An autism diagnosis tool for toddlers proved highly accurate, creating the potential for autism to be diagnosed at a younger age, results from a community-based study suggest.
The Social Attention and Communication Surveillance-Revised (SACS-R) tool had an 83% positive predictive value (95% CI 0.77-0.87) and an estimated 99% negative predictive value (95% CI 0.01-0.02) in over 13,500 toddlers ages 12 to 24 months, according to Josephine Barbaro, PhD, of La Trobe University in Melbourne, Australia, and colleagues.
The SACS-R showed 99.6% specificity, though alone it had only "modest" sensitivity, at 62% (95% CI 0.57-0.66). Adding the SACS-Preschool (SACS-PR) test -- which follows toddlers to an older age -- increased sensitivity to 96% (95% CI 0.95-0.98), the group reported in .
"Parents are often told to 'wait and see' when raising concerns about their child's development. This means the average age of diagnosis , and opportunities for early support have been missed," Barbaro said in a press release. "Putting this extremely effective tool in the hands of a trained primary health professional, so that during their routine health checks they are also screening for autism, makes a huge difference to early diagnosis."
The SACS-R is an autism surveillance tool used in community-based samples of children ages 11 to 30 months that observes their early social-communication behaviors. The SACS-PR expands the age range of the SACS-R up to 60 months by looking at "other common markers of autism in preschool-aged children," the researchers said.
The SACS-R has been rolled out in the state of Victoria, where La Trobe University is located, .
"It is important to note that the SACS-R and SACS-PR are administered by a trained professional, which is likely the reason for the high diagnostic accuracy that this paper found," said Sandhyaa Iyengar, MD, MPH, of the Children's Hospital of Philadelphia, who was not involved in the study.
"It is also best suited to longitudinal evaluation instead of one-time screening. While these may be barriers for ease of administration, the SACS-R and SACS-PR may be a very good tool for community health workers to implement in areas with otherwise limited access to medical providers in order to achieve developmental screening," Iyengar told Ƶ.
The recommends developmental surveillance during primary care visits in children ages 9 to 30 months, along with autism-specific screening at 18 and 24 months. In the U.S., Iyengar said that common autism screening tools include the Modified Checklist for Autism in Toddlers, Revised With Follow-up; the Social Communication Questionnaire; and the Screening Tool for Autism in Toddlers and Young Children.
One in 50 children in this study (n=270) assessed by SACS-R were diagnosed with autism spectrum disorder (ASD). That number jumped to one in 31 children (n=439) when results from the SACS-PR test at 42 months were included, according to Barbaro and colleagues.
The study was conducted in two phases and included children from Victoria, who attended their routine maternal and child health (MCH) consultations, which is universally available to all children up to 3.5 years of age. In phase one, which ran from 2013 to 2016, 13,511 children were assessed with the SACS-R at their 12-, 18-, and 24-month MCH consultations. A total of 48% of the children included were girls. Of the 240 children in phase one who completed a university assessment, 199 were diagnosed with ASD and 41 with a developmental or language delay.
Phase two, where the sample was followed up with SACS-PR, ran from 2014 to 2018. In phase two, 8,419 children, or 62.3% of the original sample, were assessed at their 42-month MCH consultation. An additional 168 children were identified with high-likelihood of ASD with the SACS-PR.
Neither the SACS-R or SACS-PR identified any typically developing children as high likelihood.
The researchers noted that their sample was a convenience sample and acknowledged the loss to follow-up with phase two of the study. "Another potential limitation is the time and resources required for a trained professional to administer the SACS-R and SACS-PR," the team added.
Disclosures
Barbaro reported grants from the Sir Robert Menzies Foundation and the Cooperative Research Centre for Living with Autism. The Social Attention and Communication Surveillance (SACS) tool has been licensed to the Victorian government, earning royalties for La Trobe University. The university and Barbaro receive funds from individuals signing up for online SACS training.
Primary Source
JAMA Network Open
Barbaro J, et al "Diagnostic accuracy of the social attention and communication surveillance-revised with preschool tool for early autism detection in very young children" JAMA Netw Open 2022; DOI: 10.1001/jamanetworkopen.2021.46415.