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Causation, Defenses, and Damages - Module 3 of 5

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 Medical Malpractice Module 3:

Causation, Defenses, and Damages

The Element of Causation

To sustain a medical malpractice action, the plaintiff must demonstrate negligence. This involves making the case that the physician failed to treat the plaintiff in accord with the customary care of physicians in that field of medicine. However, in addition, it must be demonstrated that the doctor’s negligence was a substantial factor in causing damages suffered by the patient. Given the complexities of the human body and the specialized nature of medical practices, the testimony of expert witnesses is often needed to establish the element of causation.

In civil suits, the standard of proof is preponderance of the evidence. This means that the burden on the plaintiff is to demonstrate that it is more likely than not that the physician’s negligence was a substantial factor in causing the harm.[1] Some jurisdictions operate under a higher standard, requiring the plaintiff to show with reasonable medical certainty that the physician’s conduct was the cause of the harm.[2]  

Unlike in most non-medical contexts, the plaintiff in medical malpractice cases is normally someone who was already sick or injured prior to interacting with the doctor. So, the issue is often the extent to which decisions by a doctor resulted in an already sick patient failing to recover or getting worse. In these cases, the question for the jury, whether it is more likely than not that a physician caused the harm, depends on whether the patient would likely have escaped the harm if the physician had acted properly.

To illustrate, consider the case of a young boy who was examined by a doctor after suffering a head injury.  The doctor failed to conduct appropriate tests which would have revealed that the child had suffered a skull fracture, which has a near 100 percent mortality rate without medical intervention. The child was sent home and died from his injuries.

In the ensuing wrongful death suit, the plaintiff succeeded in showing that the doctor had breached his duty by failing to diagnose and treat the injury to his son. However, the court held that he was not able to demonstrate that the doctor’s breach of duty caused the injury. The rationale was that even if the doctor had properly diagnosed and sent the boy to surgery, the odds of the patient surviving would have been less than 50%. The plaintiff failed to show that it was more likely than not that he would have survived, and so the plaintiff did not meet the preponderance of the evidence test.[3]

The Loss of Chance Doctrine

Over time courts have noted that one important consequence of applying the preponderance of the evidence test or tests with higher standards has been to severely limit the circumstances under which a doctor can be held liable. As in this case of the boy with a skull fracture, whenever a patient has less than 50% chance of survival even with proper medical treatment, there can be no recovery. Moreover, since the chances of suffering further injury or death from the pre-existing condition is likely even if treated properly, plaintiffs have trouble demonstrating causation in cases of patients who were already in danger or very ill before being treated.

To offer legal redress for these patients, many jurisdictions have adopted the loss of chance doctrine. Under this approach, when a defendant’s negligent action or inaction substantially increases the risk of harm or reduces a person’s chance of survival, the defendant may be held liable even if there was less than 50% chance of survival to begin with.[4] This rule also accounts for the general uncertainty when it comes to determining medical outcomes, and the difficulty in foretelling what is possible with successful medical interventions.   

In Kallenberg v. Beth Israel Hospital, a doctor failed to administer blood pressure medication in advance of life-saving surgery, a step a reasonable practitioner would have taken, leading to the death of the patient. At trial, an expert testified that the patient had “20, 30, or even 40 percent” chance of survival had the doctor properly administered the medication but faced near certain death due to the doctor’s error. The court ruled that this testimony was sufficient to find that the doctor caused the patient’s death, due to the loss of chance of life directly attributable to the doctor’s negligence.[5]

Some jurisdictions have crafted a “middle” approach, which allows physicians to be liable for increasing the risk of harm even when the chance of recovery is less than 50%, but only if the evidence meets the high standard of a ‘reasonable degree of medical certainty’ that the defendant’s negligence caused the increased risk.[6] Under this approach, there is an incentive for providing quality medical care even when the patient faces difficult odds, but it also requires strong evidence that the doctor’s decisions, rather than the pre-existing condition, increased the risk of injury or death.

Multiple Causes of Injury or Death

Medical practice often involves multiple medical practitioners, each of whom has a duty of care to a patient. As such, when more than one medical professional breaches a duty, the law must determine if one or multiple parties are responsible for harm resulting from the negligence. The question of legal responsibility for harm in tort law depends on who can be said to be the proximate cause of the injury.

The Sixth Circuit Court of Appeals faced this question in a case involving two emergency room physicians who treated a patient. The first failed to diagnose a fracture that required surgery and the second failed to communicate the situation to the patient once a senior doctor correctly diagnosed the patient, which delayed appropriate medical attention. The question before the court was whether the negligence of the second ER doctor was a superseding cause of the eventual injury suffered by the patient. If the court deemed the actions of the second doctor to be superseding, his failure to communicate to the patient would be the sole proximate cause of the injury, and he alone would be liable, cutting off the liability of the first doctor.

