Statement of Principles concerning migraine (Balance of Probabilities) (No. 8 of 2018)

The SOP organizes decision-making around a small set of legal-medical concepts that determine whether migraine or death from migraine is connected with relevant service for claims. Core concepts are: the defined clinical scope of "migraine" for the SOP, the evidentiary standard and basis for causal connection, the enumerated factors that can establish connection, and the relationship-to-service rules governing when those factors may be used to satisfy causation.

1. Defined clinical scope of migraine. Subsection 7(2) sets out inclusions and exclusions, and the Schedule provides diagnostic criteria derived from the International Classification of Headache Disorders Third Edition (ICHD-3) for chronic migraine, migraine with aura, migraine without aura and vestibular migraine. The SOP treats ICD-10-AM code G43 as corresponding to migraine but states the legal meaning is the definition in s 7(2) (s 7(3)). The Schedule also expressly excludes several other headache/neurological disorders.

2. Evidentiary stance. Section 8 records the Repatriation Medical Authority's view, on the sound medical‑scientific evidence available, that it is more probable than not that migraine and death from migraine can be related to relevant service. The SOP therefore frames its causation criteria against the balance of probabilities.

3. Enumerated causal factors. Section 9 requires that at least one of four factors exist for connection to be established. Two relate to treatment with a nitric oxide donor, one relates to prolonged obesity (BMI 30 or greater for at least five years before clinical worsening), and one to inability to obtain appropriate clinical management. Each factor is defined or further qualified in the Schedule: e.g. the Schedule lists specific nitric oxide donors and provides a definition of clinical worsening (which enumerates changes such as a two-fold increase in attack frequency, conversion to chronic migraine, hospitalisation increases, or severe episodes resulting in status migrainosus, cerebral infarct, seizure or death).

4. Relationship to service. Section 10 requires that any factor relied on must be related to the person's relevant service (as defined in the Schedule). It also limits the application of subsections 9(2)-9(4) to material contribution or aggravation where the migraine pre-existed before or during, but did not arise out of, relevant service. That creates a two-tiered causal mapping: onset linked to nitric oxide donor exposure may operate as a primary causal mechanism; other listed factors may operate only as contributors or aggravators where migraine pre-existed.

5. Cross-references to other SOPs. Section 11 provides that if a factor in section 9 refers to another injury or disease covered by a different SOP, the factors in that other SOP apply in accordance with its terms as in force. This is a mechanical cross-reference that imports the terms of other SOPs where overlap exists.

These concepts structure how administrators, clinicians and claimants must marshal evidence: diagnosing the correct migraine subtype under the Schedule definitions, establishing dates for clinical onset or worsening, documenting exposure to listed nitric oxide donors, demonstrating a sustained obesity history using the BMI formula in the Schedule, or evidencing inability to obtain care. The SOP also anchors legal linkage to the definitions of relevant service in the Schedule.

This SOP directly affects veterans and current or former members of the Australian Defence Force seeking entitlements or compensation where migraine, or death from migraine, is alleged to be connected with service. The instrument applies to claims to which section 120B of the VEA or section 339 of the MRCA apply (s 5). Those references indicate the SOP is a subordinate legal instrument used to determine causal connection within the statutory claims processes governed by the VEA and MRCA.

Practically, parties who will need to engage with this SOP include:

• Claimants and their representatives. Veterans or service members lodging claims alleging migraine or death from migraine will need to establish the SOP criteria where relevant. They will need to present medical evidence that addresses the SOP's diagnostic criteria and the existence of one or more of the factors in s 9. Where reliance is made on subsections 9(2)-9(4), claimants must also show the pre-existence of migraine before or during service, because those factors are limited to material contribution or aggravation in that context (s 10(2)).

• Treating clinicians and medical assessors. The SOP requires clinical findings to be mapped to the Schedule definitions. Clinicians will be asked to assess whether diagnostic criteria for chronic migraine, migraine with aura, migraine without aura or vestibular migraine are met, and to record dates and objective findings that align with the Schedule's definition of clinical worsening. For nitric oxide donor exposure, clinicians or anesthetic records must identify the listed donors and their timing relative to onset or worsening. For obesity, clinicians must calculate BMI using the Schedule formula and provide longitudinal weight/height records demonstrating BMI ≥ 30 for the requisite five-year period before clinical worsening.

