CERTIFICATE OF DETERMINATION OF MEMBER  	

Citation:	
Riddett v Manpower Services (Australia) Pty Ltd [2023] NSWPIC 22	
		
APPLICANT:	Gavin James Riddett	
		
RESPONDENT:	Manpower Services (Australia) Pty Ltd	
		
Member:	John Wynyard	
		
DATE OF DECISION:	18 January 2023	
		
CATCHWORDS:	WORKERS COMPENSATION - Claim for lump sum compensation for onset of gallstones; whether expert opinion based on correct assumptions; Held – applicant’s expert relied on statements by applicant as to relevant matters occurring since 2005 which were largely unsupported, vague and inconsistent both internally and with contemporaneous evidence; Cruceanu v Vix Technology (Australia) Limited and ACW v ACX considered; award for the respondent. 
	
determinations made:	1.	There is an award in favour of the respondent in respect of the claim for a consequential condition affecting the biliary tract, being cholecystitis and gallstones.
2.	I remit this matter to the President for referral to a Medical Assessor for a whole person impairment assessment on the following bases:
(a)	Date of injury:  21 May 2005.
(b)	Matter for assessment:
lumbar spine.
(c)	Evidence:	
Application to Resolve a Dispute and attached documents;
Reply and attached documents, and
respondent’s Application to 
Admit Late Documents dated 29 
November 2022.

STATEMENT OF REASONS
BACKGROUND
1.	Gavin James Riddett, the applicant, seeks lump sum compensation for impairment caused by injury to his back on 21 May 2005.  The impairment claimed was to his lumbar spine and, as a consequential condition, his digestive system.
2.	Dispute notices were issued by the insurer, and the Application to Resolve a Dispute (ARD) and Reply were duly lodged.
ISSUE FOR DETERMINATION
3.	The parties agree that the following issue remains in dispute:
(a)	did the ingestion of analgesic medication cause the applicant’s gallbladder condition?
 PROCEDURE BEFORE THE COMMISSION
4.		This matter was heard by video link on 29 November 2022.  The applicant was represented by Mr Simon Hunt of counsel, instructed by Mr Paul Mantach of Messrs MRM Lawyers.  
Mr Paul Stockley of counsel appeared for the respondent, instructed by Mr Christopher Michael of Messrs Moray & Agnew, lawyers. Mr Tom Bradford appeared for the insurer.
5.		I am satisfied that the parties to the dispute understand the nature of the application and the legal implications of any assertion made in the information supplied.  I have used my best endeavours in attempting to bring the parties to the dispute to a settlement acceptable to all of them.  I am satisfied that the parties have had sufficient opportunity to explore settlement and that they have been unable to reach an agreed resolution of the dispute.  
EVIDENCE
Documentary evidence
6.		The following documents were in evidence before the Commission and considered in making this determination: 
(a)	ARD and attached documents;
(b)	email dated 27 September 2022 of instructions to Dr Sethi, clinical notes and report of Dr Garvey (Admitted during the proceedings);
(c)	email dated 29 November 2022 containing the journal articles referred to by 
Dr Sethi – lodged pursuant to the applicant’s undertaking during the hearing;
(d)	Reply and attached documents, and
(e)	respondent Application to Admit Late Documents dated 16 November 2022.
Oral evidence
7.	No application was made regarding oral evidence.
FINDINGS AND REASONS 
Procedural
8.	At the commencement of the hearing by consent the ARD injury details were amended to add “and a consequential condition affecting the biliary tract being cholecystitis and gallstones”.
9.	The email dated 27 September 2022 referred indicated above was also admitted by consent.
Evidence
Mr Riddett’s statements
10.	Mr Riddett injured his lumbar spine on 21 May 2005, as indicated.  He was dragging a drainage pipe whilst working at the Vintage Golf Course at Pokolbin.  He made three statements dated 17 November 2020, 26 October 2021, and 27 April 2022.  In his first statement he outlined his work history, and the subsequent treatment and disabilities he was suffering as at 17 November 2020.  He said:
“2.	I left school in 1981 after completing Year 10.
3.	I worked in the building and construction industry from when I was 15 years old. I am a qualified plumber (1988) but in more recent years I have been employed as a civil labourer with Manpower Labour Hire (2002 to 2007) and later with Keller Civil Engineering (later known as KCE Pty ltd).
…….
10.	Following the injury I had physiotherapy treatment. The very severe pain settled down to a large extent and I was able to return to work but I had ongoing problems with my lower back from that time. I worked for another 2 years with Manpower. My back continued to play up and there were intermittent periods where I had very severe back pain. I kept on working and took pain relief medication consisting of over the counter codeine based drugs.
11.	In about March 2007 I became directly employed by Keller Civil Engineering and continued doing labouring work on the construction of subdivision sites and other development sites. I became a leading hand and I had some degree of control over what work I did because I could delegate to some extent but I still had to do my fair share of the heavy work. My back continued to trouble me and I continued to have to take significant amounts of pain relief to get through. I worked at various sites around the Hunter Valley in road construction and subdivision construction and there was also a period where I was working at the Roche Racquet Resort at Nelson Bay to develop that site.
12.	Drug testing came in around 2008 and each time I was tested I was found to be positive for codeine. My employer accepted that I was taking the medication for my back and allowed me to continue working but there were some sites where I could not work such as mine sites and railway construction sites where the drug testing was very strict and any positive testing for codeine was sufficient to prevent me working at those sites.
……..
