Assessment & Research

Clinical assessment of autism in high-risk 18-month-olds.

Brian et al. (2008) · Autism : the international journal of research and practice 2008
★ The Verdict

Mix ADOS social items with AOSI motor signs for a sharper 18-month ASD screen.

✓ Read this if BCBAs who assess high-risk toddlers in early-intervention or diagnostic clinics.
✗ Skip if Practitioners who only see verbal school-age clients.

01Research in Context

01

What this study did

Researchers tested a new 18-month autism screen. They mixed ADOS social-communication items with AOSI reactivity and motor-control items. The goal was to see if the combo caught autism better than either tool alone.

02

What they found

The blend raised accuracy. Social items plus motor signs sorted toddlers with ASD from peers better. The hybrid score gave clearer yes-or-no flags at the one-and-a-half-year visit.

03

How this fits with other research

Leung et al. (2014) followed infant siblings for years and showed early motor delays forecast later social delays. Their long view backs the idea that motor red flags matter.

Cohen et al. (2018) found parents spot early signs better than brief clinician clips. That seems to clash with J et al., but the methods differ. J used structured items; R relied on quick natural moments. Use both parent report and structured tasks for the best picture.

De Francesco et al. (2023) later built a full motor battery that sorted ASD from ADHD with 73–87% accuracy. Their school-age tool extends the motor-plus-classification idea J started in babies.

04

Why it matters

You can sharpen 18-month screens without buying new kits. Add AOSI motor and reactivity scores to the ADOS social total. A small jump in accuracy now can shorten the long wait families face later.

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Total the AOSI motor plus reactivity items and add them to the ADOS social score before you write the 18-month report.

02At a glance

Intervention
not applicable
Design
case control
Sample size
228
Population
autism spectrum disorder
Finding
positive

03Original abstract

Earlier intervention improves outcomes for children with autism spectrum disorders (ASDs), but existing identification tools are at the limits of standardization with 18-month-olds. We assessed potential behavioural markers of ASD at 18 months in a high-risk cohort of infant siblings of children with ASD. Prospective data were collected using the Autism Diagnostic Observation Schedule (ADOS) and Autism Observation Scale for Infants (AOSI) on 155 infant siblings and 73 low-risk controls at 18 months. Infants were classified into three groups (ASD sibs, non-ASD sibs, controls) based on blind best-estimate diagnosis at age 3. Fisher's exact tests, followed by discriminant function analyses, revealed that the majority of informative ADOS items came from the social and behavioural domains, and AOSI items measuring behavioural reactivity and motor control contributed additional information. Findings highlight the importance of considering not only social-communication deficits, but also basic dimensions of temperament including state regulation and motor control when assessing toddlers with suspected ASD.

Autism : the international journal of research and practice, 2008 · doi:10.1177/1362361308094500