Reibl v Hughes: The Modified Objective Test for Causation in Informed Consent Claims — When a Reasonable Person Would Have Said No

John Reibl was a Hungarian-born tool and die maker who had worked on the assembly line at the Ford Motor Company plant in Oakville, Ontario for more than eight years. He was about a year and a half away from completing the ten years of service that would earn him a lifetime retirement pension. He had severe, persistent headaches. He had been referred to Dr. Robert Hughes, a neurosurgeon who had discovered a significant narrowing in the artery that carried blood to the left side of Reibl’s brain, a narrowing that permitted only fifteen percent of normal blood flow.

Dr. Hughes recommended surgery. The surgery was competently performed. During or immediately after the operation, Reibl suffered a massive stroke. He was paralyzed on the right side of his body and became impotent. He would never work again. He forfeited his pension benefits. He was forty-four years old.

Reibl v Hughes, decided by the Supreme Court of Canada on October 7, 1980, became the definitive Canadian authority on two of the most consequential questions in medical malpractice law: when does a failure to disclose risks sound in negligence rather than battery; and what must a plaintiff prove about causation in an informed consent claim? The answers Laskin CJ gave, for a unanimous court, reshaped the legal landscape for informed consent litigation in Canada and continue to govern it today.

The Clinical History

John Reibl had developed severe headaches in 1968 or early 1969 that appeared to be brought on or worsened by the constant bending down required of him at the assembly line. His family physician, Dr. Szabo, who, like Reibl, was of Hungarian origin, found he had high blood pressure. Tests over the following months were inconclusive; Reibl was also found to be mildly diabetic. He was discharged on medication for both conditions.

In February 1970, Reibl was re-admitted for further investigation. It was now that Dr. Hughes, chief of neurosurgery, was brought in for consultation. Dr. Hughes detected a “bruit” (a sound indicating turbulence) over the left carotid artery in Reibl’s neck. Arteriograms taken on March 10, 1970 confirmed what Hughes suspected: a significant build-up of plaque had narrowed the left internal carotid artery by eighty to ninety percent, reducing blood flow to approximately fifteen percent of normal. A smaller plaque was also present higher up on the same side, and a very small one on the right. Dr. Hughes noted, importantly, that the major occlusion was asymptomatic: it was not causing any detectable neurological dysfunction or abnormality at that time.

Nonetheless, Dr. Hughes formed the opinion that the occlusion should be surgically removed to reduce the risk, over the coming several years, of a stroke caused by the diminishing blood supply to the brain. He recommended an elective left internal carotid endarterectomy, a procedure in which the plaque and several inner layers of the artery wall are dissected out, the vessel flushed and sutured, and blood flow restored. It was technically demanding surgery at the junction of an artery the thickness of a man’s little finger, close to the base of the skull.

The risks Dr. Hughes himself understood in 1970, based on his own experience of sixty to seventy such operations: a mortality rate of less than four percent, and a morbidity rate (neurological damage or non-fatal stroke) of approximately ten percent. Combined, a patient faced roughly a fourteen percent risk of death or serious injury from the operation itself. Eight to ten of his prior sixty to seventy operations had resulted in fatalities, most in the earlier years when the technique was newer. The risks of NOT having the operation were different in character. According to the expert evidence, a person with Reibl’s degree of occlusion faced approximately a ten percent chance of a stroke in each year they continued without surgery, though they might also go on indefinitely without neurological complications.

The surgery was scheduled for March 18, 1970. Reibl signed a formal consent form a few days beforehand; the signing had been delayed briefly to allow him to consult a lawyer about a mortgage. On March 18, Dr. Hughes performed the endarterectomy. He found good collateral blood flow and did not use a shunt. The operation appeared to proceed well. But during or immediately following surgery, Reibl suffered a massive stroke. He was paralyzed on his right side, which became hypersensitive to temperature. His right arm lost useful function. He suffered from impotence. He was transferred to a rehabilitation centre. He would never return to work at Ford.

