Wentworth Shire Council v Gray

[2023] NSWPICMP 303

DETERMINATION OF APPEAL PANEL
CITATION:	Wentworth Shire Council v Gray [2023] NSWPICMP 303
APPELLANT:	Wentworth Shire Council
RESPONDENT:	Colin Alexander Gray
Appeal Panel
MEMBER:	Marshal Douglas
MEDICAL ASSESSOR:	Dr Robert Payten
MEDICAL ASSESSOR:	Dr Brian Williams
DATE OF DECISION:	3 July 2023
CATCHWORDS:	wORKERS cOMPENSATION - Workplace Injury Management and Workers Compensation Act 1998; whether Medical Assessor (MA) incorrectly made deduction under section 323(1) by deducting proportion of respondent’s worker permanent impairment that was due to pre-existing condition from respondent’s binaural hearing impairment (BHI) rather than respondent’s whole person impairment (WPI); whether MA erred by assuming pursuant to section 323(2) that the proportion to be deducted under section 323(1) was 10% because to make that assumption was at odds with the evidence; Held – Appeal Panel found that the MA was correct to assume under section 323(2) that the deductible proportion was 10%; Appeal Panel found that MA erred by making the deduction under section 323(1) to the respondent’s BHI rather than the respondent’s WPI; Medical Assessment Certificate revoked.

BACKGROUND TO THE APPLICATION TO APPEAL

1. On 12 April 2023 Wentworth Shire Council, the appellant, lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Henley Harrison, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on 15 March 2023.

2. The medical dispute that was referred to the Medical Assessor related to the degree of permanent impairment Colin Alexander Gray, the respondent, has from an injury of hearing loss, which is deemed to have occurred on 15 July 2022.

3. The appellant 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.

4. The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The Appeal Panel has conducted a review of the original medical assessment but limited to the ground(s) of appeal on which the appeal is made.

5. Rule 128 of the Personal Injury Commission Rules 2021 (PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes 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 r 128(1) of the PIC Rules.

6. The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4^th ed
   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

1. The respondent commenced employment as a plant operator with the appellant on 12 September 2005. His employment with the respondent exposed him to hazardous noise. He said in a statement he signed on 21 November 2002 that “the level of noise I was exposed to was always of a level which would require me to shout in order to be heard by someone who was only 1 metre away from me”. The respondent said in his statement that he is still employed by the appellant, although he has not done any work for them since April 2022. It is uncontroversial that the respondent’s employment with the appellant was employment to the nature of which his injury of hearing loss from a gradual process was due.

2. Relying on a report of Ear Nose and Throat physician, Dr Joseph Scoppa, dated 1 July 2022, who assessed the respondent had 16% whole person impairment (WPI) from his injury of hearing loss, the respondent’s solicitors wrote on 15 July 2022 to the appellant, care of its insurer, advising it that the respondent claimed compensation of $41,010 under s 66 of the Workers Compensation Act 1987 (the 1987 Act) for 16% WPI and also compensation for the cost of the supply and fitting of two hearing aids.

3. Dr Scoppa had assessed the respondent had an overall WPI of 17% due to industrial deafness. He advised the respondent’s solicitors in his report that he considered that noise to which the respondent had been exposed in employment in Queensland and Victoria was sufficient to cause industrial deafness. He advised that “in such cases of unquantifiable noise induced hearing loss unrelated to employment within New South Wales a standard practice is to deduct 1/10^th of the assessed hearing loss in accordance with s 323 of the Workers Compensation Act”. He advised that, upon making that deduction, he assessed the respondent had 16% WPI as a result of noisy employment in New South Wales.

4. The appellant’s insurer upon receiving the respondent’s claim, arranged for the respondent to be examined on 13 October 2022 by Ear Nose and Throat surgeon Dr Ken Howison. On 19 October 2022 Dr Howison provided a report to the insurer in which he advised that he assessed the respondent had 8% WPI from his injury of hearing loss. He advised that he assessed the respondent had a sensori-neural noise induced hearing loss of 18.1% which reduced to 9% WPI. He also advised that “a deduction is indicated under s 323” of the 1998 Act and indicated that when that was done a WPI of 8% resulted. He further advised that he considered that hearing aids were reasonably necessary treatment for the respondent’s noise induced hearing loss.