• Administrative decision-makers within the Department of Veterans' Affairs and the Military Rehabilitation and Compensation framework. The SOP is made under s 196B(3) VEA (s 3) and forms the medical-legal framework referenced by the VEA and MRCA claims processes (s 5). Decision-makers will apply the SOP's factors and its definitions when adjudicating causal connection in claims.

• Insurers, compensation administrators and legal advisers handling appeals and reviews. Where decisions are reviewed or appealed, the SOP's precise wording, definitions and cross-referencing to other SOPs (s 11) will govern the medical causation analysis. The instrument's amendments and compilation history (endnotes) will also be relevant in determining which version applied to particular claims.

• Secondary stakeholders. Family members in death claims will need to understand the "death from migraine" extension in s 7(5), which includes terminal events or conditions contributed to by migraine, and the Schedule's definition of terminal event. Where a factor in s 9 refers to another condition governed by a different SOP, the interlocking SOPs will affect evidentiary requirements (s 11).

The SOP creates practical evidentiary burdens: claimants must produce records on timing and diagnosis, medication or anaesthetic exposure to listed nitric oxide donors, BMI history, or documented inability to obtain appropriate clinical management. Administrative actors will need to evaluate clinical measures such as the two-fold increase in attack frequency, conversion to chronic migraine, or hospitalisation rate changes, as set out in the Schedule's definition of "clinical worsening".

The SOP prescribes medical-legal thresholds rather than statutory duties in the narrow sense. Its operative effect is to set the conditions under which migraine and death from migraine are considered connected with relevant service for claims purposes. Nonetheless, the instrument creates obligations for evidence and confers entitlements contingent on meeting those thresholds.

Rights and entitlements conditioned by the SOP

• A claimant has the right to have their migraine claim assessed using the SOP where the claim falls within the application clauses (s 5). The SOP sets the framework for determining whether, on the balance of probabilities, migraine or death from migraine is connected with relevant service (s 8; s 9(1)).
• If at least one of the factors in s 9 is shown, and it is related to relevant service (s 10(1)), the SOP supports a finding of connection on the balance of probabilities. For death claims, s 7(5) extends migraine to include death from a terminal event or condition contributed to by the person's migraine.

Duties or evidentiary expectations implicit in the SOP

• Claimants and their medical advisers must present evidence that aligns with the diagnostic and causal criteria in the Schedule. Diagnostic criteria for migraine subtypes derive from ICHD-3 and are set out in detail (Schedule definitions for chronic migraine, migraine with aura, migraine without aura and vestibular migraine). Clinical worsening is tightly defined and requires measurable changes such as at least a two-fold increase in attack frequency, conversion to chronic migraine, increased hospitalisation requirements or severe episodes with specified outcomes (Schedule).
• Where a claimant relies on obesity as a factor (s 9(3)), the SOP requires demonstration of BMI 30 or greater for at least five years before clinical worsening, with BMI calculated as W/H2 where weight is in kilograms and height in metres (Schedule).
• Where reliance is placed on nitric oxide donor exposure (s 9(1)-(2)), the Schedule lists which substances qualify as nitric oxide donors, including several nitrates and nitrous oxide. Medical records or pharmacy/anesthetic records are necessary to establish timing relative to clinical onset or worsening.
• Where inability to obtain appropriate clinical management is asserted (s 9(4)), the claimant must provide evidence of lack of access to appropriate care. The SOP does not specify the precise proof required, so administrative decision-makers will need to assess what documentary or testimonial evidence demonstrates inability to obtain appropriate management.

Limitations and procedural effects

• The SOP imposes a structural limitation on aggravation claims. Subsections 9(2)-9(4) apply only where the person's migraine was suffered or contracted before or during, but did not arise out of, relevant service (s 10(2)). The legal effect is that those factors operate only as contributors or aggravators post‑onset in a particular service temporal relationship.
• Section 11 provides a duty on decision-makers to apply factors set out in other SOPs where a factor in s 9 refers to another injury or disease that is the subject of another SOP. That requires administrators to consult multiple SOPs and apply them "as in force from time to time".

