Systematic Review of Clinical Guidance Documents for Autism Spectrum Disorder Diagnostic Assessment

Background:  The reported increase in prevalence of autism spectrum disorder (ASD) has also increased the demand for ASD diagnostic assessments. Clinical guidance documents play an important role in shaping these diagnostic assessment practices.

Objectives:   The objective of this study was to perform a systematic review of clinical guidance documents for ASD diagnostic assessment, comparing and contrasting their quality and content.

Methods:  The systematic review of guidance documents included documents published from 2000 to present by Canadian, American and UK health and educational professional associations, as well as documents published by governments in Canada or the UK. Professional association statements, practice parameters, and practice guidelines were included as clinical guidance documents. Documents pertaining only to management of ASD, as well as literature reviews and commentaries were excluded. MEDLINE, EMBASE, PsychINFO, CINAHL and ERIC were searched. Search terms included Child Development Disorders, Pervasive; Asperger Syndrome; and Autistic Disorder; these were combined with Diagnosis. Titles and abstracts were screened for eligibility based on their applicability to ASD diagnostic assessment. All documents with titles and/or abstracts that were relevant underwent full text review with application of the inclusion and exclusion criteria. One reviewer extracted relevant information from each document and assessed for quality using the Appraisal of Guidelines Research and Evaluation, 2^nd edition (AGREE-II) tool. 

Results:   A total of 837 unique documents were retrieved, of which 24 were considered relevant and underwent full-text review. Of these, nine documents met the inclusion criteria and were included in the analysis. Two of these documents were no longer endorsed by their professional associations. The mean total score on the AGREE-II for all included documents was 68.6 (s.d. = 11.9, range 45, 89). Domain scores from the AGREE-II showed relatively high quality in Scope and Purpose (mean 90.6, s.d. 10.2) and Clarity of Presentation (mean 89.9, s.d. 10.6). Scores were lowest in Applicability (mean 42.7, s.d. 23.4) and Rigor of Development (mean 51.6, s.d. 25.8). Six of the nine documents strongly recommend a multidisciplinary team (MDT) for diagnostic assessment, while the remaining three state that MDT assessment is ideal. The guidelines varied substantially in their recommended personnel for diagnostic assessment, from no stated recommendations to a list of recommended MDT members.  There was little supporting evidence for MDT and personnel recommendations. Recommended tools varied from no recommended tools to recommendations that multiple specified tools be completed. Only three of the documents included recommended wait times for assessment, all of which were from governments or non-profit associations.

Conclusions:   Multiple guidance documents have been published for ASD diagnostic assessments, with varying quality and recommendations. The substantial variation in quality and content likely stems from insufficient evidence supporting diagnostic assessment practices. Further empiric evidence is needed to support diagnostic decision making in ASD and should include analysis of systems impacts, such as wait times.