Statement of Principles concerning migraine (Reasonable Hypothesis) (No. 7 of 2018)

The instrument operates around several discrete legal and clinical concepts. The central legal concept is the "reasonable hypothesis" standard, which is the statutory evidentiary threshold the Repatriation Medical Authority addresses by specifying the factors that must exist before a reasonable hypothesis that migraine is connected to service can be said to be raised (s8-s9). The SoP itself does not restate the statutory "reasonable hypothesis" test but identifies the minimum factual and clinical predicates that the Authority considers suffice for that threshold.

Key clinical concepts are defined and deployed from the Schedule 1 - Dictionary. "Migraine" is defined inclusively for the SoP as migraine without aura, migraine with aura (including basilar migraine, sporadic hemiplegic migraine and retinal migraine), chronic migraine and vestibular migraine, and expressly excludes a list of other headache disorders (s7(2)). The Schedule supplies diagnostic definitions derived from ICHD‑3 for chronic migraine, migraine with aura, migraine without aura and vestibular migraine, and a working definition of "clinical worsening of migraine" (Schedule 1). The instrument also identifies ancillary clinical states and exposures as factors: "nitric oxide donor" (a specified pharmacological class including several named agents), "severe and persistent asthma" (with objective and symptomatic criteria such as FEV1 ≤60% over specified periods), obesity (BMI ≥30 with BMI defined as W/H2), concussion and moderate to severe traumatic brain injury, and "inability to obtain appropriate clinical management" (Schedule 1 and s9).

Operationally the instrument separates factors that can establish a link to the clinical onset of migraine from those that establish material contribution to or aggravation of pre‑existing migraine. Subsections 9(1)-9(2a) relate to the clinical onset of migraine (for example, undergoing treatment with a nitric oxide donor at the time of clinical onset, s9(1); concussion or moderate to severe traumatic brain injury before clinical onset with migraine developing within seven days, s9(2a)). Subsections 9(3)-9(6) address clinical worsening and apply only to material contribution to, or aggravation of, migraine where the migraine was suffered or contracted before or during (but did not arise out of) the person's relevant service (s10(2)). The distinction between "clinical onset" and "clinical worsening" is therefore crucial to whether the SoP is being used to assess causation or aggravation (see s9 and Schedule 1 definition of clinical worsening).

The SoP also links to other Statements of Principles: where a factor refers to an injury or disease covered by another SoP determined under subsection 196B(2) of the VEA, the SoP for that injury or disease applies "in accordance with the terms of that Statement of Principles as in force from time to time" (s11). Finally, the SoP clarifies that although migraine attracts ICD‑10‑AM code G43, the meaning for application of the SoP is the instrument’s own definition (s7(3)-(4)); thus, coding alone is not determinative for claims.

The instrument affects three overlapping groups directly and several ancillary actors indirectly. Directly affected are persons lodging claims for entitlements where the VEA s120A or MRCA s338 apply (s5). That group includes veterans, members of Peacekeeping Forces and members of the Forces who seek to link migraine (or death from migraine) to their relevant service; the definitions of "relevant service" in Schedule 1 identify the service categories implicated (operational, peacekeeping, hazardous, British nuclear test defence under the VEA, and warlike or non‑warlike service under the MRCA).

Decision‑makers administering claims under the VEA and MRCA are directly affected because the SoP is an evidential tool they must apply when testing whether a "reasonable hypothesis" linking migraine to service is raised. The instrument is made by the Repatriation Medical Authority (s3), but the adjudicative application will be within the administrative machinery provided by the VEA/MRCA regimes; s5 expressly limits the instrument’s application to the statutory channels of those Acts.

