Statement of Principles concerning non-aneurysmal aortic atherosclerotic disease (Reasonable Hypothesis) (No. 52 of 2020)

This instrument is a Statement of Principles (SOP) made by the Repatriation Medical Authority under subsection 196B(2) of the Veterans' Entitlements Act 1986 (the VEA) (s3). It prescribes the medical definition, qualifying causal and aggravating factors, temporal rules and defined terms that decision‑makers must apply when deciding whether a reasonable hypothesis exists connecting non‑aneurysmal aortic atherosclerotic disease, or death from that disease, with a person’s relevant service (s7, s9, s10). The instrument explicitly applies to claims to which section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 (MRCA) applies (s5). It is therefore an administrative, non‑legislative determinant of evidentiary thresholds used in the assessment of veteran and defence member claims for entitlements under those Acts.

Mechanically, the SOP does the following things:

• It sets the medical meaning of the condition in issue (non‑aneurysmal aortic atherosclerotic disease) by reference to clinical features and the ICD‑10‑AM code I70.0, while stating that the operative meaning for decision purposes is the definition provided in subsection 7(2) rather than the code alone (s7(2)-(4)).
• It identifies the set of factual and clinical factors that, if present and linked to relevant service, are sufficient as a minimum to raise the statutory threshold of a "reasonable hypothesis" that the disease is connected to service (s9, s10(1)).
• It divides factors into two functional groups: those relevant to establishing a causal connection at clinical onset (subsections 9(1)-9(18)), and those that can be relevant to material contribution to, or aggravation of, disease where the disease pre‑existed or was suffered/contracted before or during service (subsections 9(19)-9(37) together with s10(2)).
• It supplies a detailed dictionary of defined terms (Schedule 1), which prescribes numeric thresholds and operational definitions used throughout the factors (for example, BMI ≥30 for "being obese", dyslipidaemia thresholds, the MET unit, "one pack‑year", cumulative equivalent dose methodology) (Schedule 1).
• It provides a cross‑reference mechanism where a factor in this SOP refers to an injury or disease covered by another SOP: the other SOP’s terms apply (s11).

The SOP sits within the Part XIA SOP regime: the Repatriation Medical Authority states that it is "of the view that there is sound medical‑scientific evidence" supporting relationships between the disease and relevant service (s8). The instrument does not create criminal penalties, nor does it itself grant entitlements; it functions as an evidentiary/legal standard applied by decision‑makers under the VEA and MRCA. The compilation available is current to 19 September 2022 and incorporates an amendment determined in 2022 which revised the definition of "one pack‑year" (endnotes).

Officially, the rationale is that the SOP identifies factors that must exist for a reasonable hypothesis to be raised; the instrument’s terms are framed as medical‑scientific findings and as application instructions for claims under the VEA/MRCA (s8, s9, s5). The instrument thereby operationalises how service‑connection for this specific disease is to be assessed by adjudicators. The rest of this deep dive dissects the substantive content, the decision mechanics, the administrative consequences, evidentiary and compliance burdens, key definitional thresholds, and the amendment and legislative history recorded in the compilation.

The SOP organises its substantive content around a small set of legal and medical concepts, each precisely defined or operationalised in the instrument. The central concepts are:

• Non‑aneurysmal aortic atherosclerotic disease: Defined in subsection 7(2) as atherosclerosis of the abdominal aorta causing partial or complete occlusion and either (a) warrants medical treatment; or (b) produces specified clinical manifestations (claudication in particular locations, erectile dysfunction, pallor and coldness of lower extremities, or reduced femoral pulsation). The SOP clarifies that, although the condition attracts ICD‑10‑AM code I70.0, the statutory meaning is the paragraph (2) definition (s7(2)-(4)).
• Death from the disease: The SOP includes death contributed to by the disease, defined as death from a terminal event or condition that the non‑aneurysmal aortic atherosclerotic disease contributed to (s7(5)). The instrument defines "terminal event" in the dictionary (for example, pneumonia, cardiac arrest) (Schedule 1, terminal event).
• Reasonable hypothesis: The SOP is captioned as a “Reasonable Hypothesis” instrument and is deployed to indicate those factors which, when established and related to relevant service, as a minimum suffice to raise a reasonable hypothesis linking the condition to service (s9). The instrument does not itself supply a statutory definition of "reasonable hypothesis" (that concept is part of the Part XIA regime under the VEA), but the SOP sets the factual matrix that will be taken to meet it.
• Factors and temporal bifurcation: The instrument lists factors that must exist at clinical onset (subsections 9(1)-9(18)) and an overlapping but distinct set that relate to material contribution to, or aggravation of, clinical worsening where disease pre‑existed or was present before or during service (subsections 9(19)-9(37) and s10(2)). This bifurcation assigns different factors to causation and to aggravation analysis and imposes a temporal rule for the aggravation factors.
• Relationship to relevant service: For any factor to assist in raising the reasonable hypothesis, the SOP requires that the factor be related to the person’s relevant service as defined in the dictionary (s10(1); Schedule 1 definition of "relevant service" lists forms of VEA/MRCA service).
• Cross‑reference to other Statements of Principles: If a factor in this SOP refers to an injury/disease covered by another SOP determined under subsection 196B(2) VEA, then the terms of that other SOP apply (s11). This mechanism avoids inconsistent or duplicative definitions and delegates interpretive primacy to the other SOP for that injury or disease.

The instrument affects several categories of actors and stakeholders through its operation as an evidentiary framework for claims under the VEA and MRCA (s5). The primary affected groups are:

• Claimants: Veterans, members of Peacekeeping Forces, and members of the Forces whose claims fall under section 120A of the VEA or section 338 of the MRCA. The SOP determines what medical and exposure evidence can, as a minimum, raise a reasonable hypothesis that non‑aneurysmal aortic atherosclerotic disease or death from it is connected to relevant service (s5, s9). Claimants who seek establishment of service connection for first onset, or for material contribution and aggravation where the disease pre‑existed, must marshal the specific factors and related evidence enumerated in the SOP.
• Legal and medical practitioners working for claimants: Lawyers, advocates, treating clinicians, and medical experts who prepare or give evidence for claims must align reports and documentary evidence to the SOP’s factor list and its defined thresholds (Schedule 1). For example, to rely on obesity, an expert must provide BMI history showing BMI ≥ 30 for the requisite duration (s9(3); Schedule 1). To rely on dyslipidaemia, practitioners must document the lipid thresholds or lipid‑normalising therapy (Schedule 1, dyslipidaemia).
• Decision‑makers and administrators: The Repatriation Medical Authority made the SOP (s3) and decision processes under the VEA and MRCA will use it to determine whether a reasonable hypothesis exists. Administrative officers, adjudicators, and medical panels will apply the SOP’s definitions, temporal rules and factor lists. The SOP’s cross‑reference clause (s11) requires decision‑makers to consult other SOPs where overlapping injuries/diseases are referenced.
• The Department and benefit payers: The Department administering the VEA/MRCA will experience effects in claims assessment workloads because the SOP establishes specific evidentiary trigger points (s9; Schedule 1). The instrument may change the number and character of claims accepted or rejected, thereby affecting entitlement flows, though the SOP itself does not change statutory benefits or eligibility rules beyond the evidentiary standard.
• Medical record holders and health systems: Hospitals, clinics and practitioners become sources of evidence required by the SOP , for example, records showing radiation doses, therapeutic radiation fields to the aorta, renal function markers for chronic kidney disease, psychiatric management evidence for a clinically significant mental disorder, or dental records for periodontitis (Schedule 1; s9(12), s9(13), s9(11), s9(16), s9(18)). The SOP’s numeric thresholds increase the evidentiary specificity needed from clinical record keeping.