5. The insurer then wrote to the respondent on 27 October 2022 advising him that it disputed liability to pay him compensation under s66. It advised him that its reason for that was Dr Howison had assessed his permanent impairment from his injury of hearing loss to be 9% WPI and that it preferred the report of Dr Howison over Dr Scoppa’s report. It advised him that his permanent impairment did not exceed the threshold of 10% WPI required under s 66 of the 1987 Act for him to be entitled to compensation for permanent impairment. It provided him with a copy of Dr Howison’s report of 19 October 2022.

6. The respondent said in his statement that he first commenced employment in New South Wales in 1998. His employment then was as a steel worker and truck driver. He described this employment as being loud and which necessitated him to raise his voice in order to be heard by someone a metre away. Subsequent to that employment and before he commenced employment with the respondent he was employed for around two years in Queensland which he also described as being loud such that he needed to raise his voice in order to be heard by someone who was only a metre away.

7. Preceding 1998, the respondent was employed in Victoria between 1971 and 1986 as a fitter and welder, in which he said he was exposed to loud noise such that he had to raise his voice in order to be heard by someone a metre away. He said that between 1986 and 1997 he was self-employed as a horticulturist working with tractors and rack stackers. He said that the noise to which he was exposed was often loud such that he had to raise his voice from a metre away.

8. On 17 January 2023 the respondent initiated proceedings in the Personal Injury Commission (Commission) seeking determination of his disputed claim for compensation for permanent impairment of 16% from his injury of hearing loss.

9. On 15 February 2023 a delegate of the President of the Commission referred the matter to the Medical Assessor. As indicated above, the Medical Assessor issued a MAC on 15 March 2023. He set out in that, that he assessed the respondent had a binaural hearing impairment (BHI) of 29.8% from exposure to occupational noise. He indicated that when a mandatory deduction for presbyacusis of 3.3% was done the respondent’s BHI reduced to 26.5%. He also indicated that he assessed the respondent had 3% BHI due to severe tinnitus which, when that adjustment was made, resulted in a BHI of 29.5%. The Medical Assessor also said the following:

   “However there has been occupational noise exposure outside NSW as mentioned above and because it would be difficult for costly to determine the exact extent to which this extra jurisdictional noise exposure has contributed to the total I have made a 1/10 deduction to take this into account, as explained above. 1/10 of 29.5 is 2.95 which, when rounded to the first decimal point is 3.0. Deducting this gives 26.5% BHI which equals 13% WPI.”

10. The Medical Assessor said too within Part 4 of the MAC that due to the respondent’s work in Victoria he believed “a s 323(2) of 1/10 is required”.

PRELIMINARY REVIEW

1. The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7.

2. As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination. This is because neither party requested the Appeal Panel examine the respondent. Further, the only error that the Appeal Panel identified in the MAC did not require the Appeal Panel to examine the respondent in order to correct that error.

EVIDENCE

1. The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.

SUBMISSIONS

1. Both parties made written submissions. They are not repeated in full, but have been considered by the Appeal Panel.

2. The appellant in its submissions coined the term “non-jurisdictional employment” to refer to the respondent’s employment outside New South Wales and also to his self-employment. That is, employment to which s17 of the 1997 Act does not apply. The respondent adopted that term in its submissions. The Appeal Panel shall also use this term.

3. Both parties in their respective submissions contended that s 323 of the 1998 Act applied to determine whether any deduction should be made for any proportion of the respondent’s impairment from his injury of hearing loss that was due to his non-jurisdictional employment.

4. In summary, the appellant’s submissions were that the Medical Assessor was not able to assume pursuant to s 323(2) of the 1998 Act that the deduction to be made under s 323(1) was to be 10% because making that assumption was at odds with the available evidence. The appellant submitted that “the evidence called for a greater deduction”. The appellant submitted that the Medical Assessor did not provide sufficient reasons to indicate why he considered the extent of the deduction would be too difficult or costly to determine. The appellant noted that the respondent had a history of 52 years in noisy employment “of which 30 years were outside of the jurisdiction of the New South Wales compensation scheme”. The appellant submitted that “taking a common sense approach” the period of non-jurisdictional employment was such that a greater deduction than 10% ought to have been made.

