The case against differential diagnosis: Daubert, medical causation testimony, and the scientific method

For the past decade, federal judges have been obligated to serve as gatekeepers and keep scientifically unreliable and irrelevant expert testimony out of the courtroom. The exacting evidentiary standards set forth in the landmark Daubert decision have had a significant impact on numerous areas of legal dispute. Toxic tort litigation, in particular, has been transformed by the standards. This Article reviews the Supreme Court's adoption of the scientific method as the standard for admissibility of expert testimony. It analyzes how a court's proper understanding of the scientific method can guide it in evaluating the different types of causation evidence presented in toxic tort litigation, both with respect to general and specific causation. Throughout this discussion and in the concluding section, the Article reflects the authors' firm's experience as national defense counsel in a series of product liability cases involving the prescription drug Parlodel, in which these evidentiary issues have been analyzed extensively.