SJC Rules ‘But-For’ Causation Applies in Most Negligence Cases

Issue July/August 2021 August 2021 By Richard L. Campbell and Alan Y. Wong
Civil Litigation Section Review
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From left: Richard L. Campbell and Alan Y. Wong

In its recent decision in Doull v. Foster, 487 Mass. 1 (2021), the Supreme Judicial Court (SJC) eliminated the substantial contributing factor causation standard in negligence cases involving multiple alleged causes of harm. The SJC held that the "but-for" causation standard is applicable to most negligence cases, but specifically deferred ruling on whether it applies to toxic tort and asbestos cases.

Factual Background and Procedural History

The estate of decedent Laura Doull brought a medical malpractice action against: (1) Anna Foster, a nurse practitioner who had treated Ms. Doull over a period of years; and (2) Dr. Richard Miller, Foster’s supervisor who owned the medical practice where Foster treated Doull.

In August 2008, Foster prescribed Doull a progesterone cream to treat perimenopause-related symptoms. Foster testified that she and Doull discussed alternatives to that cream, but they did not discuss the possibility that it could cause blood clots because Foster did not consider clotting to be a risk. Doull used the cream through the spring of 2011.

Earlier in the spring of 2011, Doull met with Foster three different times, complaining about shortness of breath. On each occasion, Foster performed a physical examination of Doull, and ultimately diagnosed Doull’s shortness of breath as a symptom of her preexisting allergies and asthma. Miller did not examine Doull during any of these visits.

Shortly after her spring 2011 visits to Foster, Doull was hospitalized in May 2011 following a "seizure-like event." There, she was diagnosed with a pulmonary embolism, a condition where blood clots block portions of arteries in the lungs. A pulmonary embolism may cause shortness of breath as well as a rare disease known as chronic thromboembolic pulmonary hypertension (CTEPH), which can cause heart failure. Doull was also diagnosed with CTEPH in May 2011. Following unsuccessful surgery and treatment by medications, Doull died from CTEPH complications in 2015.

The plaintiffs filed suit against both Foster and Miller alleging, inter alia, negligence in their medical care of Doull. At trial, the plaintiffs claimed that: (1) Foster and Miller failed to obtain Doull’s informed consent on the progesterone cream’s risks and alternatives; (2) Foster negligently failed to diagnose Doull’s pulmonary embolism in spring 2011; and (3) Miller was negligent in his supervision of Foster.

The jury returned a verdict for both Foster and Miller, finding that: (1) they had not failed to acquire informed consent from Doull with respect to the progesterone cream; (2) Foster negligently failed to diagnose Doull’s pulmonary embolism, but that did not cause Doull’s injuries or death; and (3) Miller had been negligent in his supervision of Foster, but his negligent supervision had not harmed Doull. The jury’s findings comported with the testimony of the defendants’ pulmonology expert, who opined that Doull’s clotting condition was chronic and her health outcomes would have been the same even if Foster had diagnosed her correctly in the spring of 2011.

On appeal, the plaintiffs argued that the trial judge erred in instructing the jury on the "but-for" causation standard, and instead was required to instruct the jury on a substantial contributing factor causation standard. The SJC transferred the case from the Appeals Court on its own motion.

SJC Decision

The SJC affirmed the Doull trial court’s jury instruction on the "but-for" causation standard, and used the occasion to discuss and change the application of Massachusetts causation standards. The court observed that, historically, "but-for" causation has been the standard used in negligence cases, with two exceptions: (1) situations with multiple sufficient (or "overdetermined") causes (e.g., two separate campfires merging and destroying a house, when either independently would have destroyed the house); and (2) toxic tort and asbestos cases. In its analysis, the SJC noted that "[t]he concern uniting these two types of cases is the great difficulty, if not impossibility, of identifying but-for causes of the harm."

However, the court distinguished these two types of cases from situations like that in Doull, in which there is no difficulty in identifying but-for causes of alleged harm:

Indeed, this case shows that the but-for test works well even when a plaintiff alleges that there are multiple causes of a harm … Here, using a but-for standard, the jury concluded that no such connection existed between the defendant’s conduct and Doull’s harm and death. This shows how, even in a case involving multiple causes in which the plaintiffs argue it was error not to use the substantial contributing factor test, the but-for standard did what it is supposed to do and prevented the defendants from being held liable where the jury concluded that they did not cause the harm.

Thus, the SJC concluded that the "but-for" standard, rather than the substantial factor standard, is the appropriate standard for factual causation in negligence cases involving multiple alleged causes of the harm. The court further noted that while the substantial factor standard was devised by the Restatement of Torts, it was abandoned by the Restatement (Third).

Still further, the SJC eliminated the use of the substantial factor test, except in asbestos and toxic tort cases, finding the test to be "unnecessarily confusing." Instead, the court held that in the rare cases where there are multiple, simultaneously operating, sufficient causes (e.g., two fires converging on one building), the jury should receive an additional instruction that they need not apply the "but-for test" in order to find causation.

The Future of the Substantial Factor Test

The SJC declined to rule on whether the substantial contributing factor standard would be entirely eliminated in Massachusetts, explicitly stating that it would continue to apply to toxic tort and asbestos cases for now. However, the Doull opinion anticipates that the court will encounter that issue in the near future, and notes that the justices would want the benefit of full briefing and argument before deciding on the continued use of the substantial factor test in toxic tort matters.

Notably, while the SJC unanimously affirmed the trial court in this matter, two of the seven justices broke away from the majority in their reasoning. Specifically, the concurring opinion disapproved of the majority’s abandonment of the substantial contributing factor test in general. Thus, should the matter reach the SJC in its current composition, at least two justices appear reluctant to eliminate the substantial factor test in asbestos and toxic tort cases. 

Richard L. Campbell is a partner at Shook, Hardy & Bacon, where he represents national and international companies in high-stakes environmental and product liability litigation. He is a member of the Massachusetts Bar Association’s Civil Litigation Section Council and a former member of the Governance Committee.

Alan Y. Wong is an associate at Shook, Hardy & Bacon, where he litigates complex disputes and investigates novel legal issues in toxic tort, employment and business litigation.