Prospectively Identifying Infants ‘at Risk' of An ASD in An Australian Community-Based Sample: Results from the Social Attention and Communication Study (SACS)

Background: Children with an Autism Spectrum Disorder (ASD) typically do not receive a diagnosis until 3-years of age, despite many parents suspecting a problem before 12-months. Although early markers of ASDs have been found as early as 6-months, there is little research on the prospective identification of these children prior to 18-months of age.

Objectives: The objective in this longitudinal study was to determine whether routine monitoring of social attention and communication behaviours, within the Victorian Maternal and Child Health (MCH) service, can prospectively identify infants who will receive a diagnosis of an ASD, in an Australian community-based sample.

Methods: Two-hundred and forty one MCH nurses from 17 Local Government Areas in metropolitan Melbourne were trained on developmental markers of ASDs in infancy. 22,168 children were then monitored at regular intervals on key items during four routine check-ups (8-, 12-, 18-, and 24-months of age) at their local MCH centre. All children deemed to be ‘at risk’ of an ASD at 12-months or older by showing a ‘pattern’ of failure on the key items were referred to the SACS for a thorough developmental and behavioural assessment. These children were followed up at 6-monthly intervals until 24-months of age, when the ADOS and ADI-R were administered.

Results: One hundred and twenty-three referrals were received. Of the 110 children assessed, 89 met criteria for an ASD (ascertainment rate for ASDs: 81%). With one exception, all remaining children met criteria for a developmental and/or language delay (DD/LD). Of the 10 12-month-olds who were referred to us, 90% showed signs of an ASD. Receptive language was the key ability within the cognitive profile that differentiated children with an ASD and DD/LD at 24-months of age. Data will also be presented on the behavioural items at each age that best predict a diagnosis of an ASD at 24-months.

Conclusions: The results indicate that it is possible to prospectively identify children with an ASD as early as 12-months of age via routine monitoring by community service providers in a community-based sample. Receptive language should be stringently monitored alongside social attention and communcation behavious in toddlers, as those children with very poor receptive language skills are more likely to traverse the trajectory towards an ASD.