The SOP thus creates practical procedural duties for claimants to assemble medically specific evidence, and for decision-makers to apply the Schedule definitions strictly when adjudicating causal connection. The rights are contingent on meeting those thresholds and on demonstrating the required temporal and service-related links.

The Statement of Principles itself does not create criminal penalties or direct sanctions. It is an administrative instrument that defines medical causation criteria used in statutory entitlement processes under the VEA and the MRCA. The SOP’s enforcement mechanism is therefore institutional rather than penal: it is enforced through administrative decision-making on claims and through the statutory review and appeal processes applicable to decisions under the VEA and MRCA.

How enforcement is operationalised

• Decision-makers within the Department of Veterans' Affairs, and related MRCA administrative bodies, use the SOP as the medical-legal framework to determine whether migraine or death from migraine is connected with relevant service. Where the SOP criteria (s 9) are met and linked to relevant service (s 10), an administrative finding of entitlement or liability to compensation may follow under the governing Acts. Conversely, failure to meet the SOP criteria will be used as a basis to deny service connection for the condition. The SOP therefore functions as a gatekeeping standard in the entitlement decision process.

No direct statutory sanctions in the SOP

• The instrument contains no express fines, imprisonment provisions, or administrative penalty regime. It does not prescribe procedural sanctions or obligations that attract penalties within its text. The SOP’s consequences are indirect: an unsuccessful claim means loss of entitlement and associated benefits under the VEA or MRCA.

Role of cross-referenced law for enforcement consequences

• Any enforcement consequences that flow from applying the SOP (granting or refusing benefits, setting liability) stem from the substantive provisions of the VEA and the MRCA, not from the SOP itself. For example, administrative decisions based on the SOP may be subject to internal review, merits review, or judicial review under the review mechanisms established by the VEA or MRCA and other applicable administrative law regimes. The SOP does not set or alter those review mechanisms.

Practical enforcement risks and administrative discretion

• Because the SOP sets medical criteria that are in technical terms, enforcement depends on accurate clinical documentation, consistent application of definitions, and the exercise of medical judgement by assessing clinicians and administrative decision-makers. The SOP allows decision-makers to accept or reject evidence on the balance of probabilities in applying s 8 and s 9. The instrument’s definitions (for example, what constitutes "inability to obtain appropriate clinical management") leave room for factual assessment and judgement, and therefore administrative discretion in enforcement outcomes.

Amendment and currency as part of enforcement

• The SOP is subject to amendment, as recorded in the compilation’s endnotes (for example, Amendment No. 16 of 2020). Enforcement outcomes in any particular claim depend on which version of the SOP applies to that claim. The compilation and its endnotes set out the commencement of amendments (Endnote 3), which is an important administrative fact when determining which SOP text governs a claim.

In sum, enforcement of the SOP occurs through its incorporation into adjudication under the VEA and MRCA and through the ordinary review channels in those regimes. The SOP itself does not impose criminal or civil penalties; its effect is to determine entitlement or non-entitlement in administrative processes.

This SOP is made under subsection 196B(3) of the VEA (s 3) and explicitly applies to claims within the VEA and MRCA frameworks (s 5). It therefore interacts with the substantive and procedural provisions of those Acts through incorporation in adjudication and claims processes. The instrument also cross-references other SOPs and international clinical classifications.

Interaction with the VEA and MRCA

• Application clause. Section 5 states the SOP applies to claims to which section 120B of the VEA or section 339 of the MRCA applies. The SOP is therefore a medical-legal input used in determining claims under those statutory provisions. The precise procedural operation,how decision-makers must use the SOP when applying the statutory tests for service connection or material contribution,derives from the VEA and MRCA themselves. The SOP does not amend the VEA or MRCA, but provides the medical criteria the Repatriation Medical Authority is empowered to determine.

Interaction with other Statements of Principles

• Section 11 provides a mechanical interaction with other SOPs: where a factor in s 9 refers to an injury or disease covered by another SOP, the factors in that other SOP "apply in accordance with the terms of that Statement of Principles as in force from time to time." This creates an operational cross-application. Decision-makers must therefore identify overlapping conditions and apply relevant SOPs together, using whichever version is in force at the relevant time.

