Weller v Healthscope Operations Pty Limited

DETERMINATION OF APPEAL PANEL
CITATION:	Weller v Healthscope Operations Pty Limited [2022] NSWPICMP 368
APPELLANT:	Tara Weller
RESPONDENT:	Healthscope Operations Pty Limited
Appeal Panel
MEMBER:	Catherine McDonald
MEDICAL ASSESSOR:	Dr Nicholas Glozier
MEDICAL ASSESSOR:	Dr Michael Hong
DATE OF DECISION:	26 September 2022
CATCHWORDS:	wORKERS cOMPENSATION - Psychological injury; application of the Psychological Impairment Rating Scale; Jenkins v Ambulance Service of NSW, Ferguson v State of NSW, Parker v Select Civil; section 323 of the Workplace Injury Management and Workers Compensation Act 1998; Bojko v ICM Property Service Pty Ltd, Ryder v Sundance Bakehouse; diagnosis of three conditions including recurrent depression and identification of symptoms; Medical Assessment Certificate confirmed.

BACKGROUND TO THE APPLICATION TO APPEAL

On 11 July 2022 Tara Weller lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Douglas Andrews, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on 24 June 2022.
Ms Weller relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (1998 Act):
· the assessment was made on the basis of incorrect criteria, and
· the MAC contains a demonstrable error.
The delegate was satisfied that, on the face of the application, at least one ground of appeal has been made out, being that in s 327(3)(d). We have conducted a review of the original medical assessment but limited to the grounds of appeal on which the appeal is made.
The WorkCover Medical Dispute Assessment Guidelines 2018 set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with the WorkCover Medical Assessment Guidelines 2018.
The assessment of permanent impairment is conducted in accordance with the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4^th ed reissued 1 March 2021 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5^th ed (AMA 5).

RELEVANT FACTUAL BACKGROUND

Ms Weller was employed by Healthscope Operations Pty Ltd (Healthscope) as an assistant in nursing at Norwest Private Hospital on a casual basis. On 8 April 2019, whilst on night shift, she was assaulted by a patient, suffering a soft tissue injury to her neck and anxiety. After two weeks Ms Weller returned to work.
In late 2019 Ms Weller’s psychiatric health deteriorated and she saw her general practitioner and a psychologist. She ceased working for Healthscope in about February 2020 and ceased working as a nurse in mid 2020 though has undertaken some casual employment in retail. She performs unpaid administrative work in her husband’s building company, of which she is a director.
The Medical Assessor diagnosed post-traumatic stress disorder, major depressive disorder with anxious distress and alcohol use disorder. He assessed 7% whole person impairment (WPI). He deducted one-tenth under s 323 of the 1998 Act, resulting in an assessment of 6% WPI.

PRELIMINARY REVIEW

We conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the WorkCover Medical Assessment Guidelines 2018.
As a result of that preliminary review, we determined that it was not necessary for the worker to undergo a further medical examination because the assessment made by the Medical Assessor was open to him in the exercise of his clinical judgement. Neither party sought that Ms Weller be re-examined.

