Standards of diagnostic assessment for ASD

Question 1

Approaches to diagnosis?

Answer 1

1. If clearly have ASD, solo practitioner can independently diagnose with clinical judgement and DSM V criteria (not sufficient to access services in all Canadian jurisdictions)
2. Share care model - if mild or complex presentation or < 2 y o, Pediatrician can use info from an ASD diagnostic assessment and liaise with another HCP to make diagnosis
3. Team based approach - diagnostic assessment performed by HCPs in interD or multiD team - in some Canadian jurisdictions, only a team-based diagnostic approach is accepted for accessing specialized services. Useful when a child’s presentation is subtle, or complicated by coexisting health concerns, or complex medical or psychosocial history

Question 2

Steps of an ASD assessment?

Answer 2

1. Records review
   - Medical records
   - Developmental history
   - School reports
2. Interviewing parents
   - Reasons for referral
   - Pregnancy history
   - Developmental and behavioural history and current function
   - Child’s medical history, with focus on ASD-associated difficulties, such as sleep problems, unusual diet, self-injury
   - Educational history
   - Family history - hx of develomental disability including ASD, learning difficulties, behavioural problems, genetic conditions
   - Psychosocial history with focus on family violence or trauma, substance abuse or neglect
   - Family functioning, strengths, routines, and resources
3. Core features
   - Use an ASD specific diagnostic tool
4. Physical exam and investigations
   - Height and weight
   - HC - 20% of individuals with ASD are macocephalic
   - Neuro exam
   - Congenital anomalies and dysmorphic features (e.g. large or prominent ears)
   - Hearing and vision assessment with referral to audiologist, optometrist, ophthalmologist, as needed

If clinically inidicated:

• EEG (seizures)
• MRI head (microcephaly, seizures, abnormal neuro exam)
• Metabolic testing (cyclic vomiting, lethargy with minor illness, developmental regression, seizures
• Chromosomal microarray genetic testing should be offered for any children with a developmental disability, dysmorphic features, or congenital anomaly
• Blood lead levels, when the child exhibits developmental delay or pica, or lives in a high risk environment

5. Consider DDx and co-occurring conditions
6. Establish ASD diagnosis
7. Communicate ASD diagnosis
8. Comprehensive assessment for intervention planning