Which factors predict cognitive outcomes in children with autism in SG?

A recent Singapore study has identified several factors, such as Autism Diagnostic Observation Schedule (ADOS) score and race, that can predict intellectual impairment among children with autism spectrum disorder (ASD).

The findings can help policymakers and practitioners worldwide to “allocate diagnostic, intervention, and educational resources, maximizing developmental outcomes for autistic children across diverse settings,” according to the researchers.

Overall, 2,124 children (82.6 percent male, 66.4 percent Chinese, 13.4 percent Malay, 9.8 percent Indian, and 10.5 percent others) had a diagnosis of autism from 2008 to 2011. Their mean age at first clinical diagnosis was 3.56 years, and the majority (85.2 percent) underwent a formal diagnostic assessment using the ADOS at a mean age of 4.16 years. [Ann Acad Med Singap 2025;54:396-409]

There were 1,326 children with cognitive and adaptive assessment results, of which 16.6 percent and 19.8 percent had mild and moderate-to-severe cognitive impairment, respectively. 

A total of 1,483 children had school placement outcomes. Of these, 45.9 percent went to mainstream schools, 21.8 percent entered SPED schools with the national curriculum, and 32.3 percent required customized curriculum SPED schools.

The following factors predicted intellectual impairment among children with autism: higher ADOS scores (adjusted odds ratio [aOR], 1.13, 95 percent confidence interval [CI], 1.08–1.19 for Comm+SI total; aOR, 1.53, 95 percent CI, 1.33–1.75 for SBRI total), higher social communication level of support (based on the DSM-5 criteria; aOR, 2.14, 95 percent CI, 1.10–4.16 for level 2; aOR, 14.94, 95 percent CI, 5.77–38.64 for level 3), and minority race (aOR, 2.82, 95 percent CI, 1.52–5.20 for Malay; aOR, 5.19, 95 percent CI, 2.36–11.44 for Indian, aOR, 4.54, 95 percent CI, 1.91–10.79 for others).

“In the absence of any other national prevalence or outcome data, the current study provides useful insights into the patterns of diagnosis, cognitive and adaptive functioning, and school placement outcomes,” the researchers said. “Such information can be useful for resource planning purposes for national agencies involved in providing autism diagnostic, early intervention, and educational services.”

Growing cases

From 2008 to 2011, a gradual increase was noted in the number of children with autism born, potentially indicating improved identification of the conditions over the years and a true increase in prevalence.

"Other data from our department have shown a substantial increase in annual numbers of children presenting with concerns for autism, from 540 in 2014 to 936 in 2020, and stabilizing around this figure since then,” the researchers said. “This is consistent with the rising prevalence of autism reported elsewhere.” [MMWR Surveill Summ 2023;72:1-14]

The current practice in Singapore is for preschoolers with suspected autism to undergo a diagnostic assessment using the ADOS and a detailed autism-specific interview. This approach resulted in resource constraints and long waiting times for psychological assessments, according to the researchers.

Based on the 2023 Clinical Practice Guidelines on ASD in Children and Adolescents, a single clinician approach in autism diagnosis may be considered if certain criteria on the experience of the clinician and the diagnostic procedure are met. [Ann Acad Med Singap 2024;53:541-552]

“The guidelines also state that standardized assessment tools are not always necessary, particularly in children with very clear features of autism,” the researchers said. 

In this study, medical records of a specialist developmental paediatric service for children were used to extract data for children born in 2008–2011 and referred to the autism clinic or were diagnosed with ASD. These data included demographic data, diagnostic methods, psychological assessment results, early intervention attendance, and school placement outcomes.

“This study is one of the largest to track school-age outcomes of a sizeable population of autistic children in Singapore,” according to the researchers.