5. The appellant submitted that the Medical Assessor ought to have adopted a “linear” method or “scaled” method to determine the deduction to be made under s 323(1) of the 1998 Act and referred to numerous decisions of other medical appeal panels to support that contention. The appellant described the linear method as involving a calculation of the percentage of a worker’s noisy employment that was non-jurisdictional and subtracting the percentage from the worker’s overall industrial deafness. The appellant described the scaled method as being based on a research article the International Organisation for Standardisation published titled “Acoustics – estimation of noise induced hearing loss” (the ISO standard).

6. The appellant also submitted that the point at which the Medical Assessor made the deduction under s 323 was incorrect. The appellant observed that the Medical Assessor applied the 10% deduction to the respondent’s total occupational BHI, rather than the respondent’s permanent impairment, which is the WPI figure that is obtained after a correction is made for presbyacusis and an addition made for tinnitus.

7. In reply, the respondent submits that the Guidelines do not incorporate the scaled method the appellant contended the Medical Assessor ought to have applied to determine the deduction to be made under s 323(1). The respondent submitted that to use the scaled method that relied upon an ISO standard would result in a denial of procedural fairness to him because the respondent had not had a chance to have its expert witness, namely Dr Scoppa, address that issue. The respondent referred to Pascoe v Mechita Pty Ltd[1] to support this submission. The respondent highlighted that neither his medical expert, Dr Scoppa, nor the appellant’s medical expert, Dr Howison, utilised the ISO standard to determine the extent to which the respondent’s non-jurisdictional employment contributed to his hearing loss. The respondent highlighted that both these medical experts, as well as the Medical Assessor, applied a 1/10^th deduction and none of them considered “that applying ISO would yield a more accurate outcome in terms of the contribution to the overall permanent impairment”.

   [1] [2019] NSWSC 454.

8. The respondent, with respect to the appellant’s submission that the Medical Assessor ought to have applied a linear method to determine the deduction to be made under s 323(1), submitted that there was no evidence that the noise to which he was exposed in his non-jurisdictional employment was the same as the noise exposure to which he was exposed in employment in New South Wales. The respondent submitted that for the Medical Assessor to make a deduction based on a linear method would have involved the Medical Assessor making an assumption or speculating that the noise to which he was exposed in non-jurisdictional employment was the same as that in which he was exposed in employment in New South Wales. The respondent submitted that that would be contrary to the authority of Pereira v Siemens Ltd.[2]

   [2] [2015] NSWSC 1133.

FINDINGS AND REASONS

1. The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made.

2. In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons.

3. The Appeal Panel agrees with the appellant’s submission relating to the stage at which the Medical Assessor made a deduction under s 323(1) of the 1998 Act. Section 323(1) requires a Medical Assessor, when assessing the degree of permanent impairment of a worker from an injury, to deduct any proportion of the worker’s permanent impairment that is due to any previous injury or that is due to any pre-existing condition or abnormality. When assessing the degree of permanent impairment that a worker has from an injury of hearing loss that is due to occupational noise and that is contracted by a gradual process, a Medical Assessor is required by clause 9.10 of the Guidelines to make a correction to the worker’s BHI for presbyacusis. Further clause 9.11 of the Guidelines allows for an increase of a worker’s BHI of up to 5% for severe tinnitus. Clause 9.11 also states these adjustments are required to be made “before determining whole person impairment (WPI)”. Hence the degree of permanent impairment resulting from an injury is assessed as WPI. If s 323(1) does apply, there is to be a deduction for any proportion of that WPI that is due to previous injury or pre-existing condition or abnormality. Section 323(2) states:

   “If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the medical evidence.”

