For your delectation and delight, desultory dicta on the law of delicts.

Vaccine Court Inoculated Against Pathological Science

October 25th, 2015

Richard I. Kelley, M.D., Ph.D., is the Director of the Division of Metabolism, Kennedy Krieger Institute, and a member of the Department of Pediatrics, in Johns Hopkins University. The National Library of Medicine’s Pubmed database shows that Dr. Kelley has written dozens of articles on mitochondrial disease, but none that concludes that thimerosal or the measles, mumps and rubella vaccine plays a causal role in causing autism by inducing or aggravating mitochondrial disease. In one article, Kelley opines:

“Large, population-based studies will be needed to identify a possible relationship of vaccination with autistic regression in persons with mitochondrial cytopathies.”

Jacqueline R. Weissman, Richard I. Kelley, Margaret L. Bauman, Bruce H. Cohen, Katherine F. Murray, Rebecca L. Mitchell, Rebecca L. Kern, and Marvin R. Natowicz, “Mitochondrial Disease in Autism Spectrum Disorder Patients: A Cohort Analysis,” 3 PLoS One e3815 (Nov. 26, 2008). Those large scale population-based studies to support the speculation of Kelley and his colleagues have not materialized since 2008, and meta-analyses and systematic reviews have dampened the enthusiasm for Kelley’s hypothesis.[1]

Special Master Denise K. Vowell, in the Federal Court of Claims, has now further dampened the enthusiasm for Dr. Kelley’s mitochondrial theories, in a 115 page opinion, written in support of rejecting Kelley’s testimony and theories that the MMR vaccine caused a child’s autism. Madariaga v. Sec’y Dep’t H.H.S., No. 02-1237V (Ct. Fed. Claims Sept. 26, 2015) Slip op. [cited as Madariaga].

Special Master Vowell fulsomely recounts the history of vaccine litigation, in which the plaintiffs have presented theories that the combination of thimerosal-containing vaccines and the MMR vaccine cause autism, or just the thimerosal-containing vaccines cause autism. Madariaga at 3. Both theories were tested in the crucible of litigation and cross-examination in a series of test cases. The first theory resulted in verdicts against the claimants, which were affirmed on appeal.[2] Similarly, the trials on the thimerosal-only claims uniformly resulted in decisions from the Special Masters against the claims.[3] The three Special Masters, hearing the cases, found that the vaccine-causation claims were not close cases, and were based upon unreliable evidence.[4] Madariaga at 4.[5]

In Madariaga, Special Master Vowell noted that Doctor Kelley had conceded the “absence of an association between the MMR vaccine and autism in large epidemiological studies.” Madariaga at 61. Kelley attempted to evade the force of his lack of evidence by retreating into a claim that “autistic regressions caused by the live attenuated MMR vaccine are rare events,” and an assertion that there are many inflammatory factors that can induce autistic regression. Madariaga at 61.

Special Master described the whole of Kelley’s testimony as “meandering, confusing, and completely unpersuasive elaboration of his unique insights and methods.” Madariaga at 66. Although it is clear from the Special Master’s opinion that Kelley was unbridled in his over-interpretation of studies, and perhaps undisciplined in his interpretation of test results, the lengthy opinion provides only a high-altitude view of Kelley’s errors. There are tantalizing comments and notes in the Special Master’s decision, such as one that reports that one study may have been over-interpreted by Kelley because he ignored the authors’ comment that their findings could be consistent with chance because of their multiple comparisons, and another that paper that failed to show statistical significance. Madariaga at 90 & n.160.

The unreliability of Kelley’s testimony appeared to be more than hand waving in the absence of evidence. He compared the child’s results on a four-hour fasting test, when the child had not fasted for four hours. When pressed about this maneuver, Kelley claimed that he had made calculations to bring the child’s results “back to some standard.” Madariaga at 66 & n.115.

Although the Special Master’s opinion itself was ultimately persuasive, the tome left me eager to know more about Dr. Kelley’s epistemic screw ups, and less about vaccine court procedure.

[1] See Vittorio Demicheli, Alessandro Rivetti, Maria Grazia Debalini, and Carlo Di Pietrantonj, “Vaccines for measles, mumps and rubella in children,” Cochrane Database Syst. Rev., Issue 2. Art. No. CD004407, DOI:10.1002/14651858.CD004407.pub3 (2012) (“Exposure to the MMR vaccine was unlikely to be associated with autism … .”); Luke E. Taylor, Amy L. Swerdfeger, and Guy D. Eslick, “Vaccines are not associated with autism: An evidence-based meta-analysis of case-control and cohort studies,” 32 Vaccine 3623 (2014) (“Findings of this meta-analysis suggest that vaccinations are not associated with the development of autism or autism spectrum disorder. Furthermore, the components of the vaccines (thimerosal or mercury) or multiple vaccines (MMR) are not associated with the development of autism or autism spectrum disorder.”).

[2] Cedillo v. Sec’y, HHS, No. 98-916V, 2009 WL 331968 (Fed. Cl. Spec. Mstr. Feb. 12, 2009), aff’d, 89 Fed. Cl. 158 (2009), aff’d, 617 F.3d 1328 (Fed. Cir. 2010); Hazlehurst v. Sec’y, HHS, No. 03-654V, 2009 WL 332306 (Fed. Cl. Spec. Mstr. Feb. 12, 2009), aff’d, 88 Fed. Cl. 473 (2009), aff’d, 604 F.3d 1343 (Fed. Cir. 2010); Snyder v. Sec’y, HHS, No. 01-162V, 2009 WL 332044 (Fed. Cl. Spec. Mstr. Feb. 12, 2009), aff’d, 88 Fed. Cl. 706 (2009).

