JCPSLP Vol 22 No 1 2020

Expanding possibilities: Foci on reading and interdisciplinary practices

Speech-language pathology assessment Key to diagnostic evaluation of ASD in 4–7 year-olds with average cognition Kate Broome and Vanessa Sarkozy

The purpose of this study was to determine how the inclusion of a speech-language pathology assessment influenced the accurate and timely diagnosis of Autism Spectrum Disorder (ASD) for children historically difficult to diagnose. A retrospective chart review and a descriptive cohort study were completed. Participants were 4;0–6;11 years, with average cognition and suspected ASD. The records of 20 children were reviewed retrospectively. The prospective descriptive cohort included 15 participants for whom language and social communication assessments were completed and degree of agreement with formal ASD diagnosis explored. Only half of the children reviewed retrospectively received a speech-language assessment prior to an ASD diagnostic assessment. Prospectively, all 15 participants were assigned to a diagnostic category – suspected ASD, within normal limits, or behaviour difficulty – following medical evaluation and SLP assessment. There was 100% agreement between the diagnostic category assigned and the eventual formal diagnosis following a comprehensive assessment process. This suggests that a SLP assessment is a vital component of the ASD diagnostic process and could assist in reaching an accurate diagnosis at an earlier stage. A utism spectrum disorders (ASD) are a group of complex neurodevelopmental disorders characterised by impairments in social communication and interaction, in addition to the presence of restricted and repetitive behaviours (American Psychiatric Association, 2013). Diagnosis is based on behavioural presentation. There is international consensus that an ASD assessment should be conducted by a multidisciplinary specialised team comprising, at minimum, a developmental paediatrician, psychologist and speech-language

pathologist (NICE, 2011). Best-practice assessment guidelines outline that, in addition to a thorough case history, hearing test and physical examination, the following standardised measures need to be completed: (a) language assessment, (b) cognitive assessment, (c) adaptive battery, and (d) an autism-specific measure (Filipek, et al., 2000; NICE, 2011; Ozonoff, et al., 2005; Silove, et al., 2008). The assessment should include direct observations of the child across a number of settings and obtain information from a number of sources (i.e., parents, childcare professionals, teachers). Despite well-recognised international gold-standard guidelines for an ASD assessment, a recent survey of health professionals in Australia reported inconsistent diagnostic practices across the country (Taylor, et al., 2016). Given the lack of national standards in ASD diagnosis and variable practices across states, these results are not surprising. Multidisciplinary teams were more frequently reported in the public sector and commonly consisted of one medical and two allied health professionals, usually a psychologist and speech-language pathologist (Taylor, et al., 2016). A complete assessment battery comprising developmental/ cognitive, language and adaptive function, in addition to ASD symptomatology was infrequently (14% of the time) completed. The speech-language pathologist’s role in the autism assessment team is to assess the child’s language, speech and social communication ability across a number of settings (SPA, 2016). Together with a developmental/ cognitive assessment, this information is essential to differentially diagnose ASD from other childhood disorders, such as language disorder, speech sound disorder, social communication disorder, and global developmental delay. The changes to the diagnostic criteria for ASD (APA, 2013) highlight the importance of a social communication assessment which needs to be interpreted by a speech- language pathologist in light of the child’s overall developmental and language profile. The inclusion of a speech-language pathology assessment, incorporating language, speech and social communication, is likely to increase the diagnostic accuracy of the ASD assessment. An early diagnosis of ASD can facilitate timely access to specialised early intervention services (Bent, Barbaro, & Dissanayake, 2020; Dawson, 2008). Parents of children with ASD appear well aware of available government services, such as the National Disability Insurance Scheme (NDIS) (Ranasinghe, Jeyaseelan, White, & Russo, 2017), and report that receiving an ASD diagnosis assists them

KEYWORDS ASSESSMENT AUTISM CHILD

DIAGNOSIS LANGUAGE SOCIAL COMMUNICATION THIS ARTICLE HAS BEEN PEER- REVIEWED

Kate Broome (top) and Vanessa Sarkozy

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JCPSLP Volume 22, Number 1 2020

Journal of Clinical Practice in Speech-Language Pathology