At the time of his stroke, Reibl had 8.4 years of service with the Ford Motor Company. He was roughly eighteen months away from completing the ten years required to vest a lifetime retirement pension under the collective agreement. As the trial judge noted, “due to this tragedy befalling him at the time it did, he was not eligible for certain extended disability benefits available under the collective agreement between the Ford Motor Company of Canada Limited and its hourly employees of ten years’ standing.”

What Dr. Hughes Did and Did Not Tell Reibl

The heart of the informed consent dispute was what Dr. Hughes communicated to Reibl before the operation, and what he did not.

What Dr. Hughes told Reibl, on his own evidence and on Reibl’s evidence where not disputed, was essentially this: there was a narrowing in the artery in his neck reducing blood flow to his brain; surgery was recommended to restore that flow; without surgery he might, within a few years, suffer a stroke; he might “fall on his nose” and that would be the end of it; with surgery, the chances of NOT having a stroke were better than without it. The defendant told Reibl he would be back at work in ten days. He explained the mechanics of what would be done: a partial plug removed from an artery in his neck. He did not use statistics.

On Reibl’s evidence, largely accepted by the trial judge, he was left with the impression that the surgery was being done to alleviate his headaches and hypertension and enable him to work effectively. He understood that if he did not have the surgery he faced the prospect of a stroke in a few years. He did not understand, because he was not told, that he faced a fourteen percent risk of death or permanent disability from the surgery itself, imminently, during or shortly after the operation.

Most tellingly, when Reibl visited Dr. Hughes’s office after the stroke, wheelchair-bound and confronting the surgeon who had changed his life, his wife asked why Hughes had not warned her husband of what might happen. According to both Reibl’s and his wife’s evidence, unchallenged on cross-examination, Dr. Hughes responded: “Mrs. Reibl, I never tell these things to my patients.”

Dr. Hughes’s own evidence in cross-examination confirmed the core finding. He admitted he did not tell Reibl that there was a specific risk of having a stroke as a result of the surgery at any specific time. He confirmed his approach had been to tell Reibl that the chances of not having a stroke were better WITH the surgery than without it. “I didn’t say that specifically,” he replied when asked whether he had told the patient he faced a specific risk of paralysis if he had the operation.

The Three Courts

Trial — Haines J. (January 20, 1977): Judgment for Plaintiff

Haines J. found for Reibl on both battery and negligence and awarded global damages of $225,000.

On the surgical conduct itself and the post-operative management, including the decision not to re-operate when the stroke became apparent, Haines J. found no negligence. The operation was competently performed. The decision not to re-operate was within the acceptable range of choices in 1970. These findings were not challenged on appeal.

On informed consent, Haines J. identified two material breaches. First, Dr. Hughes failed to communicate the purpose of the operation, leaving Reibl with the mistaken belief that the surgery was being undertaken to relieve his headaches and enable him to work. Second, and more fundamentally, Dr. Hughes failed to convey the gravity, nature, and extent of the risks specifically attendant on the endarterectomy, in particular, the risk of death or stroke as a direct consequence of the operation itself.

The trial judge framed the breach by reference to a hypothetical: had Dr. Hughes said to Reibl, “I propose to remove a partial plug in an artery a few inches from your brain. There is a risk that as a result a fragment of tissue may slip into your brain and if it does, you have a 4% chance of dying and a further 10% chance of having a stroke,” then “there is no question the plaintiff would flatly have refused.” The trial judge also found battery on the basis that the undisclosed risk of fourteen percent mortality or morbidity was so fundamental to the nature and character of the surgery that a consent given in ignorance of it was no consent at all.

Ontario Court of Appeal — Brooke J.A. (June 19, 1978): New Trial on Both Issues; Battery Rejected

Brooke J.A., writing for the majority (Blair J.A. concurring), ordered a new trial on both liability and damages. Jessup J.A. dissented in part, agreeing with Haines J. on liability and ordering only a new trial on damages.