Indirectly affected are medical practitioners and other healthcare providers who will be asked to supply clinical evidence consistent with the SoP’s definitions and timing thresholds. For example, supplying contemporaneous records that show administration of a nitric oxide donor at the time of clinical onset (s9(1)), spirometry records establishing FEV1 ≤60% during the relevant period for "severe and persistent asthma" (Schedule 1), or documentation about a person’s BMI trajectory to establish "being obese" for at least five years before clinical worsening (s9(5) and Schedule 1). Lawyers, advocates and advocates’ expert witnesses will also be affected because the SoP narrows what counts as a minimal factual basis for a reasonable hypothesis: they must assemble evidence specifically tied to the listed factors and the timing constraints set out in the instrument.

Finally, the instrument affects claim outcomes indirectly: by specifying what factors are sufficient to raise a reasonable hypothesis, it influences the likelihood that a claim proceeds to further medical investigation and, ultimately, determination under the VEA/MRCA frameworks. The SoP does not itself award compensation, but it governs a crucial evidentiary stage used by the statutory decision‑makers who do.

The Statement of Principles does not create freestanding legal duties or confer direct rights in the sense of payable entitlements; rather it functions as a prescriptive evidentiary standard that decision‑makers use when determining whether a reasonable hypothesis linking migraine or death from migraine to relevant service exists. The instrument is made under statutory authority (subsection 196B(2) VEA) and is applicable to claims under specific provisions of the VEA and MRCA (s3, s5).

From the claimant’s perspective, the practical effect is that a claimant must establish, in evidence, that at least one of the factors in section 9 existed and that the factor is related to their relevant service (s9, s10(1)). Section 10(1) makes clear that the existence of a factor is not enough; it must be related to the person’s relevant service. For factors in subsections 9(3)-9(6), section 10(2) limits their application to material contribution or aggravation of migraine where the migraine was suffered or contracted before or during (but did not arise out of) the person’s relevant service. That distinction imposes an evidential task on claimants: not only to show the factor, but to show its temporal and causal relationship to service (for onset) or to pre‑existing migraine (for aggravation).

Healthcare providers asked to provide evidence have a practical duty to document and, where appropriate, quantify the clinical markers specified in the Schedule. For example, "severe and persistent asthma" is defined with objective markers such as FEV1 at or below 60% and other symptomatic criteria over a specific cumulative period (Schedule 1). Similarly, "being obese" is operationalised by BMI ≥30 and the formula for BMI is provided (Schedule 1). The inclusion of precise medical criteria effectively requires medical evidence that maps to those criteria if a factor is to be relied upon.

Decision‑makers have the duty to apply the SoP to claims within the statutory channels identified (s5), to assess whether any of the s9 factors are present, and to determine whether they are related to relevant service (s10). The instrument also creates a procedural interaction with other SoPs: where a s9 factor refers to an injury or disease covered by another SoP, that other SoP applies and its terms govern (s11). That transfers to decision‑makers an ongoing duty to consult the current text of other SoPs when relevant.

The instrument confers no private right to enforce the SoP beyond the usual administrative and judicial review channels available for decisions under the VEA/MRCA. It does not set out appeal rights, compensation schedules, or penalties; those remain governed by the primary statutes and associated administrative processes referenced in s5 and s3.

This Statement of Principles does not create criminal offences, civil penalties or administrative fines within its text. There is no provision imposing sanctions on any person for non‑compliance with the instrument, nor does the SoP itself provide enforcement mechanisms beyond its use as an evidentiary standard in claims processing. The instrument is an administrative tool intended to inform decision‑makers charged with determining entitlement under provisions of the VEA and MRCA (see s5). Any enforcement of entitlements, sanctions for false claims, or other penalties remain matters of the primary legislation and the administrative frameworks established under those Acts; the SoP does not purport to alter those regimes.

Enforcement in practice therefore occurs as part of the claims process: decision‑makers use the SoP to assess whether a reasonable hypothesis has been raised linking migraine to relevant service. If the SoP’s criteria are met and the claim proceeds to entitlement under the VEA or MRCA, the administrative consequences (entitlement, compensation, rehabilitation measures) are governed by the statutory programs under those Acts, not by the SoP itself. Conversely, if a claimant cannot show the factors specified in s9 or cannot show that any such factor is related to relevant service (s10), the claim will likely be rejected or not progress on the basis that a reasonable hypothesis has not been raised, but the instrument does not set out procedural penalties for that outcome.

