Plaintiffs’ expert excluded in Zoloft birth defects MDL

A U.S. District Judge in Pennsylvania ruled December 3 to exclude the testimony of the plaintiffs’ general causation expert in the Zoloft birth-defect multi-district litigation. The ruling raises serious questions on whether the plaintiffs’ MDL cases are able to move forward.

Hon. Cynthia Rufe of the Eastern District of Pennsylvania denied testimony from causation expert Dr. Nicholas Jewell, a professor of biostatistics at the University of California, Berkeley.

Rufe’s opinion stated that Jewell’s position that maternal use of Zoloft during early pregnancy is capable of causing, or contributing to cause, cardiovascular birth defects is based on unreliable science.

Rufe’s ruling comes after hundreds of non-cardiac birth defect cases in the litigation were dismissed over the summer. The total number of cases were around 600 but have been reduced by nearly half. Jewell was named the expert witness on causation after the dismissal, but now with the ruling finding Jewell’s expert opinion inadmissible, the future of the remaining cases are uncertain. Plaintiffs do not know whether they will be permitted to bring in another expert.

Rufe said that the expert’s opinion was based upon his review and analysis of the medical literature, and his reanalysis of data from published Zoloft studies. Pfizer, the defendant, argued that while the expert’s methods used to draw conclusions may have been correct but he did not apply them in his Zoloft opinions.

Rufe said Jewell would have to explain, as a statistics expert, the basis of his belief as to why the positive associations between mothers’ Zoloft use and cardiac birth defects are accurate and not the result of statistical flaws or biases. Furthermore, she said that Jewell would have to then reconcile those studies that claimed there was no increased risk of cardiac birth defects with his opinion.

Rufe wrote: [Jewell] “has deviated from or downplayed certain well-established principles of his field, and has inconsistently applied methods and standards to the data so as to support his a priori opinion. It is improper for an expert to take a results-driven approach to a question, molding his methodology and selectively relying upon data so as to confirm his preconceived opinion.”