GREEN CJ In the course of her employment as an enrolled trainee nurse the appellant suffered a subarachnoid haemorrhage which has resulted in her being incapacitated for work. Pursuant to the Workers Compensation Act 1988 ("the Act") the appellant made a claim for compensation to the workers compensation commissioner who determined that the appellant was entitled to be paid compensation pursuant to the Act. The respondent appealed against that decision to a judge who allowed the appeal and set aside the commissioner's determination and order. This is an appeal against those orders.

2. The facts were not in dispute. The nature and cause of the haemorrhage suffered by the appellant were described in the following report by a neurosurgeon Mr Hunn which report formed part of the material before the Commissioner:

haemorrhage. The incidence of this in a Western

population is approximately 10 per 100,000 population

per annum. The incidence of cerebral aneurysms

(small, thin-walled, sac-like out-pouchings of the

cerebral blood vessels, usually occurring in the region

of the Circle of Willis, at points of bifurcation) has

been suggested in some studies to possibly be as high

as 5% of the population. It appears that not all

cerebral aneurysms will rupture during the course of

the lives of the people harbouring them, but a

significant percentage do so. It is felt that the risk

of rupture is approximately 3% per annum (cumulative),

and that the incidence of death or major disability as

a consequence of a subarachnoid haemorrhage is between

40% and 50% at the initial haemorrhage, with similar

risks of catastrophe with ensuing haemorrhages.

Following an initial haemorrhage there is a slightly

less than 5% risk of further bleeding in the initial

twenty-four hours, which decreases only slightly in the

subsequent twenty-four hours and thereafter

progressively diminishes.

...

With specific reference to Mrs Smith, she had mild

hypertension which had been noted to be somewhat labile and

smoked 25-30 cigarettes a day. These factors may have had

some bearing on the rupture of her aneurysm, but cannot be

implicated in its development. There is not sufficient

evidence in the literature to conclude that any other factors

in Mrs Smith's lifestyle made her particularly at risk of

aneurysm development or caused the already existing aneurysm

to bleed at the particular time at which her ictus occurred.

In particular, the contention that factors arising from the

workplace may have been involved in the precipitation of her

subarachnoid haemorrhage cannot be supported. It must be, I

am afraid, regarded as coincidence in time only that she was

at work at the time of the haemorrhage, and that the

haemorrhage itself must be regarded as a consequence of the

natural history of her anterior communicating artery

aneurysm."

3. Upon the evidence the sequence of relevant events was as follows: the appellant had a cerebral aneurism, the aneurism suddenly ruptured, no event could be identified which caused or precipitated the rupture, as a result of the rupture blood flowed into the subarachnoid space, as a result of the presence of the blood in the subarachnoid space and its effect on surrounding tissues the appellant was incapacitated for work.

4. In the course of his evidence Mr Hunn said that he thought that the rupture had occurred "acutely and suddenly". He said that it was generally accepted that aneurisms of this kind were congenital and there was "no evidence in this case that any other process was at work". He also said that such an aneurism can be present for the whole of the patient's life without producing a subarachnoid haemorrhage.

5. The learned commissioner applied the reasoning he had employed in a previous case before him and held in essence that the rupture of the aneurism was "something distinct from a defect, disorder or morbid condition which enabled it to occur" and that the rupturing of the aneurism was therefore an injury which occurred at work and was compensable under s25(1)(a) of the Act.

6. The essential issues are conveniently stated in the following passage from the reasons for judgment of the learned primary judge:

"The determination of this appeal turns on a proper

construction of the Act, s25(1) and of the definition of

'disease' contained in s3(1). The statutory definition of

'disease' contained in s3(1) is that it 'means any ailment,

disorder, defect, or morbid condition, whether of sudden or

gradual development'. Relevantly, s25(1) provides as

follows:

'25 (1) If in any employment

(a) a worker suffers an injury, not being a disease, arising

out of and in the course of his employment; or

(b) a worker suffers an injury, which is a disease, arising

out of and in the course of his employment and to which his

employment contributed to a substantial degree,

his employer is, except as is otherwise provided by this Act,

liable to pay compensation in accordance with this Act .'

It was common ground between the parties that if the injury

suffered by the respondent was a disease, then it neither

arose out of or in the course of her employment nor was it

one to which her employment had contributed to a significant

degree. It also was common ground that if the injury

suffered by the respondent was not a disease, then it arose

out of and in the course of her employment by virtue of the

deeming provision contained in s25(5)(a). The appeal falls

to be determined by reference to whether the injury suffered

by the respondent was or was not a disease. If it was, the

respondent did not become entitled to compensation. If it

was not, the respondent became entitled to compensation."

