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How do you Prove Medical Malpractice?


Medical malpractice cases are vigorously litigated.

The first step in determining whether the Plaintiff has a viable medical malpractice case is to obtain and thoroughly review the hospital records or clinical notes and records regarding the alleged negligent medical treatment. 

The burden of proof is on the Plaintiff to prove that the physician(s) or medical professional(s) provided negligent medical care and treatment, on a balance of probabilities. Accordingly, the Plaintiff must prove that the medical care and treatment was: (1) below the standard of care and (2) the breach of the standard of care caused the outcome or injury.

To prove medical malpractice, the Plaintiff is likely to require an expert opinion on both standard of care and causation.  Rule 53.03(3) prohibits an expert from testifying with respect to an issue unless the substance of her testimony with respect to that issue is set out in a report served at least 15 days before the commencement of trial.[1] In other words, the Plaintiff must retain an expert to review all relevant documents and deliver an expert report clearly setting out her opinions and the basis for her opinion.[2] If the case proceeds to trial, the Plaintiff’s expert will be called to testify and give opinion evidence in support of the medical negligence.

Recent case law suggests that, at trial, expert testimony will be confined to the “four corners” of the expert’s report. [3]  In light of the Court’s decision in Peller v. Ogilvie-Harris, the expert may be precluded from giving opinion evidence on matters which are not touched upon or explored in her report. It is imperative to ensure that the Plaintiff’s expert report does not merely outline “conclusionary statements without any specificity” and that it provides a thorough explanation and rationale in support of all findings, opinions, and conclusions within the four corners of her report.[4]

What is a breach of the standard of care?

A finding of a breach of the standard of care is fact driven and unique to the circumstances of each case. No two cases are alike. The definition of the standard of care for the general practitioner and the specialist is well settled. The Supreme Court of Canada in ter Neuzen v. Korn, held that physicians have a duty to conduct their practice in accordance with the conduct of a prudent and diligent physician in the same circumstances.[5] In Crits v. Sylvester, the Ontario Court of Appeal held:

Every medical practitioner must bring to his task a reasonable degree of skill and knowledge and must exercise a reasonable degree of care.  He is bound to exercise that degree of care and skill which could reasonably be expected of a normal, prudent practitioner of the same experience and standing, and if he holds himself out as a specialist, a higher degree of skill is required of him than one who does not profess to be so qualified by special training and ability.[6]

Therefore, the Plaintiff must lead expert evidence from a qualified expert with respect to what could be reasonably expected of a normal, prudent and diligent physician of the same experience and standing as the Defendant physician in the same circumstances as the Defendant physician.

The Plaintiff’s expert report must not simply provide a conclusionary bald statement that the Defendant had not met the standard of care. In Cheesman et al. v. Credit Valley Hospital et al., the Defendants sought to elicit an opinion from an expert that was baldly asserted, but not explained, in his report.  Justice Koehnen held:

“To accede to the defence view of latency has the same effect as the defence's first argument. It would allow the defence to file a bare-bones expert's report which simply asserts that the defendant had met the standard of care and leave it to the expert's trial testimony to explain the reasons for which the expert holds that view. This would rob the mandatory provisions of rule 53 of all effect and institute trial by ambush.”[7]

Therefore, the Plaintiff’s expert must set out the basis for her opinion that the Defendant breached the standard of care.

What is causation?

The legal issue of causation in medical malpractice litigation has been given significant attention by the Courts and is at the forefront of legal discourse. Many medical malpractice cases fail on the issue of causation given the complexities of the legal test in conjunction with the complex medical terrain.

It is well-established that the traditional legal test to be applied to causation in medical negligence cases is the “but for” test. As affirmed by Chief Justice McLachlin of the Supreme Court of Canada in Clements (Litigation Guardian of) v Clements, the “but for” test involves the question of whether the injury would have occurred “but for” the Defendant’s actions or omissions.[8]

Causation in medical negligence cases, as explained by Justice Major for the Supreme Court of Canada in Athey v Leonati [9], is found when the plaintiff proves on a balance of probabilities that the Defendant caused or contributed to his or her injury.

The Court should apply a “robust and pragmatic” approach to the issue of causation, and not require proof of the cause by scientific precision or certainty.[10]

Similar to proving a breach of the standard of care, the Plaintiff must lead expert evidence on the issue of causation. The Plaintiff’s expert must refrain from making “broad brush statements” on the issue of causation and explain with specificity and particularity how the outcome for the Plaintiff would have been different had the negligence not occurred. In Peller v. Ogilvie-Harris, Justice Darla Wilson stated:

“It is not disputed that Dr. Pichora would be qualified to provide an opinion on causation given his background and experience in hand and microsurgery. The difficulty that has arisen is that nowhere in either of his reports, and I am not being critical of Dr. Pichora, does he expressly set out an opinion on causation. The closest he comes to doing so is the one sentence relied on by counsel for the Plaintiff in her submissions—essentially that earlier detection of the nerve problem would have probably led to a better result. That is a broad brush statement, in my opinion, without any particularity which would enable the reader of his report to understand in what way the outcome for the Plaintiff would have been different had the injury to the ulnar nerve been detected earlier and further surgery undertaken.”[11]

Consequently, the Plaintiff’s expert testimony on the issue of causation is crucial to a successful outcome and the importance of a comprehensive and well-reasoned expert analysis cannot be understated. 

[1] Rules of Civil Procedure, R.R.O. 1990, Reg. 194, Rule 53.03.

[2] Hoang (Litigation Guardian of) v Vincentini, 2012 ONSC 1358.

[3] Peller v Ogilvie-Harris, 2018 ONSC 725; Cheesman et al v Credit Valley Hospital et al, 2019 ONSC 5783;

[4] Peller v Ogilvie-Harris, 2018 ONSC 725

[5] ter Neuzen v Korn, [1995] 3 SCR 674

[6] Adams v Taylor, 2012 ONSC 4208

[7] Cheesman et al v Credit Valley Hospital et al, 2019 ONSC 5783

[8] Clements v Clements, 2012 SCC 32

[9] Athey v Leonati, [1996] 3 SCR 458

[10] Clements v Clements, 2012 SCC 32

[11] Peller v Ogilvie-Harris, 2018 ONSC 725

Bogoroch & Associates LLP is experienced in all aspects of personal injury and medical malpractice litigation. We have the confidence and skill to advance your motor vehicle accident or medical malpractice claim to settlement or trial while helping you navigate the complex medical, legal, and insurance issues.

Our experience, commitment to excellence, and reputation have long been recognized.  Our founding partner, Richard M. Bogoroch, has been recognized as a leading personal injury lawyer by The Canadian Legal Lexpert Directory and by The Best Lawyers in Canada.  The Canadian Legal Lexpert Directory and The Best Lawyers in Canada are two highly regarded lawyer rating publications.

If you or your loved one has been injured in an accident or believes that you are a victim of malpractice or negligence, reach out to a personal injury or medical malpractice lawyer to understand if you too have a claim. Please contact any of our personal injury lawyers at Bogoroch & Associates LLP for a free consultation. 

Contact a personal injury lawyer near me by calling 1-866-599-1700 or visit our Contact page for all inquiries.

How do you Prove Medical Malpractice?
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How do you Prove Medical Malpractice?
Medical malpractice cases are vigorously litigated and the burden of proof is on the plaintiff to prove they were provided negligent medical care. Read this article to learn the steps to prove medical malpractice.
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Bogoroch & Associates LLP
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