Statement of Principles concerning thoracolumbar intervertebral disc prolapse (Reasonable Hypothesis) (No. 68 of 2023)

The central concept is the "reasonable hypothesis" standard under s120A VEA. A claim for service connection can succeed if the material raises a reasonable hypothesis connecting the condition to relevant service, provided the SoP sets out factors that must exist. The SoP does not create a presumption; it provides a checklist. Key concepts include "clinical onset" defined as the point backwards in time from the first imaging date confirming thoracolumbar intervertebral disc prolapse to the date at which symptoms were persistently present, as assessed by a registered medical practitioner. This means the onset date is not the imaging date but the earlier date when symptoms began. The definition of "trauma to the affected intervertebral disc" is stringent: a discrete event involving significant physical force that causes symptoms and signs of pain and tenderness and either altered mobility or range of movement of the thoracolumbar spine, persisting for at least 7 days following onset, unless medical intervention occurs (immobilisation, corticosteroid injection, or surgery). This definition excludes minor strains that resolve quickly. "Penetrating injury" means piercing of the affected disc or adjacent vertebral body by an object such as a bullet, shell fragment, knife or needle. "Load-Factor" is a novel mathematical formula: W2 x T, where W is weight in kilograms and T is time in hours. The threshold is a cumulative total of 150,000 within 10 years before clinical onset. For example, lifting 20 kg for 1 hour yields a Load-Factor of 400; achieving 150,000 requires either heavy lifts or prolonged time. This quantifies repetitive physical strain. "Motor vehicle" is defined broadly as a motorised vehicle which imparts vibration to the whole body, including cars, trucks, motorcycles, tractors, jeeps, armoured personnel carriers, tanks, and construction vehicles like forklifts, bulldozers, cranes, steam shovels, backhoes or steam rollers. That broad definition covers many military roles. "Operational crew" for flying factors means crew members performing duties in flight (not passengers). The smoking factor requires at least 5 pack-years before onset and cessation within 5 years of onset. One pack-year equals 20 cigarettes per day for one year or 7,300 grams of smoking tobacco. "Being obese" means a BMI of 30 or greater for at least 5 years within the 25 years before clinical onset. The instrument also distinguishes between clinical onset and clinical worsening. Worsening factors (section 9(10) to (19)) apply only to material contribution to or aggravation of a pre-existing thoracolumbar intervertebral disc prolapse that was suffered or contracted before or during but did not arise out of relevant service. The definition of "relevant service" covers operational, peacekeeping, hazardous and British nuclear test defence service under the VEA, and warlike and non-warlike service under the MRCA. "Death from thoracolumbar intervertebral disc prolapse" includes death from a terminal event or condition contributed to by the disc prolapse, with examples such as pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function. The dictionary also defines "imaging evidence" as an image of the interior of a body obtained by medical techniques including X-ray radiography or MRI, showing the prolapse, usually obtained after clinical onset.

