Panel upholds decision barring expert testimony about the role of Tylenol in causing liver disease.

A unanimous Appellate Division, Second Department panel has ruled that a Brooklyn judge was right to exclude testimony in a personal injury action from experts who said that the plaintiff developed cirrhosis by taking Tylenol while offering little clinical data to support their opinion. Writing for the court, Justice John M. Leventhal said that the plaintiff had not shown that her three experts' theory was founded on "generally accepted methodology" and, therefore, could not be admitted. Justice Leventhal first noted that Ms. Ratner was correct to argue that her experts' opinions were not based on any novel methods, even without clinical studies to back them up."Generally, deductive reasoning or extrapolation, even in the absence of medical texts or literature that support a plaintiff's theory of causation under identical circumstances, can be admissible if it is based upon more than mere theoretical speculation or scientific hunch," he wrote. "Deduction, extrapolation, drawing inferences from existing data, and analysis are not novel methodologies and are accepted stages of the scientific process." However, he found, in order to be admissible, the experts' opinions had to be based on a methodology that was generally accepted, and they failed to meet that burden.

Case Law Alert - 1st Qtr 2012