7. The learned primary judge concluded that the commissioner was correct in proceeding "upon the basis that the cerebral aneurism, from which the respondent had suffered for some time, fell within the definition of disease, albeit that prior to the rupture it had not led to any incapacity so that up to that time the respondent could not be said to have suffered an injury for the purposes of the Act". However his Honour held that the commissioner erred in treating the rupturing of the aneurism as quite distinct from the aneurism itself and therefore not part of that disease but an injury which was not a disease. The learned primary judge concluded:

"The respondent suffered from a disorder which initially

manifested itself in a non-disabling way and then upon

further development became disabling. Even if it is

appropriate to consider the haemorrhage as a separate event

it still is a condition which has developed suddenly which

comes within the definition of disease. Applying the

relevant legal principles the learned Commissioner could not

but have come to the conclusion that the respondent suffered

an injury which was a disease. In the light of the

concessions made by counsel the result must be that the

Commissioner's determination must be reversed."

8. The aneurism was clearly a disease within the meaning of the Act. The onset of the condition which incapacitated the appellant for work was an injury. The critical issue before this Court is whether the learned commissioner was correct in concluding on the evidence before him that the condition the onset of which incapacitated the appellant for work was not a disease.

9. Counsel for the appellant relied upon the following authorities in which it was held that for the purposes of workers compensation legislation a rupture of a cerebral aneurism was not a disease: O'Neill v Lumbey (1987) 11 NSWLR 640; Accident Compensation Commission v McIntosh [1991] VicRp 65; (1991) 2 VR 253 and Workers Rehabilitation and Compensation Corporation v Ascione (1989) 52 SASR 122. Whilst there are passages in the reasons for judgment in those cases which provide some apparent support for the appellant's submissions they are not applicable to this case because they were dealing with statutory provisions which were significantly different from those in the Tasmanian Act. Unlike the Tasmanian Act in the statutory provisions under consideration in O'Neill's case there was no definition of "disease". Further, it appears from the discussion by Clarke JA, with whom Priestley JA agreed, of the distinction between aneurisms which were the product of a congenital defect and those which were the consequence of arterial disease that whether the pre-existing aneurism was a disease was a significant issue in that case whereas that is not an issue in this appeal. A final point of distinction is that the conclusion of the majority in O'Neill's case appears to have been based upon the view that as it was open on the evidence to conclude that the aneurism was not caused by a disease it was open to the primary judge to hold that the worker suffered from an injury simpliciter. In contrast under the Tasmanian Act it is necessary for the court to decide whether it is satisfied that an injury is not a disease. In my view the view taken by Kirby P of the effect of the New South Wales legislation is apposite to the Tasmanian Act. Kirby P held that it was necessary to classify an injury as a "disease" type or "non disease" type and on the facts of that case reached the view that if the morbid injury suffered by the worker was inevitable it was part of a disease. At 646 and 647 he said:

"The mere fact that, at a given instant ('inevitably' as his

Honour felt) the pre-existing morbidity evidenced itself in a

pathological change (being the bursting and haemorrhage of

blood) does not make that instant any less a consequence and

part of a 'disease'. Despite the valiant attempts of counsel

at the trial to lead Dr Dan to draw a distinction between

disease type aneurisms and non-disease type aneurisms, it is

the pre-existing morbidity, the progressive nature of the

condition and the inevitability of the haemorrhage that makes

it impossible, in my opinion, on the facts found to classify

this worker's 'injury' as otherwise than of the 'disease'

type."

10. Similarly in Accident Compensation Commission v McIntosh (supra) the court's conclusion appears to have been based upon the view that under the legislation there being considered the issue was whether it was open to the Accident Commission Tribunal to conclude that the rupture and consequent haemorrhage was a "physical injury" as opposed to the issue which must be determined under the Tasmanian Act which is whether it was open to the commissioner to be affirmatively satisfied that the injury was not a disease. In Workers Rehabilitation and Compensation Corporation v Ascione (supra) the court's decision was based in part upon a statutory provision which had the effect of excluding from the definition of "disease" conditions for which there is an "obvious proximate cause" whereas the Tasmanian Act has no such provision.

11. In Pasminco v Fairchild A57/1991 a worker suffered from tinea which did not incapacitate him and which had not been contracted in the course of his employment. In the course of his employment the worker was required to work in conditions which exacerbated the tinea to the extent that he became wholly incapacitated for work. At 4 of his reasons Cox J held that:

"Although the worker for some time had a condition clinically

known as 'tinea' which falls within the definition of

'disease' in s3(1), no question of an entitlement in respect

of it could arise in the abstract. What gives rise to an

entitlement is the suffering by him in his employment of an

injury which arose out of and in the course of that

employment. In this case the evidence shows that the injury

suffered was a bout of tinea attended by symptoms of such

severity as to incapacitate him for work. In my view, such

condition clearly falls within the meaning of disease as

defined in the Act and is deemed to have occurred when he

became incapacitated for work."

12. With respect I agree with the learned primary judge's observations that:

"That case does not purport to lay down any definitive test

as to what is and what is not a disease for the purposes of

the Act. However it establishes that the relevant inquiry is

to be directed to the condition of the worker at the time of

disablement and that a condition which answers to the

description of being a disease remains a disease if it

becomes disabling by reason of some external occurrence."