However, the court ruled that the negligence of the second doctor did not create a new harm, but simply failed to prevent the harm caused by the first doctor. As such, both could be held liable for medical malpractice (though the court held the second doctor liable on separate grounds based an implied agreement between the doctors).[7]

Courts generally apply the intervening or superseding cause test to determine whether a second negligent act absolves the first negligent party of liability. A second cause will negate the first if the intervening act was sufficient by itself to cause the injury, was not reasonably foreseeable by the first negligent actor and was not a normal response to the original negligent conduct.[8] If the second act is held not to supersede the first, the conduct of both parties will each be considered a proximate cause of the injury.

Where a single injury is caused by two or more medical professionals acting together (such as multiple surgeons working on one surgery), the parties are jointly and severally liable for the damages. This means that the plaintiff can seek to recover the full amount of damages from any of the parties, though he cannot recover more than the total damages from the parties collectively.  

To determine whether parties are jointly liable, courts will look to factors such as whether the defendants had similar duties to the patient, whether the facts at issue are similar for both the parties and whether responsibility for the injury can be apportioned between the defendants.[9]

Defenses to Medical Malpractice Claims

A physician facing a medical malpractice lawsuit can defend against the claim by arguing that the plaintiff failed to show, by a preponderance of the evidence, that the physician’s conduct met the elements of a malpractice claim. Alternatively, the physician can argue that the circumstances of the lawsuit preclude a finding of liability, regardless of the persuasiveness of the plaintiff’s case. These affirmative defenses are available to defendants in civil suits generally, though physicians facing malpractice claims have some additional recognized defenses.

Statute of Limitations

Statutes of limitations set time limits for plaintiffs’ civil actions. The rationale is to provide some measure of assurance to potential defendants so that they need not fear impending lawsuits indefinitely. Further, with the passage of time, evidence may be lost and memories fade, making the trial process less reliable.

The time within which an action may be brought is set by state law. However, a question of concern in the medical context is determining the time that the statute of limitations begins to run. The standard rule is that the period begins at the date of the negligent conduct. In the medical setting, this would be on the date of the negligent treatment.[10] In some jurisdictions though, the start date for the statute of limitations is determined by when the damage or harm occurs, which may be later than the date of the treatment.[11]

However, harms suffered in the medical context often only become apparent over time. In the same vein, lay people often do not have sufficient medical understanding to attribute responsibility for injuries to medical treatment they have undergone. Under the traditional rule, in which the statute of limitations begins to run from the date of the treatment or the appearance of the injury, patients who initially fail to recognize the harm may be precluded from bringing the case at a later date due to the statute of limitations.

To rectify this problem, most jurisdictions recognize some form of the discovery rule. Under the discovery rule, the statute of limitations begins to run from the date the injury is discovered by the plaintiff or should have been discovered by the plaintiff with reasonable diligence. Thus, plaintiffs are not penalized for failing to take timely legal action when they could not be expected to recognize the harms they have suffered.[12]

Some jurisdictions have adopted the discovery rule, but also set an outer limit, an absolute number of years from the date of treatment within which the patient must bring the suit, regardless of the date he or she discovers the injury.[13]

Contributory Negligence and Assumption of the Risk

As medical malpractice cases are tort claims, affirmative defenses available to a defendant in a standard civil claim are likewise available in a malpractice suit. Prominent among these defenses are contributory negligence and assumption of the risk. These defenses rest on the rationale that even when a defendant is negligent, a plaintiff may assume some or all responsibility for an injury when she contributes to the harm or knowingly engages in activities likely to lead to harm.

Both defenses can be established in the medical context. For example, the failure to follow a physician’s instructions for proper care following medical treatment can eliminate or reduce the physician’s liability for ensuing injury. In one case, a doctor was found negligent for failing to prescribe antibiotics to a patient who was bitten on his finger. However, the damages awarded to the plaintiff were reduced due to his failure to follow the doctor’s discharge instructions to seek immediate medical care if he developed an infection.[14]

Another example might be a patient who continues to smoke after surgery against the instructions of his doctor. This may assume the risk of post-surgery complications.  

Moreover, failing to provide an accurate account of symptoms or a complete medical history may be contributory negligence. For example, a jury may find that a patient contributed to his own death by heart attack if he failed to inform the treating physician that he was experiencing chest pains after being asked by the doctor.[15]

Note that a plaintiff’s negligence can reduce damages proportionally to the harm contributed but does not necessarily preclude recovery for the defendant’s negligence.

Similarly, the doctrine of assumption of the risk protects doctors in cases in which a patient knew that a medical intervention was risky, but nevertheless consented to undergo the treatment. The law may preclude or limit recovery when a patient suffers harm in such cases of known risks.[16]

One such case involved a woman who refused a blood transfusion prior to a procedure, despite her doctor’s warning that it was necessary. Subsequently, the doctor negligently lacerated the patient’s uterus, and the woman bled to death. While the court held the doctor liable, the amount awarded was reduced since it was determined that the refusal of the transfusion was partially responsible for her death and constituted a knowing assumption of the risk.[17]

Good Samaritan Laws

Physicians are under no obligation to treat people simply because they need medical assistance but are open to liability for negligence if they do provide treatment negligently, even if the physician is not being paid. As such, there is a strong incentive for physicians not to treat people outside of the course of their regular practices, even in cases of emergency.

