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Zoloft MDL Relieves Matrixx Depression

January 30th, 2015

When the Supreme Court delivered its decision in Matrixx Initiatives, Inc. v. Siracusano, 131 S. Ct. 1309 (2011), a colleague, David Venderbush from Alston & Bird LLP, and I wrote a Washington Legal Foundation Legal Backgrounder, in which we predicted that plaintiffs’ counsel would distort the holding, and inflate the dicta of the opinion. Schachtman & Venderbush, “Matrixx Unbounded: High Court’s Ruling Needlessly Complicates Scientific Evidence Principles,” 26 (14) Legal Backgrounder (June 17, 2011)[1]. Our prediction was sadly all-too accurate. Not only was the context of the Matrixx distorted, but several district courts appeared to adopt the dicta on statistical significance as though it represented the holding of the case[2].

The Matrixx decision, along with the few district court opinions that had embraced its dicta[3], was urged as the basis for denying a defense challenge to the proffered testimony of Dr. Anick Bérard, a Canadian perinatal epidemiologist, in the Zoloft MDL. The trial court, however, correctly discerned several methodological shortcomings and failures, including Dr. Bérard’s reliance upon claims of statistical significance from studies that conducted dozens and hundreds of multiple comparisons. See In re Zoloft (Sertraline Hydrochloride) Prods. Liab. Litig., MDL No. 2342; 12-md-2342, 2014 U.S. Dist. LEXIS 87592; 2014 WL 2921648 (E.D. Pa. June 27, 2014) (Rufe, J.).

Plaintiffs (through their Plaintiffs’ Steering Committee (PSC) in the Zoloft MDL) were undaunted and moved for reconsideration, asserting that the MDL trial court had failed to give appropriate weight to the Supreme Court’s decision in Matrixx, and a Third Circuit decision in DeLuca v. Merrell Dow Pharms., Inc., 911 F.2d 941 (3d Cir. 1990). The MDL trial judge, however, deftly rebuffed the plaintiffs’ use of Matrixx, and their attempt to banish consideration of random error in the interpretation of epidemiologic studies. In re Zoloft (Sertraline Hydrochloride) Prods. Liab. Litig., MDL No. 2342; 12-md-2342, 2015 WL 314149 (E.D. Pa. Jan. 23, 2015) (Rufe, J.) (denying PSC’s motion for reconsideration).

In rejecting the motion for reconsideration, the Zoloft MDL trial judge noted that the PSC had previously cited Matrixx, and that the Court had addressed the case in its earlier ruling. 2015 WL 314149, at *2-3. The MDL Court then proceeded to expand upon its earlier ruling, and to explain how Matrixx was largely irrelevant to the Rule 702 context of Pfizer’s challenge to Dr. Bérard. There were, to be sure, some studies with nominal statistically significant results, for some birth defects, among children of mothers who took Zoloft in their first trimester of pregnancy. As Judge Rufe explained, statistical significance, or the lack thereof, was only one item in a fairly long list of methodological deficiencies in Dr. Bérard’s causation opinions:

“The [original] opinion set forth a detailed and multi-faceted rationale for finding Dr. Bérard’s testimony unreliable, including her inattention to the principles of replication and statistical significance, her use of certain principles and methods without demonstrating either that they are recognized by her scientific community or that they should otherwise be considered scientifically valid, the unreliability of conclusions drawn without adequate hypothesis testing, the unreliability of opinions supported by a ‛cherry-picked’ sub-set of research selected because it was supportive of her opinions (without adequately addressing non-supportive findings), and Dr. Bérard’s failure to reconcile her currently expressed opinions with her prior opinions and her published, peer-reviewed research. Taking into account all these factors, as well as others discussed in the Opinion, the Court found that Dr. Bérard departed from well-established epidemiological principles and methods, and that her opinion on human causation must be excluded.”

Id. at *1.

In citing the multiple deficiencies of the proffered expert witness, the Zoloft MDL Court thus put its decision well within the scope of the Third Circuit’s recent precedent of affirming the exclusion of Dr. Bennet Omalu, in Pritchard v. Dow Agro Sciences, 430 F. App’x 102, 104 (3d Cir.2011). The Zoloft MDL Court further defended its ruling by pointing out that it had not created a legal standard requiring statistical significance, but rather had made a factual finding that epidemiologist, such as the challenged witness, Dr. Anick Bérard, would use some measure of statistical significance in reaching conclusions in her discipline of epidemiology. 2015 WL 314149, at *2[4].

