Statement of Principles concerning bronchiolitis obliterans organising pneumonia (Balance of Probabilities) (No. 80 of 2018)

The central concept is the Statement of Principles itself, a legislative instrument that codifies the medical-scientific evidence connecting a disease to military service for the balance of probabilities standard. The SoP defines BOOP as a histological pattern of organising pneumonia involving patchy filling of alveoli, alveolar ducts, and bronchioles by loose plugs of granulation tissue containing fibroblasts, arising from lung injury and causing respiratory symptoms or other evidence of pulmonary dysfunction. The definition is careful to distinguish BOOP from other conditions: it excludes organising pneumonia secondary to infection or ARDS, organising pneumonia occurring in the presence of another interstitial lung disease where BOOP is not the dominant finding, organising pneumonia as a manifestation of a systemic disease, and pulmonary inflammation confined to the bronchioles (obliterative bronchiolitis or proliferative bronchiolitis). Notably, the source states that diagnosis can be made on typical clinical and radiographic features without a lung biopsy, even though the definition refers to a histological pattern. This is a practical concession that reduces the evidentiary burden on claimants.

The instrument establishes the concept of a factor as a specific medical event, exposure, or treatment that can link BOOP to service. Seventeen factors are listed, including taking a drug from a specified list of 40 drugs, undergoing a solid organ or stem cell transplant, therapeutic radiation for breast cancer within two years, bronchial obstruction adjacent to a focus of organisation, inhalation of a high‑concentration irritant substance with acute lower respiratory tract damage within 48 hours and onset of BOOP within 30 days, inhalation of sulphur mustard, and gastro‑oesophageal reflux disease. There is also a factor for inability to obtain appropriate clinical management. For drugs not on the specified list, factor 9(2) provides a pathway if the individual can show a temporal association between the drug and BOOP development within six months of commencing therapy, absence of BOOP before therapy, clinical improvement within weeks of ceasing therapy, and exclusion of other causes. This second pathway is more onerous and requires individualised evidence.

The concept of relevant service is defined narrowly for this instrument: eligible war service (other than operational service), defence service (other than hazardous service and British nuclear test defence service), and peacetime service under the MRCA. This means the SoP does not apply to claims involving operational service, hazardous service, or British nuclear test defence service, which are governed by a separate SoP under the reasonable hypothesis standard. The instrument also defines terminal event to include pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function, for the purpose of attributing death to BOOP.

This instrument directly affects veterans who rendered eligible war service (other than operational service), members who rendered defence service (other than hazardous service or British nuclear test defence service) under the VEA, and members who rendered peacetime service under the MRCA. It applies to anyone claiming that BOOP or death from BOOP is service‑related under those provisions. The claimant must demonstrate that at least one factor from section 9 exists and is related to their relevant service. The instrument also affects the Repatriation Commission and the Military Rehabilitation and Compensation Commission, which must apply the SoP when determining liability for claims. Decision‑makers in the Department of Veterans' Affairs and the Department of Defence rely on the SoP as the binding medical standard; they cannot accept a claim based on other medical evidence unless that evidence fits within the factors or the definitional exclusions.

The instrument indirectly affects medical practitioners who assess veterans and provide evidence for claims. They must ensure their diagnosis meets the definition of BOOP in the instrument, including the exclusions. If a claimant has organising pneumonia secondary to infection or a systemic disease, the diagnosis may not satisfy the SoP definition, and the claim will fail regardless of service exposure. Similarly, clinicians treating veterans with BOOP need to be aware that drug therapies, radiation, or transplants may be considered causative factors for compensation purposes, and documentation of timing and response to treatment will be critical.

The instrument also affects legal practitioners, advocates, and tribunal members who handle appeals under the VEA and MRCA. The SoP limits the scope of argument: the factual question is whether a factor exists and relates to service, not whether the medical evidence generally supports a connection. This reduces discretion and standardises outcomes but also imposes a rigid framework that may exclude claims where the link is plausible but not captured by the listed factors. For example, a veteran who develops BOOP after exposure to an industrial chemical not classified as a high‑concentration irritant with acute damage within 48 hours may have no pathway under factor 9(6). The exclusive list of drugs in factor 9(1) similarly means that drugs with emerging evidence linking them to BOOP cannot be used unless they are among the 40 listed or the individualised pathway under factor 9(2) is satisfied.

The instrument imposes no duties directly on claimants, but it does create a de facto evidentiary threshold. A claimant has the right to have their claim assessed under the SoP, and the decision‑maker must determine whether at least one factor exists. The claimant bears the burden of proving the factor on the balance of probabilities, but the standard is civil: more likely than not. The key duty falls on the decision‑maker to apply the factors strictly and not to substitute their own medical opinion for the SoP. The Repatriation Medical Authority, in determining the SoP, had the duty to base it on sound medical‑scientific evidence, and the instrument states that the Authority is of the view that it is more probable than not that BOOP can be related to relevant service. That view is not itself reviewable in a claim; it is the legislative premise.