Fresh evidence

Section 328(3) of the 1998 Act provides that evidence that is fresh evidence or evidence in additional to or in substitution for the evidence received in relation to a medical assessment appealed against may not be given on an appeal unless the evidence was not available to the party before the medical assessment and could not reasonably have been obtained by the party before that assessment.
Ms Weller prepared a statement dated 4 February 2022 which her counsel, Mr Robison referred to in submissions. Ms Weller said in the statement that she provided it “as evidence of my pain and suffering since my last statement dated 21 September 2021.”
Neither Ms Weller’s initial submissions not her submissions in reply included any formal application to rely on the statement so that there are no detailed submissions dealing with its admissibility. The evidence set out in the statement is not materially different to that in Ms Weller’s September 2021 statement, though there is some additional information.
Healthscope’s solicitor said that the statement was not served and that there was nothing to indicate if it was provided to the Medical Assessor. Healthscope opposed admission of the statement.
The submissions in reply prepared for Ms Weller say that the statement was not served “due to clerical error” but is not necessary to support the appeal, being confirmatory of her previous statement and the history provided to the Medical Assessor.
The referral to the Medical Assessor was made in a Certificate of Determination dated 17 January 2022. There is no reference to a further proposed statement in that certificate. The Medical Assessor said in the MAC that no additional material was provided to him.
There is no explanation as to why the statement was prepared and there are no detailed submissions supporting an application to rely on it.
The provision of an additional statement is contrary to the Personal Injury Commission’s rules and practice directions, particularly when it was not served on Healthscope. A bald reference to a clerical error in failing to provide the statement does not provide an explanation for the failure to serve evidence when required.
We have determined that the statement should not be received on the appeal because it is not fresh evidence. Referring to a statement sought to be relied on in a medical appeal, Handley AJA said in Lukacevic v Coates Hire Operations Pty Ltd[1]:
“The applicant's statement contains lengthy details of his activities and habits before and after his work injury. In so far as this adds to the history and his statement of 2 April 2008, or the histories in the medical reports before the AMS, it was available and could reasonably have been obtained before the assessment and was not admissible.
In so far as the statement repeats information in the earlier statement or in the medical reports it was not evidence ‘in addition to ... the evidence received in relation to the medical assessment’, and was not admissible.”
[1] [2011] NSWCA 112 at [98]-[99].
The Medical Assessor obtained a history from Ms Weller which is set out in the MAC and on which he based his assessment. It is not appropriate to admit a further statement on the appeal.

EVIDENCE

We have all the documents that were sent to the Medical Assessor for the original medical assessment and have taken them into account in making this determination.
The parts of the medical certificate given by the Medical Assessor that are relevant to the appeal are set out, where relevant, in the body of this decision.

SUBMISSIONS

Both parties made written submissions. They are not repeated in full, but we have considered them.
Mr Robison of counsel prepared submissions for Ms Weller. Relying on the decision of another medical appeal panel in Beatty v State of New South Wales[2] (Beatty), Mr Robison said that the task of the Medical Assessor was to compare the descriptors in the Psychiatric Impairment Rating Scale (PIRS) with the evidence before him and to determine into which class the impairment best fit. While this did not require the Medical Assessor to agree with any other medical practitioner, it did require the Medical Assessor to apply “best fit” based on the history available. He referred to “Rule 11.2” of the Guidelines and said that it states:
“the MA should also account of the person’s cultural background and consider activities that are usual for the person’s age, sex and cultural norms in comparison to the current state at the time of examination.”
[2] [2021] NSWPICMP 93.
Mr Robison said that the Medical Assessor did not consider the evidence and apply “Rule 11.2” and the rule of best fit with respect to the assessments for Self Care, Concentration Persistence and Pace and Employability.
With respect to Self Care, Mr Robison said that Class 3 was the best fit because Ms Weller has gained weight, uses alcohol in a harmful manner, serves take-away and frozen meals and has hired a cleaner.
With respect to Concentration, Persistence and Pace, Mr Robison said that the gravity of the history in the body of the reasons was not reflected in the summary in the PIRS table. He said that the Medical Assessor failed to engage with Ms Weller’s history with respect to the loss of several hobbies.
With respect to Employability, the Medical Assessor noted that Ms Weller remains employed at Bunnings but Mr Robison said that he overlooked the facts that the employment is casual and Ms Weller had not worked a shift for several months at the date of the assessment.
Mr Robison submitted that the Medical Assessor had not provided reasons for making
[3] [2015] NSWSC 1133.
a deduction under s 323 of the 1998 Act and that the fact that he entered “Nil” in paragraph 11a of the MAC form meant that the deduction could not stand. He said that a fair reading of the Medical Assessor’s reasons was that there was no previous injury to justify a deduction and that although there was past pathology, the present pathology was limited to a relapse which was not due to a previous injury. He referred to Periera v Siemens Limited[3] (Periera) to say that “it cannot be assumed that the mere existence of a pre-existing impairment means that it contributed to the current impairment.”
We disregarded any submissions based on the 2022 statement.
Ms Tancred prepared submissions on behalf of Healthscope, noting case law which elucidated the meaning of demonstrable error and use of incorrect criteria. She said that there was no demonstrable error, being an error on the face of the MAC in the application of the PIRS. Referring to the class descriptors, Ms Tancred said that the Medical Assessor took a history consistent with assessment in Class 2 for Self Care and for Concentration, Persistence and Pace and for Employability.
In respect of the deduction under s 323 of the 1998 Act, Ms Tancred said that the Medical Assessor provided reasons in setting out a history of two previous periods of treatment for depression.
Mr Robison prepared brief submissions in reply with respect to the late statement and said that it was not necessary to rely on it.