Interaction with international and national clinical classifications

• The SOP references ICD-10-AM code G43 as the ICD code for migraine, but clarifies that "in applying this Statement of Principles the meaning of migraine is that given in subsection (2)" (s 7(3)). The Schedule directs that a reference to an ICD‑10‑AM code is to the Tenth Edition, effective 1 July 2017 (s 7(4)). The Schedule also derives diagnostic criteria from ICHD-3. Those references mean clinical classification systems are incorporated as definitional aids, but the legal meaning depends on the Schedule’s text.

Interaction with administrative law and judicial review

• The SOP is an administrative instrument whose application in claims will be subject to administrative law constraints, review rights and potentially judicial review of decisions under the VEA and MRCA. The compilation does not set out those procedural review mechanisms, but the SOP’s role as a determinative medical standard means applicants may raise its proper interpretation and application in review proceedings arising under the enabling statutes.

Temporal and amendment interactions

• The compilation includes an amendment history (endnotes) indicating changes made by Amendment No. 16 of 2020. Section 11’s cross-reference to other SOPs as "in force from time to time" and the endnotes’ information about amendment dates mean that which version of an SOP applies is a live question in any given claim. Decision-makers must therefore establish which text was in force at the relevant time for the claim in question.

Limitations and exclusion of other legal causes

• The Schedule expressly excludes certain headache and neurological conditions from the definition of migraine in s 7(2). That exclusion interacts with other legal causes in that a condition excluded from the SOP’s definition will not be treated as migraine for the purpose of this SOP, potentially requiring claimants to rely on a different SOP or legal ground if they allege service connection for an excluded condition.

In short, the SOP operates as a medical-legal input within the VEA/MRCA statutory frameworks, cross-applies with other SOPs when factors refer to other injuries or diseases, and uses clinical classification systems as definitional supports. The legal effect of the SOP must be read alongside the enabling Acts, the versions of other SOPs in force, and the administrative and judicial review regimes that govern entitlement determinations.

The compilation states the SOP was made 22 December 2017 and commenced 29 January 2018 (s 1, s 2, Contents). The SOP revoked the previous Statement of Principles concerning migraine No. 57 of 2009 (s 4). The compilation includes endnotes that record legislative and amendment history up to the compilation date of 23 March 2020.

Recorded amendments in the compilation

• The primary instrument, "Statement of Principles concerning migraine (Balance of Probabilities) (No. 8 of 2018)," was registered on 3 January 2018 and commenced on 29 January 2018 (Endnote 3,Legislation history).
• An amendment instrument, "Amendment Statement of Principles concerning migraine (Balance of Probabilities) (No. 16 of 2020)," was registered on 2 March 2020 and commenced on 23 March 2020 (Endnote 3). The compilation notes the effect of that amendment in the text.

Specific provisions amended by No. 16 of 2020

• Endnote 4,Amendment history records which provisions were affected by Amendment No. 16 of 2020. According to that endnote:
  • Subsection 7(2) was restated or amended (rs. No. 16 of 2020).
  • Schedule 1 definitions for chronic migraine, migraine with aura, migraine without aura and vestibular migraine were added or amended (ad. No. 16 of 2020), and ICHD-3 was added to the Schedule (ad. No. 16 of 2020).
  • The compilation notes the compilation includes amendments up to No. 16 of 2020, with the day of commencement of that amendment recorded as 23 March 2020 in the header information.

Implications of amendments for claimants and decision-makers

• Amendments to subsection 7(2) and to the Schedule’s diagnostic definitions change the clinical criteria that must be applied when diagnosing migraine and its subtypes for the purposes of the SOP. For claims that straddle the amendment date, administrators must identify which version of the SOP applies to the particular claim, as the endnotes indicate commencement dates.
• The addition of ICHD-3 references and detailed diagnostic text in the Schedule provides more granular clinical criteria for use in decision-making. That can affect evidentiary requirements for diagnosis and the identification of "clinical worsening" or conversion from episodic to chronic migraine.

Compilation mechanics and uncommenced amendments

• The compilation includes the standard caution about uncommenced amendments: the compilation shows the text as amended and in force on 23 March 2020, and uncommenced amendments are not included in the body of the compiled law (the compilation notes and endnotes explain procedures for uncommenced amendments). The endnotes provide the legislative history and amendment history useful for identifying which text is operative at particular times.

