NSW workers compensation guidelines for the evaluation of permanent impairment

These guidelines explain permanent impairment assessment in the NSW workers compensation system. This is the fourth edition of these guidelines, published in April 2016.

Download a PDF of this document in full.

Click here to read the foreword

The State Insurance Regulatory Authority (SIRA) has issued the 4th edition of the NSW workers compensation guidelines for the evaluation of permanent impairment (Guidelines) for assessing the degree of permanent impairment arising from an injury or disease within the context of workers’ compensation. When a person sustains a permanent impairment, trained medical assessors must use the Guidelines to ensure an objective, fair and consistent method of evaluating the degree of permanent impairment.

The Guidelines are based on a template that was developed through a national process facilitated by Safe Work Australia. They were initially developed for use in the NSW system and incorporate numerous improvements identified by the then WorkCover NSW Whole Person Impairment Coordinating Committee over 13 years of continuous use. Members of this committee and of the South Australia Permanent Impairment Committee (see list in Appendix 2) dedicated many hours to thoughtfully reviewing and improving the Guidelines. This work is acknowledged and greatly appreciated.

The methodology in the Guidelines is largely based on the American Medical Association’s Guides to the Evaluation of Permanent Impairment, 5th Edition (AMA5). The AMA guides are the most authoritative and widely used in evaluating permanent impairment around the world. Australian medical specialists representing Australian medical associations and colleges have extensively reviewed AMA5 to ensure it aligns with clinical practice in Australia.

The Guidelines consist of an introductory chapter followed by chapters dedicated to each body system.

The Introduction is divided into three parts. The first outlines the background and development of the Guidelines, including reference to the relevant legislative instrument that gives effect to the Guidelines. The second covers general assessment principles for medical practitioners applying the Guidelines in assessing permanent impairment resulting from work-related injury or disease. The third addresses administrative issues relating to the use of the Guidelines.

As the template national guideline has been progressively adapted from the NSW Guideline and is to be adopted by other jurisdictions, some aspects have been necessarily modified and generalised. Some provisions may differ between different jurisdictions. For further information, please see the Comparison of Workers’ Compensation Arrangements in Australia and New Zealand report, which is available on Safe Work Australia’s website.

Publications such as this only remain useful to the extent that they meet the needs of users and those who sustain a permanent impairment. It is, therefore, important that the protocols set out in the Guidelines are applied consistently and methodically. Any difficulties or anomalies need to be addressed through modification of the publication and not by idiosyncratic reinterpretation of any part. All queries on the Guidelines or suggestions for improvement should be addressed to SIRA at

15. Digestive system

AMA5 Chapter 6 (p 117) applies to the management of permanent impairment of the digestive system. Before undertaking an impairment assessment, users of the Guidelines must be familiar with:

  • the Introduction in the Guidelines
  • chapters 1 and 2 of AMA5
  • the appropriate chapter(s) of the Guidelines for the body system they are assessing.
  • the appropriate chapter(s) of AMA5 for the body system they are assessing.

The Guidelines take precedence over AMA5.


16.1 The digestive system is discussed in AMA5 Chapter 6 (pp 117–42). This chapter can be used to assess permanent impairment of the digestive system.

16.2 AMA5 Section 6.6, ‘Hernias’ (p 136): Occasionally in regard to inguinal hernias, there is damage to the ilioinguinal nerve following surgical repair. Where there is loss of sensation in the distribution of the ilio-inguinal nerve involving the upper anterior medial aspect of the thigh, a 1% WPI should be assessed as per Table 5.1 in Chapter 5 of the Guidelines. This assessment should not be made unless the symptoms have persisted for 12 months.

16.3 Where, following repair, there is severe dysaesthesia in the distribution of the ilio inguinal nerve, a maximum of 5% whole person impairment (WPI) may be assessed as per Table 5.1 in Chapter 5 of the Guidelines. This assessment should not be made unless the symptoms have persisted for 12 months.

16.4 Where, following repair of a hernia of the abdominal wall, there is residual persistent excessive induration at the site, which is associated with significant discomfort, this should be assessed as a class 1 herniation (AMA5 Table 6-9, p 136). This assessment should not be made unless symptoms have persisted for 12 months.

16.5 Impairments due to nerve injury and induration cannot be combined. The higher impairment should be chosen.

16.6 A person who has suffered more than one work-related hernia recurrence at the same site and who now has limitation of activities of daily living should be assessed as herniation class 1 (AMA5 Table 6-9, p 136).

16.7 A diagnosis of a hernia should not be made on the findings of an ultrasound examination alone. For the diagnosis of a hernia to be made there must be a palpable defect in the supporting structures of the abdominal wall and either a palpable lump or a history of a lump when straining.

16.8 A divarication of the rectus abdominus muscles in the upper abdomen is not a hernia, although the supporting structures have been weakened, they are still intact.

16.9 Effects of analgesics on the digestive tract:

  • AMA5 Table 6-3 (p 121) Class 1 is to be amended to read ‘there are symptoms and signs of digestive tract disease’.
  • Nonsteroidal anti-inflammatory agents, including Aspirin, taken for prolonged periods can cause symptoms in the upper digestive tract. In the absence of clinical signs or other objective evidence of upper digestive tract disease, anatomic loss or alteration a 0% WPI is to be assessed.
  • Effects of analgesics on the lower digestive tract:
    • Constipation is a symptom, not a sign and is generally reversible. A WPI assessment of 0% applies to constipation.
    • Irritable bowel syndrome without objective evidence of colon or rectal disease is to be assessed at 0% WPI.
  • Assessment of colorectal disease and anal disorders requires the report of a treating doctor or family doctor, which includes a proper physical examination with rectal examination if appropriate, and/or a full endoscopy report.
  • Failure to provide such reports may result in a 0% WPI.

16.10 Splenectomy: Post-traumatic splenectomy or functional asplenia following abdominal trauma should be assessed as 3% WPI.

16.11 Abdominal adhesions: Intra-abdominal adhesions following trauma requiring further laparotomy should be assessed according to AMA5 Table 6-3 (p 121).