FINDINGS AND REASONS

The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is by way of review of the original medical assessment, limited to the grounds on which the appeal is made.
In Campbelltown City Council v Vegan[4] the Court of Appeal held that an Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
[4] [2006] NSWCA 284.

The MAC

The Medical Assessor set out a history of the injury and Ms Weller’s present treatment and symptoms. He said:
“Ms Weller described being ‘constantly on edge. She has panic attacks about once a month, triggered by things that remind her of the assault.
She has ‘flashbacks’ in which she vividly recalls the assault. These may be triggered by things she sees on television, aggressive people or loud noises.
She said that she was ‘not so much down and depressed.’ However, she has had frequent thoughts of suicide and has contemplated means. On a few occasions, she has attended the Emergency Department with suicidal thoughts.
She is irritable and prone to anger, often directed at her children.
She has long sleep latency and wakes up to 6 times during the night. In total, she estimates that she may get five hours of sleep. She is prone to distressing dreams, often about the assault.
Her appetite varies, and she has gained 10-15 kg since the assault.
Her libido is ‘non-existent’."
When setting out details of previous or subsequent accidents, injuries or conditions the Medical Assessor said:
“Ms Weller has had several episodes of depression.
During her early adolescence, she says, she ‘didn't feel like I belonged.’ She saw a psychologist and was on fluoxetine for about a year.
Depression recurred in her late teens and early 20s, and she was again briefly on treatment.
She also saw a psychologist after two family deaths.
She has been well since about 2013 until the workplace injury.
Her brother-in-law was murdered early in 2020. She was not close to him but was understandably distressed about the effect this had on her husband and his family. She feels that she has been unable to support him adequately.”
The Medical Assessor noted that Ms Weller is not on any medication. He described her alcohol intake. He set out her history of social activities and activities of daily living in detail, noting the change in those activities since the injury.
The Medical Assessor described his mental state examination, noting that the interview took 85 minutes. He provided the basis for making the diagnoses set out at [8] above. He said:
“Although Ms Weller said that she wasn't depressed, she has lost interest in her usual activities and has diminished capacity to experience positive emotions. She has five other symptoms consistent with a major depressive disorder.
The assault in April 2019 meets Criterion A for post-traumatic stress disorder. She continues to meet the criteria for this disorder. The murder of her brother-in-law and attendance at the trial of the alleged perpetrator may act as perpetuating or aggravating factors, but her workplace injury remains the main contributing factor to her condition.
Since leaving work, she has been drinking excessively in a manner that is likely to cause harm.
I found no evidence to support a diagnosis of borderline personality disorder.”
The Medical Assessor explained why he considered that Ms Weller had reached maximum medical improvement.
The Medical Assessor considered that there was a proportion of the WPI which was due to a pre-existing condition, saying:
“Yes. Ms Weller has had recurrent episodes of depression commencing in early adolescence.
Depression is known to be a recurring condition.”
When asked to comment on other medical opinions in the file, the Medical Assessor explained why he differed from the opinions of Dr Takyar, qualified for Ms Weller, and Dr Miller, qualified for Healthscope. He noted that Dr Takyar’s assessment of 17% WPI in his report dated 27 November 2020 included 2% for the effects of treatment. The Medical Assessor explained that he considered that uplift inappropriate because Ms Weller is not taking any medication and gains with her psychologist should be stable.
Dr Takyar assessed Ms Weller 18 months before the assessment by the Medical Assessor. The Medical Assessor noted that he differed from Dr Takyar in the assessment only for Travel and for Concentration, Persistence and Pace and explained why. In respect of the latter he said:
“Ms Weller has subjective difficulties with concentration. She can read for up to 20 minutes and watch television shows for one to 2 hours, although she may lose focus. She restores furniture for up to a few hours each week and also restores motor vehicles and gardens. I interviewed her for 85 minutes, during which she focused well, gave a comprehensive history and did not lose concentration.”
The Medical Assessor summarised his findings in the PIRS Rating Form. He assessed Ms Weller in Class 2 for Self-care and Personal Hygiene, Class 3 for Social and Recreational Activities, Class 1 for Travel; Class 2 for Social Functioning; Class 2 for Concentration, Persistence and Pace and Class 3 for Employability.
We will set out the Medical Assessor’s reasons with respect to s 323 below.