Because the SoP cross‑references other Statements of Principles (s11), and because the SoP may be revised or revoked (s4, endnotes), enforcement must be understood in a dynamic administrative context: decision‑makers apply the current version of the SoP and the corresponding SoPs for other conditions. The instrument’s endnotes record its amendment history and dates of effect, which are relevant to determining which text applies to a particular claim (Endnote 3 and 4). Practical enforcement risk arises where decision‑makers, claimants, or medical witnesses rely on outdated versions of the SoP, but the instrument itself does not prescribe disciplinary or penal processes to enforce correct application.

The SoP is explicitly a statutory instrument made under subsection 196B(2) of the Veterans' Entitlements Act 1986 (s3). Its application is limited to claims that fall under section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 (MRCA) (s5). The instrument therefore operates as a subsidiary evidentiary instrument within the statutory architecture of the VEA and the MRCA: it is not a standalone code but an interpretive tool for decision‑makers applying those Acts.

The instrument instructs users on interaction with external medical classification systems. Section 7(3) notes that while migraine attracts ICD‑10‑AM code G43, for the purposes of the SoP the meaning of migraine is that given in s7(2). Section 7(4) defines what an ICD‑10‑AM reference means for the SoP, explicitly identifying the edition and effective date of the ICD‑10‑AM text. The Schedule further imports diagnostic material derived from ICHD‑3; Schedule 1 defines ICHD‑3 and sets out diagnostic criteria for the subtypes of migraine used in the SoP. Those cross‑references mean decision‑makers and medical witnesses must reconcile clinical coding systems and diagnostic classifications with the SoP’s textual definitions.

Section 11 creates a direct procedural link to other Statements of Principles under subsection 196B(2) of the VEA: where a s9 factor refers to an injury or disease covered by some other SoP, "the factors in that Statement of Principles apply in accordance with the terms of that Statement of Principles as in force from time to time" (s11). That mechanism imports the content and temporal operation of other SoPs into the assessment of a particular claim, and requires claim processors to be attentive to amendments in other SoPs as well as this one.

The SoP also operates alongside administrative law principles and the broader statutory entitlements and procedural provisions contained in the VEA and the MRCA. Although those statutes are not reproduced in the instrument, the SoP’s limited scope (s5) makes the statutes operative for adjudicative outcomes such as granting entitlements, determining effective dates, or addressing compensable outcomes, while the SoP informs the necessary factual and medical thresholds for proceeding with a claim.

Finally, the SoP’s revocation clause (s4) shows its capacity to replace prior instruments: it expressly revokes the Statement of Principles concerning migraine No. 56 of 2009. The endnotes record the instrument’s own amendment history (Endnotes 3 and 4), signalling that users must consult the current compilation and be attentive to the legislative and administrative context to determine which text applies to any given claim.

The compilation and endnotes supplied with the instrument set out a concise amendment history. The original instrument is identified as Statement of Principles concerning migraine (Reasonable Hypothesis) (No. 7 of 2018) with a registration date of 3 January 2018 and commencement on 29 January 2018 (Endnote 3). Two amendments are recorded in the endnotes. The first amendment is Amendment Statement of Principles concerning migraine (Reasonable Hypothesis) (No. 98 of 2018), registered 29 October 2018 and commencing 26 November 2018 (Endnote 3). The second amendment is Amendment Statement of Principles concerning migraine (Reasonable Hypothesis) (No. 15 of 2020), registered 2 March 2020 and commencing 23 March 2020 (Endnote 3). The compilation itself indicates an inclusion of amendments up to No. 15 of 2020 (compilation date 23 March 2020).

