In BC Injury Claims (tort claims) a damage award can be reduced to account for the extent that a pre-existing condition contributes to a subsequent impairment. Reasons for judgement were released today by the BC Court of Appeal discussing this area of law in the context of a jury trial.
In today’s case (Laidlaw v. Couturier) the Plaintiff was involved in a 2004 motor vehicle accident. The Plaintiff suffered from various pre-existing difficulties including depression. He was injured in the car accident and following a Jury Trial his damages were assessed at $128,717. The Jury went on to reduce this award by 85% to take into account the “measurable risk that the plaintiff would have suffered from the (post accident) physical and psychological complaints even if the (car accident) had not happened“.
The Plaintiff appealed this jury award arguing that the trial judge made a mistake in having the Jury give a general ‘across the board’ reduction of damages for the risk of difficulties the pre-existing conditions may have posed. The BC Court of Appeal agreed that the trial judge did indeed err in instructing the Jury and ordered a new trial. In coming to this conclusion the BC high court extensively discussed the law of reduction of damages to account for risks of pre-existing conditions. The highlights of this discussion were as follows:
 Ultimately, this appeal turns on a significant error exposed in the jury charge, in the third jury question, and the ultimate verdict.
 As can be seen from the emphasized portion of the jury charge recited in paragraph 26 of these reasons, the trial judge instructed the jury that if they found that “if the May 2004 accident had not happened there was a material risk that Mr. Laidlaw would nevertheless have suffered from general anxiety or depression or back problems, then you should reduce Mr. Couturier’s liability by the amount of that material risk, whatever you find it to be.”…
 The wording of question 3, together with the judge’s charge on causation was overly simplistic. The various conditions from which the plaintiff had suffered previously, and the symptoms to which they gave rise, were not capable of reduction to a single “measurable risk”.
 One, some or none of those previous conditions might have “detrimentally affected the plaintiff in the future”. One or more of those conditions might have affected him at different points in time. The degree to which each such condition might have affected him need not have been identical.
 To lump these variables together into one question and to invite a single mathematical adjustment was unfair and inappropriate.
 Athey was a case with a single identifiable injury, a disc herniation, occurring some months after the accidents giving rise to the plaintiff’s claim. There was a single pre-existing condition, “a history of minor back problems”, which was alleged to have contributed to his injury. I do not read the language in Athey, while appropriate to the kind of case with a single measurable risk, to be transferable to the facts of a more complex case such as this one, which involves the assessment of multiple and distinct measurable risks.
 The contributing effects of a pre-existing condition to a subsequent injury can be taken into account if the trier of fact considers that to be appropriate. In many cases, it may well be a relevant factor for the jury to consider. However, the jury should be told that the effect to be given to such a “measurable risk” should be carefully related to the specific facts of the case. In a case such as this, where there were various pre-existing conditions, and where it was uncertain if, when, or to what degree those conditions might adversely affect the plaintiff in future, it was an error to invite a general reduction across the board, as is required by question 3.
 In my opinion, the first portion of the charge on causation and in question 3 directed the jury to undertake a formulaic approach to the assessment of damages attributable to the defendant rather than directing them to consider, in a nuanced fashion, all of the contingencies and risks inherent in Mr. Laidlaw’s individual circumstances and to arrive at a global assessment of damages. Question sheets such as this one that ask the jury to answer questions that tend to reveal their deliberations are not helpful, invite appeals, and are to be avoided.
 It must be said that the second portion of the trial judge’s written instructions did not mirror the wording in question 3. However, it stands to reason that by the time the jury was completing its deliberations, their focus must have been on the question sheet. Question 3 is clear in its terms but, unfortunately, incorrect in its legal effect. In my view, it amounts to misdirection…
 In the end, it is impossible to say with confidence that the jury properly understood its task in assessing the damages due to Mr. Laidlaw. In my view, the only recourse available is to order a new trial.