The instrument creates a right for a claimant to rely on the specified list of drugs at factor 9(1) without proving individual association, provided the drug was being taken at the time of clinical onset. This is a significant advantage: the claimant need not show a causal link between the drug and BOOP; only that the drug was being taken. However, the list is exhaustive and any drug not listed must go through the more demanding individualised pathway in factor 9(2). Factor 9(2) requires evidence of a temporal sequence, clinical improvement on cessation, and exclusion of other causes. That imposes a practical duty on the claimant to produce contemporaneous medical records documenting the timeline and response.

Factor 9(17), inability to obtain appropriate clinical management, is a safety‑net provision but one that carries its own evidentiary burden. The claimant must show that the inability worsened the condition or contributed to its clinical onset. Since the instrument does not define appropriate clinical management, there is room for interpretation, but the decision‑maker would need evidence that management was unavailable or denied, not merely that a different treatment might have been preferable. The right to rely on this factor is limited by the requirement that the inability to obtain management be related to service.

Section 11 of the instrument provides that if a factor refers to an injury or disease covered by another SoP, the factors in that other SoP apply. This avoids duplication but means the claimant must also satisfy the factors in the underlying SoP for the referenced condition. For example, if a factor involves a drug that caused a disease for which another SoP exists, the claimant may need to meet both SoPs. This interaction can increase the compliance burden.

This instrument does not itself impose penalties. It is a legislative instrument that sets the substantive evidentiary standard for compensation claims; it is not a regulatory or criminal law. The enforcement mechanism is indirect: if a claimant cannot establish at least one factor related to service, the claim for liability will be refused. There is no fine or sanction for non‑compliance. Instead, the consequence is loss of entitlement to compensation for BOOP under the VEA or MRCA for the relevant service.

However, the instrument does have exclusionary force. A claimant who does not meet the factors cannot circumvent the SoP by relying on general medical evidence of a connection, because sections 120B of the VEA and 339 of the MRCA require the decision‑maker to apply the SoP as the exclusive basis for determining whether the injury or disease is connected to service. The instrument therefore operates as a gatekeeper. If a factor is not present, the claim must be denied, regardless of other evidence. This makes the SoP a powerful enforcement tool for the government: it standardises and limits liability.

The instrument also creates an incentive for claimants to seek review or appeal if they believe a factor is present but the decision‑maker has applied the SoP incorrectly. Appeals proceed to the Veterans' Review Board and then to the Administrative Appeals Tribunal or the Federal Court. The risk for the claimant is that the SoP's strict definitions and time limits make errors difficult to overturn on factual grounds. For example, if the 30‑day window between sulphur mustard inhalation and onset is not met, the factor fails regardless of the plausibility of a longer latency. The absence of any discretion in the instrument means the decision‑maker cannot stretch the time limits.

There is also a potential cost to the public purse. If a factor is met, the government must accept liability. The instrument therefore allocates the risk of disease to the taxpayer for those who satisfy the factors. The specified list of drugs alone covers many common medications, including amiodarone, methotrexate, nitrofurantoin, and interferons, which are frequently prescribed to veterans for other conditions. The exposure to liability is significant, but it is bounded by the requirement that the drug was taken at the time of clinical onset and related to service.

The instrument sits within a hierarchy of three statutes: the VEA, the MRCA, and the Safety, Rehabilitation and Compensation (Defence‑related Claims) Act 1988, although the latter is not referenced in the source. The SoP is made under subsection 196B(3) of the VEA and applies to claims under section 120B of that Act as well as section 339 of the MRCA. The instrument expressly repeals the earlier SoP No. 63 of 2009, which previously governed the same condition. This means any claim determined after 24 September 2018 must be assessed under this instrument, regardless of when the condition arose.

Section 11 of the instrument creates an interaction with other SoPs: if a factor in section 9 refers to an injury or disease for which another SoP exists, the factors in that other SoP apply as in force from time to time. This cross‑referencing means that a claimant who relies on a factor involving, say, gastro‑oesophageal reflux disease must also satisfy the SoP for that condition. That SoP will have its own list of factors, definitions, and timeframes. The practical effect is that the claimant may need to prove two separate causal chains: first, that their GERD is service‑related under its own SoP, and second, that the GERD is a factor for BOOP under this instrument. This raises the evidentiary bar and increases the complexity of claims.

