Identifying and valuing the injury in lost chance cases.

• Date: 01 March 1998
• Author: Aagaard, Todd S.

Any plaintiff seeking to recover in tort must prove that the defendant has breached the duty of care.(1) Even after the plaintiff has established the defendant's breach of duty, however, issues of causation and damages remain.(2) These two issues are frequently vexing, both conceptually and in terms of evidentiary demonstration. For example, if a plaintiff proves that a defendant acted negligently, it still may be unclear whether the plaintiff would have been injured even in the absence of the defendant's negligence. Similarly, in assessing damages, factfinders often find it difficult to attach a monetary value to a plaintiff's nonpecuniary losses such as pain and suffering.

So-called "loss of chance" cases -- medical-malpractice cases in which a defendant's negligence injures a plaintiff who has a preexisting medical condition by reducing the plaintiffs likelihood of recovering from the condition -- pose a particularly difficult challenge to courts seeking to define the scope of and place a value on a defendant's liability.(3) According to traditional tort doctrine, in such cases the plaintiff must prove that the decreased likelihood of recovery attributable to the defendant's negligence -- as opposed to the preexisting condition itself -- more likely than not directly caused her subsequent failure to recover.(4) A person suffering from a preexisting condition with less than a fifty-percent chance of recovery even before diagnosis thus would have no cause of action against a doctor who negligently failed to diagnose the condition, even if the delay brought about by the missed diagnosis caused the person to lose a significant chance of recovering from the condition.(5) example, a person with a thirty-five percent chance of recovering from her cancer would, according to traditional tort doctrine, have no cause of action against a doctor whose failure to diagnose the cancer caused the person's chance of survival(6) to fall to twenty percent, or even to zero.

On the other hand, a person with an eighty-percent initial chance of recovery would have a cause of action against a doctor whose negligent misdiagnosis reduced that chance to twenty percent. In fact, under the traditional doctrine a plaintiff with an initial eighty-percent chance of recovery would have a cause of action against a doctor whose negligent misdiagnosis reduced that chance to anything less than sixty percent if the plaintiff subsequently failed to recover;(7) in such a case, the doctor's negligence is more likely than the preexisting condition to have caused the plaintiffs death. The important factor is not the absolute reduction in the plaintiff's probability of survival, but whether the reduction that the preexisting condition caused exceeds the reduction that the defendant's negligence caused. If this is the case, then the plaintiff cannot show that the defendant's negligence most likely caused the plaintiff's failure to recover.

Traditional tort doctrine's total denial of compensation in cases in which a doctor's negligence has increased but has not more than doubled(8) a plaintiff's likelihood of injury or death seems manifestly unfair. The traditional doctrine allows such a doctor to avoid any liability to a patient even though the doctor's failure to provide a timely diagnosis of the patient's malady clearly deprived the patient of an opportunity to recover from her condition. Courts and commentators, noting the traditional doctrine's failure to fulfill the fundamental tort goals of deterrence and compensation in these types of lost chance cases,(9) developed what is known as the loss of chance doctrine in response.(10) The loss of chance doctrine addresses the perceived injustice of the traditional doctrine by recognizing a potential cause of action in any case in which the defendant's negligent conduct decreased the plaintiffs chance of recovery from a preexisting condition. Thus, the loss of chance doctrine gives a cause of action to the hypothetical plaintiff whose doctor's negligence decreased her likelihood of survival from thirty-five percent to twenty percent.

Although advocates of the doctrine agree that lost chance cases demand compensation, they disagree as to the theoretical basis for allowing lost chance claims to proceed.(11) Disagreement about the nature of the compensable injury in a lost chance case spins over into confusion about how to value that injury. Unfortunately, the considerable attention that the loss of chance doctrine has generated among academic commentators(12) and in the courts(13) has served only to perpetuate rather than alleviate this doctrinal confusion. These courts and commentators have focused almost exclusively on the issue of whether jurisdictions should adopt the lost chance doctrine,(14) while largely ignoring the equally important issue of how courts in jurisdictions that have adopted the doctrine should determine the appropriate compensation in a particular case.(15) Proponents of the doctrine have proffered arguments for why the law should compensate plaintiffs in lost chance cases without addressing what the compensation should be.