This instrument directly affects veterans, members of Peacekeeping Forces, and members of the Forces under the VEA, as well as members under the Military Rehabilitation and Compensation Act 2004, who claim that their thoracolumbar intervertebral disc prolapse is related to their relevant service. It also affects their dependants in the event of death from the condition. The instrument binds the Repatriation Medical Authority itself as the body that must apply these factors when assessing medical-scientific evidence for reasonable hypothesis determinations. It also binds decision-makers: delegates of the Department of Veterans Affairs, the Veterans' Review Board, and the Administrative Review Tribunal (formerly the Administrative Appeals Tribunal). Legal practitioners and advocates representing claimants must understand the specific definitions and thresholds to assemble evidence that meets the factors. Medical practitioners are indirectly affected because they must diagnose the condition in a manner consistent with the SoP's criteria: clinical manifestations plus imaging evidence. Radiologists providing imaging reports may need to comment on whether a disc protrusion, herniation, extrusion or rupture is present, and exclude bulging discs and Schmorl's nodes. The instrument also affects compensation and health care providers who manage claims: they must ensure that claims for thoracolumbar disc conditions are assessed against this SoP rather than earlier versions. The previous SoP (No. 43 of 2016) is repealed, so any claims determined after 25 July 2023 must use this new instrument. The instrument does not apply to claims under the Safety, Rehabilitation and Compensation Act 1988 (DRCA) for ADF members before 1 July 2004, unless a separate SoP under that Act is applicable. However, the MRCA covers members after that date for warlike and non-warlike service. The SoP also has implications for the assessment of clinical worsening: for a person whose disc prolapse existed before or during service but did not arise out of service, factors 10-19 apply to material contribution to aggravation. This affects veterans who had pre-existing back problems that worsened during service. The instrument's definitions mean that service personnel in armoured units or transport roles are more likely to satisfy the driving factor. Air Force and Army aviation personnel (fixed wing and helicopter) are affected by the flying factor at 2,500 hours cumulative. Those in logistics or infantry who carried heavy loads (Load-Factor) are also covered. The instrument thus creates a map of which service-related activities are accepted as raising a reasonable hypothesis for this specific disc condition. Practitioners must identify which factor(s) best fit the veteran's service history.

The instrument does not impose duties directly on individuals but rather sets out evidentiary requirements that claimants must satisfy. The key right is the ability to raise a reasonable hypothesis connecting thoracolumbar intervertebral disc prolapse to service if at least one factor in section 9 exists and is related to the person's relevant service. The claimant has a right to have the claim assessed against this SoP rather than any non-statutory standard. The instrument also creates a right to rely on the SoP's definitions: for example, if a veteran has a Load-Factor over 150,000 from carrying loads in service, that factor is deemed sufficient if the other temporal conditions are met. The RMA has a duty under s196B(2) VEA to determine these Statements of Principles based on sound medical-scientific evidence. The instrument recites that the RMA is of the view that such evidence exists (section 8). For decision-makers, there is a duty to apply the factors exactly as defined, without adding or subtracting conditions. For example, trauma must meet the 7-day persistence rule unless medical intervention occurs; a mere back strain that resolves in 2 days does not satisfy factor 1 or 10. There is also a duty to consider the timing relationship: each factor must exist within specified timeframes. For instance, trauma must occur within 24 hours before clinical onset; the load-carrying and driving factors must be within 10 years before onset; smoking and obesity must be before onset with specific windows. The instrument creates a procedural right under section 11: if a factor refers to an injury or disease covered by another SoP (e.g., the bacterial infection factor might refer to spondylodiscitis, which has its own SoP), then the factors in that other SoP apply according to its terms as in force from time to time. This avoids re-litigating causation for intermediate conditions. The instrument also implicitly creates a right for the claimant to rely on the inability to obtain appropriate clinical management factor (19) for worsening, but only if that inability occurred before the worsening. That factor is vague: it does not define "appropriate clinical management" nor "inability to obtain", which leaves interpretive discretion to the decision-maker. The decision-maker must assess whether the veteran could not access proper treatment during service. For the RMA, there is a duty to periodically review and update SoPs; this instrument replaces one from 2016, indicating that medical evidence has been reassessed. The instrument does not create any private rights of action; it is a public law instrument used in administrative decision-making. Claimants also have a right to reasons for a decision and to seek review.