[3] Dwyer v. Sec’y, HHS, 2010 WL 892250; King v. Sec’y, HHS, No. 03-584V, 2010 WL 892296 (Fed. Cl. Spec. Mstr. Mar. 12, 2010); Mead v. Sec’y, HHS, 2010 WL 892248.

[4] See, e.g., King, 2010 WL 892296, at *90 (emphasis in original); Snyder, 2009 WL 332044, at *198.

[5] The Federal Rule of Evidence technically do not control the vaccine court proceedings, but the Special Masters are bound by the requirement of Daubert v. Merrell Dow Pharm., 509 U.S. 579, 590 (1993), to find that expert witness opinion testimony is reliable before they consider it. Knudsen v. Sec’y, HHS, 35 F.3d 543, 548-49 (Fed. Cir. 1994). Madariaga at 7.

On Amending Rule 702 of the Federal Rules of Evidence

October 17th, 2015

No serious observer or scholar of the law of evidence can deny that the lower federal courts have applied Daubert and its progeny, and the revised Federal Rule of Evidence 702, inconstantly and inconsistently, in their decisions to admit or exclude proffered expert witness opinion testimony. Opponents of trial court “gatekeeping” of expert witnesses applaud the lapses in hopes that the gates have been unhinged and that there will be “open admissions” for expert witness testimony. These opponents latch on to the suggestion that the Rules favor “liberal” admissibility with a libertine; they lose sight of the meaning of “liberal” that conveys enlightened, with an openness to progress and salutary change, and the claims of knowledge over blind faith.  Supporters of gatekeeping lament the courts’ inability or unwillingness to apply a clear statutory mandate that is designed to improve and ensure the correctness of fact finding in the federal courts. A few have decried the lawlessness of the courts’ evasions and refusals to apply Rule 702’s requirements.

Given the clear body of Supreme Court precedent, and the statutory revision to Rule 702, which was clearly designed to embrace, embody, enhance, and clarify the high Court precedent, I did not think that an amendment to Rule 702 was needed to improve the sorry state of lower court decisions. Professor David Bernstein and lawyer Eric Lasker, however, have made a powerful case for amendment as a way of awakening and galvanizing federal judges to their responsibilities under the law. David E. Bernstein & Eric G. Lasker,“Defending Daubert: It’s Time to Amend Federal Rule of Evidence 702,” 57 William & Mary L. Rev. 1 (2015) [cited below as Bernstein & Lasker].

Bernstein and Lasker remind us that Rule 702 is a statute[1] that superseded inconsistent prior judicial pronouncements. The authors review many of the more egregious cases that ignore the actual text of Rule 702, while adverting to judicial gloss on the superseded rule, and even to judicial precedent and dicta pre-dating the Daubert case itself. Like the Papa Bear in the Berenstain Bear family, the authors show us how not to interpret a statute properly, through examples from federal court decisions.

The Dodgers’ Dodges

Questions about whether expert witnesses properly applied a methodology to the facts of a case are for the jury, and not the proper subject of gatekeeping.

As Bernstein and Lasker document, this thought- and Rule-avoidance dodge is particularly shocking given that the Supreme Court clearly directed close and careful analysis of the specific application of general principles to the facts of a case.[2] Shortly after the Supreme Court decided Daubert, the Third Circuit decided a highly influential decision in which it articulated the need for courts to review every step in expert witnesses’ reasoning for reliability. In re Paoli RR Yard PCB Litig., 35 F.3d 717, 745 (3d Cir. 1994). The Paoli case thus represents the antithesis of a judicial approach that asks only the 10,000 foot level question whether the right methodology was used; Paoli calls for a close, careful analysis of the application of a proper methodology to every step in the case. Id. (“any step that renders the analysis unreliable … renders the expert’s testimony inadmissible … whether the step completely changes a reliable methodology or merely misapplies that methodology”).

While the Paoli approach is unpopular with some judges who might prefer not to work so hard, the Advisory Committee heartily endorsed Paoli’s “any step” approach in its Note to the 2000 amendment. Bernstein & Lasker at 32. Bernstein and Lasker further point out that the Committee’s Report, Professor Dan Capra, acknowledged, shortly after the amendment went into effect, that the Paoli “any step” approach had a “profound impact” on the drafting of amended Rule 702. Bernstein & Lasker at 28.[3]

Having demonstrated the reasons, the process, and the substance of the judicial and legislative history of the revised Rule 702, Bernstein and Lasker are understandably incensed at the lawlessness of circuit and trial courts that have eschewed the statute, have ignored Supreme Court precedent, and have retreated to vague judicial pronouncements that trace back to before some or any of the important changes occurred in Rule 702.[4]

Let’s Cherry Pick and Weigh of the Evidence; Forget the Scale

Along with some courts’ insistence that trial judges may not examine the application of methods to the facts of a case, other courts, perhaps mindful of their citation practices, have endorsed “cherry picking” as a satisfactory methodology for partial expert witnesses to support their opinions. Id. at 35-36. Our law review authors also trace the influence of plaintiffs’ counsel, through their “walking around money” from the breast implant litigation, in sponsoring anti-Daubert, anti-gatekeeping conferences, at which prominent plaintiffs’ advocates and expert witnesses, such as Carl Cranor presented in favor of a vague “weight of the evidence” (WOE) approach to decision making. Id. at 39. Following these conferences, some courts have managed to embrace WOE, which is usually packaged as an abandonment of scientific standards of validity and sufficiency, in favor of selective review and subjective decisions. To do this, however, courts have had to ignore both Supreme Court precedent and the clear language of Rule 702. In Joiner, the high Court rejected WOE, over the dissent of a single justice,[5] but some of the inferior federal courts have embraced the dissent to the exclusion of the majority’s clear holding, as well as the incorporation of that holding into the revised Rule 702.[6] An interesting case of judicial disregard.