On the plaintiffs’ motion for reconsideration, the Zoloft Court revisited the Matrixx case, properly distinguishing the case as a securities fraud case about materiality of non-disclosed information, not about causation. 2015 WL 314149, at *4. Although the MDL Court could and should have identified the Matrixx language as clearly obiter dicta, it did confidently distinguish the Supreme Court holding about pleading materiality from its own task of gatekeeping expert witness testimony on causation in a products liability case:

“Because the facts and procedural posture of the Zoloft MDL are so dissimilar from those presented in Matrixx, this Court reviewed but did not rely upon Matrixx in reaching its decision regarding Dr. Bérard. However, even accepting the PSC’s interpretation of Matrixx, the Court’s Opinion is consistent with that ruling, as the Court reviewed Dr. Bérard’s methodology as a whole, and did not apply a bright-line rule requiring statistically significant findings.”

Id. at *4.

In mounting their challenge to the MDL Court’s earlier ruling, the Zoloft plaintiffs asserted that the Court had failed to credit Dr. Bérard’s reliance upon what Dr. Bérard called the “Rothman approach.” This approach, attribution to Professor Kenneth Rothman had received some attention in the Bendectin litigation in the Third Circuit, where plaintiffs sought to be excused from their failure to show statistically significant associations when claiming causation between maternal use of Bendectin and infant birth defects. DeLuca v. Merrell Dow Pharms., Inc., 911 F.2d 941 (3d Cir. 1990). The Zoloft MDL Court pointed out that the Circuit, in DeLuca, had never affirmatively endorsed Professor Rothman’s “approach,” but had reversed and remanded the Bendectin case to the district court for a hearing under Rule 702:

“by directing such an overall evaluation, however, we do not mean to reject at this point Merrell Dow’s contention that a showing of a .05 level of statistical significance should be a threshold requirement for any statistical analysis concluding that Bendectin is a teratogen regardless of the presence of other indicial of reliability. That contention will need to be addressed on remand. The root issue it poses is what risk of what type of error the judicial system is willing to tolerate. This is not an easy issue to resolve and one possible resolution is a conclusion that the system should not tolerate any expert opinion rooted in statistical analysis where the results of the underlying studies are not significant at a .05 level.”

2015 WL 314149, at *4 (quoting from DeLuca, 911 F.2d at 955). After remand, the district court excluded the DeLuca plaintiffs’ expert witnesses, and granted summary judgment, based upon the dubious methods employed by plaintiffs’ expert witnesses in cherry picking data, recalculating risk ratios in published studies, and ignoring bias and confounding in studies. The Third Circuit affirmed the judgment for Merrell Dow. DeLuca v. Merrell Dow Pharma., Inc., 791 F. Supp. 1042 (3d Cir. 1992), aff’d, 6 F.3d 778 (3d Cir. 1993).

In the Zoloft MDL, the plaintiffs not only offered an erroneous interpretation of the Third Circuit’s precedents in DeLuca, they also failed to show that the “Rothman” approach had become generally accepted in over two decades since DeLuca. 2015 WL 314149, at *4. Indeed, the hearing record was quite muddled about what the “Rothman” approach involved, other than glib, vague suggestions that the approach would have countenanced Dr. Bérard’s selective, over-reaching analysis of the extant epidemiologic studies. The plaintiffs did not call Rothman as an expert witness; nor did they offer any of Rothman’s publications as exhibits at the Zoloft hearing. Although Professor Rothman has criticized the overemphasis upon p-values and significance testing, he has never suggested that researchers and scientists should ignore random error in interpreting research data. Nevertheless, plaintiffs attempted to invoke some vague notion of a Rothman approach that would ignore confidence intervals, attained significance probability, multiplicity, bias, and confounding. Ultimately, the MDL Court would have none of it. The Court held that the Rothman Approach (whatever that is), as applied by Dr. Bérard, did not satisfy Rule 702.

The testimony at the Rule 702 hearing on the so-called “Rothman approach” had been sketchy at best. Dr. Bérard protested, perhaps too much, when asked about her having ignored p-values:

“I’m not the only one saying that. It’s really the evolution of the thinking of the importance of statistical significance. One of my professors and also a friend of mine at Harvard, Ken Rothman, actually wrote on it – wrote on the topic. And in his book at the end he says obviously what I just said, validity should not be confused with precision, but the third bullet point, it’s saying that the lack of statistical significance does not invalidate results because sometimes you are in the context of rare events, few cases, few exposed cases, small sample size, exactly – you know even if you start with hundreds of thousands of pregnancies because you are looking at rare events and if you want to stratify by exposure category, well your stratum becomes smaller and smaller and your precision decreases. I’m not the only one saying that. Ken Rothman says it as well, so I’m not different from the others. And if you look at many of the studies published nowadays, they also discuss that as well.”

