Statement of Principles concerning hereditary spherocytosis (Balance of Probabilities) (No. 42 of 2023)

The document rests on a small number of discrete statutory and medical-conceptual elements. The primary legal concept is the Statement of Principles as an instrument under s 196B(3) of the VEA (s 3). Functionally, the Statement identifies the disease, states the RMA's evidential conclusion (s 8), and lists the factors which must exist and be related to relevant service before causal connection on the balance of probabilities can be found (s 9-10).

Key definitional concepts from the instrument are:

• Hereditary spherocytosis: defined in s 7(2) as a group of genetic disorders of red blood cells producing spherical cells prone to haemolysis; the instrument notes common clinical manifestations (haemolytic anaemia, jaundice, splenomegaly). The instrument also acknowledges the ICD‑10‑AM code D58.0 but reiterates the textual definition governs application (s 7(3)-(4)).

• Relevant service: defined in the Schedule as eligible war service (other than operational service) or defence service under the VEA, or peacetime service under the MRCA (Schedule, relevant service). The instrument applies to claims under s 120B VEA or s 339 MRCA (s 5), so the reach of the Statement is limited to claim types specified.

• Terminal event: defined in the Schedule to include proximate or ultimate causes of death such as pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function (Schedule, terminal event). The instrument expressly includes deaths from a terminal event that were contributed to by the person's hereditary spherocytosis (s 7(5)).

• "Clinical worsening": the Statement repeatedly refers to "clinical worsening of hereditary spherocytosis" as the time anchor for two factors (acute viral infection and pregnancy within six weeks before clinical worsening). The instrument does not define "clinical worsening" within the text or Schedule. This term therefore operates as a factual trigger established in each case.

Causation framework and burden. The RMA states that its view is founded on available sound medical‑scientific evidence and that the connection is to be regarded as capable of being established on the balance of probabilities (s 8). Legally, the instrument frames the threshold for a positive finding: at least one of the enumerated factors in s 9 must exist and be related to relevant service (s 9; s 10(1)). A further limitation in s 10(2) restricts the application of the factors to material contribution to, or aggravation of, hereditary spherocytosis where it was suffered or contracted before or during (but did not arise out of) the person's relevant service. That limitation is precise: the factors are not expressed to apply where hereditary spherocytosis first arose out of relevant service.

Interaction with other Statements of Principles. Section 11 articulates a modular interaction rule: if a factor in s 9 refers to an injury or disease covered by another SOP determined under s 196B(3) of the VEA, then that other SOP applies in accordance with its terms as in force. This creates a cross-referencing mechanism between SOPs.

Administrative scope and construction. The instrument is an RMA determination and records the date and seal of the RMA Chairperson. It repeals the prior SOP addressing the same condition (s 4). The commencement and applicability provisions specify which claims and statutory schemes the instrument is intended to serve (s 2, s 5). The RMA's statement about the medical-scientific evidence (s 8) is an express explanatory conclusion rather than a procedural step.

The instrument is addressed to and affects a focused set of actors within the veterans' and military compensation context. Primary affected persons are veterans and members of the Forces who seek to establish that hereditary spherocytosis, or death from it, is connected with "relevant service" for purposes of claims under the VEA and MRCA. The instrument applies expressly to claims to which section 120B of the VEA or section 339 of the MRCA applies (s 5). The Schedule defines "relevant service" as eligible war service (other than operational service), defence service (other than hazardous service and British nuclear test defence service) under the VEA, and peacetime service under the MRCA (Schedule, relevant service). Therefore the instrument operates in respect of those categories of service specified.

Claimants: Individuals lodging or prosecuting claims under the relevant provisions of the VEA or MRCA for hereditary spherocytosis or death from hereditary spherocytosis are directly affected because the instrument establishes the causation factors the RMA has determined should be applied when determining service connection. For a positive finding, the claimant must demonstrate that at least one of the factors in s 9 existed and that the factor was related to the person's relevant service (s 9; s 10(1)). For cases where the person's hereditary spherocytosis was suffered or contracted before or during relevant service, the factors apply only to material contribution or aggravation, not to initial onset that arose out of service (s 10(2)). This delineation affects which claims can invoke the factors at all.