This SOP does not itself create new criminal liabilities or lay down duties enforceable in a penal sense. Instead, it creates administrative evidentiary duties and affects substantive rights in the sense that it prescribes the factual prerequisites that must be established to raise a reasonable hypothesis of service connection for non‑aneurysmal aortic atherosclerotic disease or death from the disease. The key operational duties and rights are:

• Decision‑makers’ duty to apply the SOP where the SOP is applicable: The instrument is made under subsection 196B(2) of the VEA (s3) and applies to claims to which s120A VEA or s338 MRCA applies (s5). Decision‑makers assessing such claims must use this SOP as the basis for evaluating whether the minimum evidential threshold (reasonable hypothesis) is met with respect to the listed factors. The SOP thereby imposes an administrative duty to consider its factors and definitions when relevant.
• Claimant’s evidentiary duty to substantiate factors and their relationship to service: To rely on any factor in section 9, the claimant must demonstrate that the factor existed in the person and that it is related to the person’s relevant service (s9; s10(1)). For factors relevant only to material contribution/aggravation, additional temporal restrictions apply (s10(2)). The claimant’s right is the potential to have the reasonable hypothesis criterion satisfied and thus to progress to entitlement consideration under VEA/MRCA.
• Temporal and causal allocation duty: The SOP separates factors relevant to first clinical onset (9(1)-9(18)) and factors relevant to material contribution/aggravation (9(19)-9(37) with s10(2)). Where the disease was suffered or contracted before or during but did not arise out of service, only subsections 9(19)-9(37) can be used to show material contribution or aggravation (s10(2)). This is a procedural rule decision‑makers must apply in causal allocation.
• Duty to reconcile cross‑referenced SOPs: Where a factor in section 9 refers to an injury or disease that is itself the subject of another SOP, that other SOP’s factors apply according to its own terms (s11). Adjudicators must therefore cross‑check external SOPs for consistent application when such overlaps occur.
• Definition and evidentiary specificity rights: Claimants have the right to rely on precise, numerical thresholds supplied in the Schedule where those thresholds are required by a factor (for example, dyslipidaemia thresholds, BMI thresholds, cumulative radiation dose threshold of at least 0.5 sievert, pack‑year definitions) (Schedule 1; subsections 9(13), 9(3), 9(5)). The instrument gives claimants clear target evidence that, if produced and linked to service, will meet the SOP’s minimum criteria.

The Statement of Principles instrument itself contains no criminal sanctions, monetary penalties, or direct enforcement mechanisms. It is an evidentiary/administrative instrument rather than a prescriptive regulatory instrument with coercive sanctions. The enforcement and consequence architecture is indirect and operates through the VEA and MRCA claim processes:

• Administrative consequences for claims: The principal enforcement effect is that the presence or absence of the factors specified in the SOP will determine whether a decision‑maker can say that a reasonable hypothesis has been raised connecting non‑aneurysmal aortic atherosclerotic disease, or death from that disease, with relevant service (s9; s10). That determination influences whether an applicant proceeds to entitlement decisions under the VEA/MRCA. Thus the practical "enforcement" is acceptance or rejection of claims for veteran entitlements.
• No penalties in instrument: There is no section imposing fines, imprisonment or other legal penalties on individuals or organisations for non‑compliance with the SOP. The SOP is not framed as a regulatory code but as a statement of medical‑scientific findings and a statutory instrument applying to claims (s3, s8).
• Administrative review and appeal contexts: While this SOP does not set out review rights, it operates within a statutory framework (VEA/MRCA) which provides procedural avenues for review and appeal of decisions made using the SOP. The SOP itself does not specify those processes; claimants would rely on the review and appeal mechanisms of the underlying Acts. The instrument therefore affects the content of decisions that are subject to review, but does not itself create or modify review rights.
• Implementation and evidentiary enforcement: The SOP imposes evidentiary thresholds (numerical cut‑offs and time windows) that will be enforced administratively by adjudicators. For example, the radiation dose threshold of at least 0.5 sievert to the aorta (s9(13)) will require technical dose reconstruction and verification processes; adjudicators and medical officers must enforce that threshold when assessing radiation exposure evidence. Similarly, dyslipidaemia definitions require specific blood lipid results or records of regular drug therapy (Schedule 1, dyslipidaemia), and obesity requires BMI records showing BMI ≥30 for specified durations (s9(3); Schedule 1).
• Enforcement via cross‑reference to other SOPs: Section 11 requires that when a factor refers to an injury or disease covered by another SOP, the other SOP applies. Enforcement of those cross‑referenced terms is therefore embedded in the administrative application of those other SOPs as well.

