THE ERRONEOUS “LOSS OF CHANCE” JURY INSTRUCTION REQUIRED REVERSAL; THE CHARGE USED THE PHRASES “SUBSTANTIAL FACTOR” AND “SUBSTANTIAL PROBABILITY” WHEN THE CORRECT PHRASE IS “SUBSTANTIAL POSSIBILITY” IN REFERENCE TO WHETHER A BETTER OUTCOME WAS DENIED DUE TO A DEVIATION FROM THE STANDARD OF CARE (FOURTH DEPT).

The Fourth Department, reinstating the complaint and ordering a new trial in this medical malpractice action, determined the “loss of chance” jury instruction was erroneous and required reversal:

As this Court has held since at least 2011, a “loss of chance instruction” is “entirely appropriate for . . . omission theories” in medical malpractice actions … . Although the Pattern Jury Instructions did not include a loss of chance pattern charge until 2023, i.e., after the second trial in this matter took place in December 2022, this Court had already issued numerous decisions prior to December 2022 indicating that “the loss of chance theory of causation . . . requires only that a plaintiff ‘present evidence from which a rational jury could infer that there was a “substantial possibility” that the patient was denied a chance of the better outcome as a result of the defendant’s deviation from the standard of care’ ” … .

Here, the court instructed the jury that, in order for plaintiff to recover under a loss of chance theory, it was plaintiff’s burden to establish that the act or omission alleged was a “substantial factor in bringing about the death.” The court also instructed the jury that, if it should find that “there was a substantial probability that the decedent . . . would have survived . . . if he had received proper treatment,” then it could find that defendants’ alleged negligence was a “substantial factor” in causing his death … .

… [T]he charge, as given, did not ” ‘adequately convey[ ] the sum and substance of the applicable law’ ” to the jury … . The primary issue at trial was whether defendants deviated from accepted standards of care in failing to timely treat decedent. Inasmuch as the “court did not adequately charge the jury concerning” the appropriate standard to determine that issue, we conclude that “the court’s failure to define [the correct] standard for the jury” cannot be considered harmless under the circumstances of this case … . Wright v Stephens, 2025 NY Slip Op 03416, Fourth Dept 6-7-25

Practice Point: The “loss of chance” medical malpractice jury instruction requires that plaintiff show there was a “substantial possibility” that a deviation from the standard of care precluded a better outcome. Here the judge used the phrase “substantial probability,” requiring reversal.