Author: Kris Bonn
Law360 Canada (July 16, 2024, 10:52 AM EDT) — The Ontario Court of Appeal recently released a decision, Johnson v. Lakeridge Health Corporation et al., 2024 ONCA 291, that touches upon the important issues of causation and expert evidence. The case went to trial before Justice Joseph Di Luca in November and December 2022. Justice Di Luca released the decision on May 1, 2023, dismissing the plaintiffs’ claim for failing to prove causation. At the time of trial, the only remaining defendant was Dr. Rose-Anne Vieira.
On Oct. 17, 2012, the plaintiff, William Johnson suffered a minor stroke. He went to the hospital where a number of tests were ordered to look for the cause of Johnson’s stroke, including an MRI angiogram (MRA). The MRA identified the cause of Johnson’s stroke: a vertebral artery dissection (vertebral dissection). He was put on antiplatelet therapy to prevent a secondary stroke. When he was discharged from hospital on Oct. 23, 2012, Dr. Vieira failed to review the MRA. She discharged Johnson without diagnosing the vertebral dissection.
Six days later, on Oct. 29, 2012, Johnson saw his family doctor to follow up on his recent hospitalization. His family doctor saw the MRA results and contacted Johnson’s neurologist, who instructed Johnson to return to the hospital for immediate anticoagulant treatment. Johnson returned as instructed and was immediately started on anticoagulant therapy (intravenous heparin). Less than 24 hours later, Johnson suffered a major disabling stroke.
The plaintiffs argued that the delay in starting that therapy, which occurred as a result of Dr. Vieira’s failure to review the MRA report, caused the second stroke.
In the case, Dr. Vieira admitted that she was negligent in failing to review the MRA before discharging Johnson. However, she submitted that the plaintiffs failed to prove causation.
The parties agreed on damages. As such the sole issue in the trial was causation. Two experts testified on the issue of causation. Dr. Louis Caplan, a world-renowned expert in stroke, and a professor at Harvard University testified on behalf of the plaintiffs. Dr. David Gladstone, a leading Canadian expert in stroke, testified on behalf of the defendant. Justice Di Luca rejected the evidence of Dr. Caplan and accepted that of Dr. Gladstone. He found that Johnson had not proven, on a balance of probabilities, that the second stroke would have likely been avoided had Johnson been prescribed the anticoagulant Heparin instead of the antiplatelet Aspirin.
The plaintiffs appealed. The Court of Appeal heard the appeal on March 15, 2024, dismissing the plaintiffs’ appeal.
Grounds of appeal
The Court of Appeal notes that on appeal the plaintiffs raised two issues:
- the trial judge permitted “trial by ambush” by admitting Dr. Gladstone’s opinion on the likely cause of the second stroke when that opinion had not been disclosed in his expert reports, contrary to r. 53.03(3); and
- the plaintiffs had established a prima facie case on causation and the defendant failed to adduce evidence sufficient to displace that prima facie case.
However, in reading the plaintiffs’ factum for the appeal, the plaintiffs argued that the trial judge’s three errors were:
- the trial judge erred in displacing the plaintiffs’ prima facie case, relying on opinion evidence that was (1) not disclosed on any expert report and (2) premised on an assumption not established by the evidence;
- the trial judge tainted his causation analysis by engaging in a lengthy consideration of the effectiveness of appropriate anticoagulation therapy as compared to appropriate antiplatelet treatment, which (1) has a different mechanism of action and (2) Johnson did not receive.
- the trial judge erred in requiring the plaintiffs’ expert to produce randomized controlled trials supporting his opinion when no such studies exist; in doing so, the trial judge set the bar impossibly high, requiring the plaintiffs to establish causation with scientific certainty.
Court of Appeal’s reasons for dismissing the appeal
The Court of Appeal identified that the “core issue” was whether it was more likely than not that treatment with Heparin commencing on Oct. 23, 2012, would have prevented the second stroke. The Court of Appeal split the plaintiffs’ first ground of appeal into two separate grounds and did not address their second and third grounds of appeal.
There was no trial by ambush
In his expert reports served before trial, Dr. Gladstone had identified either blood clots and/or reduced blood flow in the artery as likely causes of the second stroke, his reports had not identified one mechanism as being more likely than the other. In his evidence-in-chief, Dr. Gladstone was permitted, over objection by plaintiffs’ counsel, that reduced blood flow was the likely cause of the second stroke.
On appeal, the plaintiffs argued that Dr. Gladstone ought not have been permitted to testify to this opinion, as it had not been disclosed prior to trial. The Court of Appeal did not agree. The Court of Appeal held that Dr. Gladstone’s evidence that reduced blood flow was the more likely cause of Johnson’s stroke was “… merely an elaboration of his opinion as set out in his expert reports.” Further, the Court of Appeal noted that Dr. Gladstone backed off from that opinion on cross- examination. In this context, the Court of Appeal held that the evidence to which the objection was made did not affect the outcome.
The appellants did not establish a prima facie case
The Court of Appeal disagreed with the plaintiffs that they had established a prima facie case of causation. While the trial judge accepted that stroke victims who are treated with Heparin generally only have a two per cent risk of developing a secondary stroke, the same is true of those treated with Aspirin (which Johnson received). The Court of Appeal saw no palpable or overriding error in the trial judge’s analysis and dismissed the appeal.
Failure by the Court of Appeal to address the plaintiffs’ grounds of appeal
Unfortunately, the Court of Appeal failed to address the plaintiffs’ argument on appeal that the trial judge improperly rejected the plaintiffs’ expert evidence that the trial judge characterized as being anecdotal and that they had established a prima facie case. The Court of Appeal did not provide any analysis or guidance on the argument that the trial judge required the plaintiffs to prove causation on a level approaching scientific certainty as opposed to robust common sense.
The lesson for medical malpractice lawyers is regardless of how experienced and knowledgeable an expert is in the field, their medical opinion needs to be based on accepted medical literature. (Note: The plaintiffs’ expert, Dr. Caplan, is a full professor at Harvard Medical School and has received multiple honours and awards. Over his 50-plus-year career, Dr. Caplan has treated 15,000 to 20,000 stroke patients and authored dozens of books on the subject, including Caplan’s Stroke: A Clinical Approach, which is used throughout the world as a primary stroke text.)
Kris Bonn is the managing partner at Bonn Law, a firm with offices in Belleville and Trenton that focuses on helping people with personal injury cases, medical malpractice and long-term disability denials. Bonn is the president of the Brain Injury Association Quinte District and the past president of the Ontario Trial Lawyers Association.
The opinions expressed are those of the author and do not reflect the views of the author’s firm, its clients, Law360 Canada, LexisNexis Canada or any of its or their respective affiliates. This article is for general information purposes and is not intended to be and should not be taken as legal advice.
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