Autism Diagnostic Observation Schedule

The Autism Diagnostic Observation Schedule (ADOS) is a standardized diagnostic test for assessing autism spectrum disorder. The protocol consists of a series of structured and semi-structured tasks that involve social interaction between the examiner and the person under assessment. The examiner observes and identifies aspects of the subject's behavior, assigns these to predetermined categories, and combines these categorized observations to produce quantitative scores for analysis. Research-determined cut-offs identify the potential diagnosis of autism spectrum disorder, allowing a standardized assessment of autistic symptoms.

Autism Diagnostic Observation Schedule
Purposeassess autism in children, adolescents, and adults

The Autism Diagnostic Interview-Revised (ADI-R), a companion instrument, is a structured interview conducted with the parents of the referred individual to cover the subject's full developmental history. The ADI-R has lower sensitivity but similar specificity to the ADOS. The ADI-R and ADOS are both considered gold standard diagnostic tests for autism.[1] However, neither of these tests are required by the DSM-5 for an autism diagnosis.[1]

Development and History

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ADOS

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The original ADOS was created by Catherine Lord, Michael Rutter, Pamela C. DiLavore and Susan Risi in 1989.[2] The protocol consisted of 8 tasks meant to assess the individual’s social and communicative behaviors. Behaviors were rated on the following scale:

  • (0) within normal limits
  • (1) infrequent or possible abnormality
  • (2) definite abnormality

Some ratings could also be assigned a rating of 7, indicating observed behaviors not otherwise specified.[3]

PL-ADOS

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In response to the need for diagnostic tools for autism in younger children, researchers developed the Pre-Linguistic Autism Diagnostic Observation Schedule (PL-ADOS).[4] The PL-ADOS adapted the content and format of the original ADOS to rely less on verbal communication. It consisted of 12 tasks, retaining only the free/unstructured playtime from the original ADOS and adding new activities designed to be less dependent on speech.

ADOS-G

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In 2000, Lord and her colleagues introduced the ADOS-Generic (ADOS-G) to assess a broader developmental range of individuals. The ADOS-G introduced a modular format, allowing different protocols to be used depending on developmental and language factors.[5] It became commercially available in 2001 through Western Psychological Services.[6]

ADOS-2

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The second edition, published in 2012, included updated norms, improved algorithms for Modules 1 to 3, and a new Toddler Module (T) for assessing children aged 12 to 30 months.[7][8] The scoring algorithm was also revised to align with the recent changes in the DSM-5 diagnostic criteria. While the ADOS-G had separate sections for social and communication behaviors, the ADOS-2 combined these into a single domain to represent social affect, and added a new domain to assess restrictive and repetitive behaviors (RRB).

Method

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The ADOS consists of a series of structured and semi-structured tasks that generally takes 30-60 minutes to administer. During this time, the examiner provides a series of opportunities for the subject to show social and communication behaviors relevant to the diagnosis of autism.[6] Each subject is administered activities from the module that corresponds to their developmental and language level. The ADOS should not be used for formal diagnosis with individuals who are blind, deaf, or otherwise seriously impaired by sensory or motor disorders, such as cerebral palsy or muscular dystrophy.

Following task administration and observation coding, a scoring algorithm classifies the individual with autism, autism spectrum disorder, or non-spectrum. The toddler module algorithm yields a "range of concern" rather than a definite classification.[9]

Modules

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Toddler module

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The toddler module is appropriate for children 12–30 months who use little to no phrase speech and are able to walk independently.[10] This module consists of eleven primary activities:[9]

  1. Free play
  2. Blocking toy play
  3. Response to name
  4. Bubble play
  5. Anticipation of a routine with objects
  6. Response to joint attention
  7. Responsive social smile
  8. Anticipation of social routine
  9. Functional and symbolic imitation
  10. Bath time
  11. Snack

Module 1

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Module 1 is appropriate for children 31 months and older who use little or no phrase speech. This module consists of ten activities:[7]

  1. Free play
  2. Response to name
  3. Response to joint attention
  4. Bubble play
  5. Anticipation of a routine with objects
  6. Responsive social smile
  7. Anticipation of a social routine
  8. Functional and symbolic imitation
  9. Birthday party
  10. Snack

Module 2

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Module 2 is appropriate for children six years old or younger who speak in phrases but have not yet developed fluent verbal language. This module consists of fourteen activities:[7]

  1. Construction task
  2. Response to name
  3. Make-believe play
  4. Joint interactive play
  5. Conversation
  6. Response to joint attention
  7. Demonstration task
  8. Description of a picture
  9. Telling a story from a book
  10. Free play
  11. Birthday party
  12. Snack
  13. Anticipation of a routine with objects
  14. Bubble play