On battery, Brooke J.A. held that it should not have been a ground of liability. Where the case was pleaded in negligence, where the surgery performed was the surgery to which the plaintiff had consented, and where the only alleged deficiency was a failure to disclose attendant risks (not a misrepresentation about the nature of the surgery itself or an intentional deviation from the consent given), the action should be in negligence, not battery.

On liability in negligence, Brooke J.A. was critical of the trial judge’s use of statistics and of the hypothetical proposition he had posited. He found that neither Dr. Elgie nor Dr. Schacter, the plaintiff’s expert neurosurgeons, had emphasized statistical disclosure in their own approach to patient consent. He also observed a significant discrepancy between Dr. Hughes’s figures (fourteen percent cumulative risk) and Dr. Elgie’s (about four to eight percent cumulative), which remained unexplained. He suggested it was better to explain risks comparatively, contrasting the patient’s position with and without surgery, rather than by raw statistics.

On causation, Brooke J.A. addressed what he saw as the trial judge’s failure to properly analyze whether the negligence caused the loss. He drew on American authorities, including Canterbury v Spence, Cobbs v Grant, and Barnette v Potenza, all of which had moved from a subjective test (“would this patient have refused if informed?”) to an objective test (“would a reasonable prudent person in the patient’s position have refused if informed?”). He said that while Canadian courts had so far applied a subjective test, an objective approach, or at least combining objective and subjective elements, was preferable. He ordered a new trial in part because the trial judge had not adequately addressed causation on either standard.

On damages, Brooke J.A. also ordered a new trial because the global award was inconsistent with the methodology mandated by the 1978 SCC trilogy, Andrews v Grand & Toy, Arnold v Teno, and Thornton v School District, which had been decided after the trial judgment and required separate assessment of each head of damages.

Supreme Court of Canada — Laskin CJ (October 7, 1980): Trial Judgment Restored

The SCC allowed Reibl’s appeal, set aside the ONCA order, and restored the trial judgment. The defendant accepted the damages at the SCC level, and the parties agreed neither wished a new trial given that more than ten years had elapsed since the stroke. The SCC therefore resolved liability on the existing record rather than remitting the matter again. It confirmed negligence as the basis of liability and rejected battery. It resolved the causation question for the first time at the national level in favour of the plaintiff.

Battery Rejected: The Definitive Canadian Boundary

Laskin CJ’s first major contribution in Reibl v Hughes was to settle, once and for all, that an informed consent claim founded on a failure to disclose risks sounds in negligence, not battery, provided the surgery performed was the surgery to which consent was given.

The confusion that had generated battery claims in informed consent cases, Laskin CJ observed, stemmed partly from the popularization of the phrase “informed consent.” The term had the effect of suggesting that unless consent was truly informed, meaning, qualified by full risk disclosure, it was no consent at all, leaving the surgeon without the protection that consent ordinarily provides against battery. This reasoning, though understandable, was wrong.

Battery is an intentional tort: an unprivileged, unconsented-to invasion of bodily security. The cases where battery properly applies in the medical context are those where: surgery or treatment was performed without any consent at all; surgery or treatment was performed beyond the consent given; or there was misrepresentation about the nature of the surgery such that the patient consented to one procedure and a different one was performed. The cases Laskin CJ cited as examples make this plain: Murray v McMurchy (consent to caesarian; doctor also sterilizes the patient), Schweizer v Central Hospital (consent to operate on toe; doctor operated on back instead), and similar situations of intentional deviation from what was authorized.

Where the surgery performed is the surgery the patient consented to, and the complaint is only that risks attending that surgery were not adequately disclosed, there is no intentional deviation from the consent given. The failure of disclosure is a breach of the anterior duty of due care, the same genus of obligation as the duty to perform the surgery with skill and care, not a negation of the consent itself. Unless there has been misrepresentation or fraud, a failure to disclose risks, however serious, should go to negligence rather than battery. This means, among other things, that the plaintiff must establish causation and damages in the usual way.

