On 1 October 2025, the third edition of the Impairment Assessment Guidelines (IAG3) commenced operation.  IAG3 applies to all permanent impairment assessments conducted on or after 1 October 2025 (regardless of the date of injury).

The first edition of the Impairment Assessment Guidelines (IAG1) will continue to apply to assessments if a worker has attended an appointment with an assessor for the purpose of a permanent impairment assessment before 1 October 2025.

‘Stabilised’

Under IAG1, before a worker could have a permanent impairment assessment (PIA) their injury needed to have reached ‘maximum medical improvement’.  IAG3 has replaced this term with ‘stabilised’, which is defined as:

“a work injury has stabilised if the worker’s condition is unlikely to change substantially in the next 12 months with or without medical treatment (regardless of any temporary fluctuations in the condition that might occur).  There are statutory and regulatory exceptions to the requirement of stability.  The Guidelines also provide for other timeframes for the presence of the diagnosed injury with it also being noted that in some cases these Guidelines provide for exceptions to the requirement for an injury to have stabilised, or provide for other additional periods to apply”

PIA requests and reports

When a PIA report is requested, the “requestor” must advise the assessor:

• which injuries are to be assessed;
• which injuries are not to be assessed; and
• whether any pre-existing or subsequent injuries need to be disregarded or deducted in accordance with the Return to Work Act 2014 (SA) (RTW Act) (making particular reference to Section 22(8) of the RTW Act, which, in turn, refers to Return to Work Corporation of South Australia v Summerfield [2021] SASCFC 17), and IAG3.

A requestor must provide a draft request letter to the worker and allow them at least twenty business days to review the request and provide feedback (previously only ten business days was required).  An allowance of only ten business days is required to review and provide feedback on supplementary or additional requests or correspondence to the nominated assessor.

Assessors must be provided with the request letter and other relevant material at least ten business days before a PIA appointment.

It is worth noting that an assessor cannot assign a worker a level of whole person impairment (WPI) for an injury if they cannot arrive at a diagnosis for that injury.

Updated guidance on assessment of certain conditions

IAG3 imposes new timeframes with respect to certain injuries and conditions, including the following:

• Complex Regional Pain Syndrome (CRPS) must have been present for at least 18 months, and have stabilised, before it can be assessed. Further, only three out of four physical signs now need to be present in order to confirm the diagnosis of CRPS (previously four out of four were required with respect to both symptoms and physical signs);
• Epicondylitis and adhesive capsulitis should not be assessed unless the worker has experienced symptoms for at least 18 months;
• Peripheral nerve injuries (such as Carpal Tunnel Syndrome and Ulnar Neuritis) should not be assessed unless the worker has experienced symptoms for at least 12 months;
• Lis Franc injuries and brain injuries should not be assessed unless 18 months have passed since the date of injury; and
• Plantar Fasciitis should only be assessed if the worker is experiencing persistent symptoms for at least 18 months.

In addition, there is a new framework for assessing impairment with respect to cauda equina syndrome and traumatic brain injuries.

Further, there are a modified range of categories for assessing impairment following ankle, knee and hip replacement surgeries.  There are now four classes, being “Good” (Class 1), “Fair” (Class 2), “Poor” (Class 3), and “Very Poor” (Class 4).  There were previously only three categories (Good, Fair and Poor), none of which exceeded 30%WPI.

There is now consistency in the assessment of ankle, hip and knee replacements across the relevant categories.

The introduction of the fourth category of “Very Poor” gives rise to the possibility of reaching a WPI of 35%. However, to achieve this rating, there must be either catastrophic failure of the implant and/or a recovery complicated by significant chronic infection.

Noise Induced Hearing Loss

IAG3 now requires that, where a worker is being assessed for Noise Induced Hearing Loss (NIHL), that they be examined by the assessor in person.

The guidance in IAG1 that any NIHL or tinnitus not related to work should be considered, is now a requirement in IAG3.

The Monaural tables (published in the National Acoustic Laboratory (NAL) tables found in NAL Report No. 118) are no longer used to assess NIHL, and specific guidance is provided for workers who have an ‘only hearing ear’.  Further, there is clarification that impairment arising as a result of NIHL is only to be calculated on the assessed hearing thresholds between 2000Hz and 4000Hz (inclusive).  Specific guidance is given where a worker has been exposed to prolonged continuous noise.

Observations

IAG3 will undoubtedly have an impact on workers seeking assessment of their WPI.

In particular, the requirement that CRPS symptoms must have been present for at least 18 months, and have stabilised, before assessment, makes it more likely that workers will be outside the 104 week income support entitlement period before they can seek assessment; even if a worker achieves seriously injured worker status, it will occur after their initial period of income support entitlements have already ceased.

However, the new methodology for assessing injuries such as CRPS may make it easier for a worker to achieve a diagnosis of CRPS.

In some respects, the modification to the assessment of lower limb joint replacements will make it fairer for workers who have suffered a catastrophic outcome, with the introduction of the “Very Poor” category (35% WPI) to reach seriously injured worker status.

However, in the absence of catastrophic joint failure or significant chronic infection, the WPI cannot exceed 25% for a “Poor” outcome, thereby making it more difficult to achieve seriously injured worker status in most instances.

It is also worth noting the decision of Return to Work Corporation (SA) v English; Williams v Return to Work Corporation (SA) [2023] SASCA 125 (English and Williams).  The English and Williams decision was significant as it broadened the definition of ‘same injury or cause’ for the purpose of combination of injuries under the RTW Act.  The facts of the two individual cases required an examination of whether a consequential impairment was a “natural and foreseeable consequence” of the first, such that a consequential impairment which was a “natural and foreseeable consequence” of an earlier impairment was held to have arisen from the same injury or cause, and the two impairments were capable of combination.

At the time of the English and Williams decision, which was delivered shortly after the raising of the seriously injured worker threshold for physical injuries from 30% to 35%, it was our view that there would not be a significant reduction in the number of workers able to achieve seriously injured worker status, due to the expanded ability to combine impairments.

When the seriously injured worker threshold was raised, it was in the context of a greater number of workers achieving seriously injured worker status than had previously been anticipated, which was having a compounding effect on the financial performance of the scheme.

It will be interesting to observe whether, over the coming years, IAG3 will have the desired effect that raising the seriously injured worker threshold could have had, if not for the English and Williams decision, or whether it will have no effect on the scheme and simply make it harder for some workers to achieve seriously injured worker status, while making it easier for others.