little-to-no concern range. Although broadly the findings support the toddler algorithms, further work is required to understand why they might have different properties in different samples to further inform research and clinical use.

The Screening Accuracy of the Parent and Teacher-Reported Social Responsiveness Scale (SRS): Comparison with the 3Di and ADOS

The screening accuracy of the parent and teacher-reported Social Responsiveness Scale (SRS) was compared with an autism spectrum disorder (ASD) classification according to (1) the Developmental, Dimensional, and Diagnostic Interview (3 Di), (2) the Autism Diagnostic Observation Schedule (ADOS), (3) both the 3 Di and ADOS, in 186 children referred to six mental health centers. The parent report showed excellent correspondence to an ASD classification according to the 3 Di and both the 3 Di and ADOS. The teacher report added significantly to the screening accuracy over and above the parent report when compared with the ADOS classification. Findings support the screening utility of the parent-reported SRS among clinically referred children and indicate that different informants may provide unique information relevant for ASD assessment.

Using the Autism Detection in Early Childhood (ADEC) and Childhood Autism Rating Scales (CARS) to predict long term outcomes in children with autism spectrum disorders

This study evaluated the predictive validity of the Autism Detection in Early Childhood (ADEC; Young, Autism detection in early childhood: ADEC. Australian Council of Educational Research, Camberwell, VIC 2007) and a well-established screening tool, the Childhood Autism Rating Scale (CARS; Schopler et al. The childhood autism rating scale (CARS). Western Psychological Services, Los Angeles 1988), for long term outcomes of children with ASD engaged in an early intervention program. Participants were 55 children (44 male, 11 female) aged 19–42 months (M = 33.5, SD = 5.6) at initial assessment who were followed up 2 and 6 years after their initial assessment. The ADEC and the CARS performed similarly when predicting long term outcomes such as clinical diagnostic outcome and overall adaptive functioning level. However, only the ADEC score was significantly correlated with ASD symptom severity at the 6-year follow up. Although these findings need to be replicated with additional and larger samples, this study extends our understanding of the psychometric properties of both the ADEC and the CARS.

Video-feedback Intervention to promote Positive Parenting adapted to Autism (VIPP-AUTI): A randomized controlled trial

In a randomized controlled trial, we evaluated the early intervention program Video-feedback Intervention to promote Positive Parenting adapted to Autism (VIPP-AUTI) with 78 primary caregivers and their child (16-61 months) with Autism Spectrum Disorder. VIPP-AUTI is a brief attachment-based intervention program, focusing on improving parent-child interaction and reducing the child's individual Autism Spectrum Disorder-related symptomatology in five home visits. VIPP-AUTI, as compared with usual care, demonstrated efficacy in reducing parental intrusiveness. Moreover, parents who received VIPP-AUTI showed increased feelings of self-efficacy in child rearing. No significant group differences were found on other aspects of parent-child interaction or on child play behavior. At 3-months follow-up, intervention effects were found on child-initiated joint attention skills, not mediated by intervention effects on parenting. Implementation of VIPP-AUTI in clinical practice is facilitated by the use of a detailed manual and a relatively brief training of interveners.

Effect of camel milk on thymus and activation-regulated chemokine in autistic children: double-blind study

BACKGROUND

This study aimed to investigate the role of the effectiveness of camel milk (CM) (raw and boiled) on thymus and activation-regulated chemokine (TARC) serum levels and childhood autism rating scale (CARS) score in subjects with autism and compared to placebo group (cow milk).

METHODS

Forty-five subjects diagnosed with autism were randomly assigned to receive boiled CM for group I (n = 15), raw CM for group II (n = 15), and placebo for group III (n = 15) for 2 wk. Measures included changes in professionally completed CARS score and blood samples for TARC serum level were taken before and after milk consumption of 500 ml per day in children's regular daily diet.

RESULTS

The serum levels of TARC decreased significantly (P = 0.004) in boiled CM and in raw CM group (P = 0.01) too, but no effect was observed (P = 0.68) in placebo group. Furthermore, significant improvements were observed in CARS score (P = 0.04) in raw CM group only. There were no significant relationships between the serum of TARC level and the CARS score, age, or gender for any group.

