Standardizing ADOS Scores for a Measure of Severity in Autism Spectrum Disorders

  • Katherine GothamEmail author
  • Andrew Pickles
  • Catherine Lord
Original Paper


The aim of this study is to standardize Autism Diagnostic Observation Schedule (ADOS) scores within a large sample to approximate an autism severity metric. Using a dataset of 1,415 individuals aged 2–16 years with autism spectrum disorders (ASD) or nonspectrum diagnoses, a subset of 1,807 assessments from 1,118 individuals with ASD were divided into narrow age and language cells. Within each cell, severity scores were based on percentiles of raw totals corresponding to each ADOS diagnostic classification. Calibrated severity scores had more uniform distributions across developmental groups and were less influenced by participant demographics than raw totals. This metric should be useful in comparing assessments across modules and time, and identifying trajectories of autism severity for clinical, genetic, and neurobiological research.


Autism spectrum disorders Autism diagnostic observation schedule (ADOS) Severity 



We gratefully acknowledge the help of Susan Risi, Kathryn Larson, Cristina Popa, and Mary Yonkovit, as well as the families that participated in this research. This study was funded by the National Institute of Mental Health (Validity of Diagnostic Measures for Autism Spectrum Disorders: NIMH RO1 MH066469) and an Autism Speaks Predoctoral Training Fellowship.