13. In this case the appellant's incapacity for work arose as a result of the presence of blood in the subarachnoid cavity and upon the evidence it was plain that the presence of that blood was a direct consequence of the aneurism. In one sense it could be said that the presence of the blood was distinct from the aneurism but the sequence of events which linked the aneurism to the presence of blood was not different in kind from the sequence of incremental steps which comprise the progress of all diseases. I do not accept the distinction which counsel for the appellant sought to draw between the haemorrhage in this case and the more gradual onset of the incapacitating condition in diseases such as tinea. The definition of "disease" makes it clear that the fact that a disease develops suddenly does not mean that it then ceases to be a disease nor can I see any legal or logical justification for concluding that because a particular step in the development of a disease is dramatic or results in that disease incapacitating the worker it thereby ceases to be a disease. The transition of a disease from being a condition which does not incapacitate for work to a condition which does incapacitate for work must always involve some distinct physiological change or event but that does not mean that that change or event at that instant in time ceases to be a part of the disease process. In my view adoption of the learned commissioner's reasoning would render s25(1)(b) of the Act nugatory as there would be no logical reason why the physiological change which results in a disease incapacitating the worker could not be characterised as an injury distinct from the disease in every case. I hold that although the presence of the blood in the subarachnoid cavity could for some purposes be regarded as distinct from the aneurism it could not be regarded other than as a development of and a part of "the defect or morbid condition" which gave rise to it. I hold that it was not open to the learned commissioner to find that the injury suffered by the appellant was not a disease.

14. I agree with the conclusion of the learned trial judge and would dismiss the appeal.

UNDERWOOD J Mrs Smith, the appellant, was an enrolled trainee nurse at St John's Park Hospital. Tragedy befell her on 11 May 1990. Just after completing a presentation as part of a geriatric nursing course, she sat down and without warning suffered an acute aneurismal subarachnoid haemorrhage. In result, she now has devastating long term physical disabilities.

2. The medical evidence was that there was no causal link between the haemorrhage and the appellant's employment. Its occurrence and the appellant being at work was no more than a coincidence in time. Mr Hunn's report, in evidence before the learned Workers Compensation Commissioner on the hearing of the appellant's claim for compensation, described the haemorrhage as the result of a ruptured anterior communicating artery aneurism. In his oral evidence, Mr Hunn explained that an aneurism is a structural lesion generally accepted to be genetic in origin. He described it as "a pathological structure which exists on bifurcation." He said "it is postulated that it is congenitally based from an area of weakness at the bifurcation." In his report, a cerebral aneurism is described as a "small, thin-walled, sac-like out-pouching of the cerebral blood vessels usually occurring in the region of the Circle of Willis, at points of bifurcation." This condition is found in a small percentage of the population but the risk of rupture is significant. Rupture often occurs without there being any specific precipitating factor. It is the escape of the blood into the surrounding tissue that causes disablement.

3. The learned Commissioner found that the aneurism was distinct from its rupture and that the latter was an injury not being a disease within the meaning of the Workers Compensation Act 1988, s25(1)(a). Accordingly, the learned Commissioner made an order that the appellant was entitled to compensation. From that order there was an appeal. It was determined by Zeeman J. His Honour allowed the appeal, set aside the order of the learned Commissioner and in lieu thereof ordered that Mrs Smith's application for compensation be dismissed. From those orders this appeal is brought.

4. It is beyond question that the appellant's employment did not contribute to either the aneurism or its rupture. Consequently, the primary issue before the learned Commissioner was whether the appellant suffered an injury not being a disease or whether she suffered an injury which was a disease. If the former, she is entitled to compensation. If the latter, she is not entitled to any compensation. In the days when the issue was whether there had been a "personal injury by accident" there were many cases in which it was held that a burst artery constituted a personal injury by accident even when it was the end result of a progressive disease. Such an event was a personal injury and accidental if it was unexpected and not designed by the worker. See eg, Willis v Moulded Products (Australia) Ltd [1951] VicLawRp 8; (1951) VLR 58; Clover Clayton and Co Limited v Hughes (1910) AC 242; Hume Steel Ltd v Peart [1947] HCA 34; (1947) 75 CLR 242. Personal injury by accident was held to have occurred when there was no more than an internal force causing the physiological change, eg, Kavanagh v Commonwealth [1960] HCA 25; (1960) 103 CLR 547. The issue of personal injury by accident arose under the Workers' Compensation Act 1927 (Tas), s5 which created liability to pay compensation if a worker:

(a) suffered personal injury by accident; or

(b) was disabled or died as a result of one of the diseases

listed in the Schedule to the Act or from an aggravation,

acceleration or recurrence of such a disease;

arising out of and in the course of the employment.

5. The provisions of the Workers Compensation Act 1988 (Tas) are quite different. Disease is defined by s3 as a word of wide import and is of necessity an injury. However, not all injuries are diseases and the 1988 Act, s25(1) requires the Commissioner to determine in each case whether a claimant has suffered an injury not being a disease or an injury which is a disease because the conditions precedent to liability differ in each case. Relevantly, s3(1) provides:

"'disease' means any ailment, disorder, defect, or morbid

condition, whether of sudden or gradual development.

