Cottrelle et al. v. Gerrard [Indexed as: Cottrelle v. Gerrard]

67 O.R. (3d) 737

[2003] O.J. No. 4194

Docket No. C37533

Court of Appeal for Ontario

Abella, Moldaver and Sharpe JJ.A.

October 31, 2003

*Application for leave to appeal dismissed with costs April 22, 2004 (Bastarache, LeBel and Deschamps JJ.).

Torts -- Negligence -- Causation -- Plaintiff developing sore between her toes -- Sore becoming infected after plaintiff consulted defendant doctor -- Plaintiff's leg having to be amputated -- Plaintiff having pre-existing condition of severe atherosclerosis which inhibited her ability to fight infection -- Evidence establishing that it was more likely than not that plaintiff would have lost her leg even with proper follow-up by defendant -- Trial judge erring in basing liability on finding that defendant's breach of duty of care denied plaintiff "window of opportunity" wherein aggressive treatment might have avoided need for amputation -- There was no evidence that, but for defendant's negligence, plaintiff would not have lost her leg -- Loss of chance being non-compensable in medical malpractice cases.

The plaintiff, who had suffered from diabetes for many years, developed a sore between the toes of her left foot. She consulted the defendant, who did not examine her but simply told her that he would make an appointment for her to see a skin specialist. He did not make a follow-up appointment and gave her no further instructions or warnings. The sore quickly became infected. Before the plaintiff could see the skin specialist, her leg became gangrenous and had to be amputated below the knee. Examination of the amputated limb revealed severe atherosclerosis that inhibited the plaintiff's ability to fight the infection. There was no suggestion that the defendant should have been aware of the atherosclerosis. The plaintiff brought an action for damages for medical malpractice. The trial judge found that the defendant fell below the applicable standard of care in that he failed to examine the plaintiff's foot and failed to ensure an appropriate follow-up procedure to monitor the condition of her foot. Both the defendant's and the plaintiff's expert witnesses testified that had the plaintiff received an aggressive form of treatment when the condition of her foot deteriorated, she might not have suffered the loss of her leg. However, in light of the pre-existing medical condition, no witness was prepared to say that it was more likely than not that with proper treatment, the leg could have been saved. The trial judge found that the defendant's negligence denied the plaintiff a "window of opportunity" to save her leg, and that his negligence was therefore a cause of her loss sufficient to ground liability. The defendant appealed.

Held, the appeal should be allowed.

Causation is established where the plaintiff proves on a balance of probabilities that the defendant caused or contributed to the injury. The generally applicable test is the "but for" test. This test requires the plaintiff to show that the injury would not have occurred but for the negligence of the defendant. In an action for delayed medical diagnosis and treatment, a plaintiff must prove on a balance of probabilities that the delay caused or contributed to the unfavourable outcome. If, on a balance of probabilities, the plaintiff fails to prove that the unfavourable outcome would have been avoided with prompt diagnosis and treatment, then the plaintiff's claim must fail. It is not sufficient to prove that adequate diagnosis and treatment would have afforded a chance of avoiding the unfavourable outcome unless that chance surpasses the threshold of "more likely than not". In this case, there was no evidence that, on a balance of probabilities, but for the defendant's [page738] negligence, the plaintiff would not have lost her leg. The evidence demonstrated that it was more likely than not that even if the defendant had lived up to the standard of care, the plaintiff would have lost her leg. The plaintiff established no more than the loss of a less than 50 per cent chance of salvaging her leg had the defendant not been negligent. Loss of a chance is non- compensable in medical malpractice cases.

APPEAL by the defendant from a judgment of Leitch J., [2001] O.J. No. 5472 (QL), [2001] O.T.C. 966 (S.C.J.) for the plaintiff in an action for damages for negligence.