Repeal of prior SOP

• The SOP expressly revokes the earlier Statement of Principles concerning migraine No. 57 of 2009 (s 4). Any determinations that relied on the prior SOP would, after commencement of this SOP, be made with reference to the new SOP for claims to which the VEA/MRCA provisions apply, subject to transitional or application provisions in the enabling Acts or in specific amendments (none are included in the compilation).

Overall, the amendment history recorded in the compilation shows a substantive update to the SOP between 2018 and 2020, including modifications to definitional material and the incorporation of ICHD-3 diagnostic criteria, and it highlights the need for claim-level determination of which SOP text governs a claim.

The text of this SOP compilation does not include or cite any litigation history, judicial decisions, or reported cases construing the Statement of Principles concerning migraine (No. 8 of 2018) or its predecessors. The compilation’s endnotes contain legislative and amendment history but do not record any court proceedings or tribunal decisions (Endnotes 3 and 4). Therefore, there is no litigation history recorded within this instrument to inform interpretations of the SOP’s provisions.

Practical consequences of the absence of recorded litigation in the instrument

• Where the SOP’s definitions, thresholds and relationships to service are applied in claims, the absence of reported judicial interpretation in the compilation means administrative decision-makers and claimants must apply the SOP text itself and any authoritative guidance set out in the VEA, MRCA, or administrative practice materials. If disputes arise in individual cases about how the SOP should be applied to particular facts, those issues would be resolved through the ordinary review mechanisms provided under the VEA and MRCA and, ultimately, by courts or tribunals. The compilation does not record outcomes of such processes.

Points of potential legal contention that could be litigated

• Several areas in the SOP could generate contested questions that would be litigated in individual cases, although no cases are recorded here. Those include:
  • Interpretation of "inability to obtain appropriate clinical management" (s 9(4)),what evidence suffices to show inability, and what constitutes "appropriate" care.
  • Application of the clinical worsening definition in the Schedule,whether incremental changes in frequency or severity meet the enumerated thresholds such as a two-fold increase in frequency or conversion to chronic migraine.
  • Temporal and causal linkage required by s 10, especially establishing that a listed factor was both present and related to relevant service.
  • The evidential standard in practice: applying the Repatriation Medical Authority’s view that causation is established on the balance of probabilities (s 8), and how that standard is met with available medical records and expert opinion.

Absence of formal precedent increases administrative importance

• In the absence of recorded judicial authority in this compilation, administrative practice, guidance notes, and consistency in decision-making will be particularly important in shaping how the SOP functions in practice. Decision-makers will rely on the text, the Schedule’s clinical criteria, and medical evidence in adjudication. Where novel or borderline factual situations arise, the absence of settled case law may lead to divergent decisions until clarified by a review body or court, but such litigation is not recorded in this instrument.

In short, the compilation contains no litigation history. The practical implication is that interpretation questions must be resolved against the SOP’s text and the enabling Acts, with any judicial clarification to be sourced outside the compilation.

This SOP contains several technical features and potential pitfalls that practitioners should note when preparing or opposing claims. The "gotchas" below follow directly from the instrument’s text and Schedule definitions.

1. Narrow list of causal factors (s 9). The SOP requires at least one of the four listed factors to exist (s 9(1)-(4)). If a claimant cannot establish any of those factors, the SOP does not provide an alternate general causation route. The four factors are treatment with a nitric oxide donor at time of clinical onset or worsening; long‑standing obesity prior to clinical worsening; or inability to obtain appropriate clinical management. Absent these, the SOP offers no other specified linkage.

2. Temporal limitation on aggravation factors (s 10(2)). Subsections 9(2) to 9(4) apply only to material contribution or aggravation where the migraine was suffered or contracted before or during, but did not arise out of, the person's relevant service. This wording creates a specific temporal rule: those factors cannot be used to establish material contribution/aggravation if the migraine arose out of service. Practitioners must therefore be precise in establishing whether migraine arose during or out of service and in what sense "arose out of" is evidenced in the claim record.

