Causation in negligence, once Breach of Duty has been established. The ‘but for’ test, ‘material contribution,’ and ‘loss of a chance’

  • Single negligent cause of injury. If Claimant can prove that, but for the Defendant’s negligence, the injury would not have occurred, then causation is established and the Claimant recovers damages.
  • Multiple separate or distinct causes of injury, one of which arose by negligence. The Claimant must prove that but for the negligent cause (as against the other non-negligent causes) the injury would not have occurred. If proven on the balance of probabilities (more likely than not, 51% or more likelihood), causation is established and damages are paid.
  • Combined negligent & non-negligent causes. The Claimant sustains injury due to a combination of negligent & non-negligent management. If it is possible to apportion injury to each cause, then the Claimant only recovers damages in respect of the negligently-caused injury. If the state of knowledge does not allow apportionment, the Claimant recovers damages in respect of the whole injury. In these circumstances, the Claimant only has to prove that the negligent conduct made a material contribution to the whole injury. A material contribution is one which is more than negligible. (That clears that one up, doesn’t it?)
  • Loss of a chance. If the Claimant is suffering from a condition which has a greater than 50% chance of recovery, and negligent conduct reduces that chance, the Claimant must prove that the negligence resulted in the chance being reduced from above 50% to below 50% in order to recover damages. If the chance was already less than 50% and negligence reduced it further, then the Claimant will fail to recover damages.
  • On the balance of probabilities, the expert should consider: what was the medical cause of injury? ‘But for’ the negligence, would that injury have been avoided entirely? Would some injury have been caused anyway? Can the injury be apportioned between those causes?
  • What would have happened if the negligence had not taken place? Would the Claimant have been impaired to some degree as a consequence of the disease/injury that led to treatment? Not all injuries recover completely. The Claimant is only entitled to claim for the difference between the way he/she is after the negligence, and the outcome they would have had if the negligence had not occurred.

Leave a Reply

Your email address will not be published. Required fields are marked *