Assessment & Research

A Comparative Analysis of the ADOS-G and ADOS-2 Algorithms: Preliminary Findings.

Dorlack et al. (2018) · Journal of autism and developmental disorders 2018
★ The Verdict

ADOS-2 is not a straight upgrade—algorithm choice, child age, and cultural background still sway accuracy.

✓ Read this if BCBAs who give or interpret ADOS results in clinic or school intake teams.
✗ Skip if RBTs who do not take part in diagnostic assessment.

01Research in Context

01

What this study did

Fleury et al. (2018) looked at eight past studies that compared the old ADOS-G algorithm with the newer ADOS-2. They asked: does ADOS-2 catch more true cases and send fewer typical kids to mis-diagnosis? The team pulled every paper that gave hard numbers for sensitivity and specificity.

02

What they found

The numbers were all over the map. Some studies said ADOS-2 was better; others said it missed more kids or over-called autism. When the eight studies were lined up, no clear winner appeared. The authors label the evidence 'mixed' and urge caution.

03

How this fits with other research

Bennett et al. (2008) saw the same mess earlier. In Hispanic preschoolers the revised algorithm (the heart of ADOS-2) lowered specificity in modules 2 and 3, flagging too many kids with mild social delays. That single-study red flag now shows up in the 2018 big-picture review.

Hong et al. (2021) looks like a contradiction at first glance. Their 2021 replication found excellent accuracy for the Toddler Module cut-offs. The fight disappears when you notice age: toddlers have clearer symptom profiles, while school-age kids with language or cultural differences trip up modules 2 and 3.

de Bildt et al. (2011) and Hus et al. (2014) add another layer. They showed that calibrated severity scores help compare kids across time, but module 2 still needs more work. Fleury et al. (2018) folds that warning into the wider claim: newer algorithms are not automatically better.

04

Why it matters

Before you write 'meets ADOS-2 criteria' in your report, check which module and which algorithm you used. If the child is Hispanic, bilingual, or has only mild social delays, get extra parent data or run the ADI-R to guard against false positives. Stay skeptical of cut-off labels and document your clinical override.

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Open the score form, circle the module number, and ask: does this kid match the sample that validated these cut-offs?

02At a glance

Intervention
not applicable
Design
systematic review
Population
autism spectrum disorder
Finding
mixed

03Original abstract

The Autism Diagnostic Observation Schedule (ADOS) is a widely utilized observational assessment tool for diagnosis of autism spectrum disorders. The original ADOS was succeeded by the ADOS-G with noted improvements. More recently, the ADOS-2 was introduced to further increase its diagnostic accuracy. Studies examining the validity of the ADOS have produced mixed findings, and pooled relationship trends between the algorithm versions are yet to be analyzed. The current review seeks to compare the relative merits of the ADOS-G and ADOS-2 algorithms, Modules 1-3. Eight studies met inclusion criteria for the review, and six were selected for paired comparisons of the sensitivity and specificity of the ADOS. Results indicate several contradictory findings, underscoring the importance of further study.

Journal of autism and developmental disorders, 2018 · doi:10.1007/s10803-018-3475-3