Other Dodges

The law review authors did not purport to provide an exhaustive catalogue of avoidance and evasion techniques. Here is one that is not discussed: shifting the burden of proof on admissibility to the opponent of the expert witness’s opinion:

“Testimony from an expert is presumed to be helpful unless it concerns matters within the everyday knowledge and experience of a lay juror.”

Earp v. Novartis Pharms., No. 5:11–CV–680–D, 2013 WL 4854488, at *3 (Sept. 11, 2013). See also Kopf v. Skyrm, 993 F.2d 374, 377 (4th Cir.1993); accord Koger v. Norfolk S. Ry. Co., No. 1:08–0909, 2010 WL 692842, at *1 (S.D.W.Va. Feb. 23, 2010) (unpublished).

Whence comes this presumption? Perhaps it is no more than a requirement for the opponent to object and articulate the flaws before the trial court will act. But the “presumption” sure looks like a covert shifting of the burden of proof for the requisite reliability of an expert witness’s opinion, which burden clearly falls on the proponent of the testimony.

The Proposed Amended Rule 702

There are several possible responses to the problem of the judiciary’s infidelity to basic principles, precedent, and legislative directive. Bernstein and Lasker advance amendments to the current Rule 702, as a blunt reminder that the times and the law have changed, really. Here is their proposed revision, with new language italicized, and deleted language shown to be struck:

“Rule 702. Testimony by Expert Witnesses

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the testimony satisfies each of the following requirements:

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) the testimony is based on sufficient facts or data that reliably support the expert’s opinion;

(c) the testimony is the product of reliable and objectively reasonable principles and methods; and

(d) the expert has reliably applied the principles and methods to the facts of the case and reached his conclusions without resort to unsupported speculation.

Appeals of district court decisions under this Rule are considered under the abuse-of-discretion standard. Such decisions are evaluated with the same level of rigor regardless of whether the district court admitted or excluded the testimony in question. This Rule supersedes any preexisting precedent that conflicts with any or all sections of this Rule.

Bernstein & Lasker at 44-45.

Before discussing and debating the changes, we should ask, “why change a fairly good statute just because lower courts evade its terms?” The corrupt efforts of SKAPP[7] to influence public and judicial policy, as well as the wildly one-sided Milward symposium,[8] which the authors discuss, should serve as a potent reminder that there would be many voices in the review and revision process, both from within plaintiffs’ bar, and from those sympathetic to the litigation industry’s goals and desires. Opening up the language of Rule 702 to revision could result in reactionary change, driven by the tort bar’s and allies’ lobbying. The result could be the evisceration of Rule 702, as it now stands. This danger requires a further exploration of alternatives to the proposed amendment.

Rule 702 has had the benefit of evolutionary change and development, which have made it better and also possibly burdened with vestigial language. To be sure, the rule is a difficult statute to draft, and while the authors give us a helpful start, there is many problems to be subdued before a truly workable working draft can be put be forward.

The first sentence’s new language, “the testimony satisfies each of the following requirements,” is probably already satisfied the use of “and” between the following numbered paragraphs. Given the judicial resistance to Rule 702, the additional verbiage could be helpful; it should be unnecessary. The conditionality of “if,” however, leaves the meaning of the Rule unclear when that condition is not satisfied. The Rule clearly signifies that “if” in the introductory sentence means “only if,” and the law and litigants would be better off if the Rule said what it means.

Proposed Subsection (b)

(b) the testimony is based on sufficient facts or data that reliably support the expert’s opinion;

The authors do not make much of a case for striking “sufficient.” There will be times when there are perfectly good facts and data supporting an expert witness’s opinion, in a completely reliable opinion, but the supporting facts and data do not support an epistemic claim of “knowledge,” because the support is indeterminate between the claim and many other competing hypotheses that might explain the outcome at issue. The reliably supporting facts and data may amount to little more than a scientific peppercorn, and really be too much of too little to support the claim. Deleting “sufficient” from subsection b could be a serious retrograde move, which will confuse the judiciary more than instruct it.

The revised subsection also fails to address the integrity of the facts and data, and the validity of how the data were generated. To be sure, Rule 703 could pick up some of the slack, but Rule 703 is often ignored, and even when invoked, that rule has its own drafting and interpretation problems. SeeGiving Rule 703 the Cold Shoulder” (May 12, 2012); “RULE OF EVIDENCE 703 — Problem Child of Article VII” (Sept. 19, 2011). Also missing is an acknowledgment that the facts or data must often be analyzed in some way, whether by statistical tests or some other means. And finally, there is the problem in that reliable does not necessarily connote valid or accurate. Subsection (b) thus seems to cry out for additional qualification, such as:

“the testimony is based on sufficient facts or data, reliably, accurately, and validly ascertained, and analyzed, which facts or data reliably and validly support the expert’s opinion”

Proposed Subsection (c)

Bernstein and Lasker propose modifying this subsection to inject “and objectively reasonable” before “principles and methods.” The authors do not explain what objectively reasonable principles and methods encompass, and they qualification does seem self-explanatory. Perhaps they are calling for principles and methods that are “generally accepted,” and otherwise justified as warranted to produce accurate, true results? Is so, that might be a helpful addition.