The Standard of Disclosure: Not Purely a Medical Question

The SCC’s second major contribution addressed what governs the standard of disclosure. Brooke J.A. had suggested that the manner in which risks are explained to a patient is “better left to the judgment of the doctor in dealing with the man before him.” This was, in Laskin CJ’s assessment, going too far in the opposite direction from the trial judge.

Expert medical evidence is relevant to informed consent claims in several important ways: it establishes what risks reside in or result from the recommended surgery or treatment; it addresses the medical consequences of foregoing treatment; it identifies alternative treatments and their risks; it speaks to any emergencies or special circumstances that might modify the disclosure obligation. But expert medical evidence cannot be conclusive on whether there has been a breach of the duty of disclosure. If the scope of the disclosure duty were determined entirely by reference to what physicians do and what medical experts say, the entire question would be handed over to the medical profession to answer about itself.

The disclosure obligation has two sources, not one. Material risks, those recognized as such by required medical knowledge, must be disclosed. But equally, what the doctor knows or should know that the particular patient deems relevant to a decision about whether to undergo or forgo recommended treatment also generates a disclosure obligation. A doctor who knows, or should reasonably know, that a patient has expressed concerns or has specific personal circumstances that would affect their decision is obliged to respond to those concerns. The patient’s particular position, including economic circumstances, pending events, and specific anxieties, is part of what the disclosure duty must address.

The materiality of non-disclosure of certain risks is, in the final analysis, a question of fact for the trier of fact. Medical evidence will likely be part of the picture, but other evidence, from the patient, from family members, and from the circumstances of the particular case, is equally relevant and cannot be displaced by the professional consensus.

The Modified Objective Test for Causation

The most significant and enduring contribution of Reibl v Hughes is the resolution of the causation question. The issue was, in the SCC’s words, res integra: no prior Supreme Court of Canada decision had addressed which test governs causation in a claim that a failure of informed consent caused the plaintiff’s harm.

The causation inquiry in an informed consent negligence claim has a distinctive structure. The plaintiff must establish not only that there was a breach of the duty of disclosure, that is, that material risks were not communicated, but also that the failure of disclosure caused the harm. The causal question is this: if the defendant had properly disclosed the relevant risks, would the plaintiff have declined the surgery that caused the injury?

Why a Pure Subjective Test Fails

A purely subjective test asks: would this particular plaintiff, if properly informed, have declined the surgery? The problem with a subjective test is immediately apparent. The plaintiff who is suing has already suffered serious harm from the surgery. It would be extraordinary if such a plaintiff testified, with the benefit of hindsight and the bitterness of their loss, that they would have agreed to the surgery even if properly informed. A subjective test almost inevitably produces a plaintiff’s verdict, and it does so not because the law has been properly applied but because human nature and litigation dynamics make any other outcome psychologically implausible. As the ONCA had noted citing American authority, a subjective test “exposes the physician to the patient’s hindsight and bitterness.”

Why a Pure Objective Test Also Fails

A purely objective test asks: would a reasonable person have declined the surgery if properly informed? This avoids the hindsight problem but creates a different one. If the surgery was medically indicated and recommended by an expert physician, could a reasonable person be said to have declined it? Medical endorsement of a treatment is powerful evidence that a reasonable person would accept it. A pure objective test risks treating the reasonableness of the surgery’s recommendation as effectively determinative of causation, putting the causation issue entirely in the hands of the defendant’s expert witnesses and leaving patients no real prospect of success on causation no matter how grave the undisclosed risk.

The Modified Objective Test

Laskin CJ adopted a modified objective test: what would a reasonable person IN THE PATIENT’S PARTICULAR POSITION have decided, if properly informed of all the material risks, balanced against the risks of not having the surgery?

This test is objective in the sense that it does not simply ask what the individual plaintiff says they would have done; that testimony is relevant and necessary, but it is not conclusive. The test is modified in the sense that the reasonable person is placed in the specific circumstances of the plaintiff, not in some generic hypothetical situation. The reasonable person, for purposes of causation, is endowed with the plaintiff’s particular characteristics, circumstances, and concerns, but assessed objectively rather than subjectively.