'injury' includes a disease".

"If in any employment

(a) a worker suffers an injury, not being a disease, arising

out of and in the course of his employment; or

(b) a worker suffers an injury, which is a disease, arising

out of and in the course of his employment and to which his

employment contributed to a substantial degree,

his employer is, except as is otherwise provided by this Act,

liable to pay compensation in accordance with this Act."

7. In determining that the appellant suffered an injury not being a disease, the learned Commissioner relied on two cases viz, O'Neill v Lumbey (1987) 11 NSWLR 640 and Accident Compensation Commission v McIntosh [1991] VicRp 65; (1991) 2 VR 253. Both were cases of a ruptured aneurism causally unrelated to employment.

8. Before turning to those cases it is appropriate to consider Hockey v Yelland [1984] HCA 72; (1984-1985) 157 CLR 124. This was an appeal from an order of the Full Court of Queensland discharging an order nisi for a writ of certiorari on the basis that no error of law occurred in the determination of the Neurology Board constituted under the Workers Compensation Act (Qld). The appellant suffered a subarachnoid haemorrhage while working as a labourer on a building site. Relevant to the present appeal was the issue of whether he had suffered an injury within the meaning of the Queensland Act, s3(1) which provided:

"'injury' means (without in any wise limiting the operation

and scope of section nine of this Act) personal injury

arising out of or in the course of employment, and includes -

(a) a disease which is contracted in the course of the

employment, whether at or away from the place of employment,

to which the employment was a contributing factor; and

(b) the aggravation or acceleration of any disease where the

employment was a contributing factor to such aggravation or

acceleration,

but does not include those diseases as specified in section

14B of this Act;"

9. Unlike the Tasmanian Act there was no definition of "disease". Gibbs CJ (with whose reasons three of the other four members of the court agreed) referred to some of the earlier workers compensation decisions in which a wide meaning had been given the word "injury" and the words "injury by accident", to some of which I have already referred. His Honour pointed out at 133 that remarks such as those of Latham CJ in Hume Steel Ltd v Peart (supra) at 252-253 were "no doubt correct" where the word "injury" was not specifically defined, but each case has to be determined in the light of the relevant statutory definition. His Honour applied Slazengers (Australia) Pty Ltd v Burnett (1951) AC 13 which effectively overruled Hume Steel, and held that "disease" only fell within the definition of injury if it was a disease that complied with the prescription set out in s3(1) pars(a) or (b) viz, in effect, causally related to the employment. With respect to the meaning of "disease" Gibbs CJ said at 137 that "it is clear that an autogenous disease which happens to manifest itself in the course of employment is only an 'injury' if it comes within pars(a) or par (b)". At 137-138 His Honour said:

"It follows from what I have said that if the Neurology Board

decided that the sub arachnoid haemorrhage was merely 'the

culmination or climax of a progressive disease, itself

unrelated to employment' to use the words of Windeyer J in

Darling Island Stevedoring and Lighterage Co Ltd v Hussey

[1959] HCA 55; (1959) 102 CLR 482 at 518, or that the haemorrhage was

otherwise autogenous, and that the work which the appellant

was doing played no part in causing it, it was quite right to

determine that it was not an 'injury' within the meaning of

the Act. If they took that view, the haemorrhage was not an

injury within the opening words of the definition and was not

within par(a) or part(b) because the employment was not a

contributing factor."

10. The relevant statutory provisions in the Workers Compensation Act 1988 (Tas) are different from those considered by the High Court in Hockey and therefore require separate consideration, but the reasoning in Hockey can and should be applied to the construction of those statutory provisions. The effect of that reasoning is to narrow the former wide meaning given to the word "injury", a proposition that the majority in O'Neill and the court in McIntosh found difficult to accept. In the latter case, Murphy J, with whose reasons the other members of the court agreed, said at 264:

"It is a remarkable development that today it is being

suggested that in an Act which has consistently demonstrated

a widening of cover to a worker, (being in the nature of

social insurance or security) the inclusion in the definition

of 'injury' of references to disease contributed to by the

employment has prompted argument that mishaps, formerly

accepted without debate to be 'injury', are no longer to be

so considered, but are rather to be characterised as the very

disease to which they are due, and excluded, unless work

contributes to them."