This instrument does not itself contain penalty provisions. It is a Statement of Principles, not a penal statute. Enforcement arises in the context of veterans' compensation claims rather than criminal or civil penalties. However, there are indirect consequences for misrepresenting facts. If a claimant knowingly provides false information to satisfy a factor (for example, fabricating a history of trauma or exaggerating lifting loads), they may be subject to provisions under the VEA or MRCA relating to false statements. These can lead to cancellation of benefits, recovery of overpayments, and potentially prosecution under the Criminal Code (Cth) for fraud (s 135.1 et seq). For example, a claim that relies on a trauma event that never occurred could be rejected, and if payment was made, recovery action may follow. The DVA and the Repatriation Medical Authority do not enforce the SoP itself; rather, the SoP is the framework within which decision-makers determine entitlement. The practical enforcement mechanism is the claims assessment process. If a factor is present, the claim proceeds; if not, it fails unless another factor applies. There is no penalty for failing to raise a factor; the claim simply does not succeed. For medical practitioners, incorrectly certifying that a disc prolapse meets the SoP diagnostic criteria may not be penalised under this instrument, but could under professional standards or the Health Insurance Act 1973 if Medicare billing is involved. For decision-makers, failing to apply the SoP correctly could lead to review and reversal by the Veterans' Review Board or the Administrative Review Tribunal, and possibly judicial review under the Administrative Decisions (Judicial Review) Act 1977. However, that is a remedy rather than a penalty. The instrument does not create any penalty units or infringement notices. The practical enforcement is that claims are assessed against the factors, and the decision stands unless appealed. The definitions are drafted precisely (e.g., trauma must persist 7 days; Load-Factor formula) to minimise scope for dispute, but also to provide clear evidentiary thresholds. There is also potential for adverse credibility findings if a veteran's evidence is inconsistent with service records, which may affect other claims. Overall, the "penalty" for failing to satisfy the SoP is simply that the claim is refused.

This instrument is made under the Veterans' Entitlements Act 1986, specifically subsection 196B(2). It operates within the framework of Part II, Division 2, Subdivision B of the VEA, which deals with Statements of Principles and the standard of proof for claims. Under s120A VEA, a reasonable hypothesis for operational service must be consistent with the relevant SoP. For other service (peacekeeping, hazardous, British nuclear test defence), the standard is reasonable satisfaction but still requires the SoP factors. The instrument also applies to claims under the Military Rehabilitation and Compensation Act 2004, via section 338 of that Act, which imports the SoP mechanism for warlike and non-warlike service. The instrument does not apply to claims under the Safety, Rehabilitation and Compensation Act 1988 (DRCA) for ADF members before 1 July 2004, unless a separate SoP has been made under that Act. However, the RMA may also make SoPs under the DRCA; this specific instrument is under VEA and MRCA only. Section 11 of the instrument provides that if a factor in section 9 refers to an injury or disease that itself is covered by another SoP, then the factors of that other SoP apply. For example, if a factor refers to bacterial infection, and infection is covered by a separate SoP, that SoP's factors must be considered. This creates a hierarchy of SoPs. The instrument also interacts with the general law of evidence and administrative law. The reasonable hypothesis standard is lower than the balance of probabilities but requires the hypothesis to be consistent with the SoP factors. The definition of clinical onset is unique to this SoP and affects the temporal relationship with service. The definitions of motor vehicle and Load-Factor are specific to this condition and may differ from similar definitions in other SoPs (e.g., for lumbar disc prolapse or osteoarthritis). The instrument does not purport to affect the law of negligence or workers compensation; it is solely for veterans' and military compensation. However, it may be persuasive in other contexts if a court or tribunal considers it as medical consensus. The Repeal provision (section 4) removes the 2016 SoP. Transitional issues are governed by the Acts Interpretation Act 1901 (Cth) and the VEA. Claims lodged but not yet determined before 25 July 2023 should be assessed under this new SoP if the decision is made after commencement. The instrument may also interact with the Freedom of Information Act 1982 as a legislative instrument that must be registered and publicly available.