Athey v. Leonati, 1996 183 (SCC), [1996] 3 S.C.R. 458, 140 D.L.R. (4th) 235, 203 N.R. 36, [1997] 1 W.W.R. 97, 31 C.C.L.T. (2d) 113, apld Snell v. Farrell, 1990 70 (SCC), [1990] 2 S.C.R. 311, 107 N.B.R. (2d) 94, 72 D.L.R. (4th) 289, 110 N.R. 200, 267 A.P.R. 94, 4 C.C.L.T. (2d) 229; Sohal v. Brar (1998), 1998 ABCA 375, 68 Alta. L.R. (3d) 44, [1999] 7 W.W.R. 345, 223 A.R. 141, [1998] A.J. No. 1003 (QL), 1999 ABCA 375 (C.A.), affg (1998), 63 Alta. L.R. (3d) 280, [1999] 3 W.W.R. 553, 211 A.R. 81, 1998 ABQB 177, [1998] A.J. No. 4 (QL) (Q.B.), consd Bonnington Castings Ltd. v. Wardlaw, [1956] 1 All E.R. 615, [1956] A.C. 613, [1956] 2 W.L.R. 707, 100 Sol. Jo. 207, 54 L.G.R. 153, 1956 S.C. (H.L.) 26, 1956 S.L.T. 135 (H.L.); Fairchild v. Glenhaven Funeral Services Ltd. and Others, [2002] 3 All E.R. 305, [2002] W.L.R. 89, [2002] I.C.R. 798 (H.L.); McGhee v. National Coal Board, [1972] 3 All E.R. 1008, [1973] 1 W.L.R. 1, 116 Sol. Jo. 967 (H.L.), distd Other cases referred to Hotson v. East Berkshire Area Health Authority, [1987] 2 All E.R. 909, [1987] A.C. 750, [1987] 3 W.L.R. 232, 131 Sol. Jo. 975, [1987] N.L.J. Rep. 638, [1987] L.S. Gaz. R. 2365, (1987) Times 6 July (H.L.); Laferrière v. Lawson, 1991 87 (SCC), [1991] 1 S.C.R. 541, 6 C.C.L.T. (2d) 119; St-Jean v. Mercier, [2002] 1 S.C.R. 491, 209 D.L.R. (4th) 513, 282 N.R. 310, 2002 SCC 15, [2002] S.C.J. No. 17 (QL) Authorities referred to Fleming, J.G., "Probabilistic Causation in Tort Law" (1989) 68 Can. Bar Rev. 661 Klar, L.N., Tort Law, 3rd ed. (Toronto: Thomson Carswell, 2003) Mirandola, S., "Lost Chances, Cause-in-Fact and Rationality in Medical Negligence" (1992) 50 U.T. Fac. L. Rev. 258 Waddams, S.M., "The Valuation of Chances" (1988) 30 Can. Bus. L.J. 30 Waddams, S.M., The Law of Damages, looseleaf (Toronto: Canada Law Book, 2002)

D.I.W. Hamer and J.K. Downing, for appellant. D.B. Williams, for respondents.

The judgment of the court was delivered by

[1] SHARPE J.A.: -- Darlene Cottrelle, one of the respondents, suffered from diabetes for more than 30 years. In April 1993, at the age of 54, she developed a sore between the toes of her left foot. That sore eventually became infected and by mid-July, the [page738] appellant's leg was gangrenous and needed to be amputated below the knee. Examination of the amputated limb revealed severe atherosclerosis (obstruction of the arteries) that inhibited the respondent's ability to fight the infection.

[2] The trial judge found that the appellant, Dr. Alexander Gerrard, the respondent's family physician, was negligent in the treatment of the sore that became infected. The trial judge found that the appellant failed to examine the respondent's foot when she visited his office on July 2, and that he failed to ensure an appropriate follow-up procedure to monitor the condition of her foot thereafter.

[3] Both the appellant's and the respondent's expert witnesses testified that had Ms. Cottrelle received an aggressive form of treatment when the condition of her foot deteriorated, she might not have suffered the loss of her leg. However, in light of the pre-existing medical condition of her leg, no witness was prepared to say that it was more likely than not that with proper treatment of the sore, the leg could have been saved. In the end, the trial judge found that Dr. Gerrard's negligence was a material cause of the loss of the leg and found him liable.

[4] For the reasons set out below, I conclude that [the] trial judge erred with respect to the legal test for causation, that on the evidence and on the trial judge's findings, the respondent failed to establish that the appellant's negligence was the cause of her loss. The appeal must therefore be allowed and the action dismissed.

Facts

[5] As a type 2 diabetic, the respondent was at risk for the development of vascular disease. The experts agreed that her risk was increased because she was a First Nations Canadian and because she was a smoker. It is well known that because of their high incidence of vascular disease, diabetics are at risk for the development of gangrenous tissue on their feet.

[6] At trial, the action was pursued only against the appellant. The respondent first called the appellant's office about the sore between her toes on April 19, 1993. She did not speak directly to the appellant, but he prescribed Kenelog cream for her sore. The appellant did not examine the sore, and took no steps to follow-up with the respondent. The respondent saw the appellant regarding other ailments on May 12 and May 14, 1993. She made no complaints about her foot during those two visits. She returned on May 25. This time the appellant did examine her foot. He prescribed Diprasone lotion, a topical steroid. Again, no arrangements were made for a follow-up visit. On June 30, 1993, the respondent awoke with throbbing pain between her toes, and [page739] she went to the Emergency Department at Victoria Hospital for treatment. Dr. Upfold, the emergency physician, observed a "small (2 mm) open area on left fifth toe where it rubs fourth -- no cellulitis, has sensation -- grossly normal". Her diagnosis was an ulcer on the toe. She prescribed a seven- to ten-day course of oral antibiotics and advised the respondent to follow-up with her family physician later that week.