Endnote 4 summarises how particular provisions were affected by those amendments. It records that subsections 9(2a) and 9(4a) were added by No. 98 of 2018. It also records that several definitions in Schedule 1 were replaced or added by No. 15 of 2020: subsection 7(2) was replaced and the Schedule 1 Dictionary entries for chronic migraine, ICHD‑3, migraine with aura, migraine without aura and vestibular migraine were amended or added by No. 15 of 2020 (Endnote 4). The instrument itself contains marginal notes and "Note" entries reflecting those definitions and changes; for example, the Schedule contains the detailed diagnostic criteria said to be derived from ICHD‑3.

Practically, this amendment history matters for claim timing and for which tests apply to a particular person’s claim. Section 2 sets the commencement of the instrument at 29 January 2018, and the endnotes identify later commencement dates for amendments; decision‑makers must therefore apply the version of the SoP current at the time of decision, and note any transitional or saving provisions if contained in the amending instruments (Endnote 1 indicates that the compilation notes may flag such provisions). The instrument’s revocation of the prior 2009 SoP (s4) also signals that claims assessed after commencement should be considered under the 2018 SoP and its subsequent amendments.

For practitioners, two concrete implications follow from the amendment history as recorded: (1) the addition of the concussion/moderate‑to‑severe traumatic brain injury factors in 2018 (s9(2a), s9(4a)) expands the set of factual predicates that can raise a reasonable hypothesis, and (2) the 2020 amendments revised how migraine subtypes and chronic migraine are described, which affects how expert evidence must map to the SoP’s diagnostic language. Users should consult the current compilation and verify that their evidence is aligned with the operative definitions in the Schedule, and be attentive to any future amending instruments.

The Statement of Principles compilation supplied contains no references to judicial decisions or administrative tribunal determinations that interpret or apply this instrument. The instrument itself is a non‑judicial administrative tool created by the Repatriation Medical Authority (s3), and the endnotes record only the instrument’s own registration and amendment history (Endnotes 3 and 4). There are no cases or litigation excerpts cited in the text or endnotes.

That absence in the instrument does not mean the SoP has not been the subject of litigation in external sources, but no such material is present in the provided compilation and no cases are named for citation in the instrument itself. Practitioners seeking litigation guidance will need to search case law databases and tribunal decisions external to the instrument to locate judicial or tribunal treatment of the SoP, and to identify how courts and tribunals construe terms such as "reasonable hypothesis", "related to relevant service", "clinical onset", "clinical worsening", and the Schedule’s definitions. The instrument does, however, embed features that are frequently contested in litigation around compensable injury: temporal thresholds (for example, concussion/TBI with migraine developing within seven days, s9(2a)), measurement thresholds (FEV1 ≤60% for severe asthma in Schedule 1), and the treatment of aggravation versus causation (s10(2)).

Where litigation occurs in respect of decisions that applied this SoP, the likely contested issues will include: whether the factual predicates in s9 were proved on the available evidence; whether any such predicate was sufficiently related to the claimant’s relevant service (s10(1)); the interpretation of medically framed definitions in Schedule 1 (for example, what constitutes "clinical worsening of migraine"); and the operation of s11 where a factor points to an injury or disease covered by a different SoP. Because the compilation contains no reported outcomes, practitioners should treat the instrument as authoritative for its own content but should seek external adjudicative materials if they require precedents on how the SoP is interpreted in dispute.

The instrument contains several features that commonly generate evidentiary and interpretive pitfalls.

1. Distinction between onset and aggravation. Sections 9 and 10 separate factors that can be used to establish onset from those that operate only to establish material contribution or aggravation. Subsections 9(3)-9(6) "apply only to material contribution to, or aggravation of, migraine where the person's migraine was suffered or contracted before or during (but did not arise out of) the person's relevant service" (s10(2)). Practitioners must therefore map the claimant’s timeline carefully. Mischaracterising a factor as one that proves onset when it is only admissible for aggravation (or vice versa) will produce flawed decision pathways.

