A structured parent interview for identifying young children with autism.

The team built a 33-question parent interview called the PIA. They asked parents of kids under six about play, language, and social habits.

They checked if the answers were steady across two raters and if the scores could tell autism from mental retardation.

Nine of the eleven PIA areas passed reliability tests. Six areas cleanly split the autism group from the mental-retardation group.

The tool met basic psychometric rules, so it was judged ready for clinic use.

Barton et al. (2019) later shrank the idea to a 5-item toddler screener called BADEC. Both studies show parent answers can flag autism early, but BADEC trims the work to two minutes.

Waldron et al. (2023) moved the same goal to adults. They swapped parent talk for an EHR algorithm that hunts key words and codes. The 1993 interview still rules for little kids; the 2023 code set now does it for grown-ups.

Osório et al. (2025) add a motor twist. They found autistic toddlers walk with shaky steps. The PIA catches social signs; gait variance catches body signs. Together they give you two cheap windows into the same condition.

If you assess young kids, keep the PIA close. It is long, but it separates autism from global delay without any gear. Pair it with a quick gait check or the newer BADEC to speed up the process. You get parent insight plus objective data, and you can start services sooner.