Proposed Subsection (d)

Here the authors bolster the language of the subsection with a prohibition against using unsupported speculation. OK; but would supported or inspired or ingenious speculation be any better? Subsection (a) speaks of knowledge, and it should be obvious that the expert witness’s opinion has an epistemic warrant to be something more than a mere subjective opinion.

Whether Bernstein and Lasker have opened a can or a Concordat of Worms remains to be seen.

[1] The authors provide a great resource on the legislative history of attempts to revise 702, up to and including the 2000 revision. The 2000 revision began with a proposed amendment from the Advisory Committee in April 1999. The Standing Committee on Rules of Practice and Procedure approved the proposal, and forwarded the proposed amendment to the Judicial Conference, which approved the amendment without change in September 1999. The Supreme Court ordered the amendment in April 2000, and submitted the revised rule to Congress. Order Amending the Federal Rules of Evidence, 529 U.S. 1189, 1195 (2000). The revised Rule 702 became effective on December 1, 2000. See also Bernstein & Lasker at 19 n. 99 (citing Edward J. Imwinkelried, “Response, Whether the Federal Rules of Evidence Should Be Conceived as a Perpetual Index Code: Blindness Is Worse than Myopia,” 40 Wm. & Mary L. Rev. 1595, 1595-98 (1999) (noting and supporting the Supreme Court’s interpretation and application of the Federal Rules of Evidence as a statute, and subject to the judicial constraints on statutory construction). For a strident student’s pro-plaintiff view of the same legislative history, see Nancy S. Farrell, “Congressional Action to Amend Federal Rule of Evidence 702: A Mischievous Attempt to Codify Daubert v. Merrell Dow Pharmaceuticals, Inc.”, 13 J. Contemp. Health L. & Pol’y 523 (1997).

[2] General Electric Co. v. Joiner, 522 U.S. 136 (1997) (reviewing and analyzing individual studies’ internal and external validity, and rejecting plaintiffs’ argument that only the appropriateness of the methodology in the abstract was subject of gatekeeping); Kumho Tire Co. v. Carmichael, 526 U.S. 137, 156-57 (1999) (“stressing that district courts must scrutinize whether the principles and methods employed by an expert have been properly applied to the facts of the case”) (quoting what was then the proposed advisory committee’s note to Rule 702, Preliminary Draft of Proposed Amendments to the Federal Rules of Civil Procedure and Evidence: Request for Comment, 181 F.R.D. 18, 148 (1998)).

[3] citing Stephen A. Saltzburg, Edwin J. Imwinkelried, & Daniel J. Capra, “Keeping the Reformist Spirit Alive in Evidence Law,” 149 U. Pa. L. Rev. 1277, 1289-90 (2001). The authors note that other circuits have embraced the Paoli “any steps” approach. Bernstein & Lasker at 28 at n. 152 (citing Paz v. Brush Engineered Materials, Inc., 555 F.3d 383, 387-91 (5th Cir. 2009); McClain v. Metabolife Int’l, Inc., 401 F.3d 1233, 1245 (11th Cir. 2005); Dodge v. Cotter Corp., 328 F.3d 1212, 1222 (10th Cir. 2003); Amorgianos v. Nat’l R.R. Passenger Corp., 303 F.3d 256, 267 (2d Cir. 2002) (quoting In re Paoli, 35 F.3d at 746).

[4] See, e.g., City of Pomona v. SQM N. Am. Corp., 750 F.3d 1036, 1047 (9th Cir. 2014) (rejecting the Paoli any step approach without careful analysis of the statute, the advisory committee note, or Supreme Court decisions); Manpower, Inc. v. Ins. Co. of Pa., 732 F.3d 796, 808 (7th Cir. 2013) (“[t]he reliability of data and assumptions used in applying a methodology is tested by the adversarial process and determined by the jury; the court’s role is generally limited to assessing the reliability of the methodology – the framework – of the expert’s analysis”); Bonner v. ISP Techs., Inc., 259 F.3d 924, 929 (8th Cir. 2001) (“the factual basis of an expert opinion goes to the credibility of the testimony, not the admissibility, and it is up to the opposing party to examine the factual basis for the opinion in cross-examination”).

[5] General Electric Co. v. Joiner, 522 U.S. 136, 146-47 (1997) (holding that district court had the “discretion to conclude that the studies upon which the experts relied were not sufficient, whether individually or in combination, to support their conclusions that Joiner’s exposure to PCB’s contributed to his cancer”). Other federal and state courts have followed Joiner. See Allen v. Pa. Eng’g Corp., 102 F.3d 194, 198 (5th Cir. 1996) (“We are also unpersuaded that the ‘weight of the evidence’ methodology these experts use is scientifically acceptable for demonstrating a medical link between Allen’s EtO exposure and brain cancer.”). For similar rejections of vague claims that weak evidence add up to more than the sum of its parts, see Hollander v. Sandoz Pharm. Corp., 289 F.3d 1193, 1216 n.21 (10th Cir. 2002); Magistrini v. One Hour Martinizing Dry Cleaning, 180 F. Supp. 2d 584, 608 (D.N.J. 2002); Caraker v. Sandoz Pharm. Corp., 188 F. Supp. 2d 1026, 1040 (S.D. Ill. 2001); Siharath v. Sandoz Pharm. Corp., 131 F. Supp. 2d 1347, 1371 (N.D. Ga. 2001), aff’d sub nom. Rider v. Sandoz Pharm. Corp., 295 F.3d 1194 (11th Cir. 2002); Merck & Co. v. Garza, 347 S.W.3d 256, 268 (Tex. 2011); Estate of George v. Vt. League of Cities & Towns, 993 A.2d 367, 379-80 (Vt. 2010).

