3.6.3.90 Guidelines to Table 9 - Intellectual Function

Summary

Table 9 is used to assess low intellectual function resulting in functional impairment. To use Table 9 the low intellectual function must have originated before the person turned 18 years of age.

Low intellectual function means the person has an intelligence quotient (IQ) score of 70 to 85. For people with an IQ score of less than 70, the manifest eligibility criteria should be applied.

The assessment of the 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.

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

An assessment of intellectual function is to be undertaken in the form of a Wechsler Adult Intelligence Scale IV (WAIS IV) or equivalent contemporary assessment. This assessment should be conducted after the person turns 16 years of age. A Wechsler Intelligence Scale for Children (WISC) assessment completed between the ages of 12 and 16 years is also acceptable for people aged 18 years or under at the time of assessment.

An assessment of adaptive behaviour is to be undertaken in the form of either the Adaptive Behaviour Assessment System (ABAS-II), the Scales for Independent Behaviour - Revised (SIB-R) or the Vineland Adaptive Behaviour Scales (Vineland-II).

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

• provide robust standardised scores across the three 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, and
• provide a percentile ranking.

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

The following table describes how adaptive behaviour tools have been aligned with impairment ratings under Table 9.

Act reference: Social Security (Tables for the Assessment of Work-related Impairment for Disability Support Pension) Determination 2011 Table 9 - Intellectual Function

Determining the level of functional impact

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 to 70 or be assessed within the percentile rank of 2.

Determination of the descriptor that best fits the 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 symptoms must not solely be relied on. It would be inappropriate to apply an impairment rating based solely on a person's self-reported functional history if this level of functional impairment is not consistent with the medical 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.

Act reference: Social Security (Tables for the Assessment of Work-related Impairment for Disability Support Pension) Determination 2011 Table 9 - Intellectual Function

Some conditions causing impairment commonly assessed using Table 9

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 or foetal alcohol spectrum disorder who also has a low IQ,
• childhood developmental or congenital disorders.

Example: A 16 year old male, on finishing formal schooling lodged an application for DSP. He has been diagnosed with low intellectual function, which resulted from severe bacterial meningitis he contracted in early childhood. He has undergone an assessment of intellectual functioning and has an IQ score of 80.

A psychologist has conducted an assessment of adaptive behaviour with him, using the Adaptive Behaviour Assessment System (ABAS-II). He was assessed as having a score of adaptive behaviour of 71.

The report from his psychologist outlines that he has some behavioural issues.

Under Table 9, he would receive an impairment rating of 10 points, given the moderate impact his condition has on his ability to function. As his IQ score is above 69, he is not manifestly eligible (3.6.2.20) for DSP.

Act reference: Social Security (Tables for the Assessment of Work-related Impairment for Disability Support Pension) Determination 2011 Table 9 - Intellectual Function

Impairments that should not be assessed using Table 9

Behavioural problems unrelated to intellectual impairment may be assessed using Table 5 - Mental Health Function.

Act reference: Social Security (Tables for the Assessment of Work-related Impairment for Disability Support Pension) Determination 2011 Table 5 - Mental Health Function, Table 9 - Intellectual Function

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Last reviewed: 9 February 2012