B. Causation

• Library: The South Carolina Law of Torts (SCBar) (2023 Ed.)

B. Causation

1. The Two Aspects of Causation Analysis—"Cause-in-Fact" and "Legal Cause"

One of the most basic principles of tort law is that a person who breaches a duty to a plaintiff is not liable for injuries unless the injuries were proximately caused by the breach.⁶⁰² In order to be a proximate cause of an injury, an act must satisfy two requirements.

First, the wrongful act must have been the cause-in-fact of the injury.⁶⁰³ Determining whether a breach was the cause-in-fact of an injury is primarily an empirical issue, which is often phrased in terms of a "but for" test: "Causation in fact is proved by establishing the injury would not have occurred 'but for' the defendant's negligence."⁶⁰⁴ If the injury would have occurred anyway, the defendant's breach did not cause it and, therefore, the defendant is not liable.⁶⁰⁵

This requirement is understandable in terms of a variety of the goals of tort law. For example, it seems unfair to make a person pay for an injury that would have happened anyway.⁶⁰⁶ In addition, safety is not likely to be enhanced by safety expenditures if the injury would occur regardless of the expenditures.⁶⁰⁷

These same concerns, however, indicate the need for a second requirement for causation. Although cause-in-fact is necessary and essential to a right of recovery, cause-in-fact cannot serve as the sole test of proximate cause. Some additional limit is needed because any event has a virtually infinite number of causes-in-fact and because the causal effects of an act can extend indefinitely across time and space. For example, but for John Doe's parents' negligently inadequate use of a birth control device, Doe would not have been born and thus could not have negligently driven the automobile which struck the plaintiff pedestrian thirty years after Doe's birth. Despite this causal relationship, it is not proper to make the parents liable for the pedestrian's injuries. One way of treating this problem of multiple causes-in-fact is to use the duty requirement. Thus, we could say that in conceiving Doe, his parents did not breach a duty owed to the injured pedestrian because the injured person is not foreseeable.⁶⁰⁸ An alternative method is to use the concept of legally responsible causation. With this approach, we could say that Doe's parents were not the legally responsible cause of the injury.

There is no universally accepted term to identify this second aspect of causation analysis. Most commentators refer to it as "proximate cause," in order to distinguish it from cause-in-fact.⁶⁰⁹ However, with only occasional exceptions,⁶¹⁰ the South Carolina cases do not accept this terminological usage, and many cases do not explicitly distinguish proximate cause from cause-in-fact.⁶¹¹ Despite this lack of agreement on the proper term to be used to identify the second aspect of causation analysis, the South Carolina cases must and do distinguish those causes-in-fact which are legally responsible from those which are not. For example, in Bramlette v. Charter-Medical-Columbia,⁶¹²the court recognized the need for the distinction and noted that "[p]roximate cause requires proof of (1) causation in fact and (2) legal cause."⁶¹³

The discussion of this second aspect of causation will be addressed below after a discussion of cause-in-fact. Given the need for a term to distinguish this second aspect, the Bramlette approach will be used; and the legally responsible cause will be referred to herein as the "legal cause."

2. Cause-in-Fact

a. The Burden of Proof and the Roles of Judge and Jury

(1) General Rule

As a general rule, cause-in-fact is a jury issue,⁶¹⁴ and the burden of proof is on the plaintiff.⁶¹⁵ The plaintiff need not show that it is certain that defendant's breach of duty was the cause-in-fact.⁶¹⁶ It is only necessary to show by a preponderance of the evidence⁶¹⁷ that it is reasonably probable or reasonably inferable that the breach was the cause-in-fact.⁶¹⁸

"Reasonably probable" and "reasonably inferable" are terms of art and do not refer to probability in a mathematical sense. Nor do phrases like "more likely than not" or "greater weight of the evidence"⁶¹⁹ indicate the need for a mathematical or a statistical showing of greater than fifty percent likelihood. A jury can find causation "if the evidence tends to sustain the reasonable probability of the manner or way relied upon by the plaintiff even if the injury might have occurred in one of a dozen ways."⁶²⁰ On the other hand, a mere possibility in the sense of a greater than zero percent likelihood is inadequate because such a showing does not rise above "mere speculation and conjecture."⁶²¹ In other words, where the alleged negligence is merely such a possible cause, the plaintiff has not satisfied the burden of showing that causation is reasonably inferable, and the case cannot be submitted to the jury. ⁶²²

