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The National Guideline for the Assessment and Diagnosis of Autism Spectrum Disorders defines clinical best practice for the assessment and diagnosis of autism in Australia. A series of learning resources and practical tools have been developed to support implementation of the Guideline in practice including an online course, videos, fact sheets, a Baseline Evaluation and Audit Tool, template forms and training information.

Frequently Asked Questions

The National Guideline for the Assessment and Diagnosis of Autism Spectrum Disorders was launched in October 2018.

Autism CRC developed the Guideline, led by a team of research and clinical experts. It was commissioned by the National Disability Insurance Agency (NDIA).

The National Health and Medical Research Council (NHMRC) has approved the Guideline recommendations, demonstrating they are high quality, based on the best available scientific evidence and developed to rigorous standards.

The Guideline defines clinical best practice for the assessment and diagnosis of autism, and sets a new national standard. For clinicians, it provides a step-by-step process for assessment, with recommendations for:

  • who should be involved at each stage
  • the settings for assessment
  • the types of information to collect
  • how to approach informed decision making
  • follow-up – how to share assessment findings and initiate referrals for support.

The National Health and Medical Research Council approved the Guideline recommendations. This strongly indicates that the process outlined is considered optimal clinical practice in Australia. To ensure all individuals and families receive best clinical care, we suggest that you adopt the recommendations outlined in the Guideline as soon as practical.

The Guideline makes recommendations about the roles of a range of professionals at different stages of assessment and diagnosis, as well as their qualifications and expertise. Clinicians are advised to read the Guideline to understand the specific recommendations for their profession.

A Steering Committee with representatives from 13 national peak bodies guided the development, with input from other key stakeholder groups.

There is no biological test or marker for autism. It is usually diagnosed by trained clinicians, who observe certain characteristics such as social communication, behaviours and intense or focused interests.

The Guideline defines a clear process for the assessment and diagnosis of autism. It suggests using either of the following international manuals to help make diagnostic decisions:

  • Diagnostic and Statistical Manual of Mental Disorders (DSM-5)
  • International Classification of Diseases (ICD-11)

A prompt referral for assessment is critical to an individual receiving appropriate support and diagnosis. All developmental concerns should be taken seriously. The Guideline suggests that a primary healthcare provider (such as a GP, nurse, allied health professional or Aboriginal health worker) initiates the referral for a formal assessment.

The Guideline also makes recommendations about the qualifications and expertise of the referring clinician, the information they should collect, and how to initiate a written request for assessment.

Download referral form

Following referral, the Guideline recommends a Comprehensive Needs Assessment followed, if appropriate, by a Diagnostic Evaluation.

The Comprehensive Needs Assessment will look at an individual’s level of functioning in different areas, any support needs they may have, and whether there could be a medical explanation for the behaviours or characteristics that have prompted the referral.

If required, a Diagnostic Evaluation will then take place to establish whether behaviours are consistent with autism or another diagnosis.

The purpose of the Comprehensive Needs Assessment is to understand the strengths, challenges and needs of the individual being assessed. This assessment consists of two parts: an Assessment of Functioning and a Medical Evaluation.

Assessment of Functioning

The purpose of the Assessment of Functioning is to obtain a detailed understanding of an individual’s level of ability and support needs across a broad range of areas, including cognitive abilities, speech and language function, daily living skills, relationships, school or work. The Guideline recommends the assessment covers a broad range of developmental areas, psychosocial factors, adaptive functioning and domains of health.

The Guideline makes specific recommendations in terms of the qualifications and expertise of clinicians involved in the Assessment of Functioning, as well as types of information to collect, settings for assessment and decision making.

Once an individual’s level of functioning and environmental impacts have been assessed, their support needs should be identified and met through various strategies.

Medical Evaluation

The Medical Evaluation is critical to understand whether there are medical causes or co-occurring conditions that may help explain an individual’s presentation, and inform future care. The Guideline makes detailed recommendations in terms of who should conduct the Medical Evaluation, and the types of information to collect.

Download Medical Evaluation form

If the findings from the Comprehensive Needs Assessment support the possibility that autism may be a diagnosis, the Guideline recommends a Diagnostic Evaluation. This may involve a review of collected information, interviews with the individual and other key people in their life, and professional observation and assessment of characteristics and behaviours.

The Diagnostic Evaluation should be tailored to the complexity of the individual’s clinical presentation. The Guideline recommends two sequential stages:

Single Clinician Diagnostic Evaluation – conducted by one clinician, to determine whether a diagnosis can be confirmed or ruled out with high confidence.

Consensus Team Diagnostic Evaluation – in cases where further assessment is required to reach a diagnostic decision with high confidence, involving a multidisciplinary team.

Importantly, all support needs should be documented and communicated, and referrals should be initiated without requiring a clinical diagnosis.

The Guideline does not recommend any specific standardised screening and assessment tools, however it is recognised that these tools may be helpful during the referral, Comprehensive Needs Assessment and/or Diagnostic Evaluation stages.

The Guideline provides recommendations for reaching a diagnostic decision and how to share assessment findings with the individual and/or caregiver/s through a face-to-face meeting and in a written report. We have developed a report template for your use.

Download report template

To implement the Guideline recommendations in practice, we suggest you:

  • Read all of the Guideline – including the full range of recommendations and supporting resources.
  • Complete the Baseline Evaluation and Audit Tool so you can review your current practice against the Guideline recommendations.
  • Set a goal and plan the steps to make improvements to your clinical practice. The Baseline Evaluation and Audit Tool can also help with planning.

Once you’re ready to go, consider the training and expertise you or your team may require to deliver the recommended practice. Find out more on our training information page.

No. The Guideline makes recommendations for the assessment and diagnosis of autism. The assessment team decides intervention and support strategies, within the context of their own organisation and local requirements.

For more information, please contact Autism CRC on 07 3377 0600 or

NHMRC approval of Guideline recommendations

The recommendations on pages 3-60 of the Guideline document were approved by the Chief Executive Officer of the National Health and Medical Research Council (NHMRC) on 9 July 2018, under Section 14A of the National Health and Medical Research Council Act 1992. In approving the Guideline recommendations, NHMRC considers that they meet the NHMRC standard for clinical practice guidelines. The approval is valid for a period of 5 years. NHMRC is satisfied that the Guideline recommendations are systematically derived, based on the identification and synthesis of the best available scientific evidence, and developed for health professionals practising in an Australian health care setting. The Guideline reflects the views of the authors and not necessarily the views of the Australian Government.