This SOP is expressly made under subsection 196B(2) of the Veterans' Entitlements Act 1986 (s3). It is designed to be applied in claims to which section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 applies (s5). The instrument therefore operates within and interacts with the statutory frameworks of the VEA and MRCA, and with other Statements of Principles under the Part XIA SOP scheme. Notable interaction points and cross‑references in the instrument are:

• VEA/MRCA application and decision framework: The SOP is an input into the decision‑making process established by the VEA and MRCA. Section 5 explicitly limits application to claims under VEA s120A and MRCA s338. The SOP does not alter the substantive entitlements or procedural rights provided by those Acts; rather it supplies the medical‑scientific evidentiary criteria used when applying the Acts’ tests for service connection, reasonable hypothesis and aggravation.
• Cross‑SOP application rule: Section 11 provides a direct interaction rule: if a factor in this SOP refers to an injury or disease covered by a different SOP made under subsection 196B(2) VEA, then the factors in that other SOP apply in accordance with its terms. This establishes a hierarchy and a method for resolving overlap between instruments and ensures that a given injury/disease is interpreted consistently across SOPs.
• External technical guidance and standards: The Schedule’s definition of "cumulative equivalent dose" expressly references a methodology published by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) , Guide to calculation of 'cumulative equivalent dose' ... as in force on 2 August 2017 (Schedule 1, cumulative equivalent dose). The SOP therefore interacts with that external technical standard for dose reconstruction when adjudicating radiation exposure factors (s9(13), s9(31)). Decision‑makers must apply that methodology when assessing whether cumulative dose thresholds have been met.
• ICD‑10‑AM and copyright: The SOP notes that non‑aneurysmal aortic atherosclerotic disease attracts ICD‑10‑AM code I70.0, and states that for applying the SOP the meaning is that given in subsection 7(2) (s7(3)). The instrument also acknowledges that the ICD‑10‑AM is copyrighted by the Independent Hospital Pricing Authority and provides edition details (s7(4)). This interaction is informative: it situates the condition within international classification but rejects code alone as the operative legal definition.
• Interaction with medical, clinical and record‑keeping regimes: The SOP’s definitional thresholds require specific clinical evidence (for example, lipid panel thresholds, BMI calculations, chronic kidney disease markers, psychiatric management records, dental records for periodontitis, radiation dose documentation). It therefore interacts with clinical practice and record‑keeping standards, although it does not alter clinical regulatory regimes. It may prompt increased requests for old clinical records and for expert technical reconstructions where records are incomplete.

The compilation includes an amendment history as recorded in the instrument’s endnotes and provides two discrete entries in the legislation history (endnote 3). The recorded legislative and amendment events are:

• Original determination: Statement of Principles concerning non‑aneurysmal aortic atherosclerotic disease (Reasonable Hypothesis) (No. 52 of 2020), registered 28 August 2020, commenced 28 September 2020 (Endnote 3: registration F2020L01080).
• Amendment determination: Veterans' Entitlements (Statements of Principles,definition of "one pack‑year") Amendment Determination 2022 (No. 94 of 2022), registered 26 August 2022, commenced 19 September 2022 (Endnote 3: registration F2022L01128). Endnote 4 indicates that the amendment revised the Schedule 1 definition of "one pack‑year" and updated notes associated with subsections 9(5), 9(6), 9(23) and 9(24).

Endnote 4’s amendment history table lists the specific provisions affected by the 2022 instrument: the note to subsection 9(5), the note to subsection 9(6), the note to subsection 9(23), the note to subsection 9(24), and the Schedule 1 definition for "one pack‑year" were updated (Endnote 4). The compilation notes that the day of commencement of the Amendment Determination is 19 September 2022.

The Schedule’s "one pack‑year" definition, as compiled, reads: "the amount of tobacco consumed in smoking 20 cigarettes per day for a period of 1 year, or an equivalent amount of tobacco products," with Note 1 and Note 2 providing gram‑equivalence and calculation method guidance (Schedule 1, one pack‑year). The inclusion of equivalence by weight (7,300 grams of smoking tobacco per year as an equivalent amount) and the specific conversion for different tobacco products was part of the amendment. The endnotes record that the compilation date is 19 September 2022 and indicate that the compilation includes amendments up to the 2022 determination.

