David Bernstein has posted a draft of an important new article on the law of expert witnesses, in which he documents the widespread resistance to judicial gatekeeping of expert witness opinion testimony among federal judges. Bernstein, “The Daubert Counterrevolution” (Mar. 11, 2013). Professor Bernstein has posted his draft article, set to be published in the Notre Dame Law Review, both on the Social Science Research Network, and on his law school’s website.
Professor Bernstein correctly notes that the Daubert case, and the subsequent revision to Federal Rule of Evidence 702, marked important changes in the law of expert witnesses. These changes constituted important reforms, which in my view were as much evolutionary, as revolutionary. Even before the Daubert case, the law was working to find ways to improve expert witness testimony, and to downplay “authoritative” opining in favor of well-documented ways of knowing. After all, Rule 702, with its emphasis on “knowledge,” was part of the Federal Rules of Evidence, as adopted in 1975. Pub. L. 93–595, § 1, Jan. 2, 1975, 88 Stat. 1926 (effective July 1, 1975). Since their first adoption, Rule 702 required that expert witnesses’ knowledge be helpful to the trier of fact. By implication, the rule has always suggested that hunches, speculation, and flights of fancy did not belong in the court room.
Professor Bernstein certainly acknowledges that Daubert did not spring out of a vacuum. Critics of judicial decisions on expert witnesses had agitated for decades to limit expert witness conduct by standards and guidances that operate in the scientific community itself. The Supreme Court’s serial opinions on Rule 702 (Daubert, Joiner, Kumho Tire, and Weisgram) reflect the need for top-down enforcement of a rule, on the books since 1975, while many lower courts were allowing “anything goes.”
What is perhaps surprising, but well documented by Professor Bernstein, is that after four opinions from the Supreme Court, and a revision in the operative statute itself (Rule 702), some lower federal courts have engaged in a rearguard action against expert witness gatekeeping. Professor Bernstein rightfully settles on the First Circuit’s decision in Milward as exemplifying a trend to disregard the statutory language and mandate for gatekeeping. For Bernstein, Milward represents the most recent high-water mark of counterrevolution, with its embrace of errors and fallacies in the name of liberal, if not libertine, admissibility.
I suppose that I would go a step further than Professor Bernstein and label the trend he identifies as “reactionary.” What is clear is that many courts have been willing to flout the statutory language of Rule 702, in favor of old case law, and evasive reasoning on expert witness admissibility. Indeed, the Supreme Court itself joined the trend in Matrixx Initiatives, Inc. v. Siracusano, 131 S. Ct. 1309 (2011), when it unanimously affirmed the reversal of a trial court’s Rule 12(b)(6) dismissal of a securities fraud class action. The corporate defendant objected that the plaintiffs failed to plead statistical significance in alleging causation between Zicam and the loss of the sense of smell. The Supreme Court, however, made clear that causation was not required to make out a claim of securities fraud. It was, and would be, sufficient for the company’s product to have raised sufficient regulatory concerns, which in turn would bring regulatory scrutiny and action that would affect the product’s marketability.
Not content to resolve a relatively simple issue of materiality, for which causation and statistical significance were irrelevant, the Supreme Court waxed on, in obiter dicta, about causation and statistical significance, perhaps unwittingly planting seeds for those who would eviscerate Rule 702. See Matrixx Unloaded (Mar. 29, 2011). Although the Supreme Court disclaimed any intention to address expert witness admissibility in a case that was solely about the sufficiency of pleading allegations, it cited three cases for the proposition that statistical significance was not necessary for assessing biological causation:
“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 1319.
Remarkably, two of the three cases were about specific causation, arrived at using so-called “differential etiology,” which presupposed the establishment of general causation. These cases never involved general causation or statistical reasoning, but rather simply the process of elimination (iterative disjunctive syllogism). The citation to the third case, Wells, was a notorious pre-Daubert, pre-Rule 702 revision case, revealed disappointing scholarship. Wells involved at least one study that purported to find a statistically significant association. What was problematic about Wells was its failure to consider the complete evidentiary picture, and to evaluate study validity, bias, and confounding, as well as significance probability. See Wells v. Ortho Pharmaceutical Corp. Reconsidered – Part 1 (Nov. 12, 2012).
Wells was an important precursor to Daubert in that it brought notoriety and disrepute to how federal courts (and state courts as well) were handling expert witness evidence. Significantly, Wells was a bench trial, where the trial judge opined that plaintiffs’ expert witnesses seemed more credible based upon atmospherics rather than on their engagement with the actual evidence. See Marc S. Klein, “After Daubert: Going Forward with Lessons from the Past,” 15 Cardozo L. Rev. 2219, 2225-26 (1994) (quoting trial testimony of trial testimony of Dr. Bruce Buehler: “I am sorry sir, I am not a statistician . . . I don’t understand confidence levels. I never use them. I have to use the author’s conclusions.” Transcript of Jan. 9, 1985, at 358, Wells v. Ortho Pharm. Corp., 615 F. Supp. 262 (N.D. Ga. 1985).