[7] The respondent arranged to see the appellant on July 2, 1993. Her foot was then in the same condition as when she was seen by Dr. Upfold. It was not suggested that the standard of care required the appellant to admit her to hospital for more aggressive treatment as of that date. The issue was whether the appellant properly examined the respondent and given her appropriate advice for follow-up care. The appellant testified that he examined the respondent's foot but the respondent testified that he did not. The trial judge accepted the respondent's evidence and found that the appellant did not physically examine the respondent's foot, but simply told her that he would make an appointment for her to see a skin specialist. The appellant conceded that he gave the respondent no further instructions or warnings. He testified that she had never hesitated to make appointments in the past and that as she came to see him three to four times as often as most patients, he did not expect that she would allow her foot to deteriorate without getting medical attention. The appointment with the dermatologist was not made until July 15 and not scheduled until September 21.

[8] The appellant did not see the respondent after July 2. She remained at home and the condition of her foot deteriorated. It became painful, changed colour and got darker and developed an odour. She was taken to the hospital by ambulance on July 20, 1993. According to the orthopaedic surgeon on call at the time, the respondent's foot had developed gangrene and the infection was spreading proximally. On July 21, 1993, the respondent's leg was amputated below the knee.

[9] The pathologist's examination of the amputated limb determined that the anterior and posterior tibial arteries were totally occluded and the peroneal artery was 80 per cent occluded. The limited circulation of blood to her leg significantly inhibited the respondent's ability to fight the infection in her foot, with or without the help of an antibiotic. Dr. Anne Kenshole, an endocrinologist and diabetician who practises at Women's College Hospital in Toronto and has considerable expertise in the diagnosis, treatment and prognosis of diabetic foot lesions, testified that the extent of atherosclerosis revealed by the pathology report was as severe as she had ever seen. There was no suggestion by any of [page740] the experts that the appellant could or should have been aware of this very serious atherosclerosis prior to the amputation, nor was there anything he should have done that would have allowed the respondent to avoid the complication of atherosclerosis that resulted from her diabetes.

[10] The trial judge found that the appellant fell below the appropriate standard of care in two ways: first, on July 2, 1993, he should have physically examined the respondent's foot; and second, he should have followed-up or monitored the respondent's condition after that date. The trial judge further found that the appellant's negligence denied the respondent a "window of opportunity" to save her leg, and that his negligence was therefore a cause of her loss sufficient to ground liability.

[11] The trial awarded damages for the cost of future care and assessed general damages at $125,000. Family Law Act claims were assessed at $10,000 in total. The trial judge reduced the award by 20 per cent on account of the respondent's contributory negligence in failing to seek medical attention when the condition of her foot deteriorated. The trial judge also applied a negative contingency factor of 14 per cent to reduce the award on account of the respondent's pre-existing condition. The total damages awarded, including $10,000 in favour of OHIP and including pre-judgment interest, was $157,545.99.

Issues

[12] The appellant raises the following issues:

1. Negligence. Did the trial judge err in finding that the appellant fell below the applicable standard of care?

2. Causation. Did the trial judge err in finding that the appellant's negligence caused the respondent's loss?

3. Damages.

(i) Did the trial judge err in refusing to reduce the damages on account of the government benefits to which the respondent was entitled?

(ii) Did the trial judge err by applying only a 14 per cent negative contingency factor?

(iii) Did the trial judge err in assessing the respondent's contributory negligence at 20 per cent? [page741]

Analysis

1. Negligence

[13] In his notice of appeal and in his factum, the appellant appeals the trial judge's findings relating to negligence and his failure to meet the standard of care. While the appellant did not abandon that aspect of the appeal, counsel elected to devote all of the time allocated for oral argument to what is clearly the central issue, namely causation. I intend to follow suit and I will discuss the negligence issue only briefly in these reasons.

[14] In his factum, the appellant submits that the trial judge's finding that he failed to examine the respondent's foot on July 2, 1993 should be set aside as contrary to the evidence and unreasonable. Given the deference to which the trial judge's factual findings are entitled in this court, I am unable to accept that submission. Simply put, there was conflicting evidence on the point. While another judge might have found otherwise, on this record, the trial judge was entitled to accept the respondent's evidence, reject that of the appellant, and to make the finding that she did. It was also open to the trial judge, on the evidence before her, to find that the appellant's failure to ensure that the respondent would seek medical attention if her foot deteriorated was negligent. Accordingly, I would not give effect to this ground of appeal.