This instrument (No. 68 of 2023) replaces the Statement of Principles concerning intervertebral disc prolapse (Reasonable Hypothesis) (No. 43 of 2016). The 2016 instrument was made under subsections 196B(2) and (8) of the VEA. The earlier instrument covered intervertebral disc prolapse generally without anatomical limitation in its title, though it may have had its own definitions. The 2023 version specifically limits the condition to the thoracolumbar spine, excluding cervical or purely lumbar discs unless they fall within the thoracolumbar or lumbosacral junctions. The change from "intervertebral disc prolapse" to "thoracolumbar intervertebral disc prolapse" suggests the RMA has refined the condition to a specific spinal region. The 2023 version adds specific factors for flying in engine-powered aircraft as operational crew (factors 5 and 14) and flying in helicopters as operational aircrew (factors 6 and 15), which were not present in the 2016 version. The 2016 SoP may have had a single "vibration" factor instead. The 2023 version also defines "motor vehicle" more broadly, explicitly including construction vehicles like forklifts, bulldozers, cranes, steam shovels, backhoes and steam rollers. The Load-Factor formula in the 2023 version is W2 x T (weight squared times time). The 2016 version may have used a different formula, possibly weight times time, which would give different thresholds. The obesity factor now requires BMI of 30 or greater for at least 5 years within 25 years before onset, whereas the 2016 version may have had a shorter duration. The smoking factor now specifies a cessation window of 5 years if smoking ceased before onset or worsening. The trauma definition now includes persistence of symptoms for at least 7 days unless medical intervention occurs, which may be more generous than prior definitions that required 7 days without exception. The 2016 SoP was repealed by section 4; the repeal does not affect rights that had already accrued. The instrument itself may be amended or revoked by a later SoP. Since it is a legislative instrument, it is subject to disallowance by either House of Parliament under the Legislation Act 2003. It is registered on the Federal Register of Legislation. The date of commencement is 25 July 2023, which is 32 days after making (23 June 2023). No other amendments have been made to this instrument since its commencement. The RMA may issue a revised SoP if further medical evidence emerges or if the instrument is found to be problematic in application. It is standard practice for the RMA to update SoPs every few years as medical science evolves.

This instrument itself (No. 68 of 2023) has not been the subject of reported litigation as it is relatively new (commenced 25 July 2023). However, previous SoPs for intervertebral disc prolapse have been considered in the Veterans' Review Board and the AAT. In general, SoPs are frequently challenged on the basis that the medical evidence does not support a particular factor, or that the definitions are too restrictive. For example, earlier versions have seen disputes about what constitutes "trauma" and whether a gradual onset from repetitive lifting can satisfy the factors. The Load-Factor in the current instrument is designed to address repetitive strain, but its application may be litigated. Claimants may need to prove the exact weight and duration of lifting during service, which is often poorly documented. The definition of clinical onset is likely to be litigated because it involves a retrospective assessment of when symptoms became persistently present. The instrument attempts to clarify that imaging is usually obtained after clinical onset, but the precise date of onset may be contested. Another area of potential litigation is the motor vehicle driving factor: proving an average of 25 hours per week for 2 years may be difficult without detailed service records. The flying factor threshold of 2,500 hours may be contested for aircrew who have intermittent flying but not enough cumulative hours. The smoking factor cessation window may be litigated if a veteran quit more than 5 years before onset but still develops disc prolapse. The obesity factor's use of BMI (a crude measure) may be challenged if a person has high muscle mass. The "inability to obtain appropriate clinical management" factor for worsening is vague and may be litigated on what constitutes appropriate management and inability. The Repatriation Medical Authority's findings of sound medical-scientific evidence in section 8 are generally not reviewable on the merits (see VEA s196B(11) which says the RMA's opinion is final and conclusive). However, the interpretation and application of the factors are reviewable. Cases may test whether a particular service activity falls within the definition of motor vehicle or whether a particular type of flying counts as operational crew. The instrument's exclusion of bulging discs and Schmorl's nodes may also be litigated if a veteran has a broad-based bulge causing symptoms but the imaging report calls it a "bulge" rather than a "protrusion" or "herniation". There is also potential for constitutional challenge if the instrument is alleged to be beyond power, but that is unlikely given the High Court's deference to the veterans' entitlements scheme. Practitioners should monitor decisions from the VRB and the AAT (now ART) for guidance on interpreting terms like "clinical onset", "trauma", and "Load-Factor". While No. 68 of 2023 is new, decisions on the identical provisions in other recent SoPs (e.g., for lumbar disc prolapse) may be persuasive.

