JCPSLP Vol 22 No 1 2020

to access early intervention support (Bent, et al., 2020). It is well recognised that early intervention prior to school has a positive impact (Magiati, Tay, & Howlin, 2012; Reichow, 2012) and there is evidence to suggest that children who access early intervention at a younger age have better developmental outcomes than children who access intervention at an older age (Granpeesheh, et al., 2009; Rogers., et al., 2012). International guidelines recommend that ASD diagnostic assessments start within three months of referral to an autism team (NICE, 2011). While this may be occurring in the private sector, providing a multidisciplinary gold-standard ASD assessment within this timeframe appears difficult in the public system (Bent, et al., 2020; Taylor, et al., 2016). The average age of receiving an ASD diagnosis in Australia has been reported to be approximately 4 years, taking an average of 12 months from time of referral to receive the diagnosis (Bent, Dissanayake, & Barbaro, 2015; Bent, et al., 2020). For older children, this time is substantially longer. The challenge for all health professionals differentially diagnosing ASD is how to provide a rigorous ASD assessment in a timely and cost-efficient manner. A National Guideline for the Assessment and Diagnosis of Autism Spectrum Disorders in Australia (Whitehouse, et al., 2018) recommends two stages for diagnostic evaluation. A single clinician diagnostic evaluation is the initial stage and it is reported that for individuals whose clinical presentation is clear, a diagnostic decision can be reliably made by one suitably qualified and experienced clinician. This diagnostic decision would only come following a medical evaluation and assessment of functioning by other experienced professionals. During a single clinician diagnostic evaluation, a medical practitioner or psychologist uses information already gathered, obtains new relevant information, and considers co-occurring and/or differential conditions in the context of relevant biological, environmental or personal factors to make a diagnostic decision (Whitehouse, et al., 2018). For example, children with suspected ASD are often initially seen by a medical practitioner and/or an allied health professional. The medical evaluation examines a child’s medical condition relevant to neurodevelopmental disorders and takes relevant case history information. An allied health assessment would be considered an assessment of functioning, and provides specific information on the child’s functioning. If there is high diagnostic confidence during the single clinician diagnostic evaluation, a diagnosis can be given. For individuals whose presentation is more complex or subtle, a broader multidisciplinary stage 2 team assessment, referred to as a consensus team diagnostic evaluation , is completed. This evaluation is in keeping with the previous mentioned gold-standard assessment of ASD. Given the recent publication of these guidelines, there is little evidence to date regarding the clinical effectiveness and implementation of these recommendations. Figure 1 represents these diagnostic stages as a flow chart. The Tumbatin Clinic at Sydney Children’s Hospital is a multidisciplinary developmental unit that provides diagnostic services to children with significant developmental delay. Part of the role of this team is to differentially diagnose ASD from other paediatric developmental disorders. The Tumbatin team includes developmental paediatricians, psychologists and social workers but does not have permanent funding for a speech-language pathologist. As part of quality improvement processes conducted in 2015– 2016, a retrospective chart review of clients seen in the

Medical evaluation (DPOP)

Assessment of functioning (SLP)

School observations

Group allocation

Consensus team diagnostic evaluation

Figure 1. Current assessment pathway

clinic was undertaken by the Tumbatin paediatric registrars. This process identified a group of children, aged 4–7 years with language and intellectual functioning within normal limits, who were particularly challenging to diagnose. The review showed this group of children was more likely to attend a number of multidisciplinary assessments without reaching any clear diagnosis and additional time and resources were needed. Additional time and resources are costly, not only to the health service, but ultimately to the child and their families. Such costs may include delays to appropriate early intervention and added stress to the child and family by attending multiple, and possibly unnecessary, assessments. The current study aimed to investigate whether the addition of a speech-language pathology specific assessment of functioning for this group of 4–7-year-old children would enhance the accuracy and timeliness of ASD diagnosis. Specifically, the focus was on whether a combination of formal language assessment, social communication assessment and school observation would: (a) support an increase the number of children assessed by speech-language pathology prior to diagnosis in line with best practice, (b) provide important diagnostic information and, in combination with a medical evaluation, facilitate an accurate stage 1 ASD diagnosis, and (c) reduce the number of children attending unnecessary multidisciplinary team assessments thus reducing the waiting time to diagnosis. Method Study design A retrospective chart review and a prospective descriptive cohort study were completed. The research protocol was approved by the Sydney Children’s Hospitals Network

Human Research Ethics Committee. Retrospective chart review Aim

A retrospective chart review was conducted to provide comparison data regarding the diagnostic pathway of a similar cohort of children seen in the years prior to the prospective study. Specifically, data regarding access to SLP, school visits and waiting times was collected.

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JCPSLP Volume 22, Number 1 2020

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