The instrument also interacts with the definition of relevant service, which is narrower than the full scope of service covered by the VEA and MRCA. Claims for BOOP arising from operational service, hazardous service, or British nuclear test defence service are not governed by this SoP. Instead, they fall under the reasonable hypothesis standard and would be assessed under a separate SoP for BOOP made under subsection 196B(2) of the VEA, which uses a different threshold. The source does not provide that instrument, but the practitioner must be alert to which standard applies. This division creates a two‑track system: one for operational service (reasonable hypothesis) and one for peacetime service (balance of probabilities). The same disease is treated differently depending on the character of the service.

The instrument does not interact with workers' compensation schemes, state or territory occupational health and safety laws, or clinical practice guidelines. It is a bespoke instrument for the military compensation system only. However, a veteran who receives compensation under the VEA or MRCA for BOOP may have that compensation adjusted if they also receive damages from a third party, but that interaction is governed by the parent legislation, not by this SoP.

The instrument recites only one amendment: it repeals the Statement of Principles concerning bronchiolitis obliterans organising pneumonia No. 63 of 2009 (Federal Register of Legislation No. F2009L03226). That earlier instrument was also made under subsection 196B(3) of the VEA. The current instrument commenced on 24 September 2018. The source does not provide any further amendment history, nor does it indicate whether the current instrument has been subsequently amended. No transitional provisions are included; the instrument applies to claims to which section 120B of the VEA or section 339 of the MRCA applies, without limiting it to claims made after commencement. However, the general rule under the VEA is that the SoP in force at the time of the decision applies, so a claim lodged before 24 September 2018 but determined after that date would be assessed under this instrument unless the decision‑maker applied the earlier SoP as a transitional matter. Practitioners should check whether the current instrument has been amended since 2018 by searching the Federal Register of Legislation. The listing of 40 drugs in the specified list may be updated over time as new medical evidence emerges, but the instrument itself has not been amended on the face of the source. The repeal of the 2009 SoP means that any case law interpreting the wording of that instrument may still be relevant if the current instrument uses identical language, but differences in wording would require fresh interpretation. The definition of BOOP differs from the 2009 version only if the source of the earlier instrument is consulted; the source does not provide a comparison.

The source does not name any specific cases. A deep dive cannot invent litigation history. However, it is possible to discuss the type of litigation that typically arises from a SoP of this kind. Most disputes involve whether a factor exists on the facts, particularly around the timing of clinical onset or worsening relative to the exposure or drug therapy. The time limits in factors 9(6) and 9(7) , 30 days for irritant inhalation and sulphur mustard , are likely to be contested in cases where the onset is insidious or where the claimant cannot pinpoint the exact date of onset. The definition of bronchial obstruction at factor 9(5) and 9(13) may also generate disputes about whether an endogenous process or foreign body meets the definition. The individualised drug factor 9(2) requires evidence of clinical improvement within weeks of ceasing drug therapy, which may be difficult to prove if the claimant continued the drug or if other treatments were started concurrently. The Administrative Appeals Tribunal and the Federal Court have considered these issues in other SoP contexts, but no specific decisions are cited in the source. The absence of citation does not mean litigation has not occurred; it means the source does not record it. A practitioner should search for decisions of the Veterans' Review Board, the Administrative Appeals Tribunal, and the Federal Court involving BOOP and this specific instrument. The repeal of the 2009 SoP means that previous litigation under that instrument may still be relevant if the wording is similar. However, the instrument is only five years old, and BOOP is a relatively rare condition, so the volume of litigation is likely low. The interaction between section 11 and other SoPs may also generate disputes about which SoP applies to a referenced condition and whether the factors in that SoP are met.

Several features of this instrument can trap claimants and practitioners. First, the definition of BOOP in subsection 7(2) excludes organising pneumonia secondary to infectious pneumonia or acute respiratory distress syndrome. A claimant who presents with BOOP confirmed on biopsy but who had a preceding pneumonia may find the diagnosis does not fit the definition, even though the clinical presentation is identical. The exclusion also covers organising pneumonia that occurs in the presence of another interstitial lung disease if BOOP is not the dominant histological finding. This creates a hierarchy: the other disease must be dominant. Proving dominance on histology may require a biopsy that is not always performed.

Second, the specified list of drugs is exhaustive and contains exactly 40 drugs. Many common drugs implicated in BOOP in the medical literature, such as everolimus and rituximab, are listed, but others may not be. Factor 9(2) provides an alternative for drugs not listed, but it requires proof of a temporal association, absence of BOOP before therapy, clinical improvement on cessation, and exclusion of other aetiologies. This is a high bar, especially if the claimant has multiple comorbidities or is taking multiple drugs. The requirement for clinical improvement within weeks of ceasing therapy assumes the drug was stopped; if the drug was continued despite side effects, the factor cannot be met.