Several traps exist for the unwary practitioner or claimant. First, the definition of "clinical onset" is a point backwards in time from the first imaging date to when symptoms were persistently present. Claimants often believe the imaging date is the onset, but the SoP requires an earlier date if symptoms existed. This can affect whether a factor precedes onset. For example, heavy lifting within 10 years before clinical onset may be satisfied if symptoms began years before imaging, but if the symptoms were intermittent and not persistently present, the onset date may be pushed back to when they became persistent. That might either help or hurt the claim depending on timing. Second, the trauma definition requires symptoms and signs for at least 7 days unless medical intervention occurs. If a veteran had a back injury that resolved in 3 days, it does not count as trauma even if it was severe. The exception for medical intervention is only for immobilisation, corticosteroid injection, or surgery. Simple painkillers or rest do not reset the 7-day requirement. Third, the Load-Factor formula uses weight squared times time. Doubling the weight quadruples the Load-Factor. Therefore, carrying a 20kg load for one hour gives a Load-Factor of 400; achieving 150,000 over 10 years requires about 375 hours of carrying 20kg, or 96 hours of carrying 40kg. But note the definition requires lifting or carrying loads of at least 10kg. Loads under 10kg are not counted at all. Also, carrying weight on the body (e.g., wearing a heavy pack) may count if it is "carried" - there is ambiguity about whether static wearing of a rucksack counts as carrying if the person is not actively lifting. Fourth, the driving factor requires an average of at least 25 hours per week for a period of at least 2 years within the 10 years before onset. That is roughly 3.5 hours per day, every day, for 2 years. Casual driving does not meet it. Importantly, the definition of motor vehicle includes vehicles that impart whole-body vibration, but does not quantify the amplitude. A soft-riding sedan may impart less vibration than a truck; however, the SoP does not require a minimum vibration level. If the vehicle is of a type listed or captured by the definition, the factor is satisfied regardless of actual vibration exposure. Fifth, the flying factors require operational crew status. Passengers do not count. The cumulative total must be 2,500 hours, substantial (over a year of full-time flying). Helicopter and fixed-wing hours cannot be combined unless both are operational crew. Sixth, the smoking factor has a 5-year cessation window: if the veteran quit more than 5 years before onset, the factor does not apply even if they smoked heavily. This is a strict temporal cutoff. For example, smoking 20 pack-years but stopping 6 years before onset fails the factor. Seventh, obesity must exist for at least 5 years within the 25 years before onset. A veteran who became obese only 2 years before onset does not satisfy this. BMI is measured historically, which may be difficult to prove. Military medical records often record height and weight annually, so it may be possible to demonstrate. Eighth, bacterial infection at the time of onset is very specific and rarely occurs. It is unlikely to be the basis of most claims. Ninth, the clinical worsening factors (10-19) only apply if the person's thoracolumbar disc prolapse was suffered or contracted before or during (but did not arise out of) their relevant service. If the initial onset was already service-related, you rely on the initial claim, not these worsening factors. If the condition arose out of service, it is already covered. These factors are only for aggravation of a pre-existing condition. Tenth, factor 19 (inability to obtain appropriate clinical management) is vague. It does not define "appropriate clinical management". It could be argued that if a military doctor failed to refer for physiotherapy or imaging, that constituted inability. But there is no guidance, and the decision-maker has wide discretion. Eleventh, the instrument excludes bulging discs and Schmorl's nodes. A bulging disc without herniation is not covered even if symptomatic. The imaging report must be carefully read to ensure the terminology matches "protrusion, herniation, extrusion or rupture". Twelfth, the instrument requires imaging evidence defined as X-ray radiography or MRI. A CT scan is not mentioned; presumably MRI is the gold standard. If only CT is available, it may not satisfy the definition. Thirteenth, the instrument uses ICD-10-AM codes M51.0, M51.1, M51.2 but clarifies that the definition in subsection 7(3) governs. Simply having one of those codes is not enough; the clinical and imaging criteria must be met. Finally, note that the instrument applies to claims under VEA s120A and MRCA s338, but not to DRCA claims unless a similar SoP exists under that Act.