The compilation also records two repeals in the amendment history table relating to sections 2 and 4 (which appear to be internal to earlier instrument structure) with references to rep LA s48D and rep LA s48C, but those appear as technical annotations in the amendment history rather than substantive changes to the SOP’s operative factors (Endnote 4 list).

The practical effect of the 2022 amendment is that the definition of "one pack‑year" and associated explanatory notes were clarified and formalised. This change affects how smoking exposure is quantified for the purposes of subsection 9(5), and the cessation‑dependent rules in subsection 9(6) and their equivalents for aggravation (9(23), 9(24)). The ARPANSA Guide referenced in Schedule 1 for cumulative equivalent dose is dated by reference to an in‑force edition (as in force on 2 August 2017); the SOP’s linkage to an external methodology means technical updates to that guide could be relevant for interpretation and application, and changes to that guide post‑dating the compilation are not reflected in this compilation unless otherwise amended under the SOP process (Schedule 1, cumulative equivalent dose).

The compiled Statement of Principles document contains no citations to judicial decisions, no recorded litigation history, and no reference to specific cases. The instrument’s endnotes list only the instrument’s own legislative history and amendment history (endnotes 3 and 4). Consequently, as at the compilation date (19 September 2022), the instrument itself does not record any cases in which its provisions have been litigated or judicially construed.

Implications of the absence of recorded litigation in the instrument:

• Interpretive uncertainty remains until administrative decisions using the SOP are tested in tribunal or court proceedings. The SOP provides specific factors and definitions; however, the application of those provisions to contested factual scenarios often generates litigation in other SOP contexts. The absence of a litigation history in the instrument means there is no authoritative judiciary gloss included in the compilation to guide application in marginal or ambiguous cases.
• Administrative decision‑makers will be required to apply the enumerated factors and definitions in the first instance. Decisions made using those applications may be subject to internal review, merits review under the VEA/MRCA mechanisms and judicial review on legal grounds. The SOP itself does not set out appeal mechanics; any disputes about its interpretation could appear in appeals under the applicable Act. Because the SOP includes open phrases (for example, "inability to obtain appropriate clinical management" (s9(37))) and requires nexus with "relevant service" (s10(1)), litigation addressing how those phrases are applied may be anticipated, despite none being recorded in the instrument.
• Technical evidentiary matters may arise that require specialist evidence and possibly judicial or tribunal interpretation. Examples likely to generate contested proceedings include application of the cumulative equivalent dose threshold (s9(13), Schedule 1), assessment of the duration and timing rules for exposures (for example, the 20‑year windows in s9(3), s9(6)), and the interpretation of metabolic and lipid thresholds (Schedule 1 dyslipidaemia). The instrument itself prescribes the numeric thresholds, but how those thresholds are proved and how claims are construed in borderline factual scenarios may become matters for review.
• Cross‑SOP interaction under s11 may lead to interpretive disputes over which SOP applies where a factor refers to another injury or disease. The instrument’s mechanism defers to other SOPs’ terms, but disagreements over the applicability of those other SOPs or the interaction between two SOPs can produce litigation if administrative decisions turn on such interactions.

This instrument contains multiple precise thresholds, temporal windows and cross‑reference rules that create a number of practical pitfalls for claimants, advisers and decision‑makers. The most salient "gotchas" , items likely to catch practitioners unaware or to lead to defective evidentiary strategies , are below, with references to the relevant provisions.

1. Operative statutory meaning overrides ICD code: Although the SOP notes the ICD‑10‑AM code I70.0 applies to the condition, it explicitly states that for applying the SOP the meaning is that given in subsection 7(2). A mere ICD code on a record may be insufficient if the record does not document the particular clinical manifestations or the fact that the aortic atherosclerosis causes partial or complete occlusion and either warrants treatment or produces the enumerated clinical features (s7(2)-(4)). Practitioners must therefore ensure records speak to the SOP’s statutory wording, not only to coding.