Module 3

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Module 3 is appropriate for children or young adolescents who are verbally fluent. This module consists of fourteen activities:[7]

  1. Construction task
  2. Make-believe play
  3. Joint interactive play
  4. Demonstration task
  5. Description of a picture
  6. Telling a story from a book
  7. Cartoons
  8. Conversation and reporting
  9. Emotions
  10. Social difficulties and annoyance
  11. Break
  12. Friends, relationships, and marriage
  13. Loneliness
  14. Creating a story

Module 4

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Module 4 is appropriate for older adolescents and adults. While similar to module 3, module 4 relies more heavily on questions and verbal responses rather than non-verbal actions observed during play. This module consists of ten to fifteen activities. Activities marked by an asterisk are optional:

  1. Construction task*
  2. Telling a story from a book
  3. Description of picture*
  4. Conversation and reporting
  5. Current work or school*
  6. Social difficulties and annoyance
  7. Emotions
  8. Demonstration task
  9. Cartoons*
  10. Break
  11. Daily living*
  12. Friends, relationships, and marriage
  13. Loneliness
  14. Plans and hopes
  15. Creating a story

Diagnostic accuracy

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The social communication difficulties that the ADOS and ADOS-2 seek to measure are not unique to ASD; there is a heightened risk of false positives in individuals with other psychological disorders. In particular, an increased false positive rate has been observed in adults with psychosis;[11] while case reports indicate that such false positives may also occur in cases of childhood-onset schizophrenia, which is an exceptionally rare entity with a frequency of 1 in 40000.[12] There is evidence that adults with schizophrenia demonstrate an increased incidence of autistic features compared to the general population, resulting in higher ADOS scores, though schizophrenia patients also experience positive symptoms of psychosis (e.g. hallucinations, delusions, formal thought disorders).[13][14] A 2016 study found that 21% of children with a diagnosis of ADHD (and without a concurrent diagnosis of ASD) scored in the autism spectrum range on the ADOS total score.[15] False positives have also been found in school-age subjects who have high anxiety or trauma-related disorders; in these cases, the ADOS-2 scores related to repetitive and restrictive behaviors (RRB) are usually lower than typical for ASD.[16]

A 2018 Cochrane systematic review included 12 studies of ADOS diagnostic accuracy in pre-school children (Modules 1 and 2). The summary sensitivity was 0.94 (95% CI 0.89 to 0.97), with sensitivity in individual studies ranging from 0.76 to 0.98. The summary specificity was 0.80 (95% CI 0.68 to 0.88), with specificity in individual studies ranging from 0.20 to 1.00. The studies were evaluated for bias using the QUADAS-2 framework; of the 12 included studies, 8 were evaluated as having a high risk of bias, while for the remaining four there was insufficient information available for the risk of bias to be properly evaluated. The authors could not identify any studies for the ADOS-2; the scope of the review was limited to preschool age children (mean age under 6 years), which excluded studies of Modules 3 and 4 from the meta-analysis. One included study examined the additive sensitivity and specificity of the ADOS used in combination with the ADI-R; that study found an 11% improvement in specificity (compared to ADOS alone) at the cost of a 14% reduction in sensitivity; however, due to overlapping confidence intervals, that result could not be considered statistically significant.[17]