For claimants and their representatives, compliance means assembling evidence that at least one of the factors in section 9 exists and is related to relevant service. The first step is to obtain a diagnosis of thoracolumbar intervertebral disc prolapse consistent with subsection 7(2) and (3): clinical manifestations (pain, stiffness, or symptoms of cord or nerve root compression) plus imaging evidence (X-ray or MRI showing protrusion, herniation, extrusion or rupture). The imaging must be of the thoracolumbar spine, including the thoracolumbar and lumbosacral junctions. Diagnosis must be made by a registered medical practitioner. The clinical onset date should be determined by a doctor based on when symptoms became persistently present. That date may be well before the imaging date. It is crucial to obtain a medical report that states the date of clinical onset and explains the basis for it. Then identify which factor(s) may apply. For trauma and penetrating injury, document the discrete event with date, description, and evidence of symptoms persisting at least 7 days (or medical intervention). Obtain medical records showing pain, tenderness, altered mobility or range of movement. For Load-Factor: calculate cumulative weight and time during service. This requires detailed evidence of lifting tasks: types of loads (e.g., ammunition boxes, packs, equipment), frequency and duration. Service records, training logs, and witness statements can help. Use the formula: W2 x T for each session, sum over the 10 years before clinical onset. Keep a spreadsheet. For driving factor: show average of 25 hours per week for at least 2 years within 10 years before onset. Service driving log books, posting records (e.g., as a driver, in a transport unit, or operating a vehicle as part of duties). For flying factor: logbook evidence of operational crew hours, distinguishing between fixed-wing and helicopter. Minimum 2,500 hours. For smoking factor: obtain evidence of smoking history (pack-years) and cessation date. Medical records, service medical documents, or sworn statements. Use the calculation method in the notes to the definition of one pack-year. For obesity factor: calculate BMI from weight and height at relevant times; show that BMI was 30 or greater for at least 5 years within the 25-year window before onset. Service medical records often have annual weigh-ins. For bacterial infection: microbiology results. For clinical worsening: similar evidence for each factor, plus the initial condition must have existed before or during service but not arisen out of service. Additionally, factor 19 requires showing that the veteran could not obtain appropriate clinical management before worsening. This could be demonstrated by evidence of delayed referral, lack of specialist access, or denial of treatment. All evidence must relate to the person's relevant service: the factor must have occurred during, or be caused by, service. For example, lifting carried out as part of military duties, driving military vehicles, flying in military aircraft. Smoking could be during service but not necessarily caused by service; the connection requirement may be looser. For clinical worsening factors, section 10(2) says the factors apply only to material contribution to aggravation where the condition was suffered or contracted before or during (but not arising out of) relevant service. So the worsening must be due to a factor related to service. The claim should be lodged with the DVA with all supporting evidence, referencing the relevant factor(s). The decision-maker will assess whether the factor exists and is related to service. If the claim is rejected, reasons will be given; appeal to the VRB then ART. Legal practitioners should prepare detailed written submissions mapping the evidence to each element of the chosen factor, including the precise definitions. For example, for trauma: show the discrete event, immediate symptoms, persistence for 7 days or medical intervention. For Load-Factor: provide calculations. For driving: prove average 25 hours per week. Given the complexity, early engagement of a specialist veterans' advocate is recommended.