Medical treatment
18.	My medical treatment was as follows:
•	21 May 2005 - Maitland Hospital Emergency Pain relief medication
•	X-ray (report not located)
•	Dr Kanta (GP)- 25 November 2015 Pain relief and referral for x-ray
•	X-ray (Jumbo-sacral) - 1 December 2015
•	Dr Kanta - 2 December 2015
•	25 June 2017 - Maitland Hospital
•	Taken by ambulance to hospital following onset of severe back pain and right leg pain after sneezing
•	Pain relief
•	CT scan (lumbar spine) - 28 June 2017
•	Dr Wasti (GP) - 2018
•	MRI (lumbar spine)-15 May 2018
•	Dr Khin Myat Wai (GP) of Wauchope and Port Macquarie - 30 July 2019 Complained of back pain
•	CT guided left S1 perineural steroid injection at Port Macquarie - 9 May 2019
•	January 2019 - John Hunter Hospital Orthopaedic Clinic
•	26 February 2019 and 7 March 2019 - Dr Didi Zhang - John Hunter Hospital Orthopaedic Clinic
•	13 June 2019 - John Hunter Hospital Orthopaedic Department - Dr George Awwad
•	Professor Ghabrial was involved in the consultation at the John Hunter Hospital Clinic
19.	My other health problems have included pancreatitis and gall bladder problems. I had my gall bladder removed on 24 April 2019 at Port Macquarie Base Hospital. I believe that the problems with my pancreas and gall bladder may be associated with the intensive use of codeine based pain relief medication.
26. 	[Continuing symptoms and disabilities] include:
•	I have had ongoing problems with pain, aching and restriction of movement in my lower back since 21 May 2005; these symptoms gradually became worse and more constant. I had left leg pain from the time of the original injury; this was intermittent at first but became more constant around 2011. The pain in my left leg comes from my back and into my left buttock and back of my calf and ankle. My left leg is numb from my left hip to my knee and outside of my calf. My toes are numb (but not my big toe).
•	The pain in my back and left leg is made worse with physical activity and particularly with lifting/carrying, bending, twisting, walking long distances, and standing for long periods.
•	My sleep is disturbed because of my back pain and I have difficulty getting comfortable in bed.
•	I take Panadeine Forte and Lyrica for the management of my back and left leg pain. I also take Endone when the pain is at its most severe levels but I do not like using this medication too often; I do not like the way that it makes me feel.”
11.	In his statement of 27 April 2022, Mr Riddett expanded on the history of his gallbladder condition.  He said:
“2. 	I first started having trouble with my gall bladder in about 2010 . I noticed severe pain in my stomach just under my sternum . I had been taking strong pain relief medications such as Nurofen Plus and Panadeine Forte and Panadeine Extra from the time of my back injury in 2005. When my back pain was severe I took a lot of pain relief so that I could continue working. I managed to continue in labouring work until July 2014 and by that stage, drug testing was required for some work sites and I was found to have positive tests for codeine and this prevented me from working at those sites. I could not work without the pain relief and I could not attend mine sites and railway sites with codeine in my system. My employment was terminated because of the drug testing issues.
3. 	After ceasing work there was initially some improvement in my back pain and I did not need to take as much pain relief. I noticed that my gallbladder and abdominal pain settled down when I reduced my use of pain relief medications. My back pain became severe again from 2015 and I had to rely on pain relief medication to manage the pain.  When I started to use more pain relief, the gallbladder and abdominal symptoms worsened. I reported these problems to Dr Wasti (GP). I put up with the problems for as long as I could and by April 2019, my gallbladder symptoms were severe and I could not tolerate the pain and on 
24 April 2019, I had my gall bladder removed by Dr Cooper at Port Macquarie Base Hospital.
4. 	The operation helped but I still have ongoing problems with my digestive system.  I continue to have trouble with the digestion of fatty foods and I have ongoing bowel issues; it alternates between constipation and "gastric" and it can be a bit of both on the one day.”
12.		The injury to the lumbar spine was accepted by the insurer, but the issue at large is whether there is any causal connection between the onset of Mr Riddett’s gallstone condition and the injury to the back.
Medico-legal
13.	The applicant relied on the opinion of Dr Siddarth Sethi, consultant gastroenterologist, dated 23 May 2022.  Dr Sethi said:
“On 21/5/05, Mr. Riddett was dragging a 6-metre-long plastic pipe along the ground. The pipe became caught causing him to twist his back. He experienced sudden onset lower back pain radiating to the left buttock and left leg. He attended hospital and was discharged home.
Subsequently, he received physiotherapy and was prescribed analgesia including Panadeine forte, Nurofen plus and Codeine. He was initially off work for 2 weeks and then returned.
Mr. Riddett has since experienced ongoing lower back pain radiating to the legs and feet. The pain would exacerbate every few days and required ongoing analgesic therapy including Panadeine forte, Lyrica and Endone. On 9/5/19, Computed Tomography guided injection of left Sl perineural steroid injection was performed. He ceased work in 2013 and has not worked since.
Mr. Riddett was first found to have gallstones in 2016. He had ongoing severe attacks of pain and underwent laparoscopic cholecystectomy on 24/4/19.
Since undergoing cholecystectomy, Mr. Riddett has experienced ongoing bloating, fullness and abdominal cramps. Bowel habits have been tending towards diarrhoea with loose runny stools that he passes several times daily. Previously, his bowel motions were fully formed. This is not related to any particular food or activity.
Prior to developing gallstones, Mr. Riddett did not experience any gastrointestinal symptoms. At present, his gastrointestinal symptoms are persisting.”
14.	Dr Sethis noted that Mr Riddett had ceased work in “June 2013” and has received a Newstart pension since.  In his opinion, Dr Sethi stated;
“Mr. Riddett has since experienced ongoing lower back pain radiating to the legs and feet. The pain would exacerbate every few days and required ongoing analgesic therapy including Panadeine forte, Lyrica and Endone. On 9/ 5/19, Computed Tomography guided injection of left 51 perineural steroid injection was performed . He ceased work in 2013 and has not worked since.