CONCLUSION

CM administered for 2 wk significantly improved clinical measurements of autism severity and decreased serum level of TARC in autistic children, but subsequent studies are recommended.

The added value of the combined use of the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule: diagnostic validity in a clinical Swedish sample of toddlers and young preschoolers

The diagnostic validity of the new research algorithms of the Autism Diagnostic Interview-Revised and the revised algorithms of the Autism Diagnostic Observation Schedule was examined in a clinical sample of children aged 18-47 months. Validity was determined for each instrument separately and their combination against a clinical consensus diagnosis. A total of N = 268 children (n = 171 with autism spectrum disorder) were assessed. The new Autism Diagnostic Interview-Revised algorithms (research cutoff) gave excellent specificities (91%-96%) but low sensitivities (44%-52%). Applying adjusted cutoffs (lower than recommended based on receiver operating characteristics) yielded a better balance between sensitivity (77%-82%) and specificity (60%-62%). Findings for the Autism Diagnostic Observation Schedule were consistent with previous studies showing high sensitivity (94%-100%) and alongside lower specificity (52%-76%) when using the autism spectrum cutoff, but better balanced sensitivity (81%-94%) and specificity (81%-83%) when using the autism cutoff. A combination of both the Autism Diagnostic Interview-Revised (with adjusted cutoff) and the Autism Diagnostic Observation Schedule (autism spectrum cutoff) yielded balanced sensitivity (77%-80%) and specificity (87%-90%). Results favor a combined usage of the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule in young children with unclear developmental problems, including suspicion of autism spectrum disorder. Evaluated separately, the Autism Diagnostic Observation Schedule (cutoff for autism) provides a better diagnostic accuracy than the Autism Diagnostic Interview-Revised.

Diagnostic procedures in autism spectrum disorders: a systematic literature review

At present, 'gold standard' diagnosis of autism spectrum disorders (ASD) is a lengthy and time consuming process that requires suitably qualified multi-disciplinary team (MDT) personnel to assess behavioural, historical, and parent-report information to determine a diagnosis. A number of different tools have been developed to assist in determination. To optimise the diagnostic procedures, the best diagnostic instruments need to be identified. This study is a systematic review addressing the accuracy, reliability, validity and utility of reported diagnostic tools and assessments. To be included in this review, studies must have (1) identified an ASD diagnostic tool; (2) investigated either diagnostic procedure or the tools or personnel required; (3) be presented in English; (4) be conducted in the Western world; (5) be one of three types of studies [adapted from Samtani et al. in Cochrane Database Syst Rev 3:1-13, 2011], viz. (a) cohort studies or cross-sectional studies, (b) randomised studies of test accuracy, (c) case-control studies. MEDLINE, PsychINFO, Scopus, EMBASE, and Cochrane Library databases were scrutinised for relevant literature published from 2000 inclusive on 20th January 2012. In total, 68 articles were included. 17 tools were assessed. However, many lacked an evidence base of high quality-independent studies. The Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS) stood out with the largest evidence base and highest sensitivity and specificity. When the ADI-R and ADOS were used in combination they revealed levels of accuracy very similar to the correct classification rates for the current 'gold standard' diagnostic procedure viz. 80.8% for ASD. There is scope for future studies on the use of the ADI-R and ADOS in combination.

Diagnosing autism in a clinical sample of adults with intellectual disabilities: how useful are the ADOS and the ADI-R?

Intellectual disability (ID) and autism spectrum disorder (ASD) are frequently co-occurring conditions. Carefully diagnosing ASD in individuals with ID would allow for more tailored clinical interventions that would improve mental health and quality of life. In this study, we evaluated the psychometric properties of the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R) in a clinical sample of 79 adults with ID who were suspected of also having ASD. In the testable cases (68%), the ADOS was over-inclusive (specificity 45%) but highly sensitive (100%) of ASD. In the ADI-R, the feasibility was 37%, with a sensitivity of 88% and a specificity of 80%. Previously proposed adaptations of the ADOS algorithm were evaluated, and new items and tasks were suggested. The ADOS and the ADI-R were found to be valuable diagnostic tools for adults with ID. Adjustments of the setting and the tasks may further improve their feasibility and specificity.