[6] Milward v. Acuity Specialty Products Group, Inc., 639 F.3d 11, 17-18 (1st Cir. 2011) (reversing the exclusion of expert witnesses who embraced WOE). Milward has garnered some limited support in a few courts, as noted by Bernstein and Lasker; see In re Fosamax (Alendronate Sodium) Prods. Liab. Litig., Nos. 11-5304, 08-08, 2013 WL 1558690, at *4 (D.N.J. Apr. 10, 2013); Harris v. CSX Transp., Inc., 753 S.E.2d 275, 287-89, 301-02 (W. Va. 2013).

[7]SKAPP A LOT” (April 30, 2010).

[8]Milward Symposium Organized by Plaintiffs’ Counsel and Witnesses” (Feb. 13, 2013); [].

Woodside on Access to Underlying Research Data

October 10th, 2015

Access to underlying data and materials, source codes, and other research materials is a two-edged sword. Many scientists who hold forth on the issue, including some prominent plaintiffs’ expert witnesses, have been extremely critical of the pharmaceutical and other industries for not sharing underlying data of their research. On the other hand, some of the same people have resisted sharing data and information when the litigants have sought access to these materials to understand or to challenge the published conclusions and analyses.[1]

Dr. Frank Woodside, of Dinsmore & Shohl, kindly sent me a copy of his recent law review article, written with a colleague, which advocates for full disclosure of underlying research data when research becomes material to the outcome of litigation.[2] Frank C. Woodside & Michael J. Gray, “Researchers’ Privilege: Full Disclosure,” 32 West. Mich. Univ. Cooley L. Rev. 1 (2015). The authors make the case that the so-called researcher’s privilege has little or no support in federal or state law. My previous posts have largely supported this view, at least for research that has been published, and especially for research that is being relied upon by testifying expert witnesses in pending litigation. As Lord Chancellor Hardwicke put the matter, “the public has a right to every man’s evidence,”[3] and scientists should not be immune to the requirement of giving and sharing their evidence.

Woodside and Gray have updated the scholarship in this area, and their article should be consulted in any ongoing discovery, subpoena, or Freedom of Information Act (FOIA) battle. Their discussion of the evolving case law under FOIA is especially timely. Despite the strong presumption in favor of disclosure under FOIA,[4] and President Obama’s pronouncements[5] about a new era in FOIA openness and transparency, the government’s compliance is at an all-time low. See Ted Bridis, “Obama administration sets new record for withholding FOIA requests,” PBS News Hour (Mar. 18, 2015). Court decisions have made clear that researchers cannot refuse to produce underlying data simply “because disclosure would diminish the researchers’ ability to publish their results in prestigious journals.”[6] And yet the National Institute of Environmental Health and Safety continues in its aggressive resistance to disclosure of underlying data, often by invoking FOIA exemption number four. In my cases, I have seen the NIEHS resort to this exemption that protects documents that reveal “[t]rade secrets and commercial or financial information obtained from a person and privileged or confidential,”[7] even when the research in question was conducted by academic researchers funded by the NIEHS.

[1] See, e.g., Enoch v. Forest Research Institute, Inc., N.J. Law Div. Hudson Cty., Civ. Div. L-3896-14, Order Granting Defendants’ Motion to Compel Production of Documents Necessary to Verify the Validity and Accuracy of a Study by Plaintiffs’ Expert, Anick Berard, Ph.D. (Oct. 9, 2015) (Jablonski, J.) (ordering plaintiffs to “produce the documents sought by the Forest defendants to verify the validity and accuracy of the study known as “Berard et al., Sertraline Use During Pregnancy and the Risk of Major Malformations, Am. J. Obstet. Gynecol. (2015), doi 10.1016/j.ajog.2015.01.034, namely the study’s SAS source codes and the specific generalized estimating equation models that were used to generate Table 2 of the study”).

[2] And I should thank Dr. Woodside and Mr. Gray for their generous citations to your humble blogger’s posts on this subject.

[3] Debate in the House of Lords on the Bill to Indemnify Evidence, 12 Hansard’s Parliamentary History of England, 675, 693, May 25, 1742, quoted in 8 Wigmore on Evidence at 64, § 2192 (3d ed. 1940).

[4] See S. REP. No. 89-813, at 3 (1965) (the purpose of FOIA is to “establish a general philosophy of full agency disclosure . . . and to provide a court procedure by which citizens and the press may obtain information wrongfully withheld”).

[5] See Executive Order, Memorandum, 74 Fed. Reg. 4685 (Jan. 21, 2009).

[6] See Burka v. U.S. Dep’t of Health and Human Serv., 87 F.3d 508, 515 (D.C. Cir. 1996).

[7] See 5 U.S.C. § 552(b)(4).