2. Temporal windows are strict and asymmetric: Several factors require specified durations within windows. For example, "being obese" must be established as present for at least five years within the 20 years before clinical onset (9(3)), while certain smoking cessation rules link shorter pack‑year histories to a 20‑year cut‑off for onset/worsening (9(6), 9(24)). Failure to document the timing precisely (e.g. absence of reliable BMI history across the 20‑year window) can defeat reliance on a factor even if the claimant meets a lifetime‑style exposure. The aggravation factors (9(19)-9(37)) apply only where the disease was suffered or contracted before or during but did not arise out of relevant service (s10(2)), so timing of initial disease presence relative to service is crucial.

3. Different tests for onset vs aggravation: Practitioners must not conflate the two lists of factors. Subsections 9(1)-9(18) relate to raising a reasonable hypothesis for first clinical onset or death contribution, while subsections 9(19)-9(37) relate to material contribution/aggravation for pre‑existing disease (with s10(2) constraint). Using a factor from the aggravation list to establish first onset or vice versa will be a categorical error.

4. "Permanently ceased" smoking and second‑hand smoke cessation: The SOP treats continuing smoking differently from permanent cessation (9(5)-9(6) and 9(23)-9(24) for aggravation). The definitions and notes as amended in 2022 refine "one pack‑year" (Schedule 1), but the SOP does not define "permanently ceased". Establishing the date of permanent cessation will therefore require clear documentary or contemporaneous evidence. For second‑hand smoke, thresholds are hour‑based (1,000 hours and 5,000 hours) and cessation recency limits (five years) apply (9(7)-9(8), 9(25)-9(26)); establishing enclosed‑space exposure hours historically will often be difficult without corroborative records.

For claimants and advisers preparing to rely on this SOP in a claim under section 120A VEA or section 338 MRCA (s5), compliance means assembling, documenting and presenting evidence that matches the instrument’s specified factors, definitions and temporal rules. The following practical checklist translates the SOP’s requirements into actionable compliance steps, tied to specific provisions of the instrument.

1. Confirm applicability of the SOP to the claim:

   • Ensure the claim is one to which s120A VEA or s338 MRCA applies (s5) and that the condition is non‑aneurysmal aortic atherosclerotic disease as defined in s7(2). Do not rely solely on an ICD code; the statutory definition in s7(2) controls (s7(3)-(4)).

2. Establish diagnosis in statutory terms:

   • Obtain clinical records showing atherosclerosis of the abdominal aorta with partial or complete occlusion and evidence that it either warranted medical treatment or produced one of the enumerated clinical manifestations (claudication in specified areas, erectile dysfunction, pallor/coldness of lower extremities, or reduced femoral pulses) (s7(2)). If the claim concerns death, secure pathology and clinical records demonstrating contribution to a terminal event (s7(5); Schedule 1 terminal event).

3. Map claimed causal or aggravating factors to section 9:

   • Identify which subsection(s) of s9 you propose to rely on. Distinguish between factors for onset (s9(1)-(18)) and factors for material contribution/aggravation of pre‑existing disease (s9(19)-(37)). Be aware that aggravation factors are only available where the disease was suffered or contracted before or during but did not arise out of service (s10(2)).

4. Assemble factor‑specific evidence and satisfy numerical/temporal thresholds:

   • Hypertension: Document medical diagnoses, prescriptions, blood pressure readings established before clinical onset/worsening as required (s9(1), s9(19)).
   • Diabetes mellitus: Provide records of diagnosis and treatment timeline (s9(2), s9(20)).
   • Obesity: Provide serial weight and height records to calculate BMI ≥30 and show BMI ≥30 for the required five‑year duration within the 20 years before onset/worsening (s9(3), s9(21); Schedule 1 BMI formula).
   • Dyslipidaemia: Produce lipid panels showing thresholds in Schedule 1 (HDL <1.0, LDL >4.0, TG ≥2.0, total cholesterol >5.5 mmol/L) or records of regular administration of lipid‑normalising therapy (Schedule 1; s9(4), s9(22)).