Notes of Testimony of Dr. Anick Bérard, at 76:21- 77:14 (April 9, 2014). See also Notes of Testimony of Dr. Anick Bérard, at 211 (April 11, 2014) (discussing non-statistically significant findings as a “trend,” and asserting that the lack of a significant finding does not mean that there is “no effect”). Bérard’s invocation of Rothman here is accurate but unhelpful. Rothman and Bérard are not alone in insisting that confidence intervals provide a measure of precision of an estimate, and that we should be careful not to interpret the lack of significance to mean no effect. But the lack of significance cannot be used to interpret data to show an effect.

At the Rule 702 hearing, the PSC tried to bolster Dr. Bérard’s supposed reliance upon the “Rothman approach” in cross-examining Pfizer’s expert witness, Dr. Stephen Kimmel:

“Q. You know who Dr. Rothman is, the epidemiologist?
A. Yes.
Q. You actually took a course from Dr. Rothman, didn’t you?
A. I did when I was a student way back.
Q. He is a well-known epidemiologist, isn’t he?
A. Yes, he is.
Q. He has published this book, Modern Epidemiology. Do you have a copy of this?
A. I do.
Q. Do you – Have you ever read it?
A. I read his earlier edition. I have not read the most recent edition.
Q. There’s two other authors, Sander Greenland and Tim Lash. Do you know either one of them?
A. I know Sander. I don’t know Tim.
Q. Dr. Rothman has some – he has written about confidence intervals and statistical significance for some time, hasn’t he?
A. He has.
Q. Do you agree with him that statistical significance is a not matter of validity. It’s a matter of precision?
A. It’s a matter of – well, confidence intervals are matters of precision. P-values are not.
Q. Okay. I want to put up a table and see if you are in agreement with Dr. Rothman. This is the third edition of Modern Epidemiology. And he has – and ignore my brother’s handwriting. But there is an hypothesized rate ratio under 10-3. It says: p-value function from which one can find all confidence limits for a hypothetical study with a rate ratio estimate of 3.1 Do you see that there?
A. Yes. I don’t see the top of the figure, not that it matters.
Q. I want to make sure. The way I understand this, he is giving us a hypothesis that we have a relative risk of 3.1 and it [presumably a 95% confidence interval] crosses 1, meaning it’s not statistically significant. Is that fair?
A. Well, if you are using a value of .05, yes. And again, if this is a single test and there’s a lot of things that go behind it. But, yes, so this is a total hypothetical.
Q. Yes.
A. I’ sorry. He’s saying here is a hypothetical based on math. And so here is – this is what we would propose.
Q. Yes, I want to highlight what he says about this figure and get your thoughts on it. He says:
The message of figure 10-3 is that the example data are more compatible with a moderate to strong association than with no association, assuming the statistical model used to construct the function is correct.
A. Yes.
Q. Would you agree with that statement?
A. Assuming the statistical model is correct. And the problem is, this is a hypothetical.
Q. Sure. So let’s just assume. So what this means to sort of put some meat on the bone, this means that although we cross 1 and therefore are statistically
significant [sic, non-significant], he says the more likely truth here is that there is a moderate to strong effect rather than no effect?
A. Well, you know he has hypothesized this. This is not used in common methods practice in pharmacoepi. Dr. Rothman has lots of ideas but it’s not part of our standard scientific method.

Notes of Testimony of Dr. Stephen Kimmel, at 126:2 to 128:20.

Nothing very concrete about the “Rothman approach” is put before the MDL Court, either through Dr. Bérard or Dr. Kimmel. There are, however, other instructive aspects to the plaintiff’s counsel’s examination. First, the referenced portion of the text, Modern Epidemiology, is a discussion of p-value functions, not of p-values or of confidence intervals per se. Modern Epidemiology at 158-59 (3d ed. 2008). Dr. Bérard never discussed p-value functions in her report or in her testimony, and Dr. Kimmel testified, without contradiction, that such p-value functions are “not used in common methods practice.” Second, the plaintiff’s counsel never marked and offered the Rothman text as an exhibit for the MDL Court to consider. Third, the cross-examiner first asked about the implication for a hypothetical association, and then, when he wanted to “put some meat on the bone” changed the word used in Rothman’s text, “association,” to “effect.” The word “effect” does not appear in Rothman’s text at the referenced discussion about p-value functions. Fortunately, the MDL Court was not poisoned by the “meat on the bone.”

