The legislative provisions
7 It was common ground between Comcare and ZZRP that an entitlement to compensation is to be resolved by the application of ss 16 and 20 of the Safety Compensation Act.
8 Section 16(1) provides as follows:
Where an employee suffers an injury, Comcare is liable to pay, in respect of the cost of medical treatment obtained in relation to the injury (being treatment that it was reasonable for the employee to obtain in the circumstances), compensation of such amount as Comcare determines is appropriate to that medical treatment.
Section 20(1) provides as follows:
Compensation payable to an employee who is incapacitated for work as a result of an injury is determined in accordance with this section if:
(a) the employee is retired from his or her employment (whether the employee retired voluntarily or was compulsorily retired); and
(b) the employee receives a pension under a superannuation scheme as a result of the employee's retirement.
9 The term "injury" is defined in s 5A(1) as follows:
(1) In this Act:
injury means:
(a) a disease suffered by an employee; or
(b) an injury (other than a disease) suffered by an employee, that is a physical or mental injury arising out of, or in the course of, the employee's employment; or
(c) an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee's employment), that is an aggravation that arose out of, or in the course of, that employment;
but does not include a disease, injury or aggravation suffered as a result of reasonable administrative action taken in a reasonable manner in respect of the employee's employment.
The term "disease" is defined in s 5B as follows:
(1) In this Act:
disease means:
(a) an ailment suffered by an employee; or
(b) an aggravation of such an ailment;
that was contributed to, to a significant degree, by the employee's employment by the Commonwealth or a licensee.
(2) In determining whether an ailment or aggravation was contributed to, to a significant degree, by an employee's employment by the Commonwealth or a licensee, the following matters may be taken into account:
(a) the duration of the employment;
(b) the nature of, and particular tasks involved in, the employment;
(c) any predisposition of the employee to the ailment or aggravation;
(d) any activities of the employee not related to the employment;
(e) any other matters affecting the employee's health.
This subsection does not limit the matters that may be taken into account.
(3) In this Act:
significant degree means a degree that is substantially more than material.
An "injury" and a "disease' are not mutually exclusive categories: Prain v Comcare [2017] FCAFC 143 at [72], (2017) 256 FCR 65 at 84 per Kenny, Tracey and Bromberg JJ.
10 The two concepts of "caused" and "significant degree" warrant further brief exposition.
11 As to the former term, in Comcare v Martin [2016] HCA 43, (2016) 258 CLR 467 at 479 French CJ, Bell, Gageler, Keane and Nettle JJ observed:
[42] Causation in a legal context is always purposive. The application of a causal term in a statutory provision is always to be determined by reference to the statutory text construed and applied in its statutory context in a manner which best effects its statutory purpose. It has been said more than once in this Court that it is doubtful whether there is any "common sense" approach to causation which can provide a useful, still less universal, legal norm. Nevertheless, the majority in the Full Court construed the phrase "as a result of" in s 5A(1) as importing a "common sense" notion of causation. That construction, with respect, did not adequately interrogate the statutory text, context and purpose.
[43] Within a statutory context which includes ss 5A and 5B, the exclusionary phrase "as a result of" in s 5A(1) is naturally read, not as imposing its own separate and free-standing test of causation, but rather as referring relevantly to the test of causation spelt out in s 5B(1).
[44] The application of the definition of disease in s 5B(1) means that, to have suffered a disease falling within s 5A(1)(a), the employee must have suffered an ailment or aggravation of an ailment that was contributed to, to a significant degree, by the employee's employment…
(footnotes omitted)
12 As to the latter concept, s 5B had been inserted into the Safety Compensation Act by the Safety, Rehabilitation and Compensation and Other Legislation Amendment Act 2007 (Cth). In Comcare v Power [2015] FCA 1502, (2015) 238 FCR 187 at 204 Katzmann J traced the prior legislative history which led to the introduction of the "significant degree" test and, in doing so, her Honour observed (in part) as follows:
[93] There is no room for doubt that the purpose of the 2007 amendments was to strengthen the connection necessary between the employment and the contraction or aggravation of a disease. Including a definition of "significant" as "substantially more than material" makes this abundantly clear. In other words, it is insufficient that the contribution of the employment be "more than trivial"; it had to be substantially more than trivial.
[94] Moreover, the current test of contribution also requires an evaluative exercise to be undertaken. That is apparent both from the words used in subs (1) of s 5B and also the matters to which subs (2) draws attention. The Tribunal did not engage with any of them. Indeed, it did not mention subs (2) at all …
13 Prior to the 2007 amendments, s 4 had defined a "disease" as meaning any ailment or aggravation of any ailment suffered by an employee "that was contributed to in a material degree by the employee's employment by the Commonwealth". When addressing that definition, in Comcare v Sahu-Khan [2007] FCA 15, (2007) 156 FCR 536 at 542 to 543 ("Sahu-Khan"), Finn J had observed (in part):
[15] There are, in my view, obvious hazards in allowing finely nuanced differences in dictionary definitions to contrive the answer to this question, given as I have noted, that the word "material" in this context had its legislative meaning set in part by the qualification it imposed on the nature of the contribution required to be demonstrated before the provisions of the SRC Act were engaged. This said I consider that one of the meanings of the word "materially" in the Shorter Oxford English Dictionary probably captures the essence of what the legislature was conveying. That meaning is:
"4. In a material degree; substantially, considerably."
An example given of this usage is that of contributing "materially to the funds required" for a purpose. …
[16] Bearing in mind that the course of statutory construction is often not aided by substituting for the word used in an enactment, another word which is not so used, probably the best that can ultimately be said is that the s 4 definition:
(i) requires a stronger causal relationship between the employment and the ailment, etc suffered than that exacted by the 1971 Act;
(ii) "in a material degree" requires an evaluation of all relevant contributing factors for the purpose of asking whether the employee's employment did or did not contribute materially to the suffering of the ailment, etc, in question ("the threshold evaluation");
(iii) whether this will be so in a given case will be a matter of fact and degree.
14 The 2007 amendment, by requiring that a disease be one that was contributed "to a significant degree" by the relevant employment - being "a degree that is substantially more than material" - thus "strengthen[ed] the connection necessary between the employment and the contraction or aggravation of a disease" than that required by the definition previously considered by Finn J in Sahu-Khan: Comcare v Power [2015] FCA 1502 at [93], (2015) 238 FCR at 204. The test inserted in 2007 was that of "significant degree" rather than "material degree". This was unquestionably one of the "important changes to the definition": Kowalski v Military Rehabilitation and Compensation Commission [2010] FCAFC 10 at [54] per Marshall, Tracey and Foster JJ. This "tightening of the causation standard" followed the report of the Productivity Commission into workers compensation titled National Workers Compensation and Occupational Health and Safety Frameworks, Report No 27, 16 March 2004: Zdziarski v Telstra Corporation Limited [2015] FCA 207 at [15] per Perram J.
15 After 2007, it was this "tightened" requirement which ZZRP had to satisfy and it was this requirement which the Tribunal had to apply to the facts presented.