3. Precision required for "clinical worsening" (Schedule). The Schedule defines clinical worsening with concrete thresholds: a two-fold or greater increase in attack frequency; increased severity with debilitating symptoms; conversion from episodic to chronic migraine (Schedule chronic migraine definition is itself detailed); increased hospitalisation requirement; or severe episodes causing status migrainosus, cerebral infarct, seizure or death. Documents must show these specific changes. Vague assertions of "worse" are unlikely to meet the SOP without clinical documentation that maps to these enumerated items.

4. Obesity requirement is time-defined and formulaic (Schedule). "Being obese" is defined as BMI of 30 or greater and BMI is calculated as W/H2 (Schedule). The obesity factor requires obesity for at least five years before clinical worsening (s 9(3)). This is a longitudinal evidentiary requirement: record of weight and height over time is needed, and single‑point BMI measures are insufficient to demonstrate the five-year window.

5. Nitric oxide donors include commonly used agents (Schedule). The list of nitric oxide donors includes substances such as nitrous oxide, amyl nitrate and glyceryl nitrate. Nitrous oxide is commonly used in dental or anaesthetic practice; therefore a temporal record linking administration to onset or worsening is required. Practitioners must obtain anesthetic, procedural, pharmacy, or hospital records to establish timing.

6. "Inability to obtain appropriate clinical management" is undefined (s 9(4)). The SOP does not provide a bright-line test for what constitutes inability to obtain appropriate care or what care is "appropriate". Evidence could include appointment records, waiting lists, geographic and service availability records, or communications demonstrating refusal or unaffordability, but the SOP leaves the assessment to decision-makers. This creates evidentiary uncertainty and potential for adverse case outcomes where records are incomplete.

7. Cross-application to other SOPs (s 11). If a factor in s 9 refers to an injury or disease covered by another SOP, that SOP’s factors apply "as in force from time to time". Claimants and advisers must therefore search for and apply any relevant SOPs that could be engaged by particular factors. Failure to do so may miss applicable criteria or evidentiary thresholds.

8. Death from migraine extends to terminal events contributed to by migraine (s 7(5) and Schedule). The Schedule defines terminal event broadly with examples including pneumonia, respiratory failure, cardiac arrest, circulatory failure and cessation of brain function. To establish death from migraine, medical evidence must connect migraine as a contributing cause to the terminal event. This requires causal medical records and possibly post-mortem findings.

9. Amendment timing matters (Endnotes). The instrument was amended by No. 16 of 2020 and the compilation incorporates those amendments as in force on 23 March 2020. For claims spanning amendment dates, practitioners must determine which SOP text governs the claim.

10. Exclusions in s 7(2). The Schedule excludes conditions such as 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. If a claimant’s presentation is better characterised as one of those excluded conditions, this SOP will not apply and a different SOP or legal basis must be identified.

11. Balance of probabilities standard stated by the RMA (s 8). The SOP frames causal connection as "more probable than not." That standard requires decision-makers to weigh probabilities against the enumerated factors and evidence; claimants should prepare to satisfy that standard with contemporaneous medical documentation and clear timelines.

In practice these "gotchas" produce concrete evidence risks: lack of longitudinal weight records for the obesity factor; absent or unsigned anaesthetic/pharmacy records for nitric oxide exposure; insufficient documentation of increased frequency or severity of attacks to meet the clinical worsening thresholds; or incomplete evidence of attempts to obtain appropriate clinical management. Parties should plan evidence collection with the SOP’s precise requirements in mind.

Compliance in this context means preparing a claim and evidentiary record that satisfies the SOP’s criteria so that migraine or death from migraine is accepted as connected with relevant service. The SOP itself specifies what must be shown: at least one of the factors in s 9 and a service relationship under s 10. The steps below map directly to those textual requirements.

1. Identify the applicable SOP text and dates. Confirm which version of the SOP applies to the claim. The compilation shows the SOP commenced 29 January 2018 and was amended with No. 16 of 2020 (Endnote 3). For claims that pre-date or post-date amendments, document which version governs the assessment.

2. Establish the precise diagnosis using the Schedule criteria. Map the claimant’s clinical presentation to the Schedule definitions for migraine without aura, migraine with aura, chronic migraine, or vestibular migraine. Obtain treating neurologist or headache clinic reports that explicitly state which ICHD-3 criteria are met, referencing specific elements from the Schedule (for example, frequency and duration of attacks, aura characteristics, and whether criteria B-D are satisfied).

