Specialist assessment and diagnosis

Overview

Specialist health and functional assessments for developmental disability will usually be conducted by a paediatrician (for children) and multidisciplinary team (see Referrals for further assessment). Specialist assessments include a diagnostic overview considering coexisting conditions or differential diagnoses, and assessment of:

• developmental or cognitive abilities using standardised assessment tools
• adaptive or everyday abilities using standardised assessment tools
• behavioural problems, especially those that may suggest a behavioural phenotype (eg autism spectrum disorder)
• the potential cause, with emphasis on genetic testing (see also Investigations).

Specific assessments by allied health professionals can include speech and language assessments, swallowing assessment and assessments of mobility. Functional assessments may be required to inform a National Disability Insurance Scheme (NDIS) plan and determine eligibility for funding.

For a person to be diagnosed with intellectual disability, significant impairment of cognitive function and adaptive skills must be demonstrated using standardised assessment tools. Intellectual disability may range from mild to severe or profound. Assessment of a developmental or intellectual disability should also take into account how the child or adult has developed or learned over time, and cultural and social factors.

Assessment tools

Formal assessment of development, cognition or adaptive skills is undertaken by a psychologist, or sometimes a paediatrician. Tools that may be used include:

• Bayley Scales of Infant Development
• Griffiths Scales of Child Development (Third Edition)
• adaptive scales (eg Vineland Adaptive Behavior Scales, Adaptive Behavior Assessment System [ABAS])
• Wechsler Intelligence Scales (for preschool children, older children and adults)
• Stanford–Binet Intelligence Scales (for all ages).

The NDIS has introduced the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT) as a functional assessment tool. However, it has significant limitations in determining functional impairments. It does not replace standardised screening or assessment tools used in screening programmes or by paediatricians and psychologists.

Investigations

Practitioners with expertise in assessment of developmental disability can undertake genetic testing (eg microarray, fragile X). Consider referral or liaison with a paediatrician or clinical geneticist to ensure the person or family receives appropriate counselling and follow up in relation to genetic testing. For more information, see the Royal Australian College of General Practitioners (RACGP) Genomics in general practice.

Tests such as magnetic resonance imaging (MRI) and electroencephalography (EEG) are performed if indicated (eg if the person has seizures, regression, localising neurological signs). Once a paediatrician or other specialist has diagnosed developmental delay or disability, the person will typically also have other tests (eg thyroid function, creatine kinase concentration, urine metabolic screen).