Autism diagnostic observation + interview

What is ASD?

Lifelong neurodevelopmental condition affecting how people perceive the world and interact with others.

Is the term disorder still used 

Many dislike the terms as they view neurological differences as natural human variation rather than inherently disordered conditions. However, the term is used in a clinical diagnostic setting. 

What does the umbrella term neurodevelopmental disorders cover 

Intellectual (learning) disability, autism, specific learning disorder, ADHD and many other neurodevelopmental differences 

What are clinical definitions of autism DSM-5

Deficits in reciprocal social communication and interaction, restrictive, repetitive patterns of behaviour, present in early developmental period, clinically significant impairment in social, occupational or other functioning areas. Not better explained by intellectual disability or global developmental delay. 

What are clinical definitions of autism ICD-11

Deficits in initiating and sustaining social communication and reciprocal social interactions, restricted, repetitive and inflexible patterns of behaviour, interests, or activities. Onset of the disorder occurs during the developmental period, some characteristics might not manifest until later, significant impairment in personal, family, social etc

What is the importance of a diagnosis 

Help qualify for educational or occupational adjustments, speech or occupational therapy, mental health support and disability benefits or community services. Explains lifelong experiences and can be empowering. Early identification can support language development, emotional regulation, school success and day-to-day living.

How do you get a diagnosis 

Talk to a gp, health visitor, health professional or special educational needs co-ordinator. Then have an autism assessment including observations of person interacting with other people, ask the person about issues they are facing. 

What did Russell et al find about diagnostic trends over time 

Autism diagnosis increased over 20yrs following an exponential trend. Men are still diagnosed more often but growth in diagnosis is faster for females. Slight rising levels of diagnosis in adults over time

What are screening tools

Used to identify whether a person may need a full diagnostic assessment i.e ages and stages questionnaire (ASQ-SE2), childhood autism spectrum test (CAST) etc 

What are diagnostic/comprehensive assessment tools

Used by trained clinicians as part of a full diagnostic assessment. Should not be used in isolation for formal diagnosis, advised that a combination of tools are used. 

What are examples of diagnostic assessment tools

The autism diagnostic observation schedule (ADOS-2), autism diagnostic interview-revised (ADI-R), childhood autism rating scale (CARS-2), diagnostic interview for social and communicative disorders (DISCO), ritvo autism Asperger diagnostic scale-revised (RAADS-R) 

What is the training and cost of tools like 

ADOS-2 and DI-R are restricted with no public access and require formal training before being certified to use them. Training is usually 2-3 days, costing from £650-£1,400 with test materials and manual cost ranging from £448-£2550 for materials and manual cost. 

What is ADOS 

Structured observational assessment consisting of various activities that allow observation of social and communication behaviours related to the diagnosis of pervasive developmental disorders. Can be used to evaluate almost anyone suspected of being autistic across the age range. 

What is ADOS-2 

Evolved from data and field-trials to align with new DSM-5 diagnostic criteria. Introduced toddler module for 12-30mth, not yet using phrased speech; as argument for earlier identification became more prevalent. Standardised for single administration only as primary focus is on engagement and interaction between examiner and child/adult. Admin time usually 40-60mins. 

What are the ADOS-2 module choices? 

Toddler module, pre-verbal/single words, phrase speech, fluent speech, fluent speech. 1 module is chosen based on the individual’s expressive language ability and age.

What is the ADOS-2 core test structure 

Each module has a set of activities designed to elicit behaviours relevant to autism criteria. Activities vary but usually assess social communication, social reciprocity, imagination/creativity/play, restricted/repetitive behaviours.

What does social communication include

Initiating interaction, responding to name or prompts, sharing enjoyment, facial expression and eye gaze.

What does social reciprocity include 

Back-and-forth conversation, interest in the administrator, emotional sharing, rapport development.

What does imagination/creativity/play include 

Pretend play, storytelling and symbolic use of objects

What does restricted/repetitive behaviours include 

Repetitive speech, atypical sensory interest, rigid behaviours, fixated interests, stereotyped movements, 

What is ADOS-2 reliability coding? 

In clinical settings reliability coding is not necessary. Examiners are advised to demonstrate initial scoring reliability in training, maintain competence over time and engage in periodic calibration (team consensus meetings etc). Reliability coding is essential for research, inter-rater reliability is needed and >80% agreement is a requirement. 

What is the ADOS-2 process?

Administration, coding, scoring (converting item codes to ADOS-2 algorithm scores) and classification (establishing classification or range of concern)

How does coding work for the ADOS-2?

Observations contain qualitative notes. Coding requires ratings based on participants behaviour throughout entire administration.  

What is the autism diagnostic interview revised (ADI-R)? 

Semi-structured interview with parents or caregivers. Covers 3 main areas: Language and communication, Reciprocal social interactions, Restricted, repetitive, and stereotyped behaviours and interests. Emphasis on early developmental history. Approx 3hrs. Can be used on adults if an informant who knew them in childhood is there. Can generate detailed qualitative data from stakeholders. 

What does language and communication look at?

evaluating both verbal and non-verbal communication.

 

What does Reciprocal social interactions look at? 

assessing social behaviours and relationships, including ability to form peer relationships and respond to social interactions.

What does stereotyped behaviours and interest look at? 

identifying repetitive behaviours, routines, and restricted interests in typical autistic individuals.

What is the gold standard in autism testing? 

Combining tools i.e. ADOS-2 and the ADI-R. ADOS-2 provides standardised direct observation and doesn’t rely solely on self-report data but only measures this in brief, structured and clinical assessment context. ADI-R accounts for developmental and real-world history.  

What is the global reach of the ADOS-2?

Been translated, validated and used worldwide across North America, UK, Europe and Asia. Studies exploring it in South Africa and middle eastern contexts.

 

What is the global reach of the ADOS-2?

Primarily validates in English speaking populations. Less research on psychometric properties of the ADI-R and their usefulness in diagnosing autism in non-English speaking populations. 

What are limitations and critiques of ADOS-2?

Only a snapshot in time, conducted in a clinical context (low ecological validity). May not be sensitive enough to differentiate between autism and complex psychiatric conditions. Maddox et al found ADOS-2 had high rate of false positives among adults with psychosis who did not have autism.

What are limitations and critiques of ADI-R? 

Dependent on caregiver recall and interpretation; parents/caregivers not always available. Time-intensive, reduces clinical efficiency and accessibility. Research indicating it is less influential in distinguishing ASD vs non-ASD, particularly in adults. May not be sensitive enough to differentiate between autism and complex psychiatric conditions.

What was lebersfeld et al clinical utility of ADOS-2 and ADI-R? 

Both tools performed better in respect to specificity (Sp) and sensitivity (Se) in controlled research samples compared to real-world clinical population. ADOS-2 indicated high levels of Se and Sp across settings but limited number of clincial only studies. Specificty of ADOS-2 may be more variable across clinical settings, whereas sensitivity may remain relatively stable. 

What does lebersfeld et al suggest? 

Both tools need more research utilising solely clinical populations as they are more diverse and complex. 

How do autism and gender interact? 

Dean et al suggested autistic women were more likely to mask and appear like typically developing girls but nuanced differences could be seen in terms of engagement in activities requiring social synchronisation and aligning with group norms. Brickhill et al found an implicit bias towards males and autistic traits for the IAT. This may hinder identification and understanding of female autistic phenotype.