3. Fix dates for clinical onset and clinical worsening. The SOP’s factors turn on the timing of onset and worsening. Prepare contemporaneous records that identify the date of clinical onset and the date or period of clinical worsening. Clinical worsening must meet one or more Schedule criteria (two-fold increase in frequency, conversion to chronic migraine, increased hospitalisation, severe events such as status migrainosus, cerebral infarct, seizure or death). Obtain hospital admissions, emergency department notes, and GP or specialist documentation that record these events and dates.

4. Document nitric oxide donor exposure where relied upon. If relying on s 9(1) or s 9(2), obtain contemporaneous records showing administration of a listed nitric oxide donor at the time of clinical onset or clinical worsening. This may include anaesthetic records, dental procedure notes, procedural consent forms, pharmacy dispensing records, ambulance records, or hospital medication charts. The Schedule lists qualifying donors, including nitrous oxide; ensure the substance, dose and timing are recorded.

5. For obesity claims (s 9(3)), prepare longitudinal BMI evidence. Calculate BMI using the formula in the Schedule (W/H2). Collect historical weight and height records (GP records, hospital records, defence service medical records, occupational health records) showing BMI 30 or greater for a continuous five-year period before the date of clinical worsening. Where exact records are lacking, gather corroborating evidence such as clinical notes that record repeated BMI measurements, and explain any gaps with credible contemporaneous records.

6. For inability to obtain appropriate clinical management (s 9(4)), assemble access evidence. The SOP leaves "inability to obtain appropriate clinical management" open-ended. To meet this factor, gather evidence of attempts to obtain care and the barriers encountered: referral records, specialist appointment letters showing long wait times, correspondence documenting cancellations or lack of availability, geographic distance to services, financial barriers, treatment refusals, or system-level impediments. Medical records should indicate the clinical need for care and show attempted steps taken to obtain it.

7. Link the factor(s) to relevant service (s 10). Demonstrate the relationship between the factor relied upon and the claimant’s relevant service. Provide service records that verify the period and nature of relevant service as defined in the Schedule (eligible war service, defence service, peacetime service under the MRCA). Where appropriate, explain how the exposure or condition is temporally connected to the service period.

8. Address cross-referenced SOPs when a factor refers to another condition (s 11). If a factor in s 9 refers to another injury or disease covered by a different SOP, identify that SOP and obtain the evidence required under its terms. The s 11 cross-application requires decision-makers to apply the other SOP’s factors as in force.

9. Prepare medical nexus statements aligned to the SOP text. Obtain an expert medical opinion that directly addresses the SOP elements: confirm the diagnosis against Schedule criteria, state whether one or more s 9 factors existed, explain how those factors meet the Schedule definitions (for example, demonstrate a two-fold increase in frequency), and opine on whether those factors were related to relevant service per s 10. Experts should explicitly reference the SOP provisions and explain how the clinical evidence fulfils each applicable element on the balance of probabilities.

10. Anticipate evidentiary gaps and prepare explanations. Where records are incomplete, obtain statutory declarations, contemporaneous personal journals, or corroborating statements from family or colleagues to assist in establishing timelines, symptom patterns, or attempts to obtain care. For obesity claims, explain any missing weight records with available occupational or service medical notes.

11. Keep amendment and version records for appeals or reviews. For decision-making, note the SOP version relied upon by the decision-maker and be prepared to argue which version should apply if the claim timeline straddles an amendment. The compilation’s endnotes identify amendment dates that are relevant for this purpose.

12. Use precise terminology in submissions. Reference the SOP sections and Schedule definitions directly in submissions: cite s 9 for the factors, s 10 for relationship to service, s 7(5) and the Schedule for death from migraine, and the specific Schedule definitions (for example, "clinical worsening" and "chronic migraine") when arguing that particular thresholds are met.

By following these steps and ensuring documentary and expert evidence is tailored to the SOP’s textual thresholds, claimants and advisers can align claims with the instrument’s exacting requirements. Decision-makers will evaluate whether the asserted evidence meets the balance-of-probabilities standard set out in s 8 and satisfies the temporal and service relationship requirements in s 10.