Causation
33It is necessary to refer to the Permanent Impairment Guidelines (1 October 2007) issued by the MAA ("the guidelines") on the topic of causation. These guidelines may be characterised as delegated legislation under s 44(1)(c) of the MAC Act: Ackling v QBE Insurance (Australia) Ltd [2009] NSWSC 881 at [83].
34Clauses 1.7, 1.8, 1.9, 1.33, 1.34, 1.35 and 1.36 of the guidelines read:
"Causation of injury
1.7 An assessment of permanent impairment is as prescribed under section 58(1)(d) of the Motor Accidents Compensation Act 1999. The assessment should determine the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident. A determination as to whether the claimant's symptoms and impairment are related to the accident in question is therefore implied in all such assessments. Assessors should be aware of the relevant provisions of the AMA 4 Guides, as well as the common law principles that would be applied by a court (or claims assessor) in considering such issues.
1.8 Causation is defined in the Glossary at page 316 of the AMA 4 Guides as follows: "Causation means that a physical, chemical, or biologic factor contributed to the occurrence of a medical condition. To decide that a factor alleged to have caused or contributed to the occurrence or worsening of a medical condition has, in fact, done so, it is necessary to verify both of the following.
(a) The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination.
(b) The alleged factor did cause or contribute to worsening of the impairment, which is a non-medical determination".
This therefore involves a medical decision and a non-medical informed judgement.
1.9 There is no simple common test of causation that is applicable to all cases, but the accepted approach involves determining whether the injury (and the associated impairment) was caused or materially contributed to by the motor accident. The motor accident does not have to be a sole cause as long as it is a contributing cause, which is more than negligible. Considering the question "Would this injury (or impairment) have occurred if not for the accident?" may be useful in some cases, although this is not a definitive test and may be inapplicable in circumstances where there are multiple contributing causes.
...
Pre-existing impairment
1.33 The evaluation of the permanent impairment may be complicated by the presence of an impairment in the same region that existed prior to the relevant motor accident. If there is objective evidence of a pre-existing symptomatic permanent impairment in the same region at the time of the accident, then its value should be calculated and subtracted from the current whole person impairment value. If there is no objective evidence of pre-existing symptomatic permanent impairment, then its possible presence should be ignored.
1.34 The capacity of an assessor to determine a change in physical impairment will depend upon the reliability of clinical information on the pre-existing condition. To quote the AMA 4 Guides page 10, "For example, in apportioning a spine impairment, first the current spine impairment would be estimated, and then impairment from any pre-existing spine problem would be estimated. The estimate for the pre-existing impairment would be subtracted from that for the present impairment to account for the effects of the former. Using this approach to apportionment would require accurate information and data on both impairments". Refer to 7.18 for the approach to a pre-existing psychiatric impairment.
1.35 Pre-existing impairments should not be assessed if they are unrelated or not relevant to the impairment arising from the motor vehicle accident.
Subsequent injuries
1.36 The evaluation of permanent impairment may be complicated by the presence of an impairment in the same region that has occurred subsequent to the relevant motor accident. If there is objective evidence of a subsequent and unrelated injury or condition resulting in permanent impairment in the same region its value should be calculated. The permanent impairment resulting from the relevant motor accident should also be calculated. If there is no objective evidence of the subsequent impairment its possible presence should be ignored." [emphasis in original]
35In Ackling v QBE, Johnson J stated at [86] that in undertaking the task of assessing whether an injury was caused by the relevant accident a Medical Assessor (and a Review Panel) will derive practical assistance from clauses 1.7 to 1.9 of the guidelines.
36Section 5D of the Civil Liability Act 2002 also applies. It relevantly reads:
"5D General principles
(1) A determination that negligence caused particular harm comprises the following elements:
(a) that the negligence was a necessary condition of the occurrence of the harm (factual causation), and
(b) that it is appropriate for the scope of the negligent person's liability to extend to the harm so caused (scope of liability)." [emphasis in original]
37In a recent decision, Owen v Motor Accidents Authority of NSW, Campbell J set out clauses 1.7 to 1.9 of the guidelines and had this to say about causation at [27] and [50]:
"27 Given that the task of the Medical Review Panel in determining the causation question is not solely a medical determination within the expertise of the assessor's constituting the Panel, the position has, with respect, been aptly put by Johnson J in Ackling at p. 500 [87] that the Assessors will derive practical assistance from this part of the permanent impairment guidelines. But it is well to emphasise that the question to be assessed is one of legal causation involving mixed questions of fact and law arising principally from the law of negligence as modified by Civil Liability Act 2002, s.5 D. (See s.3B(2)).
...