Application of the Guidelines and the PIRS

When examining Ms Weller and preparing his report, the Medical Assessor was required to use his clinical judgement in determining a diagnosis and making an assessment.[5] He was required to assess Ms Weller using the PIRS.
[5] Guidelines paragraph 1.6b.
Paragraph 11.12 of the Guidelines describes the application of the PIRS:
“Impairment in each area is rated using class descriptors. Classes range from 1 to 5, in accordance with severity. The standard form must be used when scoring the PIRS. The examples of activities are examples only. The assessing psychiatrist should take account of the person’s cultural background. Consider activities that are usual for the person’s age, sex and cultural norms.”
The classes “range from 1 to 5, in accordance with severity”. Class 1 of each of the scales in the PIRS is appropriate where there is “[n]o deficit, or minor deficit attributable to normal variation in the general population”. The important part of the description of each class in the PIRS is the level of impairment – eg no deficit, mild impairment, moderate impairment. What follows in each class are examples which demonstrate the level of impairment. In Jenkins v Ambulance Service of NSW[6] (Jenkins) Garling J said:
“I am satisfied that the descriptions of the activities which give rise to a conclusion by an AMS of the extent of a disability of an individual by reference to each table in the PIRS, are simply, in my view, examples of activities which would indicate an assessable level of disability. Those examples, on their face, are not necessary to be found in each case, but may, in any particular case, be sufficient to support a conclusion as to the level of disability.”
[6] [2015] NSWSC 633 at [65].
We do not agree that the Medical Assessor’s task was accurately described in the passage quoted from Beatty. The only reference to “best fit” in the Guidelines is in relation to the application of the Table for the Evaluation of Minor Skin Impairment (TEMSKI) which contains a list of features which may be applicable for the scarring being assessed. Paragraph 14.8 directs the assessor to use the principle of “best fit” to be satisfied that “the criteria within the chosen category of impairment best reflect the skin disorder being assessed.”
By contrast, the task of a Medical Assessor applying the PIRS is to assess the severity of a worker’s condition under a series of tables, each having five classes. The examples given for each class provide assistance in making that assessment.
We do not accept Mr Robison’s submission that the Medical Assessor was required to “consider activities that are usual for the person’s age, sex and cultural norms in comparison to the current state at the time of the examination” (our emphasis). The italicised words add a gloss not supported by the Guidelines. As Garling J pointed out in Jenkins, the activities for each class in each table are examples only.
When read as a whole, paragraph 11.2 deals only with the assessment of the severity of impairment and the choice of the correct class; it does not require comparison to other people of the same age, sex or cultural background. It directs the examiner to measure the severity of the impairment by considering examples of activities which are appropriate for the age, sex and cultural norms of the particular worker. It is unlikely that all of the examples in a class would apply to one person. The broad range of examples for assessment in Class 3 for Concentration, Persistence and Pace make that clear:
“Moderate impairment: Unable to read more than newspaper articles. Finds it difficult to follow complex instructions (eg operating manuals, building plans), make significant repairs to motor vehicle, type long documents, follow a pattern for making clothes, tapestry or knitting.”