2. Timing windows are strict. The concussion/moderate to severe traumatic brain injury factors require that migraine develop or worsen "within the seven days" of injury to the head, regaining consciousness, or discontinuing medication that impairs reporting (s9(2a), s9(4a)). Similarly, "severe and persistent asthma" must be present "within the five years before" clinical onset or worsening (s9(2), s9(4)). "Being obese" requires a BMI of 30 or greater "for at least the five years before" clinical worsening (s9(5)). These temporal thresholds create specific evidentiary tasks: contemporaneous records or a reliable longitudinal clinical record will usually be needed.

3. Medical-terminology traps. Although the SoP notes that migraine attracts ICD‑10‑AM code G43, it stipulates its own meaning in the statute (s7(3)). The Schedule supplies detailed diagnostic criteria derived from ICHD‑3. Courts and decision‑makers will apply the SoP’s textual definitions, not ICD coding alone; reliance on coding without mapping the clinical record into the Schedule’s criteria may be insufficient.

4. "Inability to obtain appropriate clinical management" is open-ended. Section 9(6) lists inability to obtain appropriate clinical management as a factor that can raise a reasonable hypothesis. The instrument provides no detailed, objective definition of that term in the Schedule. That open‑ended phrasing introduces administrative discretion and potential contest about what constitutes an inability versus a delay or substandard care. Expect disputes about the threshold for this factor and require documentary evidence (referrals, appointment records, correspondence) where possible.

5. Interplay with other SoPs. Section 11 requires application of other SoPs where a s9 factor refers to an injury or disease covered by another Statement of Principles. That cross‑application means a factor may call for evidence conforming to two separate SoPs, and amendments to one SoP may change how a factor is applied in future claims. Practitioners must identify whether any s9 factor implicates another SoP and then ensure compliance with that SoP’s terms as they stand at decision time.

6. Exclusions in the migraine definition. The SoP excludes certain headache disorders and conditions (s7(2)(b)) such as familial hemiplegic migraine, abdominal migraine, migrainous infarction, amaurosis fugax, cluster headache, tension‑type headache, headache attributable to structural abnormalities or inflammatory disorders of the head and neck, and headache attributable to systemic disease. Where a claimant’s presentation sits within an excluded category, the SoP will not assist in raising a reasonable hypothesis for migraine as defined by the instrument.

7. Evidence of drug exposure. The SoP identifies specific pharmacological agents as "nitric oxide donors" and includes commonly used agents such as nitrous oxide (Schedule 1). Demonstrating administration at the time of clinical onset or worsening requires medico‑administration records that precisely establish timing; non‑specific recall or generic medication lists may not suffice.

8. Objective measures required for asthma. "Severe and persistent asthma" is defined by cumulative criteria, including FEV1 ≤60% of expected value for at least six months within a continuous year (Schedule 1). If the claimant lacks historical spirometry, proving the criterion becomes difficult.

9. BMI history. "Being obese" is defined by BMI ≥30 and BMI is W/H2 with W in kilograms and H in metres (Schedule 1). Proving continuous obesity over five years will typically require serial weight/height records or supporting clinical notes.

10. Amendments affect content. The endnotes show that key clauses and the Dictionary were altered by later amending instruments (Endnote 4). Users must ensure they rely on the version of the SoP current at decision time.

These "gotchas" translate into practical risks: rejection for failure to prove the listed factors, remits for further medical evidence, and arguments about whether a factor is properly linked to relevant service. They also create opportunities for targeted evidence gathering if counsel and clinicians anticipate the SoP’s specific requirements.

For claimants, clinicians and advisers, compliance is primarily evidential: assemble clinical and service evidence that maps directly to the SoP’s factors and timing requirements, and ensure that any factor relied upon is shown to be related to relevant service.

1. Identify the operative factor(s) in s9. Work through each clause in s9 and identify which, if any, are present in the claimant’s history: nitric oxide donor at clinical onset (s9(1)); severe and persistent asthma within five years (s9(2)); concussion or moderate-severe TBI with migraine developing within seven days (s9(2a)); nitric oxide donor at clinical worsening (s9(3)); severe and persistent asthma within five years before clinical worsening (s9(4)); concussion/TBI before clinical worsening within seven days (s9(4a)); obesity for at least five years before clinical worsening (s9(5)); inability to obtain appropriate clinical management (s9(6)).