The Pit and the Pendulum

Another document glibly referenced but not provided to the MDL Court was the publication of Sir Austin Bradford Hill’s presidential address to the Royal Society of Medicine on causation. The MDL Court acknowledged that the PSC had argued that the emphasis upon statistical significance was contrary to Hill’s work and teaching. 2015 WL 314149, at *5. In the Court’s words:

“the PSC argues that the Court’s finding regarding the importance of statistical significance in the field of epidemiology is inconsistent with the work of Bradford Hill. The PSC points to a 1965 address by Sir Austin Bradford Hill, which it has not previously presented to the Court, except in opening statements of the Daubert hearings.20 The PSC failed to put forth evidence establishing that Bradford Hill’s statement that ‛I wonder whether the pendulum has not swung too far [in requiring statistical significance before drawing conclusions]’ has, in the decades since that 1965 address, altered the importance of statistical significance to scientists in the field of epidemiology.”

Id. This failure, identified by the Court, is hardly surprising. The snippet of a quotation from Hill would not sustain the plaintiffs’ sweeping generalization. The quoted language in context may help to explain why Hill’s paper was not provided:

“I wonder whether the pendulum has not swung too far – not only with the attentive pupils but even with the statisticians themselves. To decline to draw conclusions without standard errors can surely be just as silly? Fortunately I believe we have not yet gone so far as our friends in the USA where, I am told, some editors of journals will return an article because tests of significance have not been applied. Yet there are innumerable situations in which they are totally unnecessary – because the difference is grotesquely obvious, because it is negligible, or because, whether it be formally significant or not, it is too small to be of any practical importance. What is worse the glitter of the t table diverts attention from the inadequacies of the fare. Only a tithe, and an unknown tithe, of the factory personnel volunteer for some procedure or interview, 20% of patients treated in some particular way are lost to sight, 30% of a randomly-drawn sample are never contracted. The sample may, indeed, be akin to that of the man who, according to Swift, ‘had a mind to sell his house and carried a piece of brick in his pocket, which he showed as a pattern to encourage purchasers.’ The writer, the editor and the reader are unmoved. The magic formulae are there.”

Austin Bradford Hill, “The Environment and Disease: Association or Causation?” 58 Proc. Royal Soc’y Med. 295, 299 (1965).

In the Zoloft cases, no expert witness was prepared to state that the disparity was “grotesquely obvious,” or “negligible.” And Bradford Hill’s larger point was that bias and confounding often dwarf considerations of random error, and that there are many instances in which significance testing is unavailing or unhelpful. And in some studies, with large “effect sizes,” statistical significance testing may be beside the point.

Hill’s presidential address to the Royal Society of Medicine commemorated his successes in epidemiology, and we need only turn to Hill’s own work to see how prevalent was his use of measurements of significance probability. See, e.g., Richard Doll & Austin Bradford Hill, “Smoking and Carcinoma of the Lung: Preliminary Report,” Brit. Med. J. 740 (Sept. 30, 1950); Medical Research Council, “Streptomycin Treatment of Pulmonary Tuberculosis,” Brit. Med. J. 769 (Oct. 30, 1948).

Considering the misdirection on Rothman and on Hill, the Zoloft MDL Court did an admirable job in unraveling the Matrixx trap set by counsel. The Court insisted upon parsing the Bradford Hill factors[5], over Pfizer’s objection, despite the plaintiffs’ failure to show “an association between two variables, perfectly clear-cut and beyond what we would care to attribute to the play of chance,” which Bradford Hill insisted was the prerequisite for the exploration of the nine factors he set out in his classic paper. Austin Bradford Hill, “The Environment and Disease: Association or Causation?” 58 Proc. Royal Soc’y Med. 295, 295 (1965). Given the outcome, the Court’s questionable indulgence of plaintiffs’ position was ultimately harmless.

[1] See also “The Matrixx – A Comedy of Errors,” and “Matrixx Unloaded,” (Mar. 29, 2011), “The Matrixx Oversold,” and “De-Zincing the Matrixx.”

[2] See “Siracusano Dicta Infects Daubert Decisions” (Sept. 22, 2012).

[3] See, e.g., 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); In re Celexa & Lexapro Prods. Liab. Litig.,  ___ F.3d ___, 2013 WL 791780 (E.D. Mo. 2013).

[4] The Court’s reasoning on this point begged the question whether an ordinary clinician, ignorant of the standards, requirements, and niceties of statistical reasoning and inference, would be allowed to testify, unconstrained by any principled epidemiologic reasoning about random or systematic error. It is hard to imagine that Rule 702 would countenance such an end-run around the requirements of sound science.