Demonstration of Frye Gatekeeping in Pennsylvania Birth Defects Case

October 6th, 2015

Michael D. Freeman is a chiropractor and self-styled “forensic epidemiologist,” affiliated with Departments of Public Health & Preventive Medicine and Psychiatry, Oregon Health & Science University School of Medicine, in Portland, Oregon. His C.V. can be found here. Freeman has an interesting publication in press on his views of forensic epidemiology. Michael D. Freeman & Maurice Zeegers, “Principles and applications of forensic epidemiology in the medico-legal setting,” Law, Probability and Risk (2015); doi:10.1093/lpr/mgv010. Freeman’s views on epidemiology did not, however, pass muster in the courtroom. Porter v. Smithkline Beecham Corp., Phila. Cty. Ct. C.P., Sept. Term 2007, No. 03275. Slip op. (Oct. 5, 2015).

In Porter, plaintiffs sued Pfizer, the manufacturer of the SSRI antidepressant Zoloft. Plaintiffs claimed the mother plaintiff’s use of Zoloft during pregnancy caused her child to be born with omphalocele, a serious defect that occurs when the child’s intestines develop outside his body. Pfizer moved to exclude plaintiffs’ medical causation expert witnesses, Dr. Cabrera and Dr. Freeman. The trial judge was the Hon. Mark I. Bernstein, who has written and presented frequently on expert witness evidence.[1] Judge Bernstein held a two day hearing in September 2015, and last week, His Honor ruled that the plaintiffs’ expert witnesses failed to meet Pennsylvania’s Frye standard for admissibility. Judge Bernstein’s opinion reads a bit like a Berenstain Bear book on how not to use epidemiology.


Proper Epidemiologic Method

First, Find An Association

Dr. Freeman has a methodologic map that included Bradford Hill criteria at the back end of the procedure. Dr. Freeman, however, impetuously forgot that before you get to the back end, you must traverse the front end:

“Dr. Freemen agrees that he must, and claims he has, applied the Bradford Hill Criteria to support his opinion. However, the starting procedure of any Bradford-Hill analysis is ‘an association between two variables’ that is ‘perfectly clear-cut and beyond what we would care to attribute to the play of chance’.35 Dr. Freeman testified that generally accepted methodology requires a determination, first, that there’s evidence of an association and, second, whether chance, bias and confounding have been accounted for, before application of the Bradford-Hill criteria.36 Because no such association has been properly demonstrated, the Bradford Hill criteria could not have been properly applied.”

Slip op. at 12-13. In other words, don’t go rushing to the Bradford Hill factors until and unless you have first shown an association; second, you have shown that it is “clear cut,” and not likely the result of bias or confounding; and third, you have ruled out the play of chance or random variability in explaining the difference between the observed and expected rates of disease.

Proper epidemiologic method requires surveying the pertinent published studies that investigate whether there is an association between the medication use and the claimed harm. The expert witnesses must, however, do more than write a bibliography; they must assess any putative associations for “chance, confounding or bias”:

“Proper epidemiological methodology begins with published study results which demonstrate an association between a drug and an unfortunate effect. Once an association has been found, a judgment as whether a real causal relationship between exposure to a drug and a particular birth defect really exists must be made. This judgment requires a critical analysis of the relevant literature applying proper epidemiologic principles and methods. It must be determined whether the observed results are due to a real association or merely the result of chance. Appropriate scientific studies must be analyzed for the possibility that the apparent associations were the result of chance, confounding or bias. It must also be considered whether the results have been replicated.”

Slip op. at 7.

Then Rule Out Chance

So if there is something that appears to be an association in a study, the expert epidemiologist must assess whether it is likely consistent with a chance association. If we flip a fair coin 10 times, we “expect” 5 heads and 5 tails, but actually the probability of not getting the expected result is about three times greater than obtaining the expected result. If on one series of 10 tosses we obtain 6 heads and 4 tails, we would certainly not reject a starting assumption that the expected outcome was 5 heads/ 5 tails. Indeed, the probability of obtaining 6 heads / 4 tails or 4 heads /6 tails is almost double that of the probability of obtaining the expected outcome of equal number of heads and tails.

As it turned out in the Porter case, Dr. Freeman relied rather heavily upon one study, the Louik study, for his claim that Zoloft causes the birth defect in question. See Carol Louik, Angela E. Lin, Martha M. Werler, Sonia Hernández-Díaz, and Allen A. Mitchell, “First-Trimester Use of Selective Serotonin-Reuptake Inhibitors and the Risk of Birth Defects,” 356 New Engl. J. Med. 2675 (2007). The authors of the Louik study were quite clear that they were not able to rule out chance as a sufficient explanation for the observed data in their study:

“The previously unreported associations we identified warrant particularly cautious interpretation. In the absence of preexisting hypotheses and the presence of multiple comparisons, distinguishing random variation from true elevations in risk is difficult. Despite the large size of our study overall, we had limited numbers to evaluate associations between rare outcomes and rare exposures. We included results based on small numbers of exposed subjects in order to allow other researchers to compare their observations with ours, but we caution that these estimates should not be interpreted as strong evidence of increased risks.24

Slip op at 10 (quoting from Louik study).

Judge Bernstein thus criticized Freeman for failing to account for chance in explaining his putative association between maternal Zoloft use and infant omphalocele. The appropriate and generally accepted methodology for accomplishing this step of evaluating a putative association is to consider whether the association is statistically significant at the conventional level.