Several features of the test deserve emphasis.

First, the patient’s personal circumstances, including economic considerations, can legitimately be part of the objective analysis. The prospect of imminent pension vesting, for example, is not a mere quirk of the individual plaintiff’s psychology but a rational economic fact about their situation that a reasonable person in that position would weigh. The loss of a job requiring good eyesight, as another example Laskin CJ gave, would be a legitimate consideration if loss of an eye was a risk that had not been disclosed. Economic rationality is part of reasonable decision-making.

Second, the balance of risks, between having the surgery and not having it, is central to the analysis. If the risks of foregoing surgery are considerably greater than the risks of undergoing it, the objective standard would generally favour the surgeon who failed to disclose, because a reasonable person would likely still have accepted the surgery. Conversely, where the risks of surgery and no surgery are more closely balanced, particularly where the surgical risk is immediate and grave while the risk of no surgery is deferred and uncertain, the case for finding that a reasonable person would have declined strengthens considerably.

Third, any specific questions the patient asked that were not answered, or were answered inadequately or incorrectly, are particularly relevant. A patient who specifically asked about the risk of paralysis and was not honestly answered is in a different position than one who never raised the question. The specific questions Reibl asked about paralysis were answered by comparative reassurance (“chances better with surgery than without”) rather than by honest disclosure of the absolute risk from the surgery itself.

Fourth, the patient’s own testimony remains necessary to the causation analysis. The plaintiff must give evidence of what they would have done. This evidence is not conclusive (it is tested against the objective standard) but without it, the causation case cannot be established. The plaintiff cannot simply assert breach and have causation presumed.

Causation on the Facts: Why Reibl Would Have Said No

Applying the modified objective test to the facts, the SCC found that a reasonable person in Reibl’s position would, on a balance of probabilities, have opted against the surgery at that particular time.

The following circumstances combined to reach this conclusion. The condition being treated was asymptomatic; it was causing no detectable neurological dysfunction at the time of the surgery. There was no emergency requiring immediate surgical treatment; Dr. Hughes himself said there was none, and the risk of a stroke without surgery was placed at some point years in the future. The risk from the surgery itself was immediate, during or within hours after the operation, and was approximately fourteen percent for death or serious neurological injury. The risks of surgery and no surgery were therefore not balanced in the same timeframe: the surgical risk was now, the no-surgery risk was later.

Against this already favourable backdrop for Reibl was the pension consideration. He was eighteen months from completing the ten years of service required to vest a lifetime retirement pension and extended disability benefits. A reasonable person in that position, aware of the specific risks of immediate surgical injury, aware that no emergency compelled the surgery now, and aware that the no-surgery risk was a future risk, would rationally have deferred the surgery for eighteen months to protect the pension, while accepting the small incremental annual stroke risk of no surgery in the interim.

The trial judge’s finding that Reibl had been left with the mistaken impression that the surgery would relieve his headaches was also relevant. A reasonable person who understood they were consenting to surgery that would NOT cure their headaches, that carried a fourteen percent risk of immediate death or permanent paralysis, and that was not urgently necessary, would have the additional reason, namely the absence of the expected benefit, to decline at that particular time.

What Reibl v Hughes Establishes

Principle One: The Battery/Negligence Boundary in Medical Informed Consent

Reibl v Hughes settled the law in Canada on when a failure of informed consent sounds in battery and when it sounds in negligence. Battery: where surgery or treatment was performed without any consent at all, or where surgery or treatment was performed beyond the consent given (including by misrepresentation about the surgery to be performed). Negligence: where the surgery performed was the surgery consented to, and the complaint is a failure to disclose attendant risks. This line cannot be blurred by arguments that “uninformed” consent is “no consent”; the relevant question for battery is whether the plaintiff consented to the kind of treatment given, not whether they were optimally informed about its risks.