….
5.Diagnosis
The diagnosis is post-cholecystectomy syndrome that developed after taking analgesics for his work injury which contributed to him developing gallstones and subsequently requiring cholecystectomy.
7.Causation - consequential condition
There is a direct causation of the analgesic medications that Mr. Riddett was prescribed for his work injury which contributed to him developing gallstones and requiring cholecystectomy.
8. The rationale for your opinion as to causation
The rationale for my opinion as to causation is that the analgesic medication that he was prescribed contributed to him developing gallstones, which led to him requiring a cholecystectomy and subsequently developing post-cholecystectomy syndrome.”
15.	Mr Riddett was referred by the respondent to Dr John Garvey, surgeon, for an opinion as to the onset of Mr Riddett’s gallstones symptoms.  The respondent had obtained Emergency Department Triage notes dated 15 March 2005 from Maitland Hospital which pre-dated 
Mr Ridett’s back injury on 21 May 2005.    Dr Garvey reported on 8 July 2022. He took a consistent history of the back injury.  He said:
“[Mr Riddett’s] gallbladder started playing up in 2010 and was not too bad through to 2016 and he was referred to Maitland Hospital by Dr Wasti for advice on diet, but due to the stomach pain he could not breathe and this settled after 4 hours but eventually he had his gallbladder removed at Port Macquarie Hospital in 2018. It is noted that he experienced crampy right upper quadrant pain and diarrhoea on March 15, 2005 requiring admission to Maitland Hospital. This was almost certainly his 1st episode of biliary pain.”
16.	Dr Garvey found no causal relationship between the ingestion of medication and the onset of Mr Riddett’s cholelithiasis.  He said:
“‘There is no evidence that cholelithiasis developed from medication to treat his musculoskeletal injuries. His presentation to The Maitland Hospital for presumed acute biliary pain predated his date of injury by 6 days’.
So called Post cholecystectomy syndrome has no relationship to the injuries alleged in this claim.”
17.	The applicant sought a further opinion from Dr Sethi, who had not had access to the ER admission to Maitland Hospital of 15 March 2005. On 25 September 2022 Dr Sethi was advised, relevantly:
“An issue has arisen about whether Mr Ridett had relevant gallbladder symptoms prior to his back injury.  The issue has arisen because Mr Riddett had treatment at The Maitland Hospital Emergency Deapartment on 15 March 2005 for right sided chest pain and diarrhoea.”
18.	Dr Sethi was asked to comment and on 29 September 2022 he advised:
“On 15/3/05, Mr. Riddett attended the Emergency Department of Maitland Hospital with shortness of breath (SOB), diarrhoea and pain in the mid axillary chest region which was sharp in nature and worse on inspiration. 
The SOB was worse on taking deep breaths. He had not experienced similar pain before. He had occasional abdominal cramps but this was minimal. There was diarrhoea after eating food.
The impression was of either gastro or viral illness. Differential diagnosis included pneumothorax, pulmonary embolism and chest infection.
It was planned to perform a chest x ray (CXR), electrocardiograph ( ECG) and arterial blood gas (ABG). He was prescribed Ibuprofen and Codeine.
His pain improved and he was discharged home a couple of hours later on antibiotics with a plan to follow up with his genera l practitioner.”
19.	Dr Sethi said further:
“Dr. Garvey comments ‘It was noted that he experienced crampy right quadrant pain and diarrhoea on March 15, 2005 [requiring] admission to Maitland Hospital. This was almost certainly his 1st episode of biliary pain.’
I disagree with this. Mr. Riddett' s presentation was with right sided lateral chest pain and he did not experience abdominal pain. He was not admitted and was discharged home a few hours later. No mention of biliary pain was made in his clinical notes .
In summary, the new information does not cause me to alter any of the opinions expressed in my earlier report. I maintain the opinions expressed in my earlier report.”
20.	Dr Garvey’s advice was further sought, and on 14 November 2022 he wrote:
“The question… is whether NSAIDs and/or analgesic medication taken from 2005 for his low back pain contributed to the formation of gallstones. It appears the Worker took Nurofen for backache in March 2013 Panadol Osteo 2 tablets 3 times a day in December 2015. These are the only 2 prescriptions of these [medications] that are documented in the supplementary file.
 NSAIDs use does not have a significant impact on the prevalence of gallstones. It is possible that opioid analgesics have an effect on biliary motility, but this appears confined to the sphincter of Oddi and not necessarily gallbladder stone formation. I find on the balance of probabilities no causal connection between medication taken for the back injury in May 2005 and the workers biliary tract issues of cholecystitis.”
Clinical notes and records
21.		The triage notes at Maitland Base Hospital showed that Mr Riddett was admitted at 22:23 on 15 March 2005 as a Priority 4 – Semi Urgent case.  The admitting officer noted the applicant’s complaints of right chest pain.  Mr Riddett had developed diarrhoea over a four day period, and had been feeling hot and cold over that time, the entry said.  Two days prior he had developed pain in the right side of his chest laterally which had worsened the day earlier notwithstanding his taking regular Panadol.  Mr Riddett complained of pleuritic pain which was worse on inspection and movement.  Mr Riddett felt short of breath (SOB) and experienced pain on taking a deep breath. He had no cough, runny nose or earache.  He complained of occasional minimal abdominal cramps and that minimal eating caused diarrhoea with blood and pus.
22.		Clinical notes from the Rutherford Family Medical Practice showed a consultation with 
Mr Riddett by Dr Omer on 23 March 2011, with the next record being dated 19 August 2015. The earlier entry noted that Mr Riddett was taking Nurofen Plus for back ache.  The last entry in the clinical notes was dated 2 December 2015.  A prescription was printed for Panadol Osteo, 665 mg two tablets three times per day.