Decision-makers and administrators: Decision-makers administering the VEA and MRCA claims processes will use this Statement of Principles as part of the causation assessment for relevant claims. The instrument does not itself set out administrative procedures or appeal pathways, but by setting the factors "that must exist" (s 9) it supplies the evidentiary criteria that decision-makers will apply.

Medical practitioners and experts: Clinicians, treating doctors and independent medical experts who provide medical evidence in claims will be affected because their reports will need to address the elements in s 7-10. For example, to support a claim a medical expert will need to reach opinions about whether hereditary spherocytosis exists in the sense of s 7(2), whether clinical worsening occurred, whether one of the enumerated factors was present within the specified time window (six weeks), whether inability to obtain appropriate clinical management existed, and whether a terminal event that caused death was contributed to by hereditary spherocytosis (s 7(5); Schedule definition of terminal event).

Other SOPs and cross-referenced disease determinations: Section 11 binds the instrument into a network of Statements of Principles. If a factor in s 9 refers to another injury or disease that is the subject of a different SOP, then that other SOP applies in accordance with its terms. That means claimants whose cases raise overlapping disease processes need to manage a possible chain of SOPs.

Indirectly affected parties: Hospitals, defence health services, and service medical record keepers are indirectly affected because documentation they hold,records of infections, pregnancy, clinical management attempts, treatment refusals or limitations, and dates of clinical worsening and terminal events,will be evidence in support of or against claimed factors in s 9. The Schedule also enumerates specific terminal events; thus coronial and death certification records may be central to death claims (s 7(5); Schedule, terminal event).

The instrument does not create criminal penalties or new regulatory obligations on providers. Its effect is limited to defining causation factors for administrative assessment of entitlement claims under the specified statutes.

This instrument primarily defines evidentiary criteria rather than prescribing positive regulatory duties or creating new civil rights. Nevertheless it establishes clear legal thresholds that create practical duties for claimants and decision-makers in the assessment process.

Duties of claimants and their advisers. The Statement of Principles makes plain that at least one of the factors set out in s 9 must exist before it can be said, on the balance of probabilities, that hereditary spherocytosis or death from hereditary spherocytosis is connected with the circumstances of a person's relevant service (s 9). Further, the existence of any factor in s 9 must be related to the person's relevant service (s 10(1)). The instrument therefore imposes the evidentiary duty on claimants to establish both: (a) that a qualifying factor existed (e.g. an acute viral infection within six weeks before clinical worsening, pregnancy within the same window, or inability to obtain appropriate clinical management), and (b) that that factor is related to the relevant service. Those are factual elements that a claimant must prove on the balance of probabilities, consistent with the RMA's statement at s 8.

Duties of decision-makers. While the instrument does not prescribe procedural obligations, it does set substantive thresholds: decision-makers must apply the RMA's factors in determining causation for claims within the instrument's scope. The text states that "At least one of the following factors must exist before it can be said that, on the balance of probabilities, hereditary spherocytosis ... is connected with the circumstances of a person's relevant service" (s 9). That language establishes the factors as necessary elements for a positive causation finding under this Statement. Additionally, s 11 requires that where the s 9 factor 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." Decision-makers must therefore follow the relevant cross-referenced SOPs.

Rights of claimants. The instrument gives claimants the right to have their claims judged against the criteria the RMA has adopted. It includes death from a terminal event contributed to by hereditary spherocytosis within the definition of the disease for claims purposes (s 7(5)). It also clarifies that the textual definition of hereditary spherocytosis (s 7(2)) governs application rather than the mere ICD‑10‑AM code (s 7(3)-(4)). Those textual clarifications are rights-protective in that they specify what evidence and definitions matter in assessment.

Limitations and interpretive points affecting duties and rights. Section 10(2) narrows the application of the s 9 factors to "material contribution to, or aggravation of" hereditary spherocytosis where the person's disease "was suffered or contracted before or during (but did not arise out of) the person's relevant service." This is a material constraint: it excludes reliance on the s 9 factors where hereditary spherocytosis first arose out of relevant service. That qualification modifies the claimant's rights to rely on these factors, and is a discrete legal limit on duties of decision-makers to apply them.

Scope of medical evidence. The RMA's view that the factors are supported by the sound medical‑scientific evidence and that causation can be established on the balance of probabilities is stated in s 8. This is an evidentiary posture rather than a procedural rule, but it signals the standard of proof and the kind of medical connection the RMA considered when making the instrument.