Principle Two: Disclosure Standards Are Not Determined by Medical Custom Alone

The scope of the duty of disclosure cannot be handed entirely to the medical profession to define. Expert medical evidence is necessary and relevant to identifying what risks exist, what their medical significance is, and what alternatives are available. But the scope of the disclosure duty, including whether a breach has occurred, is a matter for the trier of fact. The patient’s own articulated concerns and circumstances generate disclosure obligations independently of what standard medical practice requires. A physician cannot shelter behind the professional norm if they knew or should have known that the particular patient had specific concerns or circumstances that bore on the decision.

Principle Three: The Modified Objective Test for Causation

Causation in an informed consent negligence claim is assessed by asking what a reasonable person in the patient’s particular position would have decided, if properly informed of the material risks of the proposed surgery and of the risks of foregoing it. This test is objective (it avoids the hindsight problem of a subjective standard) but sensitive to the plaintiff’s particular circumstances (it avoids the medical-endorsement problem of a pure objective standard). The patient’s own evidence about their decision-making is necessary but not conclusive. Economic and personal circumstances, including impending pension vesting, employment requirements, and family considerations, can form part of the objective assessment when they are reasonably related to the decision at hand.

Principle Four: The Balance of Risks Pro and Con Is the Core Analytical Framework

The causation analysis is organized around the pro-and-con assessment of risks: what are the risks of undergoing the proposed surgery; what are the risks of not undergoing it; how does the balance compare; and were all material aspects of this balance disclosed? The failure of full disclosure on either side of the equation, the surgical risks or the no-surgery risks, is relevant. Where the risks are closely balanced, or where surgical risk is immediate and no-surgery risk is deferred, the plaintiff’s case on causation is stronger. Where the no-surgery risk greatly exceeds the surgical risk, the case is weaker, because even a reasonable person with full information would likely have proceeded.

Principle Five: Special Patient Circumstances Can Be Decisive

Reibl v Hughes is a concrete illustration that the patient’s particular situation can tip the causation balance in a case where the risks on both sides are real. Reibl’s pending pension vesting was not a trivial personal idiosyncrasy; it was a rational economic consideration that a reasonable person in his position would have weighed heavily. The combination of an asymptomatic condition, no emergency, an immediate surgical risk of fourteen percent, a deferred no-surgery risk, and an eighteen-month window to a major financial benefit was enough to find, on balance of probabilities, that a reasonable person would have declined at that time. The decision might have been different after the pension vested.

Reibl v Hughes and the Arndt v Smith Refinement

The modified objective test from Reibl v Hughes was further refined by the Supreme Court of Canada in Arndt v Smith, 1997 CanLII 360 (SCC), [1997] 2 SCR 539. In Arndt, the SCC confirmed that the standard is what a reasonable person in the patient’s circumstances would have done, but that this reasonable person has the particular concerns and characteristics of the plaintiff, assessed objectively. Purely subjective fears not related to the material risks that should have been disclosed would not be causative; but personal circumstances rationally connected to the decision are taken into account. This refinement reinforced the Reibl v Hughes framework without displacing it.

Reibl v Hughes in the Informed Consent Series

Reibl v Hughes is the second half of the foundational informed consent dyad in Canadian medical law. It should be read in conjunction with Hopp v Lepp, 1980 CanLII 14 (SCC), [1980] 2 SCR 192 — https://canlii.ca/t/1mjv6 which was decided five months earlier on May 20, 1980 and which defined the disclosure obligation itself. Hopp v Lepp addresses what must be disclosed and when. Reibl v Hughes addresses what must be proved about causation after a breach of the disclosure obligation is established. Together they form the complete framework for Canadian informed consent litigation.

Both cases are referenced in the Birth Injury Claims Guide, the General Medical Malpractice Claims Guide, and the Surgical Errors Guide in this series. Suwary v Librach, 2015 ONSC 2100 — https://canlii.ca/t/gh8jn applies the informed consent framework from Reibl v Hughes to the consent for vacuum-assisted delivery, finding that a general consent covering all operations and procedures associated with pregnancy, labour, and delivery was sufficient in the circumstances and that a reasonable person in the patient’s position would have consented.