23.		Further clinical notes were lodged by Dr Wasti from Weston Surgery that covered the period from 3 March 2016, when Dr Wasti, recorded:
“Was seen at the hospital with abdo pain.  The pain has been mostly in the hepatic area.”
24.	An abdominal ultrasound was taken on 4 March 2016.  The report noted complaints of epigastric pain. It found:
“….The billary tree is not dilated.  The gallbladder is thin walled and contains multiple mobile calculi measuring up to 19mm in maximal dimension.
….
Comment:
Cholelithiasis without evidence of cholecystitis”
25.		Also in Dr Wasti’s notes was a referral to Dr Mark Lynn dated 9 May 2016, which stated:
“Has been complaining of pain intermittently for the past two years.  The pain, he states is getting [worse].  [A] U/S done recently is showing cholelithiasis.  He is unable to eat without getting pain in the abdomen.”
26.		Also recorded within the clinical notes was an entry dated 26 June 2017, in which Dr Wasti recorded:
“Went to TMH with exacerbation of back pain.  This was rt sided sciatic pain with chronic lower back pain.  The pain has been going on for about one week.  Usually it goes for 2/3 days.
Says it started with a sneeze and the back symptoms started.”
27.		This history was corroborated by the Maitland Hospital Discharge Referral dated 
25 June 2017.  The note referred to the plan for discharge which said:
“1. Discharge home
2 Analgesia regimen : regular paracetamol, Celecoxib twice-daily and breakthrough endone
•·> Patient counselled lo take celecoxib instead of nurofen / Ibuprofen
3. Follow up with GP, patient has appointment tomorrow.”
Orthopaedic medico-legal
28.		Dr Hopcroft, general surgeon, was retained by the applicant to advise regarding the back injury. In his report of 27 November 2020, he took a history that:
“At that review he cannot recall whether he had x-rays of his lumbar spine, but he was prescribed analgesics and sent for follow-up to his general practitioner.
Following the review by his general practitioner he undertook physiotherapeutic treatment at the physiotherapy facility directly opposite the Maitland Hospital….”
29.		Dr Hopcroft noted that Mr Riddett worked until 2013, being initially under the care of Vero, but that employment ceased following the positive drug test of 2013.  Dr Hopcroft said:
“At that time [December 2015], because of medications he was taking, he also developed some significant gastroenterological problems and was diagnosed with both pancreatitis and cholelithiasis.  (That ultimately led to his undergoing cholecystectomy at the Port Base Hospital on 24 April 2019 when he had an acute flare-up of his acute cholecystitis, at that time living with his sister at Wauchope).”
30.		In his report of 11 January 2022, Dr Machart, the respondent’s expert orthopaedic surgeon, who was concerned with the accepted back injury, noted the history that:
“Mr Riddett said that his position at KCE was terminated in 2013 because of the failed drug test. He tried to look for work. He was unsuccessful. He did a couple of months landscaping work in 2014 or 2015. The work was unrestricted. He did develop increasing pain which required analgesics, such as Panadeine Forte. This upset his gallbladder. He had a cholecystectomy in 2019.”
SUBMISSIONS
Mr Hunt
31.	Mr Hunt submitted that there was contemporaneous support within the clinical notes for 
Mr Riddett’s statement that he had been using analgesia since the occasion of his back injury on 21 May 2005. He referred to Mr Riddett’s statement of 17 November 2020 and the clinical notes which he argued confirmed that analgesic medication had always been taken since the back injury. Mr Hunt acknowledged that Mr Riddett’s complaints in the statements he lodged post-dated the gallbladder removal, but the clinical notes confirmed, he submitted, that analgesia had always been taken.
32.	Mr Hunt also relied on the third statement of 27 April 2022 which went into more detail about  the onset of the gallbladder problem in 2010.    
33.	He referred to the Maitland Hospital Emergency Department triage notes dated 
15 March 2005, some two months before the subject injury.    Whilst Mr Riddett did not refer to this admission in his statement, Mr Hunt submitted that the fact of the admission and the content of the note were not in dispute. 
34.	Although Dr Garvey had attached some significance to those notes in his report of 
8 July 2022, Mr Hunt submitted that I would accept the opinion of Dr Sethi that the symptoms described in the note were not biliary symptoms.  It was more probable that the analgesic medication for the back injury was the cause of the subsequent onset of the gallbladder and urinary tract disease. 
35.	Mr Hunt referred to various entries in the triage notes of 15 March 2005.  He noted that the presenting complaint had been of chest pain.  He also referred to the presence of diarrhoea and relied on Dr Sethi’s view that such a symptom was indicative of a respiratory ailment.    
36.	Mr Hunt then referred to the applicant’s admission to Maitland Hospital on the date of injury, 21 May 2005.  This, he said, established that Mr Riddett had been taking analgesia since 2005, as he was discharged to the care of his doctor, and Mr Riddett said in his statement that he took analgesia from that time on.
37.	Mr Hunt submitted that the clinical notes were consistent with Mr Riddett’s assertion that he had been taking analgesia regularly. He referred to the discharge summary from the Maitland Hospital of 25 June 2017 and the medication regime noted therein.  He referred to further prescriptions made in 2017 and later until Mr Riddett presented at the Port Macquarie Hospital for his gallbladder surgery in April 2019.  He noted that the ultrasound confirmed the presence of gallstones.
38.	Mr Hunt then considered the opinions of the two experts, Dr Sethi and Dr Garvey. 
39.	He first referred to the orthopaedic experts to further demonstrate that Mr Riddett’s evidence could be accepted.  Mr Hunt submitted that there was a consistency in the histories taken for the back injury with Mr Riddett’s statements. He relied on Dr Hopcroft’s history, which related that Mr Riddett was prescribed analgesics and sent for follow up to his general practitioner, who reviewed him.  The history of his working until 2013 was consistent with his statement, it was submitted.  Dr Machart also recorded that Mr Riddett took Nurofen as necessary.  