In relying heavily upon the Louik study, Dr. Freeman opened himself up to serious methodological criticism. Judge Bernstein’s opinion stands for the important proposition that courts should not be unduly impressed with nominal statistical significance in the presence of multiple comparisons and very broad confidence intervals:

“The Louik study is the only study to report a statistically significant association between Zoloft and omphalocele. Louik’s confidence interval which ranges between 1.6 and 20.7 is exceptionally broad. … The Louik study had only 3 exposed subjects who developed omphalocele thus limiting its statistical power. Studies that rely on a very small number of cases can present a random statistically unstable clustering pattern that may not replicate the reality of a larger population. The Louik authors were unable to rule out confounding or chance. The results have never been replicated concerning omphalocele. Dr. Freeman’s testimony does not explain, or seemingly even consider these serious limitations.”

Slip op. at 8. Statistical precision in the point estimate of risk, which includes assessing the outcome in the context of whether the authors conducted multiple comparisons, and whether the observed confidence intervals were very broad, is part of the generally accepted epidemiologic methodology, which Freeman flouted:

“Generally accepted methodology considers statistically significant replication of study results in different populations because apparent associations may reflect flaws in methodology.”

Slip op. at 9. The studies that Freeman cited and apparently relied upon failed to report statistically significant associations between sertraline (Zoloft) and omphalocele. Judge Bernstein found this lack to be a serious problem for Freeman and his epidemiologic opinion:

“While non-significant results can be of some use, despite a multitude of subsequent studies which isolated omphalocele, there is no study which replicates or supports Dr. Freeman’s conclusions.”

Slip op. at 10. The lack of statistical significance, in the context of repeated attempts to find it, helped sink Freeman’s proffered testimony.

Then Rule Out Bias and Confounding

As noted, Freeman relied heavily upon the Louik study, which was the only study to report a nominally statistically significant risk ratio for maternal Zoloft use and infant omphalocele. The Louik study, by its design, however, could not exclude chance or confounding as full explanation for the apparent association, and Judge Bernstein chastised Dr. Freeman for overselling the study as support for the plaintiffs’ causal claim:

“The Louik authors were unable to rule out confounding or chance. The results have never been replicated concerning omphalocele. Dr. Freeman’s testimony does not explain, or seemingly even consider these serious limitations.”

Slip op. at 8.

And Only Then Consider the Bradford Hill Factors

Even when an association is clear cut, and beyond what we can likely attribute to chance, generally accepted methodology requires the epidemiologist to consider the Bradford Hill factors. As Judge Bernstein explains, generally accepted methodology for assessing causality in this area requires a proper consideration of Hill’s factors before a conclusion of causation is reached:

“As the Bradford-Hill factors are properly considered, causality becomes a matter of the epidemiologist’s professional judgment.”

Slip op. at 7.

Consistency or Replication

The nine Hill factors are well known to lawyers because they have been stated and discussed extensively in Hill’s original article, and in references such as the Reference Manual on Scientific Evidence. Not all the Hill factors are equally important, or important at all, but one that is consistency or concordance of results among the available epidemiologic studies. Stated alternatively, a clear cut association unlikely to be explained by chance is certainly interesting and probative, but it raises an important methodological question — can the result be replicated? Judge Bernstein restated this important Hill factor as an important determinant of whether a challenged expert witness employed a generally accepted method:

“Generally accepted methodology considers statistically significant replication of study results in different populations because apparent associations may reflect flaws in methodology.”

Slip op. at 10.

“More significantly neither Reefhuis nor Alwan reported statistically significant associations between Zoloft and omphalocele. While non-significant results can be of some use, despite a multitude of subsequent studies which isolated omphalocele, there is no study which replicates or supports Dr. Freeman’s conclusions.”

Slip op. at 10.

Replication But Without Double Dipping the Data

Epidemiologic studies are sometimes updated and extended with additional follow up. An expert witness who wished to skate over the replication and consistency requirement might be tempted, as was Dr. Freeman, to count the earlier and later iteration of the same basic study to count as “replication.” The Louik study was indeed updated and extended this year in a published paper by Jennita Reefhuis and colleagues.[2] Proper methodology, however, prohibits double dipping data to count the later study that subsumes the early one as a “replication”:

“Generally accepted methodology considers statistically significant replication of study results in different populations because apparent associations may reflect flaws in methodology. Dr. Freeman claims the Alwan and Reefhuis studies demonstrate replication. However, the population Alwan studied is only a subset of the Reefhuis population and therefore they are effectively the same.”

Slip op. at 10.

The Lumping Fallacy

Analyzing the health outcome of interest at the right level of specificity can sometimes be a puzzle and a challenge, but Freeman generally got it wrong by opportunistically “lumping” disparate outcomes together when it helps him get a result that he likes. Judge Bernstein admonishes:

“Proper methodology further requires that one not fall victim to the … the ‘Lumping Fallacy’. … Different birth defects should not be grouped together unless they a part of the same body system, share a common pathogenesis or there is a specific valid justification or necessity for an association20 and chance, bias, and confounding have been eliminated.”

Slip op. at 7. Dr. Freeman lumped a lot, but Judge Bernstein saw through the methodological ruse. As Judge Bernstein pointed out:

“Dr. Freeman’s analysis improperly conflates three types of data: Zoloft and omphalocele, SSRI’s generally and omphalocele, and SSRI’s and gastrointestinal and abdominal malformations.”