Quick Reference: Reibl v Hughes

The Three Decisions

• Trial: Reibl v. Hughes, 1977 CanLII 1273 (ON HCJ), 16 OR (2d) 306 — https://canlii.ca/t/g17qr | Haines J. | January 20, 1977 | Judgment for plaintiff on battery and negligence; $225,000 global damages
• Appeal: Reibl v. Hughes, 1978 CanLII 52 (ON CA), 21 OR (2d) 14 — https://canlii.ca/t/1vm6g | Brooke and Blair JJ.A. (majority); Jessup J.A. (dissent on damages only) | June 19, 1978 | New trial on both liability and damages; battery rejected; majority dissatisfied with causation analysis and use of statistics
• SCC: Reibl v. Hughes, 1980 CanLII 23 (SCC), [1980] 2 SCR 880 — https://canlii.ca/t/1mjvr | Laskin CJ (unanimous) | October 7, 1980 | Appeal allowed; trial judgment restored; battery rejected; negligence affirmed; modified objective test for causation adopted; defendant accepted damages

The Parties

• Plaintiff: John Reibl — Hungarian-born, emigrated 1956; tool and die maker then Ford assembly line worker; 44 at time of surgery; 8.4 years at Ford (18 months from pension vesting at 10 years); suffered massive stroke during or immediately after surgery; paralyzed right side; impotent; permanently unable to work
• Defendant: Dr. Robert A. Hughes — neurosurgeon, chief of neurosurgery; had performed 60-70 carotid endarterectomies prior to Reibl’s; 8-10 fatalities in prior operations

The Clinical Facts

• Condition: Left internal carotid artery stenosis — 80-90% narrowing, only 15% normal blood flow; asymptomatic at time of surgery
• Operation: Left internal carotid endarterectomy (plaque removal), March 18, 1970 — elective; no emergency
• Surgical risks known to Dr. Hughes: approximately 4% mortality, 10% morbidity (stroke/paralysis) — cumulative 14% risk from the surgery itself
• Risk without surgery: approximately 10% annual risk of stroke, but the condition might never cause complications
• What Dr. Hughes told Reibl: chances of NOT having a stroke were better WITH surgery than without; he would be back at work in 10 days; surgery was to restore blood flow and prevent future stroke
• What Dr. Hughes did NOT tell Reibl: the specific 14% risk of death or permanent disability from the operation itself; that the surgery would NOT cure his headaches (disputed); that the risk was immediate, not deferred
• Dr. Hughes to Mrs. Reibl after the stroke: “I never tell these things to my patients”
• Dr. Hughes in cross-examination: “I didn’t say that specifically” when asked if he told Reibl of the risk of a stroke from the surgery

Battery/Negligence Boundary

• BATTERY applies: where surgery or treatment is performed WITHOUT any consent at all; OR where surgery or treatment is performed BEYOND the consent given (including by misrepresentation about the surgery to be performed)
• NEGLIGENCE (not battery) applies: where the surgery performed is the surgery consented to, and the only complaint is failure to disclose attendant risks
• Distinction cannot be avoided by arguing that “uninformed” consent is “no consent” — for battery, the question is whether the plaintiff consented to the kind of treatment given
• Examples of true battery in Canadian law: Murray v McMurchy — caesarian plus sterilization when only caesarian consented to; Schweizer v Central Hospital — consented to toe operation, back operated on instead; Murray v McMurchy and Marshall v Curry — various unauthorized extensions of consented procedures

The Standard of Disclosure

• Expert medical evidence is RELEVANT but NOT DETERMINATIVE — scope of disclosure duty cannot be handed to the medical profession to define
• TWO sources of the disclosure obligation: (1) material risks recognized by required medical knowledge; (2) what the doctor knew or should have known that the particular patient deemed relevant to their decision
• Materiality of non-disclosure is a question of FACT for the trier of fact
• Statistics need not be quoted — the duty is to disclose the material risks, not necessarily in numerical form — but the failure to communicate that there is a specific risk of stroke or death from the operation itself cannot be excused by saying the manner of disclosure is entirely for the doctor to decide