Given the Supreme Court’s opinion in Matrixx, the reactionary movement among lower courts is unsurprising. Lower courts have now cited and follow the Matrixx dicta on statistical significance in expert witness gatekeeping, despite the Supreme Court’s clear pronouncement that it did not intend to address Rule 702. See In re Chantix (Varenicline) Prods. Liab. Litig., 2012 U.S. Dist. LEXIS 130144, at *22 (N.D. Ala. 2012); Cheek v. Wyeth Pharm. Inc., 2012 U.S. Dist. LEXIS 123485 (E.D. Pa. Aug. 30, 2012).
Professor Bernstein’s article goes a long way towards documenting the disregard for law and science in this movement. The examples of reactionary decisions could easily be multiplied. Take for instance, the recent Rule 702 gatekeeping decision in litigation over Celexa and Lexapro, two antidepressant medications. Judge Rodney W. Sippel denied the defense motions to exclude plaintiffs’ principal expert witness, Dr. David Healy. In re Celexa & Lexapro Prods. Liab. Litig., ___ F.3d ___, 2013 WL 791780 (E.D. Mo. 2013). In attempting to support its decision, the court announced that:
1. Cherry picking of studies, and data within studies, is acceptable for expert witnesses. Id. at *5, *7, *8.
2. Outdated law applies, regardless of being superseded by later Supreme Court decisions, and the statutory revision in Rule 702. Id. at *2 (citing pre-Joiner case: “The exclusion of an expert’s opinion is proper only if it is so fundamentally unsupported that it can offer no assistance to the jury.” Wood v. Minn. Mining & Mfg. Co., 112 F.3d 306, 309 (8th Cir.1997) (internal quotation marks and citation omitted).”
3. The Bradford Hill factors can be disregarded. Id. at *6 (citing In re Neurontin Mktg., Sales Practices, and Prod. Liab. Litig., 612 F. Supp. 2d 116, 133 (D. Mass. 2009) (MDL 1629), and In re Viagra, 572 F.2d 1071 (D. Minn. 2008)).
These features of the Celexa decision are hardly novel. As Professor Bernstein shows in his draft article, disregard of Rule 702’s actual language, and of the post-Daubert Supreme Court decisions, is prevalent. See, e.g., In re Avandia Marketing, Sales Practices & Prod. Liab. Litig., 2011 WL 13576 (E.D. Pa. 2011)(announcing that MDL district judge was bound to apply a “Third Circuit” approach to expert witness gatekeeping, which focused on the challenged expert witnesses’ methodology, not their conclusions, in contravention of Joiner, and of Rule 702 itself).
The Celexa decision pushes the envelope on Bradford Hill. The two decisions cited downplayed Bradford Hill’s considerations, but did not dismiss them. In re Neurontin Mktg., Sales Practices, and Prod. Liab. Litig., 612 F. Supp. 2d 116, 133 (D. Mass. 2009) (MDL 1629)(“Although courts have not embraced the Bradford Hill criteria as a litmus test of general causation, both parties repeatedly refer to the criteria, seemingly agreeing that it is a useful launching point and guide. Accordingly, this Court will begin its inquiry by evaluating Plaintiffs’ evidence of an association between Neurontin and suicide-related events, the starting point for an investigation under the criteria.”); In re Viagra Prods. Liab. Litig., 572 F.Supp.2d at 1081 (“The Court agrees that the Bradford Hill criteria are helpful for determining reliability but rejects Pfizer’s suggestion that any failure to satisfy those criteria provides independent grounds for granting its Daubert Motion.”).
Of course, Sir Austin’s considerations were merely those that he identified in a speech to a medical society. They were not put forward in a scholarly article; nor are his considerations the last word on the subject. Austin Bradford Hill, “The Environment and Disease: Association or Causation?” 58 Proc. Royal Soc’y Med. 295 (1965).
Even as a précis, given almost 50 years ago, Hill’s factors warrant some consideration rather than waving them off as not a litmus test (whatever that means), followed by complete disregard for any of the important considerations in evaluating the causality of an association.
There was brief bright spot in this fairly dim judicial decision. The district judge refused to exclude Dr. Healy on grounds that his opinion about particular studies differed from the authors’ own interpretations. In re Celexa & Lexapro Prods. Liab. Litig., ___ F.3d ___, 2013 WL 791780, at *5 (E.D. Mo. 2013) (Sippel, J.).
That is the correct approach, even though there is language in Joiner that suggests that the authors’ views are dominant. See Follow the Data Not the Discussion. But the refusal to discount Healy’s opinions on this ground was done without any real inquiry whether Healy had offered a valid, competing interpretation of the data in the published studies.
At the core of the reactionary movement identified by Professor Bernstein is an unwillingness, or an inability, to engage with the scientific evidence that is at issue in various Rule 702 challenges. Let’s hope that Bernstein’s article induces closer attention to the law and the science in future judicial gatekeeping.