Third, the time limits in factors 9(6) and 9(7) are very tight: 48 hours for acute lower respiratory tract damage after irritant inhalation, and 30 days for onset of BOOP after that damage or after sulphur mustard inhalation. For an insidious disease like BOOP, the onset date is not always clear. The instrument does not define clinical onset; it is left to medical judgment. A decision‑maker may reject a claim if the onset is dated just outside the 30‑day window, even if the exposure was severe.

Fourth, factor 9(8) and 9(16) list gastro‑oesophageal reflux disease as a factor, but the instrument does not define GERD or require a specific severity. A claimant with mild reflux documented in service medical records may succeed, but proving that the GERD itself is service‑related under its own SoP (via section 11) adds another layer.

Fifth, factor 9(17) appears generous but is likely difficult to prove. Inability to obtain appropriate clinical management must be related to service. For peacetime service, this might arise if the Defence Force failed to provide follow‑up care or denied treatment. But the claimant must show that the inability worsened the BOOP, which requires a causal link between lack of management and deterioration. If the claimant simply chose not to seek treatment, the factor likely does not apply.

Sixth, the instrument only applies to relevant service as defined: eligible war service (other than operational service), defence service (other than hazardous service), and peacetime service. A veteran with operational service for BOOP who tries to rely on this SoP will be assessed under the wrong standard and will likely fail because the reasonable hypothesis SoP will not be applied. Practitioners must check the character of service first.

Seventh, note 2 to the definition states that diagnosis can be made without a lung biopsy based on typical clinical and radiographic features. While this reduces the burden, a decision‑maker may still require specialist respiratory physician evidence to confirm the diagnosis meets the definition. A diagnosis by a general practitioner or based solely on a chest X‑ray may be insufficient.

Compliance with this instrument is relevant to two groups: claimants seeking to establish service connection, and decision‑makers determining claims. For claimants, the first step is to ensure the diagnosis of BOOP fits the definition in subsection 7(2). The claimant should obtain a respiratory physician's report that explicitly states the diagnostic basis, including histology if available, or typical clinical and radiographic features. The report should also confirm that exclusions have been considered: that there is no evidence of infectious pneumonia, ARDS, another dominant interstitial lung disease, or systemic disease causing organising pneumonia. If the claimant has a history of any of these, the physician needs to explain why BOOP is the correct diagnosis despite the exclusion.

The claimant then identifies whether any factor in section 9 applies. The most common factors are likely to be drug therapy (factor 9(1) or 9(2)), gastro‑oesophageal reflux disease (factor 9(8)), or inability to obtain appropriate clinical management (factor 9(17)). For drug factors, the claimant should compile a list of all medications taken at the time of clinical onset, with dates and dosages. If the drug is on the specified list, factor 9(1) is straightforward: the claimant need only prove the drug was being taken at the time of onset. If the drug is not on the list, the claimant must satisfy factor 9(2), which requires contemporaneous medical records showing the development of BOOP within six months of starting the drug, absence of BOOP before the drug, clinical improvement within weeks of cessation, and exclusion of other causes. This may require a time‑lined medical chronology and possibly a drug rechallenge or de‑challenge documented in the notes.

For factor 9(7) involving sulphur mustard, the claimant must prove service exposure to sulphur mustard, signs and symptoms of acute lower respiratory tract damage within 30 days before onset, and onset of BOOP within 30 days after that exposure. This will require service records documenting the exposure and medical records documenting acute respiratory damage. For factor 9(6) involving other irritant substances, the claimant must prove high‑concentration exposure, acute damage within 48 hours, and onset within 30 days. The instrument does not define high concentration or irritant properties, so a toxicologist or occupational physician may need to provide an opinion.

For factor 9(8) (GERD), the claimant must prove the GERD existed at the time of clinical onset and that it is related to service. Because GERD has its own SoP under section 11, the claimant may need to satisfy that SoP first. The decision‑maker should apply the relevant SoP for GERD as in force from time to time.

Once the factor is established, the claimant must show that the factor is related to relevant service. Relevant service is defined in the dictionary and excludes operational service and hazardous service. The decision‑maker must verify that the service qualifies and that the factor arose out of that service.

For decision‑makers, compliance means strictly applying the factors and definitions. The decision‑maker should check the diagnosis against the definition, confirm that at least one factor exists on the evidence, ensure the timing requirements are met, and verify that the factor is related to relevant service. The decision‑maker must apply section 11 if the factor references another disease. The decision‑maker should also ensure that the claim falls within the scope of the instrument: if the service is operational, the balance of probabilities SoP does not apply and the reasonable hypothesis SoP must be used instead.