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.

The team gave two gold-standard autism tests to 184 youth with intellectual disability.

They compared results from the parent interview (ADI-R) and the play-based observation (ADOS-G).

Then they checked both tools against the official DSM-IV-TR diagnosis.

Each test alone matched the DSM label only some of the time.

Using the interview and observation together raised accuracy to fair-to-good levels.

Kids with intellectual disability were less likely to be missed or mis-labeled when both tools were used.

Gotham et al. (2007) later updated the ADOS scoring rules. Those new rules boost accuracy, so the 2004 numbers are now a floor, not a ceiling.

Geurts et al. (2008) ran a similar two-tool study in toddlers with developmental delay. They saw the same pattern: the ADOS carried more weight than the ADI-R in younger kids.

Perez et al. (2015) added Vineland adaptive scores to the mix. When interview and observation disagreed, Vineland data solved about one-third of conflicts, giving teams a practical tie-breaker.

Fleury et al. (2018) pooled eight studies and found mixed sensitivity between the old and new ADOS algorithms. Their review reminds us to note which version we use before trusting a cut-off.

If you assess school-age clients who have both autism and intellectual disability, schedule the ADI-R interview and the ADOS observation on the same case. The pair catches kids either tool might miss alone. When scores clash, pull in recent Vineland or day-to-day adaptive data before you finalize the label. Always check whether your ADOS software is using the original 2004 rules or the revised 2007 algorithms; the newer rules sharpen accuracy even further.