2. Causation

[15] The respondent's theory of causation was that had the appellant monitored her condition more closely after July 2, he would have observed the deteriorating condition of her foot and admitted her to hospital for more aggressive treatment, namely, the intravenous administration of antibiotics to control the infection and possibly the amputation of a toe before the infection spread to the point that the leg had to be amputated. The appellant's theory of causation was that given the serious atherosclerosis in the appellant's leg, more aggressive treatment would not have made any difference. Because of the very limited circulation in the respondent's leg, neither her body's natural defences nor the intravenous administration of antibiotics would have been effective to combat the infection. Consequently, argues the appellant, it cannot be said that the appellant's negligence caused the injury.

[16] Both parties called expert evidence on causation. The respondent's expert, Dr. Rodney Box, was a retired internal medicine specialist whose main clinical experience had been in the area of respirology. As the trial judge noted in her reasons on this point, Dr. Box's testimony did not go beyond the suggestion that [page742] the patient "might" have kept her limb if the infection had been managed more aggressively. Although the trial judge did not specifically refer to the passage in her reasons, Dr. Box admitted in cross-examination that he could not say that with a more aggressive form of treatment, it was more probable than not that the leg could have been saved:

Q. In the second last paragraph [of one of Dr. Box's reports], do you not say "I believe that it is impossible to say whether such energetic treatment as I have described could have saved her leg and for how long"?

A. I did.

Q. You stand by that statement?

A. Yes. We have no idea if it would have worked.

Q. And that all you can say, in fairness, is that there was a potential to reverse the infectious process?

A. I believe that.

Q. Now, by potential to reverse the infectious process, what you mean in other words is a chance. Correct?

A. I do.

Q. And your correct criticism of Dr. Gerrard is that you say he caused her to lose that chance?

A. The chance was missed.

Q Yes. But you certainly can't say that she had anything more than a chance?

A. No.

Q. And you can't go so far as to say that on a balance of probability that leg would have been saved based on anything that you know?

A. I won't go that far.

(Emphasis added)

[17] The trial judge placed considerable weight on the evidence of the appellant's expert, Dr. Anne Kenshole who testified that the respondent's leg was "non-salvageable" and that the "ultimate cause" of the amputation was the respondent's "extremely severe peripheral vascular disease". This vascular disease made it impossible for Ms. Cottrelle's own healing processes to fight the infection, either with or without the addition of antibiotics. According to Dr. Kenshole, the respondent's atherosclerosis was so severe that "there was no potential for healing once a break in the skin of the ulcer occurred." [page743]

[18] The trial judge quoted, at para. 68 of her reasons, the following passage from Dr. Kenshole's written report:

In that Mrs. Cottrell [sic] had been in habit of seeing Dr. Gerrard frequently and for a wide variety of minor complaints and had not hesitated to visit a hospital emergency department at 3:00 a.m., one can only surmise that she was well aware of the increasing gravity of her illness between July 2 and July 20 yet chose to deny it and by so doing missed an important window of opportunity wherein aggressive treatment with intravenous antibiotics and/or local amputation of the toe might have avoided the need for the life-saving below knee amputation which was ultimately required.

(Emphasis added)

[19] Dr. Kenshole expanded upon this opinion in cross- examination:

Q. No. What you're saying in this paragraph, Dr. Kenshole, is that what occurred between July 2nd and July 20th was important and that there was a significant window of opportunity to avoid the below-knee amputation?

A. That is not what I have said in my report. In all fairness, Mr. Williams, umm, if I can just paraphrase, if I may, uhh, what I believe happened from July the 2nd 'til approximately July the 9th, Mrs. Cottrelle, by her own testimony, was not feeling better or worse. She did not see herself any change in this two millimetre ulcer.

In and around July the 9th, she started to feel unwell. She noticed darkening of the skin in that area. That is, I believe, when the infection started to take hold. Between July the 9th and July the 20th, the situation was clearly getting graver the whole time in terms of her systemic wellbeing, in terms of the appearance, subsequently the odour of this area which by the time she got to hospital was grossly infected.

What I intended, or what I hoped to imply by what I've written there is, if Mrs. Cottrelle had from July the 9th or shortly thereafter, when she noticed a change in the appearance of the ulcer, was becoming darker. She was developing a small area of tissue death in that area.

