Cox v Secretary, Department of Education: PIRS evidence and double counting

Background to the psychiatric impairment dispute

Ms Cox worked as a student learning officer at a high school. The employer accepted liability for a psychological injury arising from alleged bullying and harassment by her direct supervisor, with a deemed injury date of 15 June 2023.

In December 2024, the insurer disputed her section 66 lump-sum claim because it did not accept that the psychiatric impairment reached the 15% threshold in section 65A. A PIC Medical Assessor examined Ms Cox in June 2025, diagnosed major depressive disorder with anxious distress and assessed 9% WPI. No deduction was made for pre-existing impairment and no treatment adjustment was applied.

The Medical Assessor's aggregate PIRS class score was 16, with a median class of 2. Applying the conversion table in the NSW permanent impairment guidelines produced 9% WPI. The contested rating was Class 2 for social and recreational activities.

The functional evidence at the centre of the appeal

Before the injury, Ms Cox said she attended a gym three times a week and regularly stayed with her family at their holiday home, where activities included fishing and waterskiing. After the injury, she said her attendance at the holiday home reduced to about six day trips, she could not stay overnight because of anxiety, and she no longer attended the gym.

Other evidence showed that she drove herself to Rotary meetings, participated when present, occasionally attended rugby league games with her husband, drove short distances alone and relied on her husband for longer or unfamiliar journeys. The Medical Assessor used her driving to the Rotary Club when explaining both social and recreational activities and travel.

What the Appeal Panel decided

Ms Cox appealed the Medical Assessment Certificate under sections 327 and 328 of the Workplace Injury Management and Workers Compensation Act 1998. Among the alleged demonstrable errors, she argued that the Medical Assessor had failed to consider the holiday and gym restrictions and had improperly relied on travel-related conduct when rating social and recreational activities.

The Appeal Panel admitted a Rotary Club letter correcting the frequency of her attendance but otherwise confirmed the certificate. It considered the worker's activities to be occasional rather than rare and concluded that Class 2 remained the best fit. The Supreme Court challenge did not ask the Court to undertake a fresh medical assessment; it challenged the lawfulness of the Panel's decision-making process.

Grounds 1 and 2: the Panel did not determine the central evidence argument

Price AJA accepted that the holiday and gym argument was substantial, clearly articulated and central to the appeal. Although the Panel briefly recorded the restrictions, it did not decide whether the Medical Assessor had considered them or reconcile them with the Class 2 score.

The Panel was not required to mention every piece of evidence. The problem was that the omitted analysis concerned the very restrictions relied on to establish the alleged demonstrable error. The Court held that the Panel had constructively failed to exercise its jurisdiction and had failed to take account of material functional evidence.

Materiality was also established. The plaintiff submitted that moving social and recreational activities from Class 2 to Class 3 could change the median class and produce 19% WPI. The Court did not decide that 19% was the correct result, but it found that the Panel's decision could realistically have been different if the argument had been addressed lawfully.

Ground 3: the reasons did not reveal the decision-making path

The Panel's statement that it could identify no error did not explain how the holiday and gym restrictions, considered with the other evidence, supported Class 2 rather than Class 3. The Court held that the reasons did not sufficiently reveal the logical path to the result.

This was not a requirement for an exhaustive response to every submission. The reasons needed to be sufficient to show that the Panel understood and resolved the central appeal ground and to permit a court to identify whether the medical appeal involved legal error.

Ground 4: driving was assigned to the wrong PIRS scale

The Court applied the principle in Ballas v Department of Education (State of NSW) [2020] NSWCA 86 that each area of functional impairment is assessed separately. Clinical judgment is used to select the class within a scale, but conduct must first be characterised under the scale to which it is directly relevant.

Ms Cox's participation at Rotary could inform social and recreational functioning. Her ability to drive there, however, was directly relevant to travel. The Medical Assessor had referred to that driving in the reasons for both scales. The Court found that driving should not also have been a consideration in the social and recreational score and that the Appeal Panel's failure to correct the error was material.

The distinction is practical: attending, interacting and participating describe the social activity, while the ability to reach it by driving describes travel. Reusing the same conduct across separate scales risks double counting and can distort the final PIRS conversion.

What the Supreme Court ordered

The Court upheld all four grounds, set aside the Appeal Panel decision of 21 October 2025 and the Commission's Certificate of Determination of 25 November 2025, and remitted the matter to the President of the Personal Injury Commission for referral to a differently constituted Appeal Panel. There was no order as to costs.

Remittal leaves the medical merits to the new Panel. It may evaluate the evidence and reach the same or a different WPI result, provided it performs the statutory task according to law and gives adequate reasons.

Medical appeal and judicial review are different tasks

1. A Medical Assessor determines the referred medical dispute and issues a Medical Assessment Certificate with reasons.
2. A medical appeal is confined to the statutory grounds and the grounds advanced by the appellant. It is not an unrestricted rehearing.
3. Judicial review under section 69 of the Supreme Court Act 1970 examines the lawfulness of the decision-making process, not whether the Court would have selected a different PIRS class.
4. If reviewable error is established, the usual result is to set aside and remit the decision rather than for the Court to calculate WPI itself.

Evidence checklist for a psychiatric WPI or PIRS review

• the permanent impairment report and the reasons given for every PIRS scale;
• the Medical Assessment Certificate, Appeal Panel decision and Certificate of Determination;
• the worker's statement describing functioning before and after the injury with concrete frequency and support details;
• treating psychiatrist, psychologist and GP records addressing day-to-day function over time;
• evidence from family members or others who observe the worker's actual functioning;
• records of discontinued or reduced activities, travel restrictions and support required;
• the exact statutory appeal grounds, submissions and supporting evidence lodged; and
• the current PIC timetable, assessment status and any deadline for appeal or review.

Points to take from the decision

• An Appeal Panel need not discuss every sentence of evidence, but it must engage with a substantial and clearly articulated argument that is central to an appeal ground.
• Social and recreational functioning is concerned with participation in those activities; the means of driving to an activity was directly relevant to the separate travel scale in this case.
• Using one item of conduct across two PIRS scales can create impermissible double counting and distort the overall WPI calculation.
• Reasons must reveal the logical path from the evidence and appeal ground to the selected class; a bare conclusion that there is no error may be insufficient.
• The plaintiff argued that Class 3 could produce 19% WPI, but the Supreme Court did not award 19% WPI or decide which class must be selected on remittal.
• The matter will be reconsidered by a different Appeal Panel, which remains responsible for the medical appeal decision.

Frequently asked questions

Decision and primary sources

• Full decision: Cox v Secretary, Department of Education [2026] NSWSC 945
• Workplace Injury Management and Workers Compensation Act 1998 (NSW), section 327 - appeal against medical assessment
• Workplace Injury Management and Workers Compensation Act 1998 (NSW), section 328 - procedure on appeal
• Workers Compensation Act 1987 (NSW), section 65A - primary and secondary psychological impairment
• Supreme Court Act 1970 (NSW), section 69 - judicial review relief
• SIRA NSW workers compensation permanent impairment guidelines - psychiatric impairment and the six PIRS scales
• SIRA information for workers about the 1 July 2026 reforms - current permanent impairment framework and transitional information

Last legally reviewed: 8 August 2026.