Skip to main content

Autism Diagnostic Observation Schedule – Second Edition (ADOS-2)

The Autism Diagnostic Observation Schedule – Second Edition (ADOS-2) is an updated, semi-structured, standardized observational assessment tool designed to assess autism spectrum disorders in children, adolescents, and adults (Lord, Rutter, DiLavore, Risi, Gotham, & Bishop, 2012).

Overview

The ADOS-2 assesses communication, social interaction, play, and restricted and repetitive behaviors.

The instrument consists of five modules selected based on age and level of expressive language. The ADOS-2 has updated protocols, revised algorithms, and a Toddler Module for children between 12 and 30 months. Observations are recorded and scored by the examiner. Modules 1 through 4 provide cutoff scores to aid in interpretation. The Toddler Module provides “ranges of concern” rather than cutoff scores. Administration time is 40 to 60 minutes.

Summary

Author (yr) Age Range (yrs) Method of Administration/Format Approx. Time to Administer Subscales
Autism Diagnostic Observation Schedule – Second Edition** (Lord, Rutter, DiLavore, Risi, Gotham, & Bishop, 2012)**. 1 year to adult

Clinician engages the examinee in a range of activities using interactive stimulus materials

40–60 min.

Modules 1–4 yield algorithm cutoff scores for autism and autism spectrum. Toddler Module yields “ranges of concern” to assist in forming clinical impressions.

Screening/Diagnosis: D

**Instrument requires special training to administer.

Availability: Western Psychological Services, http://bit.ly/1mpz859

Research

Author (yr) Sample Size Topic(s) Addressed Outcome
Gray, Tonge, & Sweeney (2008) 209 - Age Range: 1.5-4.5 years Discriminative validity

ADI-R and AU = 0.46

ADOS and AU = 0.73

ADSO and AU = 0.62

ADI-R and ADOS = 0.35 (Cohen’s kappa)

Author (yr) Sample Size Topic(s) Addressed Outcome
Gotham, Risi, Pickles, & Lord (2007) 1,630 - Age Range: 1.2-16 years Diagnostic validity

Use of new algorithms: Sensitivity:

AU vs. Non-Spectrum = 85-96

Non-AU AU vs. Non-Spectrum = 61-90; Specificity:

AU vs. Non-Spectrum = 50-97

Non-AU AU vs. Non-Spectrum = 12-79 (lowest for Module 1 – no words)

New algorithms increase specificity 12-31% in classifying Non-AU AU in lower-functioning subjects

Author (yr) Sample Size Topic(s) Addressed Outcome
Lord, Risi, Lambrecht, Cook, Leventhal, et al. (2000) 54, 55, 59, 45 (223-Total) - Age Range: Module 1: 1.25-10 Module 2: 2-7 Module 3: 3-20 Module 4: 10-40 Interrater and Test-retest reliability and discriminative validity

(Interclass correlations, weighted kappas)

Interrater:

Social = 0.93

Communication = 0.84

Social Communication = 0.92

Restricted Repetitive – 0.82

Test-Retest Social = 0.78

Communication = 0.73

Social Communication = 0.82

Restricted Repetitive = 0.59

Discriminative Validity:

95% for AU

92% for Non-Spectrum

33% for PDD-NOS as having Non-AU AU (53% of PDD-NOS fell in the AU range);

Specificity:

AU vs. PDD-NOS and Non-Spectrum = 68-79, AU and PDD-NOS vs. Non Spectrum = 87-94, AU to Non-Spectrum = 93-100,

PDD-NOS to Non-Spectrum – 88+94;

Sensitivity:

AU vs. PDD-NOS and Non-Spectrum = 87-100, AU and PDD-NOS vs. Non-Spectrum = 90-97, AU to Non-Spectrum = 93-100, PDD-NOS to Non-Spectrum = 80-94

Author (yr) Sample Size Topic(s) Addressed Outcome
deBildt, Sytema, Ketelaars, Kraijer, Molder, et al. (2004) 184 - Age Range: 5-20 years Criterion validity and reliability

Sensitivity:

PDD: ADOS-G = .874

PDD: ADI-R = .716

AD: ADOS-G = .917

AD: ADI-R = .771

Specificity:

PDD: ADOS-G = .472

PDD: ADI-R = .787

AD: ADOS-G = .647

AD: ADI-R = .632

Agreement (percentage):

Age 5-8 = 83.4 for AD, 81.0 for PDD

Age 8+ = 57.8 for AD, 58.5 for PDD Total = 63.6 for AD, 63.6 for PDD
Author (yr) Sample Size Topic(s) Addressed Outcome
Overton, Fielding, & Garcia (2008) 26 - Age Range: 1.67-16 years ADOS algorithm scores compared to new algorithm scores

+/- Revised algorithm resulted in better accuracy for more severe group

Author (yr) Sample Size Topic(s) Addressed Outcome
LeCouter, Haden, Hammal,& McConachie (2008) 101 - Age Range: 2-4 years Concurrent validity

Agreement with ADOS: AU Social Interaction = 78%, AU Communication= 74%; Above/below AU cutoff = 81%; Above/below spectrum cutoff = 78%

Author (yr) Sample Size Topic(s) Addressed Outcome
Risi, Lord, Gotham, Corsello, Chrysler, et al. (2006) 1,297 - Age Range: 1.5-14 years Diagnostic sensitivity and specificity

Strict autism criteria used in combination with ADI- R: 80% or higher for U.S. sample, 75% or higher for Canadian sample; lower for single use and use for other PDDs

Author (yr) Sample Size Topic(s) Addressed Outcome
Mazefsky & Oswald (2006) 78 - Age Range: 2-8 years Discriminative validity

77% agreement with team diagnosis

Download PDF