If she had gone to hospital at that stage, indeed if she'd seen her family physician, I strongly suspect that her family physician would have immediately sent her on to the hospital, where, given the information as I have read it, she would have been admitted to hospital. She would have been started on intravenous antibiotics. She would have had vascular studies and she had a chance, a small chance, because the infection, the infected area would then be localized to a small area, she might, and I underline "might" have got away with a localized, a more localized amputation, maybe through the ankle amputation.

I can't say obviously for sure that that would've been the outcome because in the light of the vascular tree that we subsequently know she had, I think it likely that local amputation, if undertaken, would not have been successful because of the poor vascular supply to the entire foot.

Or, if it had been tried, it would have failed, as she would ultimately have had a below-the-knee amputation at some later date. That is my best [page744] interpretation of the circumstances, having been involved in the care of not one, not ten, but many patients who followed a similar course.

(Emphasis added)

[20] The trial judge based her analysis of the causation issue on the decision of the Supreme Court of Canada in Athey v. Leonati, 1996 183 (SCC), [1996] 3 S.C.R. 458, 140 D.L.R. (4th) 235. At para. 64, the trial judge identified five principles from that case as being applicable:

(1) The plaintiff must prove to the civil standard on a balance of probabilities that the defendant's tortious conduct caused or contributed to the plaintiff's injury -- the causation test is not to be applied too rigidly and causation need not be determined by scientific precision; see Snell v. Farrell, 1990 70 (SCC), [1990] 2 S.C.R. 311, 72 D.L.R. (4th) 289.

(2) The plaintiff does not need to establish that the defendant's negligence was the sole cause of the injury.

(3) The law does not excuse a defendant from liability merely because other causal factors for which he is not responsible also helped produce the harm -- it is sufficient if the defendant's negligence was a cause of the harm.

(4) The plaintiff must be placed in the position he or she would have been in absent the defendants' negligence ("original position") -- it is the difference between the original position and the injured position that is the plaintiff's loss.

(5) If there is a measurable risk that the pre-existing condition would have detrimentally affected the plaintiff in the future, regardless of the defendants' negligence, then this can be taken into account in reducing the overall award.

[21] The trial judge then adopted the passages quoted above, at paras. 18 and 19, from Dr. Kenshole's written opinion and cross-examination. She specifically adopted Dr. Kenshole's "window of opportunity" analysis, at para. 70 of her reasons, in making her finding on causation:

As noted above I have found that Dr. Gerrard did not meet his duty of care after July 2 and I further find that the breach of his duty of care denied Mrs. Cottrelle the "window of opportunity" described by Dr. Kenshole. As a result of the breach of the duty of care, the risk that concerned Dr. Upfold -- the development of a deeper infection -- materialized. This deeper infection contributed to the development of gangrene and the resulting need for below the knee amputation. [page745]

[22] The trial judge then concluded her analysis of causation, at paras. 71 and 72, by considering the "loss of chance" doctrine:

The remaining issue is whether the "loss of chance" doctrine is applicable and if so whether a plaintiff is entitled to compensation for such a loss. The defendant asserts that Mrs. Cottrelle lost only a chance of reversing the infectious process and that such a loss of chance cannot ground liability in a medical context (see Laferriere v. Lawson, 1991 87 (SCC), [1991] 1 S.C.R. 541). In Athey v. Leonati the Supreme Court of Canada at p. 474 described the loss of chance doctrine as one which suggests that plaintiffs may be compensated where their only loss is the loss of a chance at a favourable opportunity or of a chance of avoiding a detrimental event. The Court concluded that such a doctrine was not applicable to the facts of that case and they neither approved nor disapproved of the doctrine.

In my view the loss of chance doctrine is not applicable to this case. I am satisfied that Dr. Gerrard's failure to meet the requisite standard of care caused the infection to deepen and that such infection contributed to the development of gangrene which mandated the amputation.

[23] From her reasons, it is difficult to know precisely what legal test of causation the trial judge applied. Simply put, there was no evidence that, on a balance of probabilities, but for the appellant's negligence, the respondent would not have lost her leg. Indeed, counsel for the respondent conceded in oral argument that there was no evidence suggesting that it was more likely than not that had the appellant lived up to the standard of care, the respondent's leg would have been saved. He submitted, however, that the evidence of a possibility, lower than a probability, that the respondent's leg might have been saved satisfied the test in Athey, and it seems likely that the trial judge proceeded on that same basis. I am unable to accept the correctness of that proposition.

[24] As explained in Athey, at para. 13, causation is established when the plaintiff proves on a balance of probabilities, that the defendant caused or contributed to the injury. The generally applicable test is the "but for" test. This test "requires the plaintiff to show that the injury would not have occurred but for the negligence of the defendant" (Athey, at para. 14).

