An employer disputed liability for a physical injury based on a medical opinion that was ambiguous on its face as to the nature and cause of a worker’s injury, an injury which clearly had some relationship to work.
Whether, at s81A hearing stage:
- The worker's claim is limited to what is described in the claim form and medical certificate; and
- A medical opinion which does not provide a conclusive opinion on causation is sufficient for a reasonably arguable case finding.
The worker made a claim for compensation for an injury that was asserted to have occurred on 4 May 2018 after driving a 'battery reach fork'. As he walked away, he felt severe pain in his lower back and pain through his right hip. The initial workers' compensation medical certificate described the condition as an injury and a new condition (not an aggravation of a pre-existing one). There was a history of back pain and treatment pre-dating the claim.
The worker was examined by a neurosurgeon who diagnosed aggravation of lumbar spondylosis and concluded that a reasonable argument can be made that his employment has been a major contributing factor to the aggravation of lumbar spondylosis. The neurosurgeon suggested the worker did not suffer a traumatic incident on 4 May however the acute symptoms he experienced on that day were due to pre-existing lumbar spondylosis to which employment over a long period of time has made some contribution including by acceleration.
The employer relied upon this opinion to dispute that the worker had suffered an injury in accordance with s25 of the Act.
The Tribunal’s decision
The Tribunal found that there was a reasonably arguable case in accordance with s81A of the Act that the employer was not liable for the worker's injury. Accepting the employer's argument that based on the neurosurgeon's opinion, it was reasonably arguable that the worker had not suffered a work related injury on 4 May 2018. It was conceded that there may well have been a pre-existing condition which was work related, but that the claim (as described by the worker in the claim form and the treating GP in the medical certificate) related to an injury in the primary sense (not an aggravation or acceleration) which had occurred on 4 May 2018, and the neurosurgeon's opinion was that there was no work related event or activity on that date that resulted in a such an injury. In any event, the neurosurgeon's evidence did not establish a causal link between an incident on 4 May and a specific injury or aggravation.
The Supreme Court decision
The Court did not accept that the claim is defined and constrained by what the worker describes in the claim form, nor what the GP states in the medical certificate. The worker is not required to identify which pathway under s25 (be it injury, disease or aggravation) his condition falls under. All that is required is that he provide sufficient information for the employer to be able to identify the injury.
However, the Tribunal's reasonably arguable case finding was upheld because the neurosurgeon's opinion may or may not support a finding that employment was the major or most significant contributing factor to the aggravation (as required by s25 and s3(1)). In these circumstances (as St Helens Oysters Pty Ltd v Coatsworth  TASSC 90) it was not possible to determine whether the employment was the major or most significant factor in the aggravation which was sufficient for a reasonably arguable case finding.
The Full Court decision
The Supreme Court decision was upheld.
The Full Court confirmed that the issue for the Tribunal was whether the neurosurgeon's opinion might reasonably be argued as establishing that the major or most significant contributing factor could not be said to be the worker's employment, because it was not possible to determine what role his employment actually played in the exacerbation of his congenital spondylosis, as opposed to other factors, including the natural progression of the degenerative changes in his spine.
Confirming importantly: what the employer is required to prove is not that there is no liability under s25 of the Act, but only that there exists a reasonable chance that the worker will be unable to discharge his onus of proof that will ultimately rest with the worker on a final s42 hearing of the worker's claim. The employer was not required to positively prove that some specific factor other than the worker's employment was the major or most significant contributing factor.
The Full Court accepted that the neurosurgeon's opinion was insufficient to establish employment as the major or most significant contributing factor, inferring that he had the opportunity to clearly state that employment was the major or most significant contributing factor if he had believed so. However he did not use those words in his report.
Implications for you
It can be difficult to pin an expert down on his or her opinion. At s81A stage, where there is limited time to investigate causation, it will usually be sufficient to bring a claim into dispute if the evidence suggests that employment may not be the cause of the injury, disease or aggravation. If relying upon medical evidence it is important that the assessor has taken a complete history and undertaken a comprehensive analysis of issues to support an argument that the expert opinion complies with expert codes of conduct. Mercifully, an employer should not have to establish that a possible non-work related cause is the cause of the injury.