3.6.3.90 Guidelines to Table 9 - Intellectual Function

Summary

Table 9 is used where a person has a meaningful intelligence quotient (IQ) between 70 and 85 resulting in functional impairment. A meaningful IQ is one which best represents the person's general intellectual function. To use Table 9, this impairment in intellectual function must have originated before the person turned 18 years of age.

People with an autism spectrum disorder (ASD), fetal alcohol syndrome (FAS) or fetal alcohol spectrum disorder (FASD) who also have a meaningful IQ between 70 to 85 resulting in function impairment should be assessed under Table 9, as their condition presented with an intellectual impairment originating before they turned 18. However, in cases of ASD which do not have a meaningful IQ between 70 and 85 resulting in functional impairment, Table 7 or Table 5 may be applied.

For people with a meaningful IQ score of less than 70, the manifest eligibility criteria should be applied. The manifest eligibility criteria should also be applied for people whose intellectual impairment is so severe they are unable to undertake an IQ test. When another table is being considered in addition to Table 9, care must be taken not to double-count the impairment.

The assessment of IQ can be complex, for example if there are significant discrepancies in indices. In some instances, a variable cognitive profile may not make a full scale IQ score the most meaningful summary of a person's intellectual function. In some instances, the General Ability Index (GAI) or other suitable index score may be used, if appropriate. However, if these scores are not meaningful, Table 7 may be a more appropriate table.

Assistance may be required in interpreting test results that are reported in psychological, neuropsychological, or educational reports. In such instances, consultation with a Services Australia psychologist or a referral to the HPAU should be undertaken.

Consideration must be given to whether recognised assessments of intellectual function should be adapted for use with Aboriginal and Torres Strait Islander peoples. The Kimberley Indigenous Cognitive Assessment (KICA) may be appropriate for Aboriginal and Torres Strait Islander people.

For culturally and linguistically diverse (CALD) people, the Tests of Nonverbal Intelligence - Fourth Edition (TONI-4), or other equivalent tests of intelligence validated for CALD populations, may be considered.

The assessment of a person's condition must be made by an appropriately qualified psychologist who is able to administer an assessment of intellectual function and an assessment of adaptive behaviour.

A PERSON'S SELF-REPORTED SYMPTOMS MUST NOT BE SOLELY RELIED UPON in determining the functional impacts of the person's permanent condition (impairment). There must be corroborating medical evidence of the person's impairment.

Under Table 9, both an assessment of intellectual function and an assessment of adaptive behaviour must be undertaken.

An assessment of intellectual function is to be undertaken using an appropriate assessment tool that was current and valid at the time of testing intellectual function, such as the Wechsler Adult Intelligence Scale IV (WAIS IV) or equivalent contemporary assessment tool. This assessment should be conducted after a person turns 16 years of age. A Wechsler Intelligence Scale for Children (WISC) assessment completed when the person was between the age of 12 years and the age of 16 years and 11 months is also acceptable for people aged 18 years or under at the time of assessment. If the assessment tool used is not appropriate or there are any concerns that existing scores do not reflect the person's current circumstances, re-testing should be considered following consultation with a Services Australia psychologist.

Depending on the cause of the intellectual impairment, the impaired functioning measured before a child turns 12 years of age may not remain constant into adulthood. Therefore, any additional evidence should be reviewed to determine if further assessment is required after the age of 12 years.

An assessment of adaptive behaviour is to be undertaken using an appropriate standardised assessment tool that was current and valid at the time of testing adaptive behaviour, such as the Adaptive Behaviour Assessment System (ABAS-II), the Scales for Independent Behaviour - Revised (SIB-R) or the Vineland Adaptive Behaviour Scales (Vineland-II). As these measures are based on responses from carers, teachers or self-report, consideration should be given to the capacity of the person reporting on the adaptive behaviour, for example, insight, observations in various settings, and social and cultural expectations. Consideration should be given to the validity of the assessments of adaptive function and whether the results are consistent with other corroborative evidence such as developmental history, formal assessment, school or work records and/or direct observation. If the measure of adaptive function is inconsistent with this, clinical judgement should be used to determine the level of adaptive behaviour that is consistent with the scores of adaptive behaviour found in the Table 9 descriptors.

Consideration must be given to the adaptation of recognised assessments of adaptive behaviour for use with Aboriginal and Torres Strait Islander peoples, as required.