[25] I agree with the appellant's submission that in an action for delayed medical diagnosis and treatment, a plaintiff must prove on a balance of probabilities that the delay caused or contributed to the unfavourable outcome. In other words, if, on a balance of probabilities, the plaintiff fails to prove that the unfavourable outcome would have been avoided with prompt diagnosis and treatment, then the plaintiff's claim must fail. It is not sufficient to prove that adequate diagnosis and treatment would have afforded a chance of avoiding the unfavourable outcome unless that chance surpasses the threshold of "more likely than not". [page746]

[26] In Athey, the plaintiff proved on a balance of probabilities that the defendants' negligence caused the loss. The defendants sought to escape liability by pointing to other more significant causes for which they were not responsible. It was in that context that Athey held that if the defendant's negligence materially contributed to the occurrence of the injury, the defendant could not escape liability by pointing to other causes. However, Athey does not excuse the plaintiff from proving on a balance of probabilities that but for the defendant's negligence, the plaintiff would not have suffered the loss.

[27] The plaintiff in Athey had a history of back problems. He suffered neck and back injuries in two accidents two months apart involving the two defendants. He then suffered a herniated disc while following a course of exercise recommended by his physician. The defendants contended that they had not caused the herniated disc and that it was attributable to the plaintiff's pre-existing condition. Writing for a unanimous court, Major J. identified the issue on the appeal, at para. 1, as being "whether the loss should be apportioned between tortious and non-tortious causes where both were necessary to create the injury" (Emphasis added). In Athey, the evidence clearly established that but for the defendants' negligence, the plaintiff would not have suffered a herniated disc. The issue was instead whether the defendants could escape liability because the plaintiff's back problems were also caused by his pre-existing condition. Major J. held that the answer to that question was "no", so long as the negligence of the defendants materially contributed to the loss.

[28] The respondent relies on the following passages, at paras. 15-20 of Athey, which qualify the basic "but for" rule:

The "but for" test is unworkable in some circumstances, so the courts have recognized that causation is established where the defendant's negligence "materially contributed" to the occurrence of the injury: Myers v. Peel County Board of Education, 1981 27 (SCC), [1981] 2 S.C.R. 21; Bonnington Castings, Ltd. v. Wardlaw, [1956] 1 All E.R. 615 (H.L.); McGhee v. National Coal Board, supra. A contributing factor is material if it falls outside the de minimis range: Bonnington Castings, Ltd. v. Wardlaw, supra; see also R. v. Pinske (1988), 30 B.C.L.R. (2d) 114 (B.C.C.A.), aff'd 1989 47 (SCC), [1989] 2 S.C.R. 979.

In Snell v. Farrell, supra, this Court recently confirmed that the plaintiff must prove that the defendant's tortious conduct caused or contributed to the plaintiff's injury. The causation test is not to be applied too rigidly. Causation need not be determined by scientific precision; as Lord Salmon stated in Alphacell Ltd. v. Woodward, [1972] 2 All E.R. 475, at p. 490, and as was quoted by Sopinka J. at p. 328, it is "essentially a practical question of fact which can best be answered by ordinary common sense". Although the burden of proof remains with the plaintiff, in some circumstances an inference of causation may be drawn from the evidence without positive scientific proof. [page747]

It is not now necessary, nor has it ever been, for the plaintiff to establish that the defendant's negligence was the sole cause of the injury. There will frequently be a myriad of other background events which were necessary preconditions to the injury occurring. . . . As long as a defendant is part of the cause of an injury, the defendant is liable, even though his act alone was not enough to create the injury. There is no basis for a reduction of liability because of the existence of other preconditions: defendants remain liable for all injuries caused or contributed to by their negligence. . . .

The law does not excuse a defendant from liability merely because other causal factors for which he is not responsible also helped produce the harm. . . .

This position is entrenched in our law and there is no reason at present to depart from it. If the law permitted apportionment between tortious causes and non-tortious causes, a plaintiff could recover 100 percent of his or her loss only when the defendant's negligence was the sole cause of the injuries. Since most events are the result of a complex set of causes, there will frequently be non-tortious causes contributing to the injury. Defendants could frequently and easily identify non-tortious contributing causes, so plaintiffs would rarely receive full compensation even after proving that the defendant caused the injury. This would be contrary to established principles and the essential purpose of tort law, which is to restore the plaintiff to the position he or she would have enjoyed but for the negligence of the defendant.

[Emphasis in original omitted]

[29] In my opinion, these qualifications or refinements to the basic rule requiring the plaintiff to meet the ordinary burden of proving "but for" causation on a balance of probabilities do not assist the respondent.