2. Map clinical records to Schedule 1 definitions. The Schedule contains the diagnostic and measurement criteria that the SoP uses. For chronic migraine, migraine with aura, migraine without aura, vestibular migraine, and clinical worsening of migraine, extract the elements (for example, frequency thresholds, duration of attacks, associated features such as photophobia/phonophobia) and ensure treating clinicians address these criteria in reports, or that clinical notes explicitly record the features required by the Schedule.

3. Assemble objective evidence for measurement thresholds. For factors that rely on objective measures, secure documentary evidence:

   • Nitric oxide donor: hospital medication administration records or anaesthetic charts showing the named agent and the timing relative to clinical onset/worsening (Schedule 1 list of agents).
   • Severe and persistent asthma: spirometry records indicating FEV1 and documentation of frequency of symptoms, night‑time symptoms, flare‑ups, activity restriction, and the required timeframe (Schedule 1).
   • Obesity: serial weight/height measurements or clinical notes showing BMI ≥30 sustained for the five‑year period prior to clinical worsening (Schedule 1 provides BMI formula).
   • Concussion/TBI: hospital/emergency department notes, imaging reports, and notes on regaining consciousness or discontinuation of consciousness‑affecting medication; ensure documentation establishes the timing within seven days required by s9(2a) and s9(4a).

4. Connect factors to relevant service. Section 10(1) requires that any s9 factor relied on must be "related to the relevant service rendered by the person." For service linkage, collect service medical records, deployment and incident reports, occupational health notes, and contemporaneous reports of injury or exposure. For aggravation factors (s9(3)-(6)), demonstrate that the migraine was suffered or contracted before or during (but did not arise out of) service where the aggravation is alleged (s10(2)).

5. Prepare clinicians for the SoP’s language. When seeking medico‑legal reports, advise doctors to address the SoP language directly: set out whether any s9 factor is present, provide dates/timestamps, apply the Schedule’s diagnostic criteria, and discuss the relationship between the factor and relevant service. For contested items such as "inability to obtain appropriate clinical management," clinicians should describe the specific obstacles (dates of attempted appointments, referrals that were not filled, geographical or provider shortages) rather than using generic terms.

6. Check conflicting SoPs. If a s9 factor refers to an injury or disease that is the subject of another SoP, obtain and address that other SoP because s11 requires that the other SoP’s factors apply as in force from time to time. Practitioners should verify the current text of any other SoP implicated.

7. Verify the applicable version of the SoP. Use the compilation and endnotes to confirm which amending instruments and dates are operative for the claim. The version at the time of decision governs the evidentiary thresholds (see s2 commencement, s4 revocation, and Endnotes 3 and 4).

8. Anticipate administrative questions. Decision‑makers may seek clarification on temporal sequencing (onset versus worsening), objective measures, and links to service. Prepare concise, evidenced responses rather than broad clinical narratives.

9. Preserve contemporaneous records. Many of the instrument’s thresholds require historical data: administration of a named medication on a particular day, spirometry values in prior years, serial weight measures. Retaining and producing contemporaneous documentation avoids reliance on recollection.

10. Where evidence is thin, identify remediable gaps. If objective records do not exist (for example, lack of spirometry), consider whether secondary evidence (repeat clinical assessments demonstrating ongoing impairment, historical hospitalisation records, corroborative statements) can establish the necessary criteria, recognising that some thresholds (for example, FEV1 ≤60%) are inherently objective and will be harder to meet without direct measurement.

By aligning evidence to the s9 factors, the Schedule’s definitions, and the temporal and relational tests in s10, claimants and their advisers can make targeted submissions that correspond to the minimum factual basis the Repatriation Medical Authority identified as raising a reasonable hypothesis.