11. Although that might be the case in Victoria, I do not see the scheme as enacted by the Workers Compensation Act 1988 (Tas), ss3(1) and 25(1) as being such a remarkable development at all. Under the 1927 Act, the extended meaning given the expression "personal injury by accident" created liability to pay compensation for a wide range of "conditions" which as a matter of fact, had no causal relationship with the employment. Conversely, under that Act, the very limited provisions for the payment of compensation in the case of incapacity caused by disease, resulted in many workers receiving no compensation for incapacity for work caused by a work related disease. The 1988 Act, drafted after the High Court decision in Hockey v Yelland (supra), set out to remedy all of this. The statutory intention is clear. It is to increase workers' protection by creating liability to pay compensation for any injury that is in fact causally related to employment. At the same time, the general statutory intention is to remove employers' liability to pay compensation in cases where the injury has no connection with employment other than a coincidence in time. The definition of "disease" is very wide but, in the case of incapacity for work by reason of a disease, liability to pay compensation is dependent upon the worker establishing that the disease not only arose out of and in the course of the employment, but also that it was one to which the employment contributed to a substantial degree. However, in the case of an injury not being a disease it is sufficient merely to show that it arose out of and in the course of employment. The existence of the statutory intention is reinforced by the deeming provisions in s25. Subsection (5) provides, in substance, that in the case of an injury not being a disease, it shall be deemed to arise out of and in the course of employment if there is a temporal connection between the injury and the employment. If the injury has an external cause, the relationship between injury and work will be easy to identify so the well established proposition that such injury is deemed to have arisen out of and in the course of the employment continues. The situation is not the same in the case of diseases and autogenous conditions where the causal relationship with the employment is not self-evident. However, s26 provides that with respect to certain specified diseases there shall be a presumption, in the absence of evidence to the contrary, that the disease arose out of and in the course of employment and that the employment contributed to a substantial degree to that disease. In the case of all other diseases, the onus is on the worker to establish the relevant causal connection with the employment. Although the Act narrows the meaning hitherto given the word "injury", it considerably expands the range of compensible injuries provided there is the requisite nexus with the employment. As the long title states, the Act provides "for the compensation and rehabilitation of workers with respect to occupational injuries suffered by workers ...".

12. In O'Neill v Lumbey (supra) the issue before the New South Wales Court of Appeal was whether a finding in the Compensation Court that the ruptured aneurism was an injury constituted an error of law on the basis that no other conclusion was open to the learned judge other than that the rupture was a disease. So far as I can see, the definition in that case was for all practical purposes identical to that considered by the High Court in Hockey. Kirby P, who dissented, said that the statutory definition required the tribunal of fact to classify injuries into "disease injuries" and "non-disease injuries." He said that the result was to narrow the definition of "injury".

"If this decision stands there should be no doubt as to its

significance. In the past, it has been considered that where

a sudden catastrophe occurs as the end stage or natural and

inevitable outcome of an underlying pathology, such a case is

to be dealt with not as one of frank 'injury' simpliciter but

as a 'disease' class of injury. Thus the incapacity

resulting is only compensible if one of the conditions in

par(a) or (b) of the definition 'injury' is fulfilled.

Normally this means that, for example, a coronary occlusion

will only be compensible if it is shown that it has been,

relevantly, aggravated etc, by the employment." (647)

13. Clarke JA, with whose reasons Priestley JA concurred, sought to avoid the application of the reasoning in Hockey and held that the conditions in pars(a) and (b) did "not widen the meaning of the word 'disease' or otherwise narrow the word 'injury'" (654). With respect to the passage in the judgment of Gibbs CJ in Hockey at 137-138 that I have set out, Clarke JA said that the words "or that the haemorrhage was otherwise autogenous" were not ratio decidendi, for each case depends on the evidence adduced before the tribunal of fact. His Honour referred to Hornsby and Kavanagh and said that although it would be too wide to state that a rupture of an aneurism is not a disease, an external event was not necessary to constitute an injury simpliciter (654-655). However O'Neill is of little assistance to the present matter for the Tasmanian Act s25(1) is quite clear; the tribunal of fact is required to classify all injuries into those which are a disease as defined by the Act and those which are not and the New South Wales legislation contained no definition of "disease".

14. Accident Compensation Commission v McIntosh (supra) was a decision of the Full Court of Victoria. Like O'Neill, the issue was whether it was open to the Workers Compensation Tribunal to find on the evidence that the haemorrhage was a physical injury. Murphy J, with whose reasons the other members of the court agreed, held that the finding in the court below that the rupture was an injury within the meaning of the Accident Compensation Act 1985 (Vic) reflected no error. He said at 262:

"The argument is that it (the rupture) is not, of itself, a

'physical injury'. I have the utmost difficulty in accepting

such a proposition. If the rupture is due to blood pressure,

arteriosclerosis, arteriovenous malformation, or any other

congenital or diagnostic aetiology, it is nonetheless a

rupture - something quite distinct from the defect, disorder

or morbid condition, which enables it to occur. An occlusion

caused by the distinct flaking off of a platelet, and the

blocking of an already narrowed arteriosclerotic artery is

quite distinct from the diseased condition of the artery

itself. So also is a rupture distinct from its aetiology,

whether progressive or not."

15. It seems to me that for practical purposes, the relevant statutory definition is indistinguishable from that before the court in Hockey. Murphy J distinguished Hockey on the basis that the question he had to resolve was the reverse of that before the court in Hockey. He said at 261:

"Here the question is whether it was open to the tribunal on

the material before it to find that the respondent suffered

an 'injury'. The onus was upon the respondent before the

tribunal: s117(8). He succeeded and an appeal lies to this

court only on a point of law."