4. In this case, the Medical Assessor deducted from the respondent’s total percentage BHI, a proportion of the BHI that the Medical Assessor considered was due to a pre-existing condition that the respondent had. The Medical Assessor consequently made the deduction prior to making the adjustments required to be made under clauses 9.10 and 9.11 of the Guidelines for presbyacusis and tinnitus. The Medical Assessor was, in accordance with s 323(1), required to make the deduction from the degree of the respondent’s permanent impairment, (that is the respondent’s WPI), which is calculated after presbycusis correction, if any, and addition for tinnitus, if applicable, and after conversion to WPI under clauses 9.10 and 9.11.

5. Simply put, the Medical Assessor erred because he made the deduction to the respondent’s BHI rather than the degree of permanent impairment the respondent had from his injury of hearing loss. Consequently the MAC contains a demonstrable error.

6. The Appeal Panel does not accept the appellant’s submission that the Medical Assessor erred by assuming the deduction to be made under s 323(1) of the 1998 Act was, in accordance with s 323(2), 10%. Section 323(2) reads as follows:

   “If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence.”

7. The respondent had a condition in his hearing organs, specifically his cochleas, at the time he commenced employment in New South Wales and that condition would have contributed to his occupational hearing impairment arising from his employment in New South Wales. That condition was damage to the hair cells of the respondent’s cochleas. That damage was caused by the respondent’s exposure to occupational noise between 1971 and 1997 when he was either employed in noisy employment in Victoria or in noisy self-employment. The cochlea is part of the inner ear and is similar in structure to a seas shell. It is approximately 33 millimetres in length. It has hair cells along its length and damage to those hair cells will cause hearing loss. The hair cells 10 millimetres along the cochlea from its basal opening are the first to be permanently damaged by exposure to hazardous occupational noise of a nature and duration to do so. The first permanent partial hearing loss occurs at frequencies affected in this region of the cochlea, namely at 3, 4 and 6 kHz even if asymptomatic. And with continuing exposure to that hazardous occupational noise the damage here gradually worsens causing increasing permanent partial hearing loss at these frequencies even if asymptomatic. Hence the damage is permanent and irreversible at the time it is caused. Further exposure to noise will progress the damage of the hairs deeper into the channel of the cochlea. The damage only progresses with exposure to hazardous noise.

8. Hence, at a particular date, if a worker has prior to that date been exposed to hazardous noise the worker will have permanent and irreversible damage to the hair cells of his or her cochleas. With further exposure after that date, the damage will progress. The damage at any particular date may not be severe enough to manifest the symptom of hearing loss but ultimately if the damage progresses due to further exposure to hazardous noise it will become severe enough such that it will manifest in the symptom of hearing loss.

9. The respondent’s statement indicates that he would have suffered some damage to his cochleas as at the time he commenced employment in New South Wales in 1998. He says in his statement that the noise to which he was exposed in self-employment and employment outside of New South Wales prior to 1998 required him to raise his voice in order to be heard by someone who was only one metre away from him. That is hazardous noise and would have been causing permanent and irreversible damage to his cochleas such that he would have had permanent partial hearing losses at 3 and 4 kHz. That is the case even though the respondent may not have been aware of it in 1998. And this permanent damage causing permanent partial hearing losses prior to 1998 contributes to his current hearing loss. The damage to his cochleas that occurred before 1998 has made a difference to his outcome, in terms of his current permanent hearing impairment, because without that damage his hearing loss now would not be as great.

1. Consequently, the Medical Assessor was right to apply s 323(1). As said, the Appeal Panel also considers that the Medical Assessor was right to also apply s 323(2) to determine the deduction that was to be made under s 323(1). In this matter, whilst there is evidence to establish that the respondent had permanent damage to his cochleas as at 1998, there is no evidence that establishes the extent to which his cochleas were damaged at this time. There is no medical evidence, specifically an audiogram, that may have established that. Based on the evidence that was before the Medical Assessor it was simply too difficult to determine the extent to which, whatever damage that had occurred to the respondent’s cochleas as at 1998, contributed to the respondent’s present permanent impairment from his injury of hearing loss.