Mr Hunt also relied on Dr Machart’s history that Mr Riddett took Lyrica and Endone in 2015.
40.	Mr Hunt then referred to Dr Sethi’s report of 23 May 2022.  He submitted that there was no evidence of any problems prior to the injury with Mr Riddett’s gallbladder and in addition to the medication indicated in the clinical notes, Dr Sethi noted that Mr Riddett had been taking other medication such as Endone and Lyrica. 
41.	Mr Hunt relied on the opinion of Dr Sethi particularly inclusion in the opinion of articles from medical journal. 
42.	Mr Hunt then considered Dr Sethi’s supplementary opinion regarding the hospital admission in March 2005, noting that there had been a comment that there was minimal abdominal symptomatology and there are no investigation of Mr Riddett’s digestive gastroenteritis system. 
43.	In contrast he submitted that Dr Garvey’s opinion was an ipse dixit. He had not taken the correct history in any event in his subsequent report dated 14 November 2022 contained in the Application to Admit Late Documents when he said there were only two prescriptions of Panadol Osteo or Nurofen that were documented in the “supplementary file”.  That was clearly inaccurate compared to the contents of the previous notes.
44.	He submitted that there is a clear history of back symptomatology.  The applicant stated he had ongoing pain for which he took medication which also could not be challenged and that on the ordinary application of Kooragang Cement Pty Ltd v Bates principle there was a causal connection made.
Mr Stockley
45.	Mr Stockley submitted that the interpretation of the hospital notes regarding the 
15 March 2005 differed between the two experts Dr Sethi and Dr Garvey.  He discussed the detail of the entries, but submitted that the resolution of this issue was not definitive so far as the essential issue in the case was concerned. Mr Stockley said that the nub was the difference between the two experts as to the cause of the gallstone condition.
46.	Mr Stockley submitted that the matter in the case was the resolution of the different opinions from Dr Garvey and Dr Sethi.  He noted that nothing had been lodged by Dr Lynn following the referral of Mr Riddett’s case in 2016 when the gallbladder problem was first diagnosed, and neither was any opinion obtained from Dr Wasti in the clinical notes Mr Hunt had been relying on so heavily.
47.	Mr Stockley said it was odd, in view that it was said that the ingestion of analgesia was the cause of the gallstones that in fact nonetheless Dr Wasti continued to prescribe analgesia even after the diagnosis of cholecystitis had been made.  He said there was no obvious causal nexus in the contemporaneous evidence. There was no suggestion that any of the medical practitioners had counselled against taking the medication which raised the question that any causal connection with the gallbladder problems was somewhat problematic.
48.	Mr Stockley said that Dr Sethi’s opinion as to causation was the nub of the case.  He diverted to observe that none of the experts assisted by explaining what the multi-syllabic terminology used actually meant.  Mr Stockley explained his understanding of what a gallbladder was and that led to a discussion as to the admissibility of such statements in the light of the availability of Google to cross reference these terms and indeed the anatomical site and function of the gallbladder.
49.	In any event Mr Stockley referred to the operation report of Dr Enoch, which noted that an ultrasound showed “impacted stones within Hartmann’s pouch, gallbladder wall thickening and pericholecystic fluid”.  Mr Stockley noted Dr Enoch’s diagnosis of cholecystitis and that a laparoscopic cholecystectomy was the removal of the gallbladder.  There was unanimity that the treatment was appropriate.
50.	The next question, Mr Stockley asked rhetorically, was how did the back injury and ingestion of opioids and other analgesics cause the gallstones? 
51.	Mr Stockley referred to Dr Sethi’s opinion in his first report of 23 May 2022 and noted that 
Dr Sethi’s opinion was that Mr Riddett had developed gallstones secondary to the analgesic medication that he was prescribed for his work injury.  This could lead to only one inference, Mr Stockley said, which was that analgesic medication somehow caused gallstones to develop.  Dr Sethi then referred to academic journals, which as I understood Mr Stockley, were not concerned with gallstones, but with gastrointestinal and biliary tract motility.
52.	Mr Stockley advised that he had read the first article, but was not able to find the second.  (As indicated, the applicant kindly furnished me with copies of both). The first journal  confirmed the scientific and medical literature that opioid medications such as the type 
Mr Riddett had been prescribed reduced gastrointestinal and biliary tract motility.  
Mr Stockley suggested however that it did not assist the applicant’s case, because it did not explain how the actual gallstones had been caused by the analgesia.  
53.	When Dr Sethi said that the opioid medications Mr Riddett was prescribed caused him to develop gallstones Mr Stockley submitted there needed to be an explanation as to why that was so.  Mr Stockley did not discount the possibility that there might have been some support for that opinion within the medical science but Dr Sethi did not explain what that was. 
54.	Dr Sethi’s opinion was unambiguous, Mr Stockley submitted. He said that the gallstones were caused by the analgesic medication.  That was not the proposition the journal articles stood for at all, Mr Stockley argued.
55.	Mr Stockley acknowledged that the same criticism could be made of his own expert 
Dr Garvey who was equally terse and short. Mr Stockley repeated again that the interpretation of what the cause of the hospital admission in March 2005 was something that needed a determination but he said did not consist of primary challenge to the applicant’s claim.
56.	In his second report Dr Garvey acknowledged the academic literature and agreed with 
Dr Sethi’s summary thereof – that they related to motility and not gallstone formation. The question then posed by Dr Garvey was a proper summation of the issue, Mr Stockley submitted, which was whether the NSAIDS and/or analgesic medication taken from 2005 for the applicant’s low back pain contributed to the formation of gallstones.