Each of the PIRS tables is assessed separately and particular conduct must be applied to the appropriate scale - Ballas v Department of Education.[7] Bell P and Payne JA said:
“Whilst it is no doubt correct that an AMS must exercise a degree of clinical judgment in assigning a class of seriousness to each area which he or she is required to address in completing a medical assessment, the characterisation of conduct as going to ‘social and recreational activities’ on the one hand, as opposed to any of the other five scales on the other hand, is not a matter of discretion.
Even if there may, as a matter of English language, be some overlap between some of the scales or categories of functional impairment, for the purposes of the WPI assessment exercise, particular conduct will fit within one or other of the scales. This calls for the correct characterisation of the conduct, ie whether it goes to ‘self care and personal hygiene’, ‘social and recreational activities’, ‘travel’, ‘social functioning (relationships)’, ‘concentration, persistence and pace’ or ‘employability’. This does not involve an exercise of discretion. If conduct is wrongly assigned to one scale, when it should have been assigned to another, this will result in the AMS taking into account an irrelevant consideration in the context of assigning a class to each of the distinct scales. This will inevitably bear upon the calculation of the WPI which is critical for an injured worker’s entitlement to compensation.”[8]
[7] [2020] NSWCA 86.
[8] At [93]-[94].
In Ferguson v State of New South Wales[9] (Ferguson) Campbell J said:
“The Appeal Panel accepted that intervention was only justified: if the categorisation was glaringly improbable; if it could be demonstrated that the AMS was unaware of significant factual matters; if a clear misunderstanding could be demonstrated; or if an unsupportable reasoning process could be made out. I understood that all of these matters were regarded by the Appeal Panel as interpretations of the statutory grounds of applying incorrect criteria or demonstrable error. One takes from this that the Appeal Panel understood that more than a mere difference of opinion on a subject about which reasonable minds may differ is required to establish error in the statutory sense.
The Appeal Panel also, with respect, correctly recorded that in accordance with Chapter 11.12 of the Guides ‘the assessment is to be made upon the behavioural consequences of psychiatric disorder, and that each category within the PIRS evaluates a particular area of functional impairment’: Appeal Panel reasons at [37]. The descriptors, or examples, describing each class of impairment in the various categories are ‘examples only’: see Jenkins v Ambulance Service of New South Wales [2015] NSWSC 633. The Appeal Panel said ‘they provide a guide which can be consulted as a general indicator of the level of behaviour that might generally be expected’…”[10]
[9] [2017] NSWSC 887.
[10] At [24].
Harrison AsJ cited Ferguson in Parker v Select Civil Pty Ltd[11] (Parker) and said[12]:
“To find an error in the statutory sense, the Appeal Panel’s task was to determine whether the AMS had incorrectly applied the relevant Guidelines including the PIRS Guidelines issued by WorkCover. Even though the descriptors in Class 3 are examples not intended to be exclusive and are subject to variables outlined earlier, the AMS applied Class 3. The Appeal Panel determined that the AMS had erred in assessing Class 3 because the proper application of the Class 2 mild impairment is the more appropriate one on the history taken by the AMS and the available evidence.
The AMS took the history from Mr Parker and conducted a medical assessment, the significance or otherwise of matters raised in the consultation is very much a matter for his assessment. It is my view that whether the findings fell into Class 2 or Class 3 is a difference of opinion about which reasonable minds may differ. Whether Class 2 in the Appeal Panel’s opinion is more appropriate does not suggest that the AMS applied incorrect criteria contained in Class 3 of the PIRS. Nor does the AMS’s reasons disclose a demonstrable error. The material before the AMS, and his findings supports his determination that Mr Parker has a Class 3 rating assessment for impairment for self-care and hygiene, that is to say, a moderate impairment of self-care and hygiene…”
[11] [2018] NSWSC 140.
[12] At [70]-[71].
We have taken those principles into account in considering the appeal.