Measurement Issues: Screening and diagnostic instruments for autism spectrum disorders - lessons from research and practise

BACKGROUND AND SCOPE

Significant progress has been made over the past two decades in the development of screening and diagnostic instruments for autism spectrum disorders (ASDs). This article reviews this progress, including recent innovations, focussing on those instruments for which the strongest research data on validity exists, and then addresses issues arising from their use in clinical settings.

FINDINGS

Research studies have evaluated the ability of screens to prospectively identify cases of ASD in population-based and clinically referred samples, as well as the accuracy of diagnostic instruments to map onto 'gold standard' clinical best estimate diagnosis. However, extension of the findings to clinical services must be done with caution, with a full understanding that instrument properties are sample-specific. Furthermore, we are limited by the lack of a true test for ASD which remains a behaviourally defined disorder. In addition, screening and diagnostic instruments help clinicians least in the cases where they are most in want of direction, as their accuracy will always be lower for marginal cases.

CONCLUSION

Instruments help clinicians to collect detailed, structured information and increase accuracy and reliability of referral for in-depth assessment and recommendations for support, but further research is needed to refine their effective use in clinical settings.

The structure of autism symptoms as measured by the autism diagnostic observation schedule

The current study tested several competing models of the autism phenotype using data from modules 1 and 3 of the ADOS. Participants included individuals with ASDs aged 3-18 years (N = 1,409) from the AGRE database. Confirmatory factor analyses were performed on total samples and subsamples based on age and level of functioning. Three primary models were tested, including a one-factor model, the DSM-IV model, and the anticipated DSM-V model. Results indicated all models fit similarly. Module 1 ratings yielded better indices of fit across all models and higher inter-factor correlations than Model 3. Model fits were impacted by age and level of functioning. The lack of differentiation between models suggests that the structure of ASD symptoms is complex to measure statistically.

How useful are screening instruments for toddlers to predict outcome at age 4? General development, language skills, and symptom severity in children with a false positive screen for autism spectrum disorder

Screening instruments for autism spectrum disorder (ASD) often generate many false positives. It is argued that these children may have other developmental difficulties and are also in need of thorough assessment and early intervention. The current study looked at the predictive validity of positive screens on the Checklist for Early Signs of Developmental Disorders (CESDD) and the Early Screening of Autistic Traits questionnaire (ESAT) at age 2 towards language, cognitive function, and symptom severity at age 4. Children who screened positive on the ESAT scored lower for both language and cognitive functioning at age 4 compared with children who screened negative on the ESAT. Also, the more signs of ASD that were recognized on the CESDD or ESAT, the lower the scores for language and cognitive functioning at age 4. False positive screens could be differentiated from true positive screens on the CESDD only in symptom severity score on the Autism Diagnostic Observation Schedule (ADOS). It seems that early screeners for ASD also detect children with other developmental disorders and that diagnostic instruments such as the ADOS are warranted to differentiate between children with ASD and other developmental problems.

A genome-wide association study of autism incorporating autism diagnostic interview-revised, autism diagnostic observation schedule, and social responsiveness scale

Efforts to understand the causes of autism spectrum disorders (ASDs) have been hampered by genetic complexity and heterogeneity among individuals. One strategy for reducing complexity is to target endophenotypes, simpler biologically based measures that may involve fewer genes and constitute a more homogenous sample. A genome-wide association study of 2,165 participants (mean age = 8.95 years) examined associations between genomic loci and individual assessment items from the Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Schedule, and Social Responsiveness Scale. Significant associations with a number of loci were identified, including KCND2 (overly serious facial expressions), NOS2A (loss of motor skills), and NELL1 (faints, fits, or blackouts). These findings may help prioritize directions for future genomic efforts.