To encourage doctors to offer treatment to people in emergency cases, states have enacted so-called good Samaritan laws¸ which offer a measure of protection to physicians. These laws immunize doctors from medical malpractice lawsuits for harms suffered during emergency medical treatment unless those injuries result from gross negligence or recklessness.[18]

States may differ on the circumstances in which the higher liability standards of good Samaritan laws are applicable to medical treatment. A common test applies the rule when the emergency treatment was provided by a physician without advance notice of the illness or injury and takes into account whether the physician charged a fee for the treatment.


The final element of a medical malpractice suit is damages, which are the harm caused to the patient by the doctor’s breach of duty.[19] Generally recognized damages include out-of-pocket costs, such as medical bills, loss of income, financial loss due to permanent impairment and monetary value assigned to pain and suffering. These all qualify as compensatory damages.[20]

In addition to compensatory damages, plaintiffs in civil actions may also recover damages beyond compensation for harm in cases of gross negligence by the defendant. These punitive damages are means of punishing defendants for engaging in egregious behavior in cases of conscious indifference to the welfare of the plaintiff or willful, wanton, willful, wanton, and reckless conduct.[21]

While difficulties in evaluating damages can be complex in any area, unique questions of putting a dollar value on loss arise in the medical context. One example of a tort claim unique to medical practice is the so-called ‘wrongful birth’ action. In a wrongful birth lawsuit, the plaintiffs are the parents of a child who was either born despite a sterilization procedure or was born with birth defects which a doctor failed to detect and inform the parents, depriving them of the chance to terminate the pregnancy. The plaintiffs are suing for damages in the form of financial and emotional costs of giving birth to and raising a child they did not want.[22]

Even more difficult are the related ‘wrongful life’ claims, in which the parents sue on behalf of a child who was born with birth defects. Since the only way to avoid having been born with defects is not to be born at all, courts must compare the harm and suffering of being born with birth defects against not existing at all to calculate the harm caused by the physician’s failure to diagnose the defects. In fact, due to the difficulties in calculating damages in these and related cases, most courts refuse to award damages in wrongful life lawsuits.[23]

In our next module, we will look at procedural matters in medical malpractice cases, including preparing the lawsuit, filing the claim and settlement negotiations.

[1] Preponderance of the Evidence, Cornell Law School, https://www.law.cornell.edu/wex/preponderance_of_the_evidence.

[2] See Steineke v. Share Health Plan, 518 N.W.2d 904, 907 (Neb. 1994).

[3] Cooper v. Sisters of Charity of Cincinnati, Inc., 272 N.E.2d 97, 104 (1971).

[4] Herskovits v. Group Health, 664 P.2d 474, 478-79 (Wash. 1983).

[5] Kallenberg v. Beth Israel Hosp., 45 A.D.2d 177, 179-80 (N.Y. App. Div. 1974).

[6] Holton v.Memorial Hosp., 679 N.E.2d 1202, 1206 (Ill. 1997).

[7] Siggers v. Barlow, 906 F.2d 241 (6th Cir. 1990).

[8] See Waste Management v. South Central Bell, 15 S.W.3d 425, 432 (Tenn. Ct. App. 1997).

[9] See Riff v. Morgan Pharmacy, 508 A.2d 1247, 1252 (Pa. Super. Ct. 1986).

[10] See Payton v. Benson, 717 F. Supp. 1346, 1347 (S.D. Ind. 1989).

[11] Paul v. Skemp, 625 N.W.2d 860, 868 (WIs. 2001).

[12] Cloutier v. Dalkon Shield Claimants Trust, 152 B.R. 1, 2 (D. Me. 1993).

[16] See Weil v. Seltzer, 873 F.2d 1453, 1458 (D.C. Cir. 1989).

[17] Shorter v. Drury, 695 P.2d 116, 123 (Wash. 1985).

[19] Wright v. St. Mary's Medical Center of Evansville, 59 F. Supp. 2d 794, 800 (S.D. Ind. 1999).

[20] Compensatory Damages, Sweeney Law Firm, https://sweeneylawfirm.com/content/compensatory-damages

[21] McPhearson v. Sullivan, 463 S.W.2d 174, 174-75 (Tex. 1971); see also Restatement (First)of Torts § 908 (1939).

[22] See Troppi v. Scarf, 187 N.W.2d 511, 520-21 (Mich. 1971).

[23] See Lininger v. Eisenbaum, 764 P.2d 1202, 1210 (Colo. 1988).