Consideration

The submissions made with respect to Self-Care and Personal Hygiene merely state that Class 3 was the best fit, relying on Ms Weller’s weight gain, use of alcohol and provision of take-away and frozen meals for her family. While each of those factors reveals an impairment, the history provided to the Medical Assessor shows that Ms Weller is able to care for herself and her family, albeit with some deficits.
The examples for assessment in Class 3 in the Guidelines apply to a more serious impairment and to a person who is unable to live alone without support. Dr Takyar had also assessed Ms Weller in Class 2.
The assessment made by the Medical Assessor to assess Ms Weller in Class 2 for Self Care and Personal Hygiene was open to him in the exercise of his clinical judgement.
The Medical Assessor assessed Ms Weller in Class 2 for Concentration, Persistence and Pace. This is the only one of the impugned categories where the Medical Assessor’s assessment differed from that of Dr Takyar.
The submissions prepared for Ms Weller stress her inability to maintain focus when reading for more than 20 minutes or watching television. While a Medical Assessor will take a worker’s reported deficits into account, the interview provides him or her with an opportunity to assess the worker’s ability to concentrate, their ability to persist with a cognitively demanding and stressful task, and the pace at which they can do this. It allows the Medical Assessor to form an assessment which is more objective and less dependent on reported symptoms than the other Tables of the PIRS.
The Medical Assessor considered and contrasted Dr Takyar’s assessment with his own. He said that his own interview lasted 85 minutes “during which she focused well, gave a comprehensive history and did not lose concentration.” That description is consistent with assessment in Class 2 and there is no error in his assessment.
The third category which is the subject of appeal is Employability. The Medical Assessor assessed Ms Weller in Class 3, as Dr Takyar did.
The examples for Class 3 are:
“Moderate impairment: Cannot work at all in same position. Can perform less than 20 hours per week in a different position, which requires less skill or is qualitatively different (eg less stressful).”
The Medical Assessor took into account the factors on which Mr Robison relied – that Ms Weller’s employment with Bunnings is casual and that she had not worked a shift for three months at the time of the assessment. He noted that Ms Weller performs work in her husband’s business and that she could not return to nursing. Based on that history, assessment in Class 3 was open to the Medical Assessor.

