Third Circuit Rejects Plaintiffs’ Attempt to Lower “Daubert” Standard in “In re Zoloft Products Liability Litigation”

Featured Expert Column –Judicial Gatekeeping of Expert Evidence

Tager_09181Evan M. Tager, a Partner in the Washington, DC office of Mayer Brown LLP, with Carl J. Summers, an Associate with Mayer Brown LLP.

The US Court of Appeals for the Third Circuit recently rejected an attempt to substantially lower the standard for admission of expert testimony resting on studies that have not produced replicated and statistically significant findings. Specifically, the plaintiffs in In re Zoloft Products Liability Litigation argued that the district court erroneously imposed a rigid, bright-line rule that an expert must present replicable, statistically significant findings. The Third Circuit held that the district court had not established such a bright-line rule, but rather had made a factual finding that teratologists—scientists who study abnormalities in human development—“generally required replication of significant results.” After dispensing with the plaintiffs’ flawed interpretation of the district court’s decision, the Third Circuit affirmed the exclusion of the expert testimony on the ground that the expert had selectively chosen data that supported his opinion and inconsistently applied his methodology, thus rendering his opinions unreliable. Continue reading