2. The Appeal Panel considers that the Medical Assessor’s assumption, in accordance with s 323(2), that the deduction to be made under s 323(1), was 10% was not at odds with the available evidence. The Appeal Panel observes that whilst the respondent in his statement revealed that he was exposed to hazardous noise in non-jurisdictional employment, the respondent does not in any way describe the exact duration of his exposure to hazardous noise in that non-jurisdictional employment. He does not indicate whether he worked fulltime or part time or casually. Whilst he provided a general description of the loudness of noise to which he was exposed, he did not provide any detail to establish the frequency characteristics of the noise. These are all matters that are relevant to determining to what extent his cochleas would have been damaged by exposure to hazardous noise both in the period before 1998 and in the period thereafter. Absent such evidence, the assumption the Medical Assessor made that the deduction to be applied under s 323(1) for the pre-existing condition the respondent had from non-jurisdictional employment was to be 10%, was not at odds with the evidence. The evidence there was does not contradict that assumption.

3. To apply a linear method or a scaled method, as the appellant suggested, would be making an assumption regarding the extent to which the respondent’s cochleas were damaged as at 1998, in the circumstance where there is no legislative mandate to do that. The assumption that would need to be made if a linear method were to be used would be that the noise to which the respondent was exposed over the entirety of the period 1971 to 2022 was consistent in terms of the type of noise, the frequency of the noise, the intensity of the noise and the duration of the noise with respect to the number of days and hours the respondent worked in any particular period. The assumption that would need to be made if a scaled method was used, relying on the ISO standard, which provides a basis for calculating hearing disabilities according to statistical measures, is that the respondent’s circumstances correlate with the median upon which the standard is based. Unless s 323(2) is engaged in a particular case, the deduction to be made under s 323(1) must be based on fact determined by the available evidence and not assumption or hypothesis or speculation.[3]

   [3] Pereira v Siemens Ltd [2015] NSWSC 1133 at [81].

4. The Appeal Panel also observes that it is not open to it to examine that respondent so as to obtain a more complete history from him regarding his exposure to hazardous noise. This is because the Appeal Panel is unable to examine a worker so as to obtain evidence to establish whether there is or is not an error in a MAC.[4]

   [4] NSW Police Force v Registrar of the Workers Compensation Commission of NSW [2013] NSWSC 1792 at [35].

5. As said, the MAC does contain a demonstrable error regarding the stage at which the Medical Assessor made a deduction under s 323(1), which error the Appeal Panel is able to correct based on the evidence before it.

6. For these reasons, the Appeal Panel has determined that the MAC issued on 15 March 2023 should be revoked, and a new MAC should be issued. The new certificate is attached to this statement of reasons.

PERSONAL INJURY COMMISSION

APPEAL PANEL

MEDICAL ASSESSMENT CERTIFICATE

Injuries received after 1 January 2002

Matter number:	W373/23
Applicant:	Wentworth Shire Council
Respondent:	Colin Alexander Gray

This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act1998.

The Appeal Panel revokes the Medical Assessment Certificate of Medical Assessor Henley Harrison and issues this new Medical Assessment Certificate as to the matters set out in the Table below:

Table - calculation of whole person impairment (WPI) for industrial deafness as set out in the Table immediately below in accordance with Chapter 9 of the Guidelines for the Evaluation of Permanent Impairment and 1988 NAL Tables:

Notional date of injury	Frequency Hz	Left dB HL Air Bone	Right dB HL Air Bone	Total % BHI	Occupational % BHI
15/7/2022	500	60 35	35 25	6.3	0
1000	65 35	40 30	9.6	0
1500	60 35	40 35	7.5	6.4
2000	65 50	45 45	6.7	6.1
3000	80 70	70 70	8.0	7.7
4000	95 >60	85 >6.0	9.6	9.6
72.3	42.2	47.7	29.8
TOTAL % BHI: 47.7
Less Pre-existing non-related loss: (17.9) 29.8
Less Presbyacusis correction: 3.3
Add % of severe tinnitus: 3.0
Adjusted total % BHI: 29.5
Resultant total BHI of 29.5 % = 15 % whole person impairment (Table 9.1) Less deduction of 1/10 under s 323(1) = 13.5%, which when rounded is 14% WPI due to the injury.

The above assessment is made in accordance with the SIRA NSW Guidelines for the Evaluation of Permanent Impairment for injuries received after 1 January 2002