If a valid and current assessment of adaptive behaviour is not available, referral for specialist assessment may be necessary.

Other contemporary standardised assessments of adaptive behaviour may be undertaken as long as they:

• provide robust standardised scores across the 3 domains of adaptive behaviour (conceptual, social and practical adaptive skills)
• have current norms developed on a representative sample of the general population
• demonstrate test validity and reliability
• provide a percentile ranking
• are a measure of stable adaptive deficit, rather than a temporary reduction in adaptive behaviour, and
• are indicative of the person's adaptive behaviour due to their intellectual function at the time of DSP assessment.

The following table describes how adaptive behaviour tools align with impairment ratings under Table 9.

Determining the level of functional impact - general rules

When determining which impairment rating applies to a person the rating that best describes the person's abilities or difficulties must be applied.

The descriptors in Table 9 outline how a score of adaptive behaviour aligns with an impairment rating. For example, to meet the 20-point descriptor a person must have either a score of adaptive behaviour between 50 and 70 or be assessed within the percentile rank of 0.1 to 2.

The structure of the Tables requires that, in assessing the level of functional impact, a comparison must be made of all the descriptors for each level of impairment. An assessment starts by considering the descriptors for 0 points, and, if a person has more than 'no functional impact', the descriptors for 5 points are then considered, and so on for the descriptors for higher impairment levels. When it is determined that a person meets all the required descriptors for a certain impairment rating level, but does not meet all the required descriptors for the next impairment rating level, the appropriate impairment rating applicable to the person's circumstances will be the lower of those 2 impairment ratings (i.e. the rating at which all the required descriptors are met).

Note: Individual descriptors or their parts must not be applied in isolation from one another.

In determining whether the required descriptors for a specific impairment level are met or not, ALL the descriptors for that level must be considered and applied as set out in the descriptor. NO descriptors or their parts are to be disregarded. One of several descriptor points may be sufficient for that rating when the word 'or' links the descriptors.

Determination of the descriptor that best fits a person's impairment level must be based on the available medical evidence including the person's medical history, investigation results and clinical findings. A person's self-reported adaptive functioning must not solely be relied on. It would be inappropriate to apply an impairment rating based solely on a person's self-reported functional capacity if the self-reported level of functional impairment is not consistent with the evidence available.

Professional judgement is required regarding the best source of intellectual function and adaptive functioning information as in some instances it will be appropriate to obtain input from a parent, caregiver or teacher. A person's IQ and adaptive functioning test results should not be considered in isolation as they may also have insufficient insight into their condition.

0-point impairment rating level

The 0-point descriptor specifies that the person has NO functional impact on intellectual function. At least one of the descriptors (1)(a), or (1)(b) applies.

5-point impairment rating level

The 5-point descriptor requires that there is a MILD impact on intellectual function and at least (1)(a) or (1)(b) applies.

10-point impairment rating level

The 10-point descriptor requires that there is a MODERATE impact on intellectual function and at least (1)(a) or (1)(b) applies.

20-point impairment rating level

The 20-point descriptor requires that there is a SEVERE impact on intellectual function and at least (1)(a) or (1)(b) applies.

30-point impairment rating level

The 30-point descriptor requires that there is an EXTREME impact on intellectual function and at least (1)(a) or (1)(b) applies.

Some conditions causing impairment commonly assessed using Table 9

There are a range of conditions a person may have which cause impairment affecting intellectual function that can be appropriately assessed using Table 9. These include intellectual impairment resulting from:

• Down syndrome
• congenital/perinatal or early childhood infections (eg rubella, cytomegalovirus (CMV), bacterial meningitis, encephalitis)
• extreme prematurity or birth trauma
• a person with either autism spectrum disorder, fragile X sydnrome or foetal alcohol spectrum disorder who also has a meaningful IQ between 70 and 85 resulting in function impairment
• childhood developmental or congenital disorders.

Impairments that should not be assessed using Table 9

Behavioural problems unrelated to intellectual impairment may be assessed using Table 5 - Mental Health Function, if there is a permanent mental health condition.

For people with an autism spectrum disorder (ASD) or fetal alcohol syndrome (FAS) or fetal alcohol spectrum disorder (FASD) who do not have a meaningful IQ between 70 and 85 resulting in function impairment, Table 7 or Table 5 may be applied.