C. Lord receives royalties for the ADOS; profits related to this study were donated to charity.


  1. Baird, G., Simonoff, E., Pickles, A., Chandler, S., Loucas, T., Meldrum, D., et al. (2006). Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames–the Special Needs and Autism Project (SNAP). Lancet, 368, 210–215. doi: 10.1016/S0140-6736(06)69041-7.PubMedCrossRefGoogle Scholar
  2. Bertrand, J., Mars, A., Boyle, C., Bove, F., Yeargin-Allsopp, M., & Decoufle, A. (2001). Prevalence of autism in a United States population: The Brick Township, New Jersey, investigation. Pediatrics, 108(5), 1155–1161. doi: 10.1542/peds.108.5.1155.PubMedCrossRefGoogle Scholar
  3. Centers for Disease Control and Prevention. (2007). Prevalence of autism spectrum disorders–autism, developmental disabilities monitoring network, 14 sites, United States, 2002. MMWR. Morbidity and Mortality Weekly Report, 56, 12–27.Google Scholar
  4. Chakrabarti, S., & Fombonne, E. (2005). Pervasive developmental disorders in preschool children: Confirmation of high prevalence. The American Journal of Psychiatry, 162(6), 1133–1141. doi: 10.1176/appi.ajp.162.6.1133.PubMedCrossRefGoogle Scholar
  5. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale: Lawrence Erlbaum Associates.Google Scholar
  6. Constantino, J. N., Davis, S. A., Todd, R. D., Schindler, M. K., Gross, M. M., Brophy, S. L., et al. (2003). Validation of a brief quantitative measure of autistic traits: Comparison of the social responsiveness scale with the autism diagnostic interview-revised. Journal of Autism and Developmental Disorders, 33(4), 427–433. doi: 10.1023/A:1025014929212.PubMedCrossRefGoogle Scholar
  7. de Bildt, A., Sytema, S., Ketelaars, C., Kraijer, D., Mulder, E., Volkmar, F., et al. (2004). Interrelationship between autism diagnostic observation schedule-generic (ADOS-G), autism diagnostic interview-revised (ADI-R), and the diagnostic and statistical manual of mental disorders (DSM-IV-TR) classification in children and adolescents with mental retardation. Journal of Autism and Developmental Disorders, 34(2), 129–137. doi: 10.1023/B:JADD.0000022604.22374.5f.PubMedCrossRefGoogle Scholar
  8. DiLavore, P. C., Lord, C., & Rutter, M. (1995). The pre-linguistic autism diagnostic observation schedule. Journal of Autism and Developmental Disorders, 25, 355–379. doi: 10.1007/BF02179373.PubMedCrossRefGoogle Scholar
  9. Elliot, C. D. (1990). Differential abilities scale (DAS). San Antonio: Psychological Corporation.Google Scholar
  10. Gilliam, J. E. (1995). Gilliam autism rating scale. Austin: Pro-Ed.Google Scholar
  11. Gotham, K., Risi, S., Pickles, A., & Lord, C. (2007). The autism diagnostic observation schedule (ADOS): Revised algorithms for improved diagnostic validity. Journal of Autism and Developmental Disorders, 37, 400–408. doi: 10.1007/s10803-006-0280-1.CrossRefGoogle Scholar
  12. Gotham, K., Risi, S., Dawson, G., Tager-Flusberg, H., Joseph, R., Carter, A., et al. (2008). A replication of the autism diagnostic observation schedule (ADOS) revised algorithms. Journal of the American Academy of Child and Adolescent Psychiatry, 47(6), 643–651. doi: 10.1097/CHI.0b013e31816bffb7.CrossRefGoogle Scholar
  13. Joseph, R. M., Tager-Flusberg, H., & Lord, C. (2002). Cognitive profiles and social-communicative functioning in children with autism spectrum disorder. Journal of Child Psychology and Psychiatry, and Allied Disciplines, 43(6), 807–821. doi: 10.1111/1469-7610.00092.PubMedCrossRefGoogle Scholar
  14. Krug, D. A., Arick, J. R., & Almond, P. J. (1980). Behavior checklist for identifying severely handicapped individuals with high levels of autistic behavior. Journal of Child Psychology and Psychiatry, and Allied Disciplines, 21(3), 221–229. doi: 10.1111/j.1469-7610.1980.tb01797.x.PubMedCrossRefGoogle Scholar
  15. Lord, C., & Spence, S. (2006). Autism spectrum disorders: Phenotype and diagnosis. In S. Moldin & J. Rubenstein (Eds.), Understanding autism: From basic neuroscience to treatment (pp. 1–23). New York: Taylor and Francis.Google Scholar
  16. Lord, C., Risi, S., Lambrecht, L., Cook, E. H., Jr, Leventhal, B. L., DiLavore, P. C., et al. (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, 205–223. doi: 10.1023/A:1005592401947.PubMedCrossRefGoogle Scholar
  17. Luyster, R., Gotham, K., Guthrie, W., Coffing, M., Petrak, R., Pierce, K., Bishop, S., Esler, A., Hus, V., Richler, J., Risi, S., & Lord, C. (2009). The autism diagnostic observation schedule—toddler module: A new module of a standardized diagnostic measure for ASD. Journal of Autism and Developmental Disorders, submitted.Google Scholar
  18. McCarthy, P. L., Cicchetti, D. V., Sznajderman, S. D., Forsyth, B. C., Baron, M. A., Fink, H. D., et al. (1991). Demographic, clinical and psychosocial predictors of the reliability of mothers’ clinical judgments. Pediatrics, 88, 1041–1046.PubMedGoogle Scholar
  19. Mullen, E. (1995). Mullen scales of early learning (AGS Ed.). Circle Pines: American Guidance Service.Google Scholar
  20. Pickles, A., Starr, E., Kazak, S., Bolton, P., Papanikolaou, K., Bailey, A., et al. (2000). Variable expression of the autism broader phenotype: Findings from the extended pedigrees. Journal of Child Psychology and Psychiatry and Allied Disciplines, 41, 491–502. doi: 10.1017/S0021963099005557.CrossRefGoogle Scholar
  21. Rutter, M., Le Couteur, A., & Lord, C. (2003). Autism diagnostic interview-revised–WPS (WPS ed.). Los Angeles: Western Psychological Services.Google Scholar
  22. Schopler, E., Reichler, R. J., & Renner, B. R. (1986). The Childhood Autism Rating Scale (CARS) for diagnostic screening and classification of autism. Irvington: Irvington.Google Scholar
  23. South, M., Williams, B. J., McMahon, W. M., Owley, T., Filipek, P. A., Shernoff, E., et al. (2002). Utility of the gilliam autism rating scale in research and clinical populations. Journal of Autism and Developmental Disorders, 32(6), 593–599. doi: 10.1023/A:1021211232023.PubMedCrossRefGoogle Scholar
  24. Sparrow, S., Balla, D., & Cicchetti, D. (1984). Vineland adaptive behavior scales. Circle Pines: American Guidance Service.Google Scholar
  25. Sparrow, S. S., Cicchetti, D. V., & Balla, D. A. (2005). Vineland adaptive behavior scales (2nd ed.). Circle Pines: American Guidance Service, Inc.Google Scholar
  26. Spiker, D., Lotspeich, L. J., Dimiceli, S., Myers, R. M., & Risch, N. (2002). Behavioral phenotypic variation in autism multiplex families: Evidence for a continuous severity gradient. American Journal of Medical Genetics, 114(2), 129–136. doi: 10.1002/ajmg.10188.PubMedCrossRefGoogle Scholar
  27. Szatmari, P., Bryson, S. E., Boyle, M. H., Streiner, D. L., & Duku, E. (2003). Predictors of outcome among high functioning children with autism and Asperger syndrome. Journal of Child Psychology and Psychiatry and Allied Disciplines, 44, 520–528. doi: 10.1111/1469-7610.00141.CrossRefGoogle Scholar
  28. Volkmar, F. R., Cicchetti, D. V., Dykens, E., Sparrow, S., Leckman, J. F., & Cohen, D. F. (1988). An evaluation of the autism behavior checklist. Journal of Autism and Developmental Disorders, 18, 81–97. doi: 10.1007/BF02211820.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Katherine Gotham
    • 1
    Email author
  • Andrew Pickles
    • 2
  • Catherine Lord
    • 1
  1. 1.University of Michigan Autism and Communication Disorders CenterAnn ArborUSA
  2. 2.University of ManchesterManchesterUK

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