On February 26, 2021, the Massachusetts Supreme Judicial Court issued a landmark 52-page decision addressing causation in tort and opting to depart from long standing precedent and practice in a concerted effort to bring greater clarity and more certainty to an area that has long been confusing and confounding. The decision, Doull v. Foster Slip Op. SJC-12921, authored by Justice Kafker held that substantial factor or substantial contributing factor terminology would no longer be used to define or instruct on the issue of actual or factual causation in negligence actions. It proceeded to adopt the approach taken by the American Law Institute (“ALI”) in the Restatement (Third) of Torts: Liability for Physical & Emotional Harm (2010) (“R3”) agreeing that the use of such language and concept was impermissibly evaluative tending to either lessen or heighten the applicable burden of proof. Substantial factor had been part of Massachusetts jurisprudence for decades but had long been a source of misunderstanding and debate.
The underlying medical malpractice action was tried by Boston Partner Noel Dumas who obtained a defense verdict on behalf of his nurse practitioner client and who was able to persuade the trial judge to issue an instruction on causation without the use of the substantial factor terminology. Boston Partner Tory A. Weigand, an appellate specialist, ALI member, and long-standing proponent for such change, Tory A. Weigand, “The Wrongful Demise of But For Causation,” 41 W. New. Engl. L. Rev. 75 (2019); Tory A. Weigand, “Duty, Causation, Palsgraf: Massachusetts and the Restatement (Third) of Torts, 96 Mass. L. Rev. 55 (2015). handled the appeal with the Supreme Judicial Court taking the matter on Direct Appellate Review to examine and consider the issue of whether the instruction was proper and whether Massachusetts should adopt R3’s approach. In the 5-2 decision, the Supreme Judicial Court agreed that the instruction was proper and that it was time to abandon the use of substantial factor as it had not withstood the test of time.
The action involved claims for lack of informed consent and negligence against the decedent’s primary care providers, a nurse practitioner and her supervising physician. The decedent died of an underlying clotting disorder, Chronic Thromboembolic Pulmonary Hypertension (“CTEPH”). The allegations included that the clotting disorder was caused by a progesterone prescription; that there was a failure to inform of the risk of clotting; and that there was a failure to diagnose and refer for treatment in a more timely manner resulting in the failure to prevent a subsequent stroke and death. The defense was that the progesterone cream did not carry any risk of clotting; was not the cause of the disorder; that there was no failure to diagnose; and that any such earlier intervention at that time would not have prevented the subsequent death.
The jury found negligence but further found that the health providers negligence was not the cause of the stroke or death. The trial court opted not to instruct the jury with “substantial factor” opting to utilize “but for” (i.e., “without which the harm would not have occurred”). It determined that the “substantial factor” test was not applicable with the Court otherwise influenced by R3’s approach.
The case is significant because causation has remained a difficult area particularly in conveying the requisite obligation to a lay jury in cases in which there are multiple defendants and/or multiple or sufficient causes. There had remained uncertainty and a measure of confusion and misunderstanding as to the role and use of “substantial factor,” whether it replaces or supplements the traditional “but for” test, and whether it provides helpful guidance or should not be used at all due to concerns it is too evaluative either heightening or lowering the burden of proof and otherwise conflating both factual and proximate or legal cause.
In its thoughtful and thorough decision, the majority set out in detail the history and purpose of the “but for” and “substantial factor” tests or terminology, the difference between factual and legal causation, and the influence of the Restatements including the misunderstanding created by the Second Restatement which defined factual causation in terms of “substantial factor” that otherwise subsumed “but for.” It confirmed and made clear that “substantial factor” was devised as a limited exception in multiple sufficient cause or inextricable tangle situations like toxic tort but that it was never intended to replace “but for” causation generally. The real concern was that this limited exception was swallowing the rule and displacing “but for,” long considered an absolute prerequisite for legal responsibility.
While the Supreme Judicial Court recognized the conceptual difficulty in applying “but for” in cases involving multiple defendant and cause cases where it may be difficult to demonstrate whether the particular defendant’s conduct, amidst other sufficient causes, was a “but for” cause of the harm, it appropriately made clear that the concern was not present in most cases involving multiple causes. Equating “but for” with “necessity,” the high Court stated that “there is nothing preventing a jury from assessing the evidence and determining which of the causes alleged by the plaintiff were actually necessary to bring about the harm, and which had nothing to do with the harm.” The point was made rather emphatically: “Indeed, these types of cases, alleging multiple causes, may be where the but-for test is most important and useful, as it serves to separate the necessary causes from conduct that may have been negligent but may have had nothing to do with the harm caused.”
The Court further found that the use of substantial factor was confusing. It was deemed to impose a more demanding standard then “but for;” “invite[s] jurors to skip the factual causation step altogether;” and “conflates and collapses factual and legal causation.” There was real and appropriate concern that “[a]bsent a but for requirement, a jury presented with negligence that is ‘substantial’ may decide to impose liability without coming to terms with whether the negligence was even a cause of harm.”
The Court proceeded to make clear that “but for” or necessity is the appropriate test for factual causation and that given the confusion caused by substantial factor it should no longer be used even in multiple sufficient causes. As to toxic tort or inextricable tangle cases it reserved its ruling saying it would address whether substantial factor should still be used in such cases when such a case and briefing was properly before the Court. As to multiple sufficient causes, the Court proceeded to adopt R3’s approach. Specifically, it declared that where there are two or more competing causes each sufficient without the other to cause the harm and each is operating at time of harm, they are both factual causes. As such, a jury is not required to make a “but for” determination in such circumstance so long as the competing causes alone were sufficient or necessary to have caused the harm. The issue of whether a particular defendant’s conduct while sufficient was trivial or insignificant compared to the competing causes would be considered as part of the legal cause or scope of liability constituent of causation.
The concurring opinion of Justice Lowy with whom Justice Gaziano joined, agreed that there was no reversible error in the instruction but disagreed that substantial factor should be abandoned. According to Justice Lowy, “[a]bandoning the substantial contributor factor in circumstances where there is more than one legal cause of an injury will…inure to the detriment of plaintiffs with legitimate causes of action while not clarifying the existing law of causation.” The concern was that using but for’s counterfactual paradigm in multiple cause cases, would “invite the jury to get caught up in speculative combinations of ‘what if’ and ‘if only’” including “alternative realities,” and that the “substantial contributing factor test better replicates how people understand causation…” Justice Lowy stated that while the “Restatements deserve respect,” there was no real problem with the use of substantial factor and that Massachusetts’s case law and use for decades “deserved more.” Ringing a somewhat doomsday tenor, Justice Lowy remarked that the majority’s conclusion that “the test is unworkable defies experience and unravels precedent” and doing so “at the price of fairness.”
In no uncertain terms, Doull v. Foster is a landmark decision. The debate as to the use of substantial factor has long circled the law of causation with the Supreme Judicial Court taking the courageous step of attempting to have Massachusetts’ common law rise to a greater understanding and clarity. While at least two other states (Virginia and Iowa) have agreed with R3 and abandoned substantial factor terminology as to factual causation, the Supreme Judicial Court’s decision will likely serve as further impetus for other states to consider and address the issue. While substantial factor had a long-standing presence in Massachusetts jurisprudence, the Supreme Judicial Court, as steward of the common-law, took the opportunity to refine and clarify such law and move toward a more proper understanding and application.