[30] The "but for" test has been relaxed as "unworkable" in cases where, practically speaking, it is impossible to determine the precise cause of the injury. In Athey, for example, the Supreme Court affirmed the "material contribution" test as a qualification to the strict "but for" test only when used in cases similar to Bonnington Castings Ltd. v. Wardlaw, [1956] 1 All E.R. 615, [1956] A.C. 613 (H.L.), and McGhee v. National Coal Board, [1972] 3 All E.R. 1008, [1973] 1 W.L.R. 1 (H.L.). The more recent House of Lords decision in Fairchild v. Glenhaven Funeral Services Ltd. and Others, [2002] 3 All E.R. 305, [2002] W.L.R. 89 (H.L.) also reflects this same tendency to depart from the "but for" standard, but only where the precise cause of the injury is unknown. Bonnington, McGhee, and Fairchild all involved situations where the plaintiff was exposed to a harmful substance from various sources, but could not prove precisely that the substance resulting from the defendant's tortious conduct caused the loss. In Fairchild, the plaintiffs had been exposed to asbestos while working for various employers for various periods. The plaintiffs developed a fatal disease caused by asbestos, but could not establish which exposure or exposures to asbestos had actually caused the [page748] disease. The House of Lords allowed the plaintiffs' appeals from lower court decisions dismissing their claims and held that they were entitled to recover. The salient feature of Fairchild was that the plaintiffs were definitely injured by the negligence of one of the defendants, and there was no other operative cause or explanation for the injury. As pointed out in Lewis N. Klar, Tort Law, 3rd ed. (Toronto: Thomson Carswell, 2003), at p. 400: "courts will strive to fashion a just solution in this type of case to allow a wronged plaintiff to recover. Courts will not allow wronged plaintiffs to fall between the cracks due to the formal requirements of proving cause."

[31] In my view, the principle followed in this line of cases does not assist the respondent. In the case at bar, there is no practical uncertainty as to the impact of the appellant's wrongful conduct upon the plight of the respondent. It was clearly established that the respondent lost her leg because of an infection. The question was whether the appellant could have prevented an outcome that was unquestionably caused by the infection and the respondent's pre-existing vascular condition. The evidence demonstrated that it is more likely than not that even if the appellant had lived up to the standard of care, the respondent would have lost her leg.

[32] Nor, in my view, is the respondent assisted by the principle established in Snell v. Farrell, supra. Snell involved a situation in which the plaintiff became blind following cataract surgery. The court found the defendant negligent in proceeding with the operation despite retrobulbar bleeding. The expert witnesses who testified were unable to say with certainty what caused the plaintiff's blindness, but the retrobulbar bleeding was found to be a possible cause. In Snell, Sopinka J. held that the plaintiff did not need to prove with scientific precision that the bleeding was the cause of her blindness, particularly since the facts as to precisely what had occurred during the surgery were within the knowledge of the defendant.

[33] The "robust and pragmatic" approach to proof of causation utilized in Snell v. Farrell does not assist the respondent. In the case at bar, there is no uncertainty over why Darlene Cottrelle suffered the amputation of her leg and this is not a case where the appellant is in a better position to say what happened. Here, the issue is not whether the appellant created a situation that might have caused the respondent's loss. Instead, the issue is whether the appellant could have prevented the loss of the respondent's leg in any event. In this case, the experts agree that it is more likely than not that even if the appellant had met the appropriate standard of care, the respondent still would have lost her leg. [page749]

[34] In Athey, Major J. summarized his reasons for imposing liability on the defendants by pointing to the plaintiff's pre- existing condition at para. 41:

The applicable principles can be summarized as follows. If the injuries sustained in the motor vehicle accidents caused or contributed to the disc herniation, then the defendants are fully liable for the damages flowing from the herniation. The plaintiff must prove causation by meeting the "but for" or material contribution test. Future or hypothetical events can be factored into the calculation of damages according to degrees of probability, but causation of the injury must be determined to be proven or not proven. This has the following ramifications:

1. If the disc herniation would likely have occurred at the same time, without the injuries sustained in the accident, then causation is not proven.

2. If it was necessary to have both the accidents and the pre-existing back condition for the herniation to occur, then causation is proven, since the herniation would not have occurred but for the accidents. Even if the accidents played a minor role, the defendant would be fully liable because the accidents were still a necessary contributing cause.

3. If the accidents alone could have been a sufficient cause, and the pre-existing back condition alone could have been a sufficient cause, then it is unclear which was the cause-in-fact of the disc herniation. The trial judge must determine, on a balance of probabilities, whether the defendant's negligence materially contributed to the injury.