In drawing the line between "reasonable probability" and "mere speculation" it is not possible to speak in terms of statistical probability or of a precise rule because circumstances vary from case to case. Moreover, such numerical measures are only one factor in determining whether a case will go to the jury. Where fairness and justice necessitate it—for example, where facts indicate wrongdoing and proof of causation is difficult, if not impossible—a very liberal approach has been used in determining whether the issue will go to the jury.⁶²³

(2) Experts and the "Most Probably Rule"

Expert testimony is required where lay persons are not competent to render an opinion on causation.⁶²⁴ In such case, "before expert testimony is admissible upon the question of the causal connection between plaintiff's injuries and the acts of the defendant, the testimony must satisfy the 'most probably rule.'"⁶²⁵ Under this rule, "the expert must, with reasonable certainty, state that in his professional opinion the injuries complained of most probably resulted from the alleged negligence of the defendant."⁶²⁶

In determining whether particular evidence meets this test it is not necessary that the expert actually use the words "most probably." . . . It is sufficient that the testimony is such "as to judicially impress that the opinion . . . represents his professional judgment as to the most likely one among the possible causes."⁶²⁷

(3) "Loss of Chance" of Survival Resulting from Medical Malpractice

There are situations where the most probably rule makes it impossible for the plaintiff to recover. One instance arises where a pre-existing condition of the injured person makes it likely that injury would occur regardless of negligence. For example, if a patient has a fifty percent or less chance of survival if reasonable medical care is provided, there would be no right of recovery for unreasonable medical care because the evidence could not support a finding that the malpractice most probably caused the injury.

Some courts have addressed such problems by using a "substantial possibility"⁶²⁸ rule rather than the most probably rule or by using the "loss of chance" doctrine.⁶²⁹ Under the loss of chance doctrine, the injured person can recover even though the injury would probably have occurred despite malpractice; however, the injured person's recovery is reduced so that it is proportional to the chances of no injury occurring. For example, if a patient had only a one in three chance of surviving a properly performed operation, the wrongful death recovery for an improperly performed operation would be only one third of the loss from the death. Such proportional recovery is viewed by some courts as better than always denying recovery because it makes a wrongdoer pay at least some part of the injury and thus furthers the goals of fairness, deterrence, and expectations.⁶³⁰

Other courts have refused to alter the most probably rule and have, therefore, denied recovery in such cases.⁶³¹ The reasons for this refusal are that the proportional approach is a fundamental change in causation analysis and that there appears to be no logical reason not to utilize the approach in other contexts. For example, if an expert testifies that the patient "most probably" would have survived because sixty percent of patients survive in a properly performed operation, should the recovery be limited to sixty percent of the loss?⁶³² In Jones v. Owings,⁶³³the South Carolina Supreme Court found such reasons persuasive and refused to adopt the loss of chance doctrine. Jones notes:

"[T]he loss of chance doctrine is fundamentally at odds with the requisite degree of medical certitude necessary to establish a causal link between the injury of a patient and the tortious conduct of a physician." . . . Legal responsibility in this approach is in reality assigned based on the mere possibility that a tortfeasor's negligence was a cause of the ultimate harm This formula is contrary to the most basic standards of proof which undergird the tort system.⁶³⁴

(4) Informed Consent and Disclosure of Risks

A difficult causation issue arises where a person is suing for breach of a duty to disclose risks.⁶³⁵ For example, if a physician breaches his or her duty to inform the patient of the risks of an operation,⁶³⁶ two basic types of tests could be used to determine whether this lack of disclosure caused the patient to undergo the treatment and thus suffer the undisclosed risk. The first type of test focuses on whether this individual patient would have refused the treatment had the risks been disclosed. In Hook v. Rothstein,⁶³⁷the South Carolina Court of Appeals rejected this "subjective" approach and adopted the second test, which utilizes an "objective" measure of causation based on the reasonable person concept:

. . . [A] causal connection exists between a physician's failure to inform and the patient's injury only if a reasonable person in the patient's position would have refused the treatment had he or she been told of the risk that resulted in injury.

This decision is supported by...