16. With respect to his Honour, I find a little difficulty in seeing the point of distinction although I accept for the reasons expounded by all the members of the Court in O'Neill, that Hockey is not authority for the broad proposition that all aneurisms under the New South Wales or Victorian legislation are diseases unless traumatically induced. However, like O'Neill, McIntosh is not of assistance to the matter in hand because of the differences between the relevant Tasmanian legislation and the statutory provisions on which that case was decided.

"I consider that the key to the distinction between injuries

which are and which are not diseases is to be found in the

word 'development' appearing in the definition of 'disease'.

That word suggests that the definition is limited to

conditions which might be said to develop. It is implicit

from the use of that word that the definition is concerned

with autogenous conditions and conditions which find their

origin in the environment in which a worker finds himself

which naturally progress (whether gradually or suddenly) as

distinct from physiological change, not related to any such

condition, which results from external trauma. The external

trauma which made the pre-existing tinea (which in itself was

a disease) in Pasminco Australia Ltd v Fairchild (supra)

incapacitating did not result in the worker having suffered

an injury other than a disease. It remained a disease,

namely tinea. On the other hand the physiological change

which occurs when a worker falls and breaks his leg is not an

injury which is a disease because it cannot aptly be

described as having developed in the relevant sense. Where

an injury finds its origin in an external traumatic event

causing immediate injury and is unrelated to any condition

from which the worker is suffering, it is not an injury which

is a disease because it cannot be said to have developed.

That view is consistent with the approach taken by Crawford J

in FAI General Insurance Company v Morrisson A79/1993. Where

an injury is suffered by a developing clinical condition

becoming disabling, then it is an injury which is a disease,

even if some external trauma has caused it to become

disabling. I find it unnecessary to further define what is

and what is not an injury which is a disease. I have not

purported to lay down an exhaustive test. It is preferable

to develop this on a case by case basis. What I have said is

sufficient to determine the present appeal."

18. I am in complete agreement with that passage in his Honour's reasons for judgment. The mere existence of a disease is of no significance in the Workers Compensation Act. The event that creates liability is the suffering of injury, and in the case of an injury that is a disease, that event does not occur until there is incapacity or deemed incapacity as provided by s3(5). See Pasminco Australia Ltd v Fairchild FC A57/1991. Thus, in the present case, prior to its rupture the aneurism was not an injury being a disease and of course, was not an injury not being a disease.

19. Having regard to the wide definition of the word "disease", it is clear that "development" is the key word in the statutory definition to distinguish injuries that are diseases from those that are not. The statute provides that the development of the prescribed state of affairs may be gradual or sudden but "disease" presupposes the existence of a condition which gradually or suddenly develops to a stage where the worker is incapacitated. This definition obviously encompasses autogenous or self generated conditions; morbid conditions that become incapacitating without the application of external trauma. This approach is consistent with the apparent philosophy of the Act that in cases where the condition is the result of the application of external trauma whilst at work or travelling to and from work, the deeming provisions operate to satisfy the necessary nexus with employment. In the case of autogenous conditions that develop either gradually or suddenly to the stage where they result in incapacity, the worker is obliged to satisfy that there was the necessary nexus between employment and incapacity.

20. In the present case the only conclusion reasonably open upon the evidence before the learned Workers Compensation Commissioner was that the aneurismal subarachnoid haemorrhage was the sudden development of a morbid condition, that it was an injury being a disease and as the conditions precedent for liability did not exist, the application for compensation should have been dismissed.

SLICER J The appeal is concerned with the question of whether a spontaneously occurring physiological condition can be regarded as an injury within the ambit of the Workers Compensation Act 1988 ("the Act"), s25(1)(b) if the condition has effect during a time in which a person was at a place of employment.

2. The learned primary judge had determined that a worker who had suffered an aneurysmal sub-arachnoid haemorrhage occurring as a result of an aneurysm in the anterior communicating artery could not be said to have suffered an injury which was not a disease. In his reasons for judgment A35/1994 Zeeman J expressed his conclusion, at 5-6, as being based on:

"... the distinction between injuries which are and which are

not diseases (which) is to be found in the word 'development'

appearing in the definition of 'disease'. That word suggests

that the definition is limited to conditions which might be

said to develop. It is implicit from the use of that word

that the definition is concerned with autogenous conditions

and conditions which find their origin in the environment in

which a worker finds himself which naturally progress

(whether gradually or suddenly) as distinct from

physiological change, not related to any such condition,

which results from external trauma."

3. The appellant was a trainee nurse at a hospital. Following a seminar presentation made to a nursing course she suffered an aneurysmal sub-arachnoid haemorrhage which was the result of a ruptured aneurysm. As Zeeman J accepted, at 3:

"The aneurysm was a structural lesion of a type which

develops at sites of congenital weakness of the cerebral

arterial walls. Such an aneurysm is prone to haemorrhage,

generally without there being any specific precipitating

factor."