References

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  1. ^ a b Kaufman, Noah K. (2022-07-03). "Rethinking "gold standards" and "best practices" in the assessment of autism". Applied Neuropsychology: Child. 11 (3): 529–540. doi:10.1080/21622965.2020.1809414. ISSN 2162-2965.
  2. ^ "Autism Diagnostic Observation Schedule." Western Psychological Services. Western Psychological Services. n.d. Web. 6 March 2010.
  3. ^ Lord, C; Rutter, M; Goode, S; Heemsbergen, J; Jordan, H; Mawhood, L; Schopler, R (1989). "Austism diagnostic observation schedule: A standardized observation of communicative and social behavior". Journal of Autism and Developmental Disorders. 19 (2): 185–212.
  4. ^ DiLavore, P; Lord, C; Rutter, M (1995). "Pre-Linguistic Autism Diagnostic Observation Schedule (PL-ADOS)". Journal of Autism and Developmental Disorders. 25 (4): 355–379.
  5. ^ Lord, C; Risi, S; Lambrecht, L; Cook, Jr, E H; Leventhal, B L; DiLavore, P C; Pickles, A; Rutter, M (2000). "The Autism Diagnostic Observation Schedule–Generic: A Standard Measure of Social and Communication Deficits Associated with the Spectrum of Autism". Journal of Autism and Developmental Disorders. 30 (3): 205–223. doi:10.1023/A:1005592401947. PMID 11055457.
  6. ^ a b Akshoomoff, Natacha; Corsello, Christina; Schmidt, Heather (2006). "The Role of the Autism Diagnostic Observation Schedule in the Assessment of Autism Spectrum Disorders in School and Community Settings". The California School Psychologist. 11 (1). Springer Science and Business Media LLC: 7–19. doi:10.1007/bf03341111. ISSN 1087-3414. PMC 1868476. PMID 17502922.
  7. ^ a b c d Lord C, DiLavore PC, Gotham K, Guthrie W Luyster RJ, Risi S, Rutter M. Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) Manual. Torrance, CA: Western Psychological Services; 2012.
  8. ^ Lord C, Luyster R, Gotham K, Guthrie W. Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) Manual (Part II): Toddler Module. Torrance, CA: Western Psychological Services; 2012.
  9. ^ a b McCrimmon, Adam; Rostad, Kristin (February 2014). "Test Review: Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) Manual (Part II): Toddler Module". Journal of Psychoeducational Assessment. 32 (1): 88–92. doi:10.1177/0734282913490916. ISSN 0734-2829. S2CID 145257612.
  10. ^ Esler, Amy N.; Bal, Vanessa Hus; Guthrie, Whitney; Wetherby, Amy; Weismer, Susan Ellis; Lord, Catherine (September 2015). "The Autism Diagnostic Observation Schedule, Toddler Module: Standardized Severity Scores". Journal of Autism and Developmental Disorders. 45 (9): 2704–2720. doi:10.1007/s10803-015-2432-7. ISSN 0162-3257. PMC 4898775. PMID 25832801.
  11. ^ Maddox BB, Brodkin ES, Calkins ME, Shea K, Mullan K, Hostager J, Mandell DS, Miller JS (September 2017). "The Accuracy of the ADOS-2 in Identifying Autism among Adults with Complex Psychiatric Conditions". Journal of Autism and Developmental Disorders. 47 (9): 2703–2709. doi:10.1007/s10803-017-3188-z. PMC 5813679. PMID 28589494.
  12. ^ Reaven JA, Hepburn SL, Ross RG (January 2008). "Use of the ADOS and ADI-R in children with psychosis: importance of clinical judgment". Clinical Child Psychology and Psychiatry. 13 (1): 81–94. doi:10.1177/1359104507086343. PMC 4426195. PMID 18411867.
  13. ^ Barlati S, Deste G, Gregorelli M, Vita A (January 2019). "Autistic traits in a sample of adult patients with schizophrenia: prevalence and correlates". Psychological Medicine. 49 (1): 140–148. doi:10.1017/S0033291718000600. PMID 29554995. S2CID 4020382.
  14. ^ De Crescenzo F, Postorino V, Siracusano M, Riccioni A, Armando M, Curatolo P, Mazzone L (2019-02-21). "Autistic Symptoms in Schizophrenia Spectrum Disorders: A Systematic Review and Meta-Analysis". Frontiers in Psychiatry. 10: 78. doi:10.3389/fpsyt.2019.00078. PMC 6393379. PMID 30846948.
  15. ^ Grzadzinski R, Dick C, Lord C, Bishop S (December 2016). "Parent-reported and clinician-observed autism spectrum disorder (ASD) symptoms in children with attention deficit/hyperactivity disorder (ADHD): implications for practice under DSM-5". Molecular Autism. 7 (1): 7. doi:10.1186/s13229-016-0072-1. PMC 4717584. PMID 26788284.
  16. ^ Greene, Rachel K.; Vasile, Iulia; Bradbury, Kathryn R.; Olsen, Aarika; Duvall, Susanne W. (July 2022). "Autism Diagnostic Observation Schedule (ADOS-2) elevations in a clinical sample of children and adolescents who do not have autism: Phenotypic profiles of false positives". The Clinical Neuropsychologist. 36 (5): 943–959. doi:10.1080/13854046.2021.1942220. ISSN 1744-4144. PMID 34294006.
  17. ^ Randall M, Egberts KJ, Samtani A, Scholten RJ, Hooft L, Livingstone N, Sterling-Levis K, Woolfenden S, Williams K (July 2018). Cochrane Developmental, Psychosocial and Learning Problems Group (ed.). "Diagnostic tests for autism spectrum disorder (ASD) in preschool children". The Cochrane Database of Systematic Reviews. 2018 (7): CD009044. doi:10.1002/14651858.CD009044.pub2. PMC 6513463. PMID 30075057.

Further reading

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