[5] Adhering to Bradford Hill’s own admonition might have saved the Court the confusion of describing statistical significance as a measure of strength of association. 2015 WL 314149, at *2.

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The Lie Detector and Wonder Woman – Quirks and Quacks of Legal History

January 27th, 2015

From 1923, until the United States Supreme Court decided the Daubert case in 1993, Frye was cited as “controlling authority” on questions of the admissibility of scientific opinion testimony and test results. The decision is infuriatingly cryptic and unhelpful as to background or context of the specific case, as well as how it might be applied to future controversies. Of the 669 words, these are typically cited as the guiding “rule” with respect to expert witness opinion testimony:

“Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while the courts will go a long way in admitting expert testimony deduced from a well recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.”

Frye v. United States, 293 F. 1013, 1014 (D.C. Cir. 1923).

As most scholars of evidence realize, the back story of the Frye case is rich and bizarre. The expert witness involved, William Marston, was a lawyer and scientist, who had made advances in a systolic blood pressure cuff to be used as a “lie detector.” Marston was also an advocate of free love and, with his wife and his mistress, the inventor of Wonder Woman and her lasso of truth.

Jill Lepore, a professor of history in Harvard University, has written an historical account of Marston and his colleagues. Jill Lepore, The Secret History of Wonder Woman (N.Y. 2014). More recently, Lepore has written an important law review on the historical and legal record of the Frye case, which is concealed in the terse 669 words of the Court of Appeals’ opinion. Jill Lepore, “On Evidence: Proving Frye as a Matter of Law, Science, and History,” 124 Yale L.J. 1092 (2015).

Lepore’s history is an important gloss on the Frye case, but her paper points to a larger, more prevalent, chronic problem in the law, which especially afflicts judicial decisions of scientific or technical issues. As an historian, Lepore is troubled, as we all should be, by the censoring, selecting, suppressing, and distorting of facts that go into judicial decisions. From cases and their holdings, lawyers are taught to infer rules that guide their conduct at the bar, and their clients’ conduct and expectations, but everyone requires fair access to the evidence to determine what facts are material to decision.

As Professor Lepore puts it:

“Marston is missing from Frye because the law of evidence, case law, the case method, and the conventions of legal scholarship — together, and relentlessly — hide facts.”

Id. at 1097. Generalizing from Marston and the Frye case, Lepore notes that:

“Case law is like that, too, except that it doesn’t only fail to notice details; it conceals them.”

Id. at 1099.

Lepore documents that Marston’s psychological research was rife with cherry picking and data dredging. Id. at 1113-14. Despite his degree magna cum laude in philosophy from Harvard College, his L.L.B from Harvard Law School (with no particular distinction), and his Ph.D. from Harvard University, Marston was not a rigorous scientist. In exploring the historical and legal record, not recounted in the Frye decision, Lepore’s history provides a wonderful early example, of what has become a familiar phenomenon of modern litigation: an expert witness who seeks to achieve acceptance for a dubious opinion or device in the courtroom rather than in the court of scientific opinion. Id. at 1122. The trial judge in Frye’s murder case, Justice McCoy, was an astute judge, and quite modest in his ability to evaluate the validity of Marston’s opinions, but he had more than sufficient perspicacity to discern that Marston’s investigation was “wildly unscientific,” with no control groups. Id. at 1135. The trial record of defense counsel’s proffer, and Justice McCoy’s rulings and comments from the bench, reproduced in Lepore’s article, anticipate and predict much of the scholarship surrounding both Frye and Daubert cases.

Lepore complains that the important historical record, including Marston’s correspondence with Professor Wigmore, the criminal fraud charges against Marston, and the correspondence of Frye’s lawyers, lies “filed, undigitized” in various archives. Id. at 1150. Although Professor Lepore tirelessly cites to internet URL sources when available, she could have easily made the primary historical materials available for all, using readily available internet technology. Lepore’s main thesis should encourage lawyers and law scholars to look beyond appellate decisions as the data for legal analysis.

Posted in Expert Witnesses, Frye, Scientific Evidence | Comments Off on The Lie Detector and Wonder Woman – Quirks and Quacks of Legal History

The Erosion of Employer Immunity in Tort Litigation

January 20th, 2015

The present workman’s compensation system in the United States has serious flaws. Scheduled awards are inadequate in some states, and their inadequacy fosters specious litigation against remote third parties who are not able to control the workplace use of hazardous materials. In many states, premiums are set on an industry-wide basis, and thus careless employers are not handed incentives to improve workplace hygiene. With awards low, and without the need to rate individual employers, compensation insurers do not adequately inspect and control