The Modified Objective Test for Causation

• REJECTED: Pure subjective test — “would this plaintiff have declined if properly informed?” — exposes physician to patient’s hindsight and bitterness
• REJECTED: Pure objective test — “would a reasonable person have declined?” — risks putting causation entirely in the hands of medical endorsement of the surgery
• ADOPTED: Modified objective test — “what would a reasonable person IN THE PATIENT’S PARTICULAR POSITION have decided, if properly informed of the material risks of surgery and no surgery balanced against each other?”
• Patient’s own testimony: necessary but not conclusive
• Patient’s particular circumstances: taken into account objectively — economic considerations, pending events, specific concerns communicated to the doctor are all relevant when rationally connected to the decision
• Fears unrelated to material risks: not causative
• Balance of risks pro and con: the core analytical framework — immediate vs deferred risks, surgical vs no-surgery risks, gravity of each

Application on the Facts

• Causation ESTABLISHED: a reasonable person in Reibl’s position would have declined surgery at that time on balance of probabilities
• Reasons: asymptomatic condition; no emergency; 14% immediate surgical risk vs deferred no-surgery risk; approximately 18 months from pension vesting; mistaken impression that surgery would relieve headaches (itself a consequence of the breach); these factors combined to make deferral the rational choice for a reasonable person in his position

Key Cases Referenced

• Hopp v. Lepp, 1980 CanLII 14 (SCC), [1980] 2 SCR 192 — https://canlii.ca/t/1mjv6 — the companion SCC decision on the scope of the disclosure duty; article in this series
• Kelly v. Hazlett (1976), 1976 CanLII 568 (ON HCJ), 15 OR (2d) 290 — the Kelly/Hazlett distinction between battery and negligence in consent cases; cited by Haines J. and Laskin CJ
• Arndt v. Smith, 1997 CanLII 360 (SCC), [1997] 2 SCR 539 — SCC refinement of the modified objective test; confirmation that the reasonable person has the plaintiff’s particular concerns and characteristics, assessed objectively
• Canterbury v. Spence (1972), 464 F 2d 772 — American authority on objective test for causation; considered by ONCA and SCC
• Cobbs v. Grant (1972), 502 P 2d 1 — American authority on negligence as the proper cause of action for disclosure failures; considered by ONCA
• Kenny v. Lockwood, 1931 CanLII 184 (ON CA), [1932] OR 141 — foundational Canadian case on the surgeon’s disclosure duty; cited throughout the Reibl litigation
• Murray v. McMurchy, 1949 CanLII 220 (BC SC), [1949] 2 DLR 442 — example of true battery: caesarian consent; doctor also sterilizes patient
• Schweizer v. Central Hospital et al. (1974), 1974 CanLII 580 (ON HCJ), 6 OR (2d) 606 — example of true battery: consented to operation on toe; operated on back instead

Related Articles in This Series

• Hopp v. Lepp, [1980] 2 SCR 192 — https://canlii.ca/t/1mjv6 — the companion decision on the scope of the disclosure duty; what must be disclosed without being asked; the specific-questions rule; the qualified specialist’s first post-certification operation; article in this series
• Suwary v. Librach, 2015 ONSC 2100 — https://canlii.ca/t/gh8jn — applies the Reibl/Hopp framework to consent for vacuum-assisted delivery; non-elective procedures covered by general consent; reasonable person in patient’s position would have consented; article in this series
• Wilson v. Swanson, [1956] SCR 804 — the error of judgment doctrine; the specialist standard of care; cited in the Reibl v Hughes litigation; article in this series
• Crits v. Sylvester, 1956 CanLII 34 (ON CA) — the normal prudent practitioner standard; article in this series