57.	Mr Stockley noted that Dr Garvey had stated that it was “possible” that opioid analgesics have an effect on biliary motility but motility did not resolve the question of whether gallstones had been caused by the ingestion of the analgesics.  The causal chain had not been established. 
Mr Hunt in reply
58.	Mr Hunt submitted that the concession made by Dr Garvey was relevant because he did not only say that it was possible that opioid analgesics would have an effect on biliary motility but also it was possible that opioid analgesics would have an effect on the formation of gallstones, the words “not necessarily” allowing for such a possibility.
Mr Stockley (by leave)
59.	Mr Stockley submitted that it could not be that the ingestion of Panadeine caused a gallstone or made it bigger.  He repeated that Dr Sethi said that medication had caused the gallstone but did not give any explanation as to how that could be.
Discussion
60.	The nub of this case concerns an assessment of the expert evidence of Dr Sethi and 
Dr Garvey.  Dr Sethi was unambiguous in his opinion of 23 May 2022.  He said both that opioid medications of the type that the applicant was “prescribed” were well described in the medical and scientific literature to reduce gastrointestinal and biliary tract motility, and that the opioid medications the applicant was “prescribed” for his back injury “directly” caused the development of gallstones. Dr Sethi said further that the analgesia “contributed” to the development of gallstones.  There was a “direct causation”.  He also relied on medical and scientific literature.
61.	To deal with the scientific literature first, Dr Sethi referred to an article published online from jnm.snmjournals.org. It was entitled “Effect of Sequential Administration of an Opioid and Cholecystokinin on Gallbladder Ejection Fraction: Brief Communication” by Shakuntala Krishnamurthy and Gerbail T. Krishnamurthy from the Nuclear Medicine Department, Tuality Community Hospital, Hillsboro, Oregon, published in the September 2006.  This was a study that tested the effects of opioid intake on a sample of 49 patients.  It was concerned with the ejection fraction and the effect of opioids on the tonus of the pyloric and Oddi sphincters.  The effect was in general that opioids decreased gastrointestinal and biliary tract motility, and increased the tonus of the two sphincters.
62.	The second article was published in MDEdge Internal Medicine on 19 May 2019.  It was entitled “Opioid use associated with common bile duct dilation”. By Kari Oakes.  This reported on a sample of 867 patients who used opioids and 818 patients who did not.  Those who did were found to have a significantly larger bile duct diameter.
63.	It can accordingly be accepted that the two articles supported Dr Sethi when he advised that opioids can reduce biliary tract motility and cause biliary dilatation. Dr Sethi noted that 
Mr Riddett’s surgery was required because Mr Riddett had developed gallstones.  I did not read either article as suggesting that the effect of opioids in reducing biliary tract motility or causing biliary dilation actually caused gallstones to develop.  
64.	On 8 July 2022 Dr Garvey’s opinion was that there was no evidence that medication was responsible for the development of his cholethiasis. Dr Garvey had available the Maitland Hospital Discharge of 15 March 2015 and presumed that biliary pain had been responsible. I shall return to that issue presently.
65.	Dr Garvey reported further on 14 November 2022, confirming his opinion that there was no causal link.  His explanation referred to “the supplementary file” which apparently showed only two prescriptions for medication – one in March 2013 and the other in December 2015.  Mr Hunt submitted that the clinical notes demonstrated more medication being taken than that assumed by Dr Garvey and that accordingly Dr Garvey’s report could not be seen as probative.  
66.	As to Dr Garvey’s opinion whether the ingestion of analgesia could cause gallstones, his reasoning did not entirely exclude such a possibility.  It is settled law that a concession of a medical possibility is capable, after examination of the lay evidence, of being found to be probable.    Dr Garvey conceded that it was “possible” that opioid analgesics have an effect on biliary motility, but that this “appeared to be” confined to the sphincter of Oddi, and “not necessarily” gallbladder stone formation.  Dr Garvey has accordingly conceded that there was a possibility that opioid medication could cause gallstones.
67.	It does not however follow that because Dr Garvey made that concession, I must accept the opinion of Dr Sethi.    
68.	Dr Sethi’s opinion that analgesic medication had caused Mr Riddett’s gallstone condition was necessarily based on assumptions as to the identities of the medicines, their strength, and the regularity with which they were taken.  Dr Sethi at no time attempted to describe this part of his opinion, and did not explain over what period of time it could be expected that the consumption of the various opioid analgesics would result in the formation of gallstones, nor of what strength he would expect the medication to be. 
69.	Support for the assumptions he did make came principally from Mr Riddett’s statements.  The clinical notes were said by Mr Hunt to provide probative weight in that they demonstrated that from time to time Mr Riddett sought medical attention, and inferences could therefore be drawn. 
70.	It was submitted that the discharge summary from the Maitland Hospital on the date of injury, 21 May 2005, afforded corroboration for Mr Riddett’s evidence.  However the hypothesis that Mr Riddett was discharged into the care of his doctor and therefore had been taking analgesia since, was somewhat compromised by the fact that there was no evidence of any care by a doctor until 23 November 2011.  It is convenient to set out the chronology of 
Mr Riddett’s recorded treatment.
71.	The clinical notes demonstrate that Mr Riddett sought medical treatment as follows:
“Rutherford Family Medical Centre
•	23 March 2011. Dr Omer noted a tooth abscess and carbuncle on the right arm. Noted “on nurofen” for back  
•	19 August 2015.  Dr Kantta noted complaints of a personal nature that were not connected with either the applicant’s back or gallstones.  A series of tests were scheduled. Prescribed Fluocloxaclinnen and Amoxil. 
