Helen Huang
Special Counsel
CTP Insurance, Insurance
Revisiting the Medical and Non-Medical Tests for Causation
22 April, 2025
In Brief
- The test of causation in involves both medical and factual questions.
- Causation is established if an accident could have caused the alleged injury, from a medical perspective, and on the balance of probabilities did cause that injury, from a factual perspective.
- Factual causation only requires material contribution rather than scientific certainty.
Facts
The Personal Injury Commission (PIC) published its decision in Witt v Insurance Australia Limited t/as NRMA Insurance [2025] NSWPICMP 238 on 17 April 2025.
The Claimant was involved in a motor accident on 28 May 2023.
The original Medical Assessor determined the Claimant sustained soft tissue injuries to her cervical spine, thoracic spine and lumbar spine and a muscle strain to her groin, which are all threshold injuries for the purposes of the Act.
The Claimant sought a review of the medical assessment. She argued that the original Medical Assessor did not consider the MRI scan to the lumbar spine which revealed the presence of a compression fracture at T12/L1.
The Review Panel’s Determination
The Panel determined the accident caused soft tissue injuries to the groin and cervical spine, which are threshold injuries for the purposes of the Act.
The Panel accepted that MRI scan evidence of a disc protrusion with an annular tear at the L5/S1 level was likely age-related degeneration, rather than, caused by the accident because the Claimant did not experience immediate severe pain and the Claimant reported that her symptoms in that region had improved.
The Panel accepted the accident caused the compression fractures depicted on the MRI scan, which are non-threshold injuries, because:
- The Claimant complained of pain in her thoracic spine and lumbar spine in the initial days after the motor accident.
- The thoraco-lumbar junction can be subject to greater forces in a flexion-extension injury.
- The Claimant is more likely to have reduced bone strength considering her long standing history of schizophrenia, anti-psychotic medications and smoking.
- The Claimant underwent the MRI scan six months after the motor accident which disclosed a compression fracture of the T12 and L1 vertebrates.
- The Claimant’s treating spinal surgeon determined the fractures were caused by the accident.
The Review Panel revoked the Medical Assessor’s Certificate and certified that the accident caused non-threshold injuries.
Why This Case is Important
The Review Panel in Witt reminded itself at [90] that the test of causation involves a medical decision and a non-medical informed judgment. That is:
- Whether, from a medical perspective, the compression fractures could have been caused by the forces involved in the accident, and
- Whether, from a factual perspective, the compressions were, on the balance of probabilities, caused by the accident.
The Review Panel also reminded itself, again at [90], that the second limb of the test is satisfied where the accident made a material contribution to the cause of the injury and that the legal test does not require scientific certainty.
If you have a query relating to any of the information in this case note please don’t hesitate to get in touch with CTP Insurance Special Counsel Helen Huang today.