Slip op. at 8. Freeman’s approach, which sadly is seen frequently in pharmaceutical and other products liability cases, is methodologically improper:

“Generally accepted causation criteria must be based on the data applicable to the specific birth defect at issue. Dr. Freeman improperly lumps together disparate birth defects.”

Slip op. at 11.

Class Effect Fallacy

Another kind of improper lumping results from treating all SSRI antidepressants the same to either lump them together, or to pick and choose from among all the SSRIs, the data points that are supportive of the plaintiffs’ claims (while ignoring those SSRI data points not supportive of the claims). To be sure, the SSRI antidepressants do form a “class,” in that they all have a similar pharmacologic effect. The SSRIs, however, do not all achieve their effect in the serotonergic neurons the same way; nor do they all have the same “off-target” effects. Treating all the SSRIs as interchangeable for a claimed adverse effect, without independent support for this treatment, is known as the class effect fallacy. In Judge Bernstein’s words:

“Proper methodology further requires that one not fall victim to the ‘Class Effect Fallacy’ … . A class effect cannot be assumed. The causation conclusion must be drug specific.”

Slip op. at 7. Dr. Freeman’s analysis improperly conflated Zoloft data with SSRI data generally. Slip op. at 8. Assuming what you set out to demonstrate is, of course, a fine way to go methodologically into the ditch:

“Without significant independent scientific justification it is contrary to generally accepted methodology to assume the existence of a class effect. Dr. Freeman lumps all SSRI drug results together and assumes a class effect.”

Slip op. at 10.


Dr. Freeman was also offered by plaintiffs to provide a specific causation opinion – that Mrs. Porter’s use of Zoloft in pregnancy caused her child’s omphalocele. Freeman claimed to have performed a differential diagnosis or etiology or something to rule out alternative causes.


In the field of birth defects, one possible cause looming in any given case is an inherited or spontaneous genetic mutation. Freeman purported to have considered and ruled out genetic causes, which he acknowledged to make up a substantial percentage of all omphalocele cases. Bo Porter, Mrs. Porter’s son, was tested for known genetic causes, and Freeman argued that this allowed him to “rule out” genetic causes. But the current state of the art in genetic testing allowed only for identifying a small number of possible genetic causes, and Freeman failed to explain how he might have ruled out the as-of-yet unidentified genetic causes of birth defects:

“Dr. Freeman fails to properly rule out genetic causes. Dr. Freeman opines that 45-49% of omphalocele cases are due to genetic factors and that the remaining 50-55% of cases are due to non-genetic factors. Dr. Freeman relies on Bo Porter’s genetic testing which did not identify a specific genetic cause for his injury. However, minor plaintiff has not been tested for all known genetic causes. Unknown genetic causes of course cannot yet be tested. Dr. Freeman has made no analysis at all, only unwarranted assumptions.”

Slip op. at 15-16. Judge Bernstein reviewed Freeman’s attempted analysis and ruling out of potential causes, and found that it departed from the generally accepted methodology in conducting differential etiology. Slip op. at 17.

Timing Errors

One feature of putative terotogenicity is that an embryonic exposure must take place at a specific gestational developmental time in order to have its claimed deleterious effect. As Judge Bernstein pointed out, omphalocele results from an incomplete folding of the abdominal wall during the third to fifth weeks of gestation. Mrs. Porter, however, did not begin taking Zoloft until her seventh week of pregnancy, which left Dr. Freeman opinion-less as to how Zoloft contributed to the claimed causation of the minor plaintiff’s birth defect. Slip op. at 14. This aspect of Freeman’s specific causation analysis was glaringly defect, and clearly not the sort of generally accepted methodology of attributing a birth defect to a teratogen.


All in all, Judge Bernstein’s opinion is a tour de force demonstration of how a state court judge, in a so-called Frye jurisdiction, can show that failure to employ generally accepted methods renders an expert witness’s opinions inadmissible. There is one small problem in statistical terminology.

Statistical Power

Judge Bernstein states, at different places, that the Louik study was and was not statistically significant for Zoloft and omphalocele. The court’s opinion ultimately does explain that the nominal statistical significance was vitiated by multiple comparisons and an extremely broad confidence interval, which more than justified its statement that the study was not truly statistically significant. In another moment, however, the court referred to the problem as one of lack of statistical power. For some reason, however, Judge Bernstein chose to explain the problem with the Louik study as a lack of statistical power:

“Equally significant is the lack of power concerning the omphalocele results. The Louik study had only 3 exposed subjects who developed omphalocele thus limiting its statistical power.”

Slip op. at 8. The adjusted odds ratio for Zoloft and omphalocele, was 5.7, with a 95% confidence interval of 1.6 – 20.7. Power was not the issue because if the odds ratio were otherwise credible, free from bias, confounding, and chance, the study had the power to observe an increased risk of close to 500%, which met the pre-stated level of significance. The problem, however, was multiple testing, fragile and imprecise results, and inability to evaluate the odds ratio fully for bias and confounding.


[1] Mark I. Bernstein, “Expert Testimony in Pennsylvania,” 68 Temple L. Rev. 699 (1995); Mark I. Bernstein, “Jury Evaluation of Expert Testimony under the Federal Rules,” 7 Drexel L. Rev. 239 (2014-2015).

[2] Jennita Reefhuis, Owen Devine, Jan M Friedman, Carol Louik, Margaret A Honein, “Specific SSRIs and birth defects: bayesian analysis to interpret new data in the context of previous reports,” 351 Brit. Med. J. (2015).