The ADOS calibrated severity score: relationship to phenotypic variables and stability over time

Measurement of the severity of autism at a single time point, and over time, is a widespread challenge for researchers. Recently, Gotham, Pickles, and Lord published a severity metric (calibrated severity scores; CSS) that takes into account age and language level and is based on raw total scores of the Autism Diagnostic Observation Schedule (ADOS), a standardized measure commonly used in autism diagnosis. The present study examined psychometric characteristics of the CSS compared to raw scores in an independent sample of 368 children aged 2 to 12 years with autism, pervasive developmental disorder-not otherwise specified (PDD-NOS), non-spectrum delay, or typical development. Reflecting the intended calibration, the CSS were more uniformly distributed within clinical diagnostic category and across ADOS modules than were raw scores. Cross-sectional analyses examining raw and severity scores and their relationships to participant characteristics revealed that verbal developmental level was a significant predictor of raw score but accounted for significantly less variance in the CSS. Longitudinal analyses indicated overall stability of the CSS over 12 to 24 months in children with autism. Findings from this study support the use of the CSS as a more valid indicator of autism severity than the ADOS raw total score, and extend the literature by examining the stability over 12 to 24 months of the CSS in children with ASD.

Support for a dimensional view of autism spectrum disorders in toddlers

We examined whether clinically distinct subgroups can be derived from a sample of toddlers (n = 186) who failed the Modified Checklist for Autism in Toddlers, received a comprehensive clinical evaluation, and were diagnosed with an autism spectrum disorder (ASD). Three subgroups emerged from cluster analysis distinguished by (a) social, communication, and intellectual skills and (b) the rate and intensity of repetitive behaviors and abnormal sensory response. Preoccupations, compulsions, and rituals did not distinguish resultant subgroups. These results support a dimensional diagnostic view of ASDs in toddlers since subgroup differences were based on symptom severity rather than different symptom profiles. Results also identify specific types and levels of behavioral deficit relevant to toddler populations. Implications for early diagnosis are discussed.

Diagnosing autism spectrum disorders in adults: the use of Autism Diagnostic Observation Schedule (ADOS) module 4

Autism Diagnostic Observation Schedule (ADOS) module 4 was investigated in an independent sample of high-functioning adult males with an autism spectrum disorder (ASD) compared to three specific diagnostic groups: schizophrenia, psychopathy, and typical development. ADOS module 4 proves to be a reliable instrument with good predictive value. It can adequately discriminate ASD from psychopathy and typical development, but is less specific with respect to schizophrenia due to behavioral overlap between autistic and negative symptoms. However, these groups differ on some core items and explorative analyses indicate that a revision of the algorithm in line with Gotham et al. (J Autism Dev Disord 37: 613-627, 2007) could be beneficial for discriminating ASD from schizophrenia.

Standardized ADOS scores: measuring severity of autism spectrum disorders in a Dutch sample

The validity of the calibrated severity scores on the ADOS as reported by Gotham et al. (J Autism Dev Disord 39: 693–705, 2009), was investigated in an independent sample of 1248 Dutch children with 1455 ADOS administrations (modules 1, 2 and 3). The greater comparability between ADOS administrations at different times, ages and in different modules, as reached by Gotham et al. with the calibrated severity measures, seems to be corroborated by the current study for module 1 and to a lesser extent for module 3. For module 2, the calibrated severity scores need to be further investigated within a sample that resembles Gotham’s sample in age and level of verbal functioning.

Evaluation of the revised algorithm of Autism Diagnostic Observation Schedule (ADOS) in the diagnostic investigation of high-functioning children and adolescents with autism spectrum disorders

The Autism Diagnostic Observation Schedule (ADOS) is a semi-structured, standardized assessment designed for use in diagnostic evaluation of individuals with suspected autism spectrum disorder (ASD). The ADOS has been effective in categorizing children who definitely have autism or not, but has lower specificity and sometimes sensitivity for distinguishing children with milder ASDs. Revised ADOS algorithms have been recently developed. The goals of this study were to analyze the predictive validity of different ADOS algorithms for module 3, in particular for high-functioning autism spectrum disorder. The participants were 252 children and adolescents aged between four and 16 years, with a full-scale IQ above 70 (126 with a diagnosis of ASD, 126 with a heterogeneous non-spectrum diagnosis). As a main finding, sensitivity was substantially higher for the newly developed 'revised algorithm', both for autism versus non-spectrum, as well as for the broader ASD versus non-spectrum, using the higher cut-off. The strength of the original algorithm lies in its positive predictive power, while the revised algorithm shows weaknesses in specificity for non-autism ASD. As the ADOS is valid and reliable even for higher functioning ASD, the findings of the present study have been used to make recommendations regarding the best use of ADOS algorithms in a high-functioning sample.