•	26 August 2015.  Dr Kantta discussed abnormal blood test results with Mr Riddett
•	3 September 2015.  Dr Kantta noted improvement.  Further blood tests to be taken in 4 weeks.
•	23 September 2015. Dr Kantta recorded episodic epigastric pain for a few weeks – more after stress.
•	1 October 2015.  Blood tests taken, and breath test to be taken the following weeks, Dr Kantta noted.
•	14 October 2015.  Dr Kantta recorded that the applicant had a helicobacter pylori infection, for which he was prescribed Nexium.
•	25 November 2015.  Dr Kantta noted epigastric pain for a few days, and a further breath test was ordered.  Dr Kantta noted a complaint of worsening back pain and prescribed Panadol “PRN” (when required). 
•	2 December 2015.  Health assessment by Michelle Hudson, recording danger of developing diabetes and other unrelated health matters.
•	2 December 2015.  Dr Kantta recorded complaints of ongoing pain in the left thigh and leg.  Nexium and Panadol osteo prescribed.
Weston Surgery
•	3 March 2016.  Dr Wasti noted that Mr Riddett had been seen at the hospital for abdo pain.  (No record of that admission was lodged). Pain was located mainly in the hepatic rea. Prescribed nexium
•	8 March 2016.  Dr Wasti recorded that a recent ultrasound showed cholelithiasis no relevant medication.
•	20 April 2016.  Dr Wasti noted complaints of pain in the hepatic area, and advised Mr Riddett to ‘see the surgeon ASAP’.  Prescriptions for Nexium and another irrelevant medication were printed.
•	9 May 2016. Dr Wasti noted persisting pain. No prescription
•	7 June 2016.  Dr Wasti noted that Mr Riddett did not see the surgeon. Relevant medication Tramadol Actavis
•	13 July 2016.  Dr Watsi prescribed Tramadol Activis.
•	16 August and 23 September 2016.  Dr Wasti issues one month Centrelink certificates for ‘the current disability.’
•	25 October 2016. Dr Wasti noted that Dr Lynn had been seen and Mr Riddett was on a waiting list.  ‘Some medications have been introduced das an interim measure to cholecystectomy.’ Medications started were Panadeine Plus, Nurofen Plus and Buscopan.
•	20 April 2017.  Dr Khan noted that surgery was booked for the following month.
•	26 June 2017.  Dr Wasti recorded that Mr Riddett had been to The Maitland Hospital after an exacerbation of back pain caused by sneezing.
•	6 September 2017.  Dr Wasti noted that Mr Riddett wanted a MC (medical certificate) for the CL (cholecystitis).
•	11 October 2017.  Dr Wasti recorded complaints of back pain all the time. ‘This happened in 2005 and has been getting gradually [worse].’
•	Further entries in November and December 2017 were uninformative, as 
Mr Riddett was obtaining Centrelink certificates.
•	23 February 2018.  Dr Wasti reported a complaint of severe abdo pain since 2am. An ambulance was called, but Mr Riddett ‘absconded.’
•	5 March 2018.  Dr Wasti reported that Mr Riddett had ‘pancreatitis – acute’.” 
72.	The remaining entries are of less interest, as it is clear that Mr Riddett’s gallstone problems were diagnosed by 8 March 2016.  Indeed an ultrasound dated 4 March 2016 found multiple mobile calculi of up to 19mm dimension.  It also found that the biliary tree was not dilated. 
73.	Mr Stockley submitted that the continued prescription of opioid medication by Dr Wasti after that diagnosis was remarkable, if indeed it were thought that analgesic medication had a causal relationship to the onset of gallstones.  The point is well made, and it leads to a consideration of just what medication had in fact been taken by Mr Riddett.
74.	In the period 21 May 2005 to 23 August 2015 only the visit of 23 November 2011 occurred. Panadol was noted.  From 3 March 2015 Mr Riddett was prescribed Tramadol Actavis after he had been diagnosed with his gallstone problem, on 7 June 2016 and 13 July 2016. He was prescribed Panadeine Plus, and Nurofen Plus from 25 October 2016. Dr Garvey noted Nurofen in March 2013 and Panadol Osteo in December 2015 in the material available to him.
75.	Dr Sethi’s opinion of 23 May 2022 was therefore largely dependent on the accuracy of 
Mr Riddett’s history. Even assuming that the “supplementary file” referred to by Dr Garvey was accurate (which I decline to find as a fact, as the evidence was not before me), that would be only three references, 2011, 2013 and 2015 to the ingestion of analgesia. 
76.	Dr Sethi’s assumption that Mr Riddett “was subsequently” after the injury in 2005 prescribed analgesia which included Panadeine Forte, Nurofen Plus and Codeine, has no contemporaneous independent corroboration.  Dr Sethi also assumed that “since,” 
Mr Riddett had required “ongoing analgesic therapy including Panadeine Forte, Lyrica and Endone”.
77.	The assumptions are obtuse in any event, as the sense of Dr Sethi’s meaning seems to imply that these medications have been ingested since 2005, but his use of the word “subsequently” makes it impossible to be sure.  It raises the question, subsequent to what? He repeated the history twice that the back pain would exacerbate every few days, but gave no indication as to whether those symptoms had been suffered since the injury, or any other time.  The use of the word “since” is equally devoid of utility.  This makes it difficult to understand his opinion that “the medication Mr Riddett was prescribed contributed to him developing gallstones”.    
78.	In his first statement dated 17 November 2020, Mr Riddett was concerned with his back injury.  He stated that he medicated with over-the-counter codeine-based drugs whilst he worked the next two years with the respondent.  He did not allege he was prescribed any medicine, and particularly not, it would seem, the opioid analgesia identified by Dr Sethi.  As at the date of his statement, Mr Riddett said he was taking Panadeine Forte, Lyrica and occasionally Endone, but did not suggest he had been taking it when he was diagnosed in March 2016 with his gallstones condition.  