For example, proponents argue that denying compensation to plaintiffs in lost chance cases would allow tortfeasors to avoid responsibility for the consequences of their tortious conduct.(16) Without further elaboration as to the injury being compensated, however, this argument begs the question it purports to answer. That is, negligent conduct is not always tortious conduct; an act gives rise to liability only to the extent that it causes an injury.(17) Until proponents of the loss of chance doctrine identify the injury suffered as a result of the negligent conduct, it is not at all clear that the defendant has in fact "avoided" liability for her conduct, because it is not clear that such conduct was tortious.

This Note seeks to define precisely the tort injury in lost chance cases and to ascertain the proper method for measuring the damages associated with that injury. Part I defines the types of losses that constitute the tort injury in lost chance cases and argues that courts have, for the most part, failed to identify these losses properly. For this reason, they have failed to measure damages in a way that accurately compensates for these losses. Part II advocates a method of damages determination that relies on direct assessment of the tort injury by the factfinder, informed by a clear understanding of the distinct tort injury at issue and by the guidance traditionally offered by the judge's instructions. In advancing such a formulation, Part II criticizes two alternative methods of damage valuation. This Note concludes that the loss, of chance doctrine can achieve legitimacy as a valid extension -- rather than an ill-fitting alteration -- of traditional principles of tort law precise terms the lows that constitute the tort injury in loss chance cases and, by allowing juries the discretion to assess the those losses without undue constraints.

1. CONCEPTUALIZING THE TORT INJURY IN LOST CHANCE CASES

   Neither judges nor juries can accurately measure damages in lost chance cases without an adequate conceptualization of the precise nature of the injury they are compensating. A judge must have a clear vision of the nature of the injury so that she can rule on evidentiary matters, properly instruct the jury in its deliberations, and subsequently evaluate the validity of the jury's verdict. A jury must understand thoroughly the nature of the injury if it is to determine accurately whether the injury has occurred and, if it finds that such injury has occurred, to measure accurately the loss that the plaintiff has suffered.

   This Part conceptualizes the harm suffered in a lost chance case in order to enable the development of a framework for measuring the damages associated with such harm. Section I.A addresses the antecedent issue of distinguishing the compensable losses from the noncompensable losses -- an area of particular confusion to courts and commentators. It concludes that the plaintiff's tort "injury" in a lost chance case is actually an amalgamation of losses, all directly related to the plaintiffs deprivation of an opportunity for a better result. Section I.B identifies the types of compensable losses that arise in lost chance cases and describes the case-specific, fact-intensive inquiry necessary to identify, first, which of these losses are present and, second, which of the losses that are present have occurred as a consequence of the defendant's negligent conduct -- which of these harms make up the tort injury in a given case.

   1. Distinguishing the Tort Injury from the Underlying Injury

      The coexistence of multiple injuries -- some of which the defendant's negligence proximately caused and some of which are at tributable to the preexisting condition -- makes identification of the lost chance tort injury particularly difficult. The fact that courts have adopted two competing premises for compensating lost chance plaintiffs -- the causation approach and the damages approach -- further confuses this task, because a court's rationale for compensating lost chance plaintiffs affects how it conceptualizes the plaintiff's tort injury. This section argues that the damages approach properly focuses on those portions of the plaintiffs losses that the defendant's negligence proximately caused. It then distinguishes these losses from the losses resulting from the underlying condition and asserts that only the former constitute the compensable tort injury in lost chance cases.

      The loss of chance doctrine represents a departure from traditional tort doctrine.(18) There has been considerable dispute, however, as to the precise nature and extent of this departure. Because the loss of chance doctrine allows a legal claim in cases in which the plaintiff cannot prove that the defendant more likely than not caused the plaintiffs ultimate failure to recover, some...