50 The statement of the Review Panel that the material before it had not provided any evidence to indicate that the claimed lumbar spine injury was causally related to the subject accident is only explicable on the basis that the panel misdirected itself as to law. As the extract from Clause 1.9 of the MAA Guidelines set out at page 8 of Exhibit A makes clear - albeit in the context of the left shoulder - in general terms (subject to 5D Civil Liability Act 2002) it is sufficient if the injury ... was caused or materially contributed to by the motor accident. The motor accident does not have to be the sole cause as long as it is a contributing cause, which is more than negligible. The absence of a reference by the Review Panel to this important matter suggests that in relation to the back, it did not direct itself as to the law as required. This impression is reinforced by the emphasis the Panel placed upon the construct as a result of the injury caused by the motor accident at the top of page 8. The emphasised language suggests to me that the panel of experts, as legal laymen, looked to a more direct or proximate relationship than that mandated by the relevant legal principles."
38The plaintiff submitted that the Medical Assessor's Statement of Reasons demonstrates the misapplication, and the misapprehension, of the correct legal principles to be applied in determining causation. The plaintiff said that the emphasised words in the passage above, extracted from the Assessor's Reasons, demonstrate that his approach to the notion of material contribution is premised on a direct causal requirement and that the notion of material contribution does not operate in that manner.
39The reasons for a decision under review are not to be construed minutely and finely with an eye keenly attuned to the perception of error: Minister for Immigration and Ethic Affairs v Wu Shan Lian (1996) 185 CLR 259 at 272. In that case Brennan CJ, Toohey, McHugh and Gummow JJ continued at 272:
"... the reasons of an administrative decision-maker are meant to inform and not to be scrutinised upon over-zealous judicial review by seeking to discern whether some inadequacy may be gleaned from the way in which the reasons are expressed. ...
The duty and jurisdiction of the court to review administrative action do not go beyond the declaration and enforcing of the law which determines the limits and governs the exercise of the repository's power. If, in so doing, the court avoids administrative injustice or error, so be it; but the court has no jurisdiction simply to cure administrative injustice or error. The merits of administrative action, to the extent that they can be distinguished from legality, are for the repository of the relevant power and, subject to political control, for the repository alone."
40The plaintiff submitted that, even applying the approach discussed by the High Court in Minister for Immigration and Ethic Affairs v Wu Shan Lian concerning the appropriate approach to the reading of an administrative decision maker's reasons, the reasons in the extracted passage demonstrate a material error in the test of legal causation applied. As such, the plaintiff submitted that there was a relevant jurisdictional error.
41The second defendant submitted that the expert medical practitioner in the present case was specifically appointed to administer Part 3.4 of the MAC Act and that throughout the guidelines there is an emphasis on the use of clinical judgment and non-medical opinion in making an assessment. The second defendant submitted that the Medical Assessor was well aware of his obligations under the guidelines and had applied the causation tests described there.
42The second defendant submitted that medical assessors are not partisan. They are properly held to be "independent arbiters of medical disputes" and "independent decision-makers" who are "independent of all parties to a medical dispute". To support this proposition senior counsel for the second defendant relied upon Goodman v The Motor Accidents Authority of NSW [2009] NSWSC 875; (2009) 53 MVR 420 at [80] - [82] (per Hoeben J).
43The second defendant further submitted that medical assessments and reviews are not adversarial proceedings, they are inquisitorial processes under the MAC Act and the relevant guidelines: Goodman v The Motor Accidents Authority of NSW at [79].
44Finally, the second defendant submitted that as to causation, the Medical Assessor reviewed clause 1.9 of the guidelines in making his decision and that what occurred was a "medical assessment by expert medical practitioners". Determining the issue of causation was part and parcel of that duty in the discharge of the Medical Assessor's statutory function under s 61 of the MAC Act: Ackling v QBE at [77] and [79].
45On the issue of causation, the Medical Assessor stated (p13):
"I am therefore of the view that the motor vehicle accident is not materially contributing to the claimant's level of incapacity and is not causally related to the subject incident; that is, the request for domestic assistance I believe is not directly causally related to the subject accident."
46The Medical Assessor has referred to two concepts: firstly, he was of the view that the motor vehicle was not materially contributing to the level of incapacity and was not causally related to the subject accident and secondly, he said that the request for domestic assistance was not directly causally related to the subject accident.
47I accept that determinations of causation under the MAC Act should not be rendered "unduly complex by legal terminology": Ackling v QBE at [86]. However, the Medical Assessor has misapplied the test as to causation. The test, found in the general law, the guidelines and the Civil Liability Act, is whether the injury was caused or materially contributed to by the motor accident.
48It appears that the Medical Assessor concluded and determined that the request for domestic assistance was not directly caused by the motor accident. In my view the Medical Assessor has sought to apply a higher test of "directly causally related" and has therefore fallen into jurisdictional error by asking himself the wrong question. Furthermore, the Medical Assessor has sought to determine whether the request for domestic assistance was causally linked to the subject accident, rather than determining whether the plaintiff's injury was caused or materially contributed to by the motor accident, and then assessing whether the proposed assistance relates to that injury, and is necessary and reasonable. The confusion may have arisen in part because questions 1 and 2 are badly framed in that they ask whether the proposed care services are "causally related" to the injury. As there is jurisdictional error this Court should intervene to set aside his determination.