[Emphasis in original omitted]

[35] I agree with the appellant's submission that the case at bar falls within the first category and does not fall into either the second or the third category. Proper treatment might have saved the respondent's leg, but, according to the medical experts, in view of the severe pre-existing atherosclerosis in her leg, she likely would have lost her leg in any event. The appellant's negligence was not a necessary cause to bring the case within the second category, nor could the appellant's negligence alone have been a sufficient cause to bring the case within the third category.

[36] In my view, the respondent established no more than the loss of a less than 50 per cent chance of salvaging her leg had the appellant not been negligent. Unfortunately for the respondent, under the current state of the law, loss of a chance is non-compensable in medical malpractice cases: see Laferrière v. Lawson, 1991 87 (SCC), [1991] 1 S.C.R. 541, 6 C.C.L.T. (2d) 119; St-Jean v. Mercier, [2002] 1 S.C.R. 491, 2002 SCC 15; Hotson v. East Berkshire Area Health Authority, [1987] A.C. 750, [1987] 2 All E.R. 909 (H.L.). The trial judge did not explain the basis for her conclusion that "the loss of chance doctrine is not applicable to this case." In view of the evidence I have reviewed, and in view of the respondent's concession that there was no evidence to suggest that it was more than likely [page750] a better outcome would have followed had the appellant acted with care, the trial judge's finding reveals either a misapprehension as to the law or a palpable and overriding error on the facts.

[37] The exclusion of recovery for the loss of a chance in medical malpractice cases has been criticized as being unduly rigid and harsh: see, Klar, supra, at pp. 403-05; John G. Fleming, "Probabilistic Causation in Tort Law" (1989) 68 Can. Bar Rev. 661; S.M. Waddams, "The Valuation of Chances" (1988) 30 Can. Bus. L.J. 30; S.M. Waddams, The Law of Damages, looseleaf (Toronto: Canada Law Book, 2002) at 13.260-13.370; Salvatore Mirandola, "Lost Chances, Cause-in-Fact and Rationality in Medical Negligence" (1992) 50 U. T. Fac. L. Rev. 258. Recovery based upon the loss of a chance would require substantial reduction of the damages to reflect the value of the less than 50 per cent chance that was lost. In any event, the authorities cited in para. 36 preclude us from considering such an award.

[38] Finally, I note that in a case with facts very similar to those presented here, the Alberta courts have concluded that the plaintiff failed to meet the legal test for causation. In Sohal v. Brar (1998), 1998 ABQB 177, 211 A.R. 81, [1999] 3 W.W.R. 553 (Q.B.), the defendant doctor was found to have been negligent in failing to advise the plaintiff, a diabetic with a cut on his foot, to seek immediate treatment when the cut became infected. Within days, the plaintiff's foot had to be amputated. As in the present case, the expert evidence on causation did not establish that it was more likely than not that that earlier aggressive treatment would have saved the foot. McBain J. reviewed Snell and Athey, and considered the plaintiff's argument that the evidence established a material contribution to the injury beyond the de minimis range. He concluded, at para. 185 that the evidence "does not prove to the civil standard on a balance of probabilities that the Defendant caused the injury nor [did] it . . . establish on a balance of probabilities that the delay by the Defendant doctor materially contributed to the injury". As a result, the legal test for causation had not been met and the defendant could not be held liable. In coming to this conclusion, McBain J. held that the plaintiff had proved no more than the loss of a chance, and that this type of loss, on the authorities cited above, is not compensable. A panel of the Alberta Court of Appeal dismissed the plaintiff's motion to extend the time for serving a notice of appeal, on the ground that there was no basis for arguing that the trial judge erred in law in his characterization of the test for causation: (1998), 1998 ABCA 375, 223 A.R. 141, [1999] 7 W.W.R. 345 (C.A.), at para. 5.

[39] For these reasons, I conclude that the trial judge either erred in law in her appreciation of the appropriate legal test for [page751] causation, or she made a palpable and overriding error in her appreciation of the evidence. As there was no evidence to suggest that it was more probable than not that the respondent would have avoided the loss of her leg had the appellant not been negligent, the action should have been dismissed.

3. Damages

[40] In view of the conclusion I have reached on the issue of causation, it is not necessary for me to consider [the] appellant's contention that the trial judge erred in her assessment of the damages.

Conclusion

[41] For these reasons I would allow the appeal, set aside the trial judgment and dismiss the action. The appellant is entitled to his costs of the trial and of this appeal but, as suggested by Mr. Hamer, I would order costs on a partial indemnity basis only if demanded.

Appeal allowed.