79.	In his statement of 27 April 2022 however, Mr Riddett alleged that he had first noted gallbladder problems in “about 2010”.  This history was recorded by Dr Sethi and Dr Garvey but no enquiry was made as to further detail.  There is no record of Mr Riddett having sought medical treatment in 2010, and he did not indicate on what basis he concluded that he had gallbladder trouble.  The symptoms of gallbladder related trouble were discussed by Dr Sethi and Dr Garvey in the context of the symptoms recorded by the Maitland Hospital on 
15 March 2005, and it does not appear that a person with no medical knowledge could self-diagnose gallbladder trouble.  I note that Mr Riddett described his condition as “gallbladder and abdominal pain” when he continued his narrative and it may be that he was conflating his egigastric symptoms with his gallbladder condition in hindsight.  
80.	Mr Riddett also said that his back became severe again in 2015, as a result of which he “started to use more pain relief”.    The evidence from the Rutherford Family Medical Practice demonstrated that Mr Riddett did indeed seek medical treatment in 2015, but it was not initially in regard to his back, but rather of a more personal nature when he first visited 
Dr Kantta on 19 August 2015.  He was also having episodic gastric pain which he complained about on 23 September 2015 as having been experienced for a few weeks.  Subsequent tests showed that he had a helibacter pylori infection, and he was prescribed Nexium.  Thus the abdominal complaints in 2015, which he attributed to his gallbladder in 2022, were demonstrated to be stomach problems caused by a helibacter pylori infection. He did however complain of worsening back pain on 25 November 2015 and the entry shows he was prescribed Panadol.
81.	In any event the helibacter pylori infection demonstrates that Dr Sethi was also incorrect to find that prior to his developing gallstones, Mr Riddett did not experience any gastrointestinal symptoms.    Dr Hopcroft was also incorrect when he recorded that Mr Riddett was diagnosed with pancreatitis and cholithiasis in December 2015.  The divergence in histories from Mr Riddett is emblematic of the difficulty facing the applicant’s proof.
82.	Mr Riddett’s statement of 27 April 2022 was in the most general terms, which is understandable, as he was attempting to recall in 2022 the events of the past 17 years. However, he stated that when his “gallbladder and abdominal symptoms” worsened, he reported them to Dr Wasti.  The clinical notes demonstrate that this occurred on 
3 March 2016, following an admission to hospital for abdominal pain.  As indicated, an ultrasound the following day demonstrated multiple calculi in the gallbladder.  
83.	Mr Riddett also said in his statement of 27 April 2022 that he had been taking Nurofen Plus, Panadeine Forte and Panadeine Extra “from the time of my back injury in 2005”.  This allegation was inconsistent with his first statement two years earlier that said he only took over-the-counter codeine-based analgesia.
84.	Mr Riddett was struggling with other life issues, and he told Dr Kantta on 19 August 2015 that he had not seen a doctor in four years.  He was homeless for a while in 2019, and has been in receipt of a Centrelink pension since 2014.  
85.	It can be seen then that Dr Sethi based his assumptions of fact principally on what he was told by Mr Riddett.  However, Mr Riddett’s evidence suffered from both the inconsistencies I have alluded to, and a lack of objective contemporaneous support. In view of these matters I decline to draw the inferences urged by Mr Hunt.
86.	I hasten to add, however, that I do not doubt that Mr Riddett was doing his best to assist the Commission by recalling his history as accurately as he could.  I make no criticism of his honesty and do not intend to suggest that he has deliberately sought to portray the events he has described dishonestly.  The difficulty is that he was attempting to recall events in both 2020 and 2022 that stretched back over almost two decades. There is a danger that, in attempting to recall these events, he may have innocently but inaccurately reconstructed the sequence of events.  The danger is heightened when a deponent has an interest in the outcome, as Mr Riddett does.
87.	I intimated that I would return to the dispute as to the cause of Mr Riddett’s admission to Maitland Hospital on 15 March 2015, where Dr Garvey advised that its cause had been biliary pain, whereas Dr Sethi advised to the contrary. In view of my determination it is not necessary to express any concluded view. The issue has become something of a red herring, and I put it to one side, noting that the relevant investigation, the ultrasound of 
4 March 2016, showed that the biliary “tree” was not dilated.
88.	In summary, I do not accept Dr Sethi’s opinion, as the assumptions upon which it was based were not substantiated.  The vagaries and inconsistencies in Mr Riddett’s statements prevent a finding that Dr Sethi’s opinion was made in a fair climate. In ACW v ACX President Judge Phillips stated at [60]:
“The question identified in Paric No. 1 was “whether the hypothetical material put to the expert witnesses represents a fair climate for the opinions they expressed”. In the context of the Commission, applying the decision in Hancock (see [53] above), the lack of correlation between the facts assumed and the facts as proven, deprived Dr Coughlan’s opinion of probative force. This is inherent in the Member’s finding in the reasons at [103], that the appellant had failed to prove the relevant causal connection.”
(Citations omitted).
89.	Further, Dr Sethi’s opinion at best only suggested that the ingestion of opioid analgesia affected biliary motility. That was the effect of the scientific journals he relied on, and he did not satisfactorily explain how such ingestion actually caused the gallstones.  His opinion regarding motility was further affected as he did not discuss the ultrasound of 4 March 2016, which demonstrated that there was no biliary duct dilation, and that multiple mobile calculi measuring up to 19mm in maximal dimension were seen within the gallbladder. How they got there was not explained.
90.	Accordingly, there is an award in favour of the respondent in respect of the claim for a consequential condition affecting the biliary tract being cholecystitis and gallstones.
91.	The claim for lump sum compensation for the back injury is remitted.