Section 323

Paragraph 11 of the standard MAC form deals with the s 323 deduction, if appropriate. That part of the MAC reads:
“11. DEDUCTION (IF ANY) FOR THE PROPORTION OF THE IMPAIRMENT THAT IS DUE TO PREVIOUS INJURY OR PRE-EXISTING CONDITION OR ABNORMALITY
a. In my opinion, the worker suffers from the following relevant previous injuries, preexisting conditions or abnormalities:
Nil.
b. The previous injury, pre-existing condition or abnormality directly contributes to the following matters that were taken into account when assessing the whole person impairment that results from the injury, being the matters taken into account in 10a, and in the following ways:
Ms Weller has suffered a relapse of a pre-existing depressive disorder.
c. The extent of the deduction is difficult or costly to determine, so in applying the provisions of s.323(2) I assess the deductible proportion as one-tenth.”
A Medical Assessor is an administrative decision maker with respect to the assessment of WPI resulting from an injury. In Bojko v ICM Property Service Pty Ltd[13] Handley AJA (with whom the other members of the Court agreed) said that the worker had failed to establish his grounds of appeal because:
“Both involved a hyper-critical approach to the reasons of the Panel which is contrary to authority and ignores the presumption of regularity which attends administrative action. The correct approach is that mandated by the joint judgment in Minister for Immigration and Ethnic Affairs v Wu Shan Liang [1996] HCA 6, 185 CLR 259, 272 which approved the following statement of principle in a decision of the full Federal Court:
‘… a court should not be concerned with looseness in the language nor with unhappy phrasing of the reasons of an administrative decision-maker. … the reasons for the decision under review are not to be construed minutely and finely with an eye keenly attuned to the perception of error.’ "
[13] [2009] NSWCA 175 at [36].
The insertion of “Nil” in answer to paragraph 11a was clearly a typographical error.
The Medical Assessor noted Ms Weller’s history of depression. He set out the present symptoms described to him and diagnosed three conditions, including major depressive disorder with anxious distress. Despite Ms Weller’s statement that she was not depressed, the Medical Assessor diagnosed the cardinal symptom of anhedonia – the loss of interest in usual activities and the diminished capacity to experience positive emotions. He noted that Ms Weller had five other symptoms consistent with a major depressive disorder, referring to those he had set out under Present Symptoms – suicidal thoughts, irritability, difficulties with sleep, variable appetite and loss of libido.
The purpose of the standard MAC form is to assist the Medical Assessor to ensure that all relevant matters are considered. The opinions expressed are not vitiated merely because of a typographical error. The substance of the certificate makes clear that the Medical Assessor considered that Ms Weller suffered depression in addition to the other diagnoses resulting from the injury. He identified the relapse of an identified, pre-existing, relevant condition and explained his reasons for making a deduction.
The passage from Pereira to which Mr Robison referred is as follows:
“It cannot be assumed that the mere existence of a pre-existing injury means that it has contributed to the current whole person impairment: Clinen at [32]; Cole at [30]; Elcheikh at [91]. What must occur is that there must be an enquiry into whether there are other causes of the whole person impairment which reflect a difference in the degree of impairment: Ryder at [45].”
In Ryder v Sundance Bakehouse[14] Campbell J said:
“What s 323 requires is an inquiry into whether there are other causes, (previous injury, or pre-existing abnormality), of an impairment caused by a work injury. A proportion of the impairment would be due to the pre-existing abnormality (even if that proportion cannot be precisely identified without difficulty or expense) only if it can be said that the pre-existing abnormality made a difference to the outcome in terms of the degree of impairment resulting from the work injury. If there is no difference in outcome, that is to say, if the degree of impairment is not greater than it would otherwise have been as a result of the injury, it is impossible to say that a proportion of it is due to the pre-existing abnormality. To put it another way, the Panel must be satisfied that but for the pre-existing abnormality, the degree of impairment resulting from the work injury would not have been as great.”
[14] [2015] NSWSC 526 at [45].
Ms Weller told the Medical Assessor that she had had several episodes of depression, though had been well since 2013. Dr Takyar obtained a similar history. As the Medical Assessor said, depression is known to recur. Once a patient has had two or more episodes of depression, the condition is diagnosed as a relapsing and remitting chronic condition - Recurrent Major Depressive Disorder. In general the question is not “if” but “when” the condition will recur, often, but in many cases not, when triggered by stressful events. In Ms Weller’s case, the condition has relapsed as a result of the injury in April 2019, which also resulted in other injuries.
The Medical Assessor carefully set out the symptoms of this recurrent depression suffered by Ms Weller, which he separated from the symptoms of a new primary psychiatric injury - post-traumatic stress disorder – the feeling of being “on edge”, panic attacks and flashbacks. The symptoms of depression are significantly contributing to Ms Weller’s impairment.
It is not possible to precisely calculate the extent of the contribution of the pre-existing condition and this is an appropriate case for the application of s 323(2). The deduction of one-tenth was appropriate.
For these reasons, we have determined that the MAC issued on 24 June 2022 should be confirmed.

[2022] NSWPICMP 368

26 September 2022