4. Evidence given before the learned Commissioner by a neurosurgeon was that the incidence of such a haemorrhage is "approximately 10 per 100,000 population per annum" and that "not all cerebral aneurysms will rupture during the course of the lives of the people harbouring them". With specific reference to the appellant, the neurosurgeon observed, at 3, that:

"With specific reference to Mrs Smith, she had mild

hypertension which had been noted to be somewhat labile and

smoked 25-30 cigarettes a day. These factors may have had

some bearing on the rupture of her aneurysm, but cannot be

implicated in its development. There is not sufficient

evidence in the literature to conclude that any other factors

in Mrs Smith's lifestyle made her particularly at risk of

aneurysm development or caused the already existing aneurysm

to bleed at the particular time at which her ictus occurred.

In particular, the contention that factors arising from the

workplace may have been involved in the precipitation of her

subarachnoid haemorrhage cannot be supported. It must be, I

am afraid, regarded as coincidence in time only that she was

at work at the time of the haemorrhage, and that the

haemorrhage itself must be regarded as a consequence of the

natural history of her anterior communicating artery

aneurysm".

5. There was evidence capable of supporting the conclusion reached by the learned primary judge that the inclusion of the word "development" in the definition of disease afforded an appropriate basis for the interpretation given by him. The appellant was precluded from contending that the occurrence of the haemorrhage was a compensable disease since the Act, s25(1)(b) requires that any such disease arises "out of and in the course of his employment and to which his employment contributed to a substantial degree". Instead, the appellant initially and successfully contended that it was the act of rupture which constituted the injury. The learned Commissioner in his reasons for determination made reference to a previous case WC82/1993 in which he had set out the manner in which he had concluded that a haemorrhage was a compensable injury. In that decision (WC82/1993) he had, at 4, relied on the decision of the Court of Appeal of New South Wales in O'Neill v Lumbey (1987) 11 NSWLR 640 as authority for the proposition that the question of the nature of a compensable disease is one of fact. Applying his reasoning in the previous decision to the evidence of the present case, he concluded:

- the existence of an aneurysm is distinct from the act of

rupture;

- the act of rupture is distinct from a defect disorder or

condition which enables or facilitates such act; and

- the rupture not being a disease is an "injury not being a

disease, arising ... in the course of ... employment"

and accordingly that it was compensable. Zeeman J rejected that approach. In doing so he correctly declined to apply as authority a decision of the Supreme Court of Victoria in Accident Compensation Commission v McIntosh [1991] VicRp 65; (1991) 2 VR 253.

6. The Accident Compensation Act 1985 (Vic), the legislation under consideration by the court in McIntosh (supra), contained a definition of "disease" in the following terms:

"'Injury' means any physical or mental injury and without

limiting the generality of the foregoing includes

...

(b) a disease contracted by a worker in the course of the

worker's employment whether at or away from the place of

employment and to which the employment was a contributing

factor; and

(c) the recurrence, aggravation, acceleration, exacerbation

or deterioration of any pre-existing ... disease where the

employment was a contributing factor to that recurrence,

aggravation, acceleration, exacerbation or deterioration."

7. On the basis of that definition, Murphy J, as one of the appellate judges, concluded at 262:

"It is not, I think, possible to say that, as a matter of law

a sudden rupture of an artery or vein at work, or during a

protected period, causing an immediate extravasation of blood

to result in a haemorrhage cannot be a 'physical injury' as

that term is used in the definition of injury in s5."

8. But the terms of the legislation there being considered differ significantly from that comprised in the Tasmanian Act. If it could be said that the differences in the legislation do not affect the logic of the ratio in the Victorian decision then I would decline to follow the authority. In doing so I would follow the approach taken by the High Court in Hockey v Yelland [1984] HCA 72; (1984) 157 CLR 124, a case in which consideration was given to whether the occurrence of a sub-arachnoid haemorhage was an injury within the meaning of Queensland legislation. The definition of "injury" contained in the Workers Compensation Act (Qld), s3 included "(b) ... the aggravation or acceleration of any disease where the employment was ...". The legislation was similar in construct to that considered by the court in Accident Compensation Commission v McIntosh (supra). Gibbs CJ said at 136-137:

"I respectfully agree with the opinion of Stephen and Mason

JJ that Slazengers (Australia) Pty Ltd v Burnett and Darling

Island Stevedoring and Lighterage Co Ltd v Hussey establish

that the definition of injury in s 6(1) of the NSW Act, which

is indistinguishable for present purposes from that in s 3(1)

of the Queensland Act, includes a disease only if it falls

within par (a) or par (b), and so only if employment was a

contributing factor. I see no reason to doubt the

correctness of the construction placed upon the definition in

those cases, but even if, contrary to my present view, a

disease which is not autogenous, but is caused or exacerbated

by an external stimulus, can come within the description of

injury simpliciter and so within the opening words of the

definition, it is clear that an autogenous disease which

happens to manifest itself in the course of employment is

only an 'injury' if it comes within par (a) or par (b)."

9. Rather, the argument was dependent on the interrelationship of the definition of "disease" as provided in the Act, s3 and its use in s25(1)(a).

