In writing for a unanimous Court in Matrixx Initiatives, Inc. v. Siracusano, Justice Sotomayor wandered far afield from the world of pleading rules to flyblow the world of expert witness jurisprudence. How and why did this happen? Why did Matrixx invoke the concept of statistical significance to counter case reports of adverse events? Did Matrixx oversell its scientific position, thereby handing Justice Sotomayor an opportunity to unravel decades of evolution of law on the admissibility of expert witness opinion testimony? Inquiring minds want to know.
Still, whatever the occasion for the obiter dicta, Court’s pronouncements on expert witnesses are stunning for their irrelevance and questionable scholarship:
“We note that courts frequently permit expert testimony on causation based on evidence other than statistical significance. See, e.g., Best v. Lowe’s Home Centers, Inc., 563 F. 3d 171, 178 (6th Cir 2009); Westberry v. Gislaved Gummi AB, 178 F. 3d 257, 263–264 (4th Cir. 1999) (citing cases); Wells v. Ortho Pharmaceutical Corp., 788 F. 2d 741, 744–745 (11th Cir. 1986). We need not consider whether the expert testimony was properly admitted in those cases, and we do not attempt to define here what constitutes reliable evidence of causation.”
Id. at 12. What is remarkable about this passage is that the first two cases cited involved differential etiology or diagnosis to assess specific causation, not general causation. As most courts have recognized, this assessment strategy requires that general causation has already been established. See, e.g., Hall v. Baxter Healthcare, 947 F. Supp. 1387 (D. Ore. 1996).
The citation to the third case, Wells, is noteworthy because the case has nothing to do with adverse event reports or statistical significance. Wells involved a claim of birth defects caused by the use of spermicidal jelly contraceptive, which had been the subject of several studies, one of which at least yielded a statistically significant increase in detected birth defects over what was expected. Wells v. Ortho Pharmaceutical Corp., 615 F. Supp. 262 (N.D.Ga. 1985), aff’d and rev’d in part on other grounds, 788 F.2d 741 (11th Cir.), cert. denied, 479 U.S.950 (1986). Wells could thus hardly be an example of a case in which there was a judgment of causation based upon a scientific study that lacked statistical significance in its findings. Of course, finding statistical significance is just the beginning of assessing the causality of an association; Wells was notorious for its poor assessment of all the determinants of scientific causation.
The citation to Wells is thus remarkable because the Wells decision was rightly and widely criticized for its failure to evaluate the entire evidentiary display, as well as for its failure to rule out bias and confounding in the studies relied upon by the plaintiff. See , e.g., James L. Mills and Duane Alexander, “Teratogens and ‘Litogens’,” 15 New Engl. J. Med. 1234 (1986); Samuel R. Gross, “Expert Evidence,” 1991 Wis. L. Rev. 1113, 1121-24 (1991) (“Unfortunately, Judge Shoob’s decision is absolutely wrong. There is no scientifically credible evidence that Ortho-Gynol Contraceptive Jelly ever causes birth defects.”). See also Editorial, “Federal Judges v. Science,” N.Y. Times, December 27, 1986, at A22 (unsigned editorial); David E. Bernstein, “Junk Science in the Courtroom,” Wall St. J. at A 15 (Mar. 24,1993) (pointing to Wells as a prominent example of how the federal judiciary had embarrassed American judicial system with its careless, non-evidence based approach to scientific evidence). A few years later, another case in the same judicial district against the same defendant for the same product resulted in the grant of summary judgment. Smith v. Ortho Pharmaceutical Corp., 770 F. Supp. 1561 (N.D. Ga. 1991) (supposedly distinguishing Wells on the basis of more recent studies).
Perhaps the most remarkable aspect of the Court’s citation to Wells is that the case, and all it stands for, was overruled sub silentio by the Supreme Court’s own decisions in Daubert, Joiner, Kumho Tire, and Weisgram. And if that did not kill the concept, then there was the simple matter of a supervening statute: the 2000 amendment of Rule 702, of Federal Rules of Evidence.
Citing a case as jurisprudentially dead and discredited as Wells could have been sloppy scholarship and lawyering. The principle of charity, however, suggests it was purposeful, and that is a frightful prospect.
