WorkSafe VIC, SIRA NSW, the TAC and Comcare: how the report actually changes by scheme.

Four letters of instruction arrive at the same practice in the same week: a WorkSafe Victoria claim, a workers-compensation dispute under SIRA in New South Wales, a Transport Accident Commission file, and a Comcare matter for a Commonwealth employee. The same doctor could examine all four people, and the clinical work would look much the same. The reports could not. Each scheme is its own statute with its own assessment guide, its own psychiatric instrument, its own impairment thresholds and its own vocabulary, which means "the IME report" is not one document type but a family of them - and a report built for the wrong member of the family reads as incompetent to the people who receive it. This is the operational reality a medico-legal practice actually runs on, so it is worth laying out concretely.

One examination, four rulebooks

The starting point is that these are not four variations on a theme; they are four separate legal regimes that happen to buy a similar clinical service. Victorian workers compensation, New South Wales workers compensation, Victorian transport accident compensation and the Commonwealth scheme each define in their own legislation what impairment is, who may assess it, which guide the number must come from, and what follows from it. What stays constant is the layer above the schemes: the expert's paramount duty to the court or tribunal that may eventually read the report, which overrides any duty to the insurer, agent or lawyer who commissioned it.¹ Everything below that layer forks by scheme, and the forks start with the most basic question a report answers: how impaired is this person, measured how?

The forking starts earlier than most people expect - at the booking, not the writing. Who is allowed to perform a given assessment is itself a scheme rule: in Victoria, for example, whole person impairment is assessed by independent impairment assessors who are medical doctors and have completed training approved by the Victorian Government for exactly that task.² A practice coordinating examiners across schemes is therefore not just matching a doctor's specialty to an injury; it is matching a doctor's accreditations to a scheme's assessor rules, per claim, before anyone is examined. Get that wrong and the problem is not a weak report but an appointment that should never have been made.

The guides differ, and so do the editions

Whole person impairment sounds like a single quantity, but the number depends on the rulebook it is calculated under, and the schemes have deliberately chosen different ones. WorkSafe Victoria determines impairment using the American Medical Association's Guides to the Evaluation of Permanent Impairment, 4th edition, as modified by the Act and ministerial directions.² New South Wales assesses under SIRA's own workers-compensation guidelines, which are built on the 5th edition of the AMA Guides with NSW-specific modifications.³ The TAC is required to use the 2nd or the 4th edition depending on when the accident occurred.⁴ Comcare does not use the AMA Guides at all: assessments under the Safety, Rehabilitation and Compensation Act 1988 are bound to Comcare's own Guide to the Assessment of the Degree of Permanent Impairment, a legislative instrument in its own right, currently in Edition 3.0.⁵ These editions and guides differ in method - in which findings they count, how they combine, and what tables they route through - so the same clinical picture does not automatically produce the same percentage under each. An assessor who quotes the wrong edition has not made a rounding error; they have answered a question the scheme did not ask.

The spread of editions is not carelessness; it is how statutory schemes age. Each Act fixed the assessment method that was current when its compensation provisions were drafted, and because moving to a newer edition would change outcomes across every open and future claim, the fixed edition tends to stay fixed. That is why the TAC's rulebook varies with the accident date within a single scheme,⁴ and why no amount of clinical currency lets an assessor swap in a newer edition they happen to prefer. The editions are not medical choices any more; they are legal facts, and a report practice has to treat them the way it treats any other statutory requirement - looked up per claim, never assumed.

Psychiatric impairment is its own fork again

The forks multiply for psychological injury. Victoria rates psychiatric impairment under a dedicated instrument, the Guide to the Evaluation of Psychiatric Impairment for Clinicians (GEPIC), separate from the AMA Guides used for physical injury, and a worker claiming both physical and psychiatric injuries may be sent to separate independent impairment assessors for each, every one of them trained and approved for that kind of assessment.² New South Wales takes a different route again, rating psychiatric impairment under its own chapter of the SIRA guidelines with its own NSW-specific instrument rather than Victoria's GEPIC.³ So even the sentence "this claim includes a psychological component" changes what the report must contain, who is permitted to write which part of it, and which instrument the numbers must come from - and a practice that books the wrong assessor category for the psychiatric limb loses the appointment, not just a formatting point.

Thresholds decide what the number means

The percentage that comes out of the assessment then lands on a threshold, and the thresholds are scheme-specific law rather than clinical convention. In New South Wales workers compensation, lump-sum permanent impairment compensation requires a degree of permanent impairment greater than 10 per cent for physical injury,⁶ while a primary psychological injury attracts no permanent impairment compensation at all below 15 per cent - and secondary psychological consequences of a physical injury are excluded from the rating.⁷ The TAC pays its impairment benefit once impairment is assessed at 11 per cent or more, following an independent examination.⁴ Comcare's thresholds are set by the SRC Act and worked through its legislated Guide.⁵ The consequence for report writing is sharp: the same 12 per cent means different things in different schemes, sitting above one threshold and below another, and the report's job is to make the assessment so methodologically clean that the number can carry that weight. None of this changes what the honest number is - the doctor's assessment is the doctor's assessment - but it does change which questions the report must answer precisely, and which methodological details a reviewing tribunal will scrutinise.

The vocabulary is not interchangeable either

Around the numbers sits language, and the language is statutory. Each scheme's letter of instruction asks its own questions in its own defined terms - the capacity constructs, the causation tests, the treatment questions and the certificate forms all differ, because each is anchored to a different Act. A report that answers a New South Wales brief in Victorian vocabulary, or treats a Comcare file like a state workers-compensation claim, signals unfamiliarity before the opinion is even reached, and invites the follow-up correspondence that erodes both turnaround and credibility. Writing for the scheme is not window dressing; it is part of answering the questions actually asked, which is what the instructing party is paying for and what the expert's duty requires.¹

The same discipline extends to knowing what a given report must not do. Under the Victorian arrangements a psychiatric limb belongs to a differently-credentialed assessor than a physical one,² and in New South Wales an impairment attributable to a secondary psychological injury is excluded from the rating altogether,⁷ so a report that quietly folds the excluded material into its numbers is wrong even when every individual observation in it is clinically sound. Scheme competence, in other words, is partly the ability to leave things out on purpose and say so - which is the same honesty discipline that makes a report survive scrutiny everywhere else.

Scheme-awareness is an operations problem, not a memory test

Put together, a practice that writes across schemes is maintaining at least four parallel sets of knowledge: which guide and edition governs, which assessor accreditations are needed for which limb, which thresholds frame the questions, and which vocabulary the report must speak. Holding that in the heads of doctors and practice staff works until it doesn't - a template reused across state lines, an edition cited from habit, a psychiatric limb rated under the wrong instrument. The structural fix is the same one that works everywhere else in clinical software: encode the differences once, and let the system apply them. That is how we are building Trenthos IME: the scheme is identified from the letter of instruction, and the draft is assembled scheme-aware - the right structure, the right guide and edition named, the right question set answered, every factual line referenced to its source page. The doctor still examines, reasons, forms the opinion and signs; the software never rates an impairment or nudges a conclusion, because it is drafting software a doctor reviews and signs, not a decision-maker and not a registered medical device. What it removes is the scheme-shaped clerical risk - the part of medico-legal work where being wrong has nothing to do with clinical judgement, and everything to do with which of four rulebooks was open on the desk.