10. The Act, s3 defines "injury" as including a disease. "Disease" is defined as meaning "any ailment, disorder, defect, or morbid condition, whether of sudden or gradual development". The appellant contended that since s25(1)(a) provided for "injury, not being a disease" and although it may have been possible for a finding as a matter of fact that there had been a development, the learned primary judge was in error in determining that the word is concerned with autogenous conditions as distinct from a condition "which results from external trauma" (A35/1994 at 6).

11. Central to the argument is the proposition that a condition possessing no developmental phase cannot be a disease within the meaning of the definition.

12. I do not accept the appellant's contention. In dealing with the question of disease in Pasminco Australia Ltd v Fairchild A57/1991 Cox J, at 5, said:

"... until he was disabled by the symptoms of ..., the

respondent did not, within the meaning of the Act, 'suffer'

any injury and whatever disorder or defect to which he was

subject prior thereto was not a disease which he suffered.

When disability eventuated he was shown, on the evidence, to

be suffering from a morbid condition which could itself

properly be described as a disease and for which he was

entitled to compensation if he could establish that it arose

out of and in the course of his employment and that it was a

condition to which his employment contributed to a

substantial degree. ... it is the condition at the time of

disablement which must be classified as a disease or not ..."

and as Kirby P concluded in his dissenting judgment in

O'Neill v Lumbey (supra) at 646-647: "The mere fact that, at

a given instant ... the pre-existing morbidity evidenced

itself in a pathological change (being the bursting and

haemorrhage of blood) does not make that instant any less a

consequence and part of a 'disease' ... it is the pre

existing morbidity, the progressive nature of the condition

and the inevitability of the haemorrhage that makes it

impossible, in my opinion, on the facts found to classify

this worker's 'injury' as otherwise than of the 'disease'

type."

13. The legislation being considered by Kirby P in O'Neill was the Worker's Compensation Act 1926 (NSW), s6(1) which defines "injury" as meaning:

"... personal injury arising out of or in the course of

employment, and includes

(a) a disease which is contracted by the worker in the course

of his employment ...; and

(b) the aggravation, acceleration, exacerbation or

deterioration of any disease, where ..."

14. In relation to that legislative scheme, Kirby P observed at 647:

"That structure anticipates that in some cases there will be

internal catastrophes which have a connection with a

'disease' and are part of it. It might have been different

if the additional words relating to 'disease' had been

omitted. But they are there. They necessitate the task of

classification to which I have referred. Where the rupture

of an aneurism (or the occlusion of a coronary artery)

occurs, this will normally (depending on the evidence)

require classification, in cases other than those caused by

frank external trauma, as steps in the chain of the pathology

of an underlying disease. When this classification is

applied, it is then necessary for the worker, in order to

recover compensation, to bring his or her disease injury,

including the sudden manifestation of it, into those

requirements which Parliament has laid down in pars(a) and

(b) ..."

15. That is the approach appropriate to the Tasmanian legislation.

16. Separate approaches lead to the same conclusion. The act of rupture or haemorrhage could be regarded as a continuum of the disease in the same way that the observable spots of measles are an outward manifestation of that disease. It is the manifestation which produces the disability. Alternatively, if the act of rupture forms an intrinsic part of the disease then its occurrence is itself a sudden development. Used in this sense the word "development" could be given the meaning ascribed by Oxford, 1975 ed, as "a fuller working out of the details of anything". On either test the condition satisfied the legislative criteria of what constitutes a disease.

17. A third approach suggests itself. The word "whether" may be used as an interrogative particle introducing a disjunctive direct question. Such use would not amount to a qualifying clause and would leave the definition of "disease" as an ailment, disorder, defect, or morbid condition whether static or developing. The use of the word "whether" would operate in such a way that any form of development does not derogate from the condition. I express no concluded view on that method of interpretation but believe that it would accord with the purpose of the legislation.

18. Whilst it is correct to contend that an injury may be a disease (see the Act, s3(5)) it is incorrect to determine that every injury could come within that definition. The distinction need not be dependent on causation and Parliament has chosen to give the term "disease" wide scope limited by the operation of s25(1)(b) rather than prescribe certain conditions which are compensable since experience has shown that such diseases are usually caused by the work environment. It has maintained in the Act, Sch4, a list of diseases in respect of which there is presumption of cause. It has defined the word disease in wide terms but limited compensability to such diseases as are injuries within the meaning of the Act, s25(1)(b). In taking this approach it could not be said that Parliament intended to restrict the word "disease" to those physiological or psychological conditions which are in a state of change at the time of entitlement. In my opinion the conclusion expressed by Zeeman J at 7 that:

"The event causing the disablement must be treated as part of

the development of the condition. To hold otherwise would be

to hold contrary to what was decided in Pasminco Australia

Ltd v Fairchild (supra). The respondent suffered from a

disorder which initially manifested itself in a non-disabling

way and then upon further development became disabling. Even

if it is appropriate to consider the haemorrhage as a

separate event it still is a condition which has developed

suddenly which comes within the definition of disease.

Applying the relevant legal principles the learned

Commissioner could not but have come to the conclusion that

the respondent suffered an injury which was a disease ..." is

correct.

19. I am of the opinion that the appeal should be dismissed.