No penal enforcement. The instrument contains no criminal penalties, fines, or administrative sanctions against individuals or providers. Its operative impact is to define the causation criteria to be applied in adjudicating claims under the specified statutory provisions.

The instrument contains no express penalty provisions and does not create offences, fines, licensing requirements, or other coercive sanctions. It is a determinative medical-causation instrument made under the authority of subsection 196B(3) of the VEA (s 3), intended to guide the application of the VEA and MRCA in claims settings (s 5). Its enforcement role is administrative: the Statement supplies the RMA's causation criteria that adjudicators and medical assessors will apply when determining entitlement to benefits under the specified sections of the VEA and MRCA. The instrument itself does not describe enforcement mechanisms for non-compliance by third parties, nor does it authorise any regulatory action against clinicians or institutions.

Administrative effect. The practical enforcement mechanism is the use of these principles in decision-making; if a claimant cannot establish the requisite factor(s) that the RMA specifies (s 9) and their relationship to relevant service (s 10(1)), a decision-maker administering section 120B of the VEA or section 339 of the MRCA will be unable to find the requisite connection on the basis of this Statement. Thus the "enforcement" is the negative administrative consequence of failing to satisfy the criteria. The instrument places the evidentiary burden on the claimant to show, on the balance of probabilities, that at least one of the factors existed and was related to relevant service (s 9; s 10(1); s 8).

Discretion and interpretive enforcement. Several terms in the instrument are open to clinical and administrative interpretation,most notably "clinical worsening" and "inability to obtain appropriate clinical management",and the instrument contains no further statutory definitions or procedural prescriptions for how decision-makers should resolve such ambiguities. That absence means adjudicators and medical assessors retain interpretive discretion when applying the factors; enforcement therefore depends on administrative practice, medical expert evidence, and the decision-maker's application of the standard ("balance of probabilities") endorsed in s 8.

Cross-references to other SOPs. Section 11 creates an enforcement linkage: if a factor in s 9 refers to an injury or disease covered by another Statement of Principles, then the factors in that other SOP apply "in accordance with the terms of that Statement of Principles as in force from time to time." Where such cross-reference exists, administrative enforcement requires adjudicators to consult and apply other SOPs alongside this instrument.

No formal appeal or review procedure in the instrument. The Statement does not itself set out review or appeal rights or processes; those processes, if any, are provided by the enabling statutes (the VEA and MRCA) and their administrative mechanisms. The Statement's enforcement effect is therefore indirect,it shapes entitlement determinations but does not itself prescribe judicial or administrative remedies.

This Statement of Principles is expressly made under subsection 196B(3) of the VEA (s 3) and applies to claims to which section 120B of the VEA or section 339 of the MRCA applies (s 5). Its interaction with other laws is therefore primarily an internal one within the veteran and military compensation statutory framework, and via cross-references to other Statements of Principles.

Application to VEA and MRCA claim processes. The instrument is intended to be applied in adjudicating claims under the statutory provisions specified in s 5: section 120B of the VEA and section 339 of the MRCA. It supplies the RMA-determined causation criteria that decision-makers must take into account when assessing whether hereditary spherocytosis or death from it is connected with relevant service. The Schedule defines "relevant service" by reference to categories arising in the VEA and MRCA: eligible war service and defence service under the VEA and peacetime service under the MRCA (Schedule, relevant service). Thus the instrument interacts with those statutes by delimiting which service categories are within its operational ambit.

Interaction with other Statements of Principles. Section 11 provides a direct textual interaction mechanism with other SOPs determined under s 196B(3) of the VEA: if a factor in s 9 refers to an injury or disease covered by another SOP, then 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 a mandatory cross-referencing rule. In practice, where a claimant's clinical course involves injuries or diseases addressed by multiple SOPs, decision-makers must apply the relevant SOPs in tandem according to their respective terms.

References to ICD‑10‑AM. Section 7(3) and (4) note that hereditary spherocytosis attracts ICD‑10‑AM code D58.0 and clarifies that in applying the Statement of Principles the meaning of hereditary spherocytosis is the textual definition in s 7(2). The instrument therefore uses the ICD‑10‑AM code only as an identifying reference but displaces reliance on the code alone by prescribing the statutory textual meaning. This affects how external coding systems interact with the instrument: a claim supported only by an ICD code, without evidence addressing the statutory definition and factors, would not automatically satisfy the Statement's requirements.

Interplay with death certification and coronial records. The instrument includes death from a terminal event or condition contributed to by hereditary spherocytosis within its scope (s 7(5)), and defines terminal event in the Schedule to include causes such as pneumonia, respiratory failure, cardiac arrest and circulatory failure. Thus death certification, pathology reports and coronial findings may be relevant to applying this Statement for death claims; the instrument does not, however, create new death-related procedures or modify coronial or vital statistics law.

No express conflict or supremacy language. The instrument does not assert primacy over other statutory provisions beyond its authorising provision under s 196B(3) of the VEA. Its operation is as an RMA-determined SOP to be applied in claims processes governed by the VEA and MRCA. It does not amend those Acts or change their appeal processes; it simply supplies the medical-causation criteria for adjudication within those frameworks.

Administrative law context implied but not stated. The Statement does not itself set out appeal mechanisms or review standards; those are provided by the VEA and MRCA. The Decision‑maker's application of this Statement would be subject to the usual administrative law principles and remedies available under the governing Acts and general administrative law, but the Statement itself contains no procedural or remedial provisions.

The instrument contains a brief, explicit amendment history limited to the immediate legislative action it takes. It repeals the prior Statement of Principles concerning hereditary spherocytosis No. 68 of 2015 (Federal Register of Legislation No. F2015L00650), which was also made under subsection 196B(3) of the VEA (s 4). The new instrument is dated 24 April 2023 and commenced on 23 May 2023 (s 2). Those are the only express amendments or historical steps recorded in the text of the instrument.

No other amendments, transitional provisions, savings clauses, or retrospective changes are contained in this Statement of Principles. The instrument does not, for example, include transitional arrangements for claims that were in progress under the 2015 Statement; it simply states that the earlier Statement is repealed (s 4) and that the current instrument commences on 23 May 2023 (s 2). Practitioners advising claimants with matters pending around the commencement date will therefore need to consult the administering department's guidance or case law (outside this document) to determine how pending claims were handled, because the instrument itself contains no transitional language.

There is no schedule of future or contingent amendments in the instrument. The text does not specify any review period, sunset date, or mechanism for automatic revision. Changes to the Statement in future would require a new instrument made under the enabling provision (subsection 196B(3) of the VEA) and would be reflected by repeal or amendment in the Federal Register of Legislation as necessary; the current instrument simply records the replacement of the 2015 instrument with the 2023 instrument.

Finally, the instrument references other Statements of Principles in s 11 and contemplates their ongoing force "as in force from time to time." That phrasing effectively recognises that SOPs are a living body of instruments that may be amended independently; this instrument's interaction rule ensures that updates to other SOPs will feed into cross-referenced assessments without the need to amend this instrument itself.

The instrument contains no litigation history. It is a statutory instrument recording the RMA's Statement of Principles and does not include references to judicial decisions, appeals, or administrative tribunal determinations. The text provides no account of any litigation challenging the 2023 Statement, no summaries of contested applications, and no indication of prior case law that influenced its drafting. The only historical legal action recorded in the instrument is the repeal of the earlier 2015 Statement (s 4).

Because this Statement of Principles is administrative in character and intended to be applied in adjudication of claims under the VEA and the MRCA (s 5), litigation or appeals may arise in individual cases when decision-makers apply these principles. However, any such litigation is external to the instrument and is not reported in the text provided. Practitioners seeking reported decisions that interpret or apply this 2023 Statement will therefore need to consult case law databases, tribunal decisions and administrative determinations beyond the instrument itself.

The instrument does not provide examples, hypothetical applications, or guidance on disputed interpretive points such as the meaning of "clinical worsening" or "inability to obtain appropriate clinical management". These interpretive gaps may be the subject of litigation in individual claim contexts, but the Statement contains no record of such proceedings.

This Statement of Principles is concise but contains several features that create practical pitfalls for claimants, advisers, and decision-makers. These are specific textual and structural issues in the instrument that can affect outcomes if not handled carefully.

1. Narrow list of qualifying factors (s 9). The instrument requires that at least one of the three enumerated factors exist before a connection to service can be established. The list is short and discrete: (1) an acute viral infection within six weeks before clinical worsening, (2) pregnancy within six weeks before clinical worsening, or (3) inability to obtain appropriate clinical management for hereditary spherocytosis. If a claimant's clinical course does not implicate any of these factors, the Statement provides no other route to establish causation. Practitioners must map the claimant's factual record precisely to one of these factors.

2. Temporal anchoring to "clinical worsening" and a strict six-week window (s 9(1)-(2)). The first two factors operate only if the acute viral infection or pregnancy occurred within six weeks before the "clinical worsening" of hereditary spherocytosis. The instrument does not define "clinical worsening". That absence introduces evidentiary and interpretive friction: parties must establish not only that a viral infection or pregnancy occurred but also when clinical worsening occurred and that it is the appropriate anchor for the six-week window.

3. "Inability to obtain appropriate clinical management" is undefined and potentially broad (s 9(3)). The instrument offers no statutory definitions or examples of what constitutes "appropriate clinical management" or what level or quality of inability suffices. Decision-making in this area may therefore depend heavily on administrative practice and expert medical opinion. That creates a risk of variable outcomes and discretionary determinations by adjudicators.

4. Limits on when factors apply (s 10(2)). The s 9 factors apply only to material contribution to, or aggravation of, hereditary spherocytosis where the disease "was suffered or contracted before or during (but did not arise out of) the person's relevant service." This is a material limitation. If hereditary spherocytosis first arose out of relevant service, the factors in s 9 are not expressed to apply. Claimants and advisers must be attentive to the timing of disease onset relative to service when framing claims.

5. Reliance on ICD code insufficient (s 7(3)-(4)). Although the condition is associated with ICD‑10‑AM code D58.0, the instrument makes clear that the statutory meaning for the Statement is the textual definition in s 7(2). A diagnosis recorded only as an ICD code, without evidence addressing the statutory definition and the s 9 factors, may be insufficient.

6. Death claims hinge on "contributed to" language (s 7(5)). Death from a "terminal event or condition that was contributed to by the person's hereditary spherocytosis" falls within scope. The term "contributed to" is causally permissive but the instrument does not quantitate contribution. Practitioners must secure medical opinions that expressly state a contribution relationship between hereditary spherocytosis and the terminal event defined in the Schedule.

7. Cross-references to other SOPs may complicate causation chains (s 11). If a factor in s 9 refers to another injury or disease covered by a separate SOP, that SOP "applies in accordance with the terms of that Statement of Principles as in force from time to time." Practically, this can produce multi-instrument analyses requiring careful mapping of facts across instruments.

8. No procedural guidance, transitional rules or definitions for evidentiary standards beyond "balance of probabilities" (s 8-9). The instrument states the standard (s 8) but provides no procedural prescriptions on record types, weight of medical evidence, or how to resolve conflicting expert opinions. This omission may lead to divergent administrative practice.

9. The instrument repeals the 2015 SOP but contains no transitional direction (s 4). Claims initiated under the earlier SOP and continued after commencement may raise questions about which principles apply; the instrument does not address transitional application.

These features are "gotchas" because they require careful factual and evidentiary work by claimants and precise medico-legal framing by advisers. Failure to align a case to the instrument's narrow factors, or to address undefined terms like "clinical worsening" and "appropriate clinical management", can materially affect claim outcomes.

Complying with the requirements of this Statement of Principles means structuring a claim so that the decision-maker can be satisfied, on the balance of probabilities, that at least one of the factors in s 9 existed and that the factor was related to relevant service (s 9; s 10(1)). Below are practical, instrument-grounded steps for claimants, medical experts, and advisers to increase the prospect of satisfying the Statement's requirements. Each recommendation ties to the relevant provisions of the instrument.

1. Confirm applicability of the instrument to the claim (s 5; Schedule). Ensure the claim is brought under the statutory provisions to which the instrument applies: section 120B of the VEA or section 339 of the MRCA (s 5). Verify that the claimant's service falls within the definition of "relevant service" in the Schedule (eligible war service other than operational service; defence service other than hazardous service and British nuclear test defence service; or peacetime service under the MRCA). If service falls outside those categories, the instrument will not apply.

2. Establish the diagnosis in terms of the statutory meaning (s 7(2)-(4)). Obtain medical records and expert reports that address hereditary spherocytosis as defined in s 7(2): group of genetic disorders of red blood cells producing spherical red blood cells susceptible to haemolysis, with associated clinical manifestations (haemolytic anaemia, jaundice, splenomegaly). Do not rely solely on an ICD‑10‑AM D58.0 code; the instrument requires application of the textual definition rather than the code alone (s 7(3)-(4)).

3. Document the timing and nature of "clinical worsening". Because the first two factors in s 9 use "within the 6 weeks before the clinical worsening of hereditary spherocytosis" as the temporal anchor, compile contemporaneous clinical notes, test results, hospital admissions, lab reports, or treating practitioner statements that identify when clinical worsening occurred. An expert report should define the event constituting clinical worsening in clinical terms and anchor it to dates.

4. For factor (1) (acute viral infection within six weeks before clinical worsening) assemble evidence that an acute viral infection occurred within the six-week window. Evidence can include pathology or laboratory confirmation, GP or hospital notes diagnosing an acute viral illness, or treatment records. The medical report should link the acute viral infection temporally and mechanistically to the clinical worsening.

5. For factor (2) (pregnancy within six weeks before clinical worsening) provide obstetric records, antenatal notes, delivery records, and treating clinician statements establishing pregnancy timing relative to clinical worsening. The medical expert should explain the plausible physiological pathway by which pregnancy could contribute to clinical worsening in the six-week window.

6. For factor (3) (inability to obtain appropriate clinical management) document attempts to access care and reasons for the inability. Because the Statement does not define "appropriate clinical management," assemble comprehensive evidence of denied, delayed, inadequate or unavailable care: referral letters, appointment logs, hospital admission refusals, service medical records, communications with health providers, and contemporaneous notes showing unmet clinical need. Expert opinion should address that the care sought was "appropriate" in standard clinical terms and explain how the inability to access such care materially contributed to clinical worsening or aggravation.

7. For death claims, document the terminal event and link it to hereditary spherocytosis (s 7(5); Schedule). Obtain death certificate, hospital records, pathology, and treating clinician or forensic pathology opinions that identify the proximate or ultimate cause of death and state whether hereditary spherocytosis contributed to that terminal event. The Schedule provides examples of terminal events (pneumonia, respiratory failure, cardiac arrest, circulatory failure, cessation of brain function) which should be specifically addressed.

8. Where s 9 factors implicate other diseases covered by other SOPs, map the interaction (s 11). If the claimed factor refers to an injury or disease that is itself governed by another Statement of Principles, obtain and apply that SOP to the facts, and obtain expert opinion that addresses both instruments as required by s 11.

9. Prepare medico-legal reports to the RMA standard. Because the Statement is a medical-causation instrument, decision-makers will expect coherent clinical reasoning linking facts to the statutory factors on the balance of probabilities. Experts should state whether, in their opinion, the requisite factor existed, whether it was related to relevant service, and whether the factor materially contributed to or aggravated hereditary spherocytosis, using plain clinical language tied to dates and records.

10. Address the onset timing relative to service (s 10(2)). If hereditary spherocytosis was first suffered or contracted out of relevant service, note that the s 9 factors apply only to material contribution or aggravation where the disease was suffered or contracted before or during (but did not arise out of) relevant service. Clarify whether the claimant's disease onset was before, during, or after relevant service, and tailor the claim accordingly.

11. Anticipate and pre-empt interpretive questions. Because terms like "clinical worsening" and "appropriate clinical management" are not defined, expect decision-makers to seek clarifying medical evidence. Direct your medical expert to provide definitionally precise statements and to explain why the chosen clinical markers meet those criteria.

12. Keep administrative chronology and service records. Service medical records, deployment health records, and relevant defence health documentation are likely to be central to proving connection to relevant service. Where the claim implicates inability to obtain care during service, contemporaneous service health logs or administrative communications about medical access will be critical.

13. Monitor SOP currency and cross-referenced instruments (s 11). Because s 11 requires that other relevant SOPs apply as "in force from time to time," ensure that advisers check for updates to other SOPs that may affect cross-referenced factors.

Following these steps does not guarantee success, as the ultimate finding depends on the decision-maker's assessment of the evidence against the statutory criteria. The Statement of Principles sets the substantive thresholds (s 8-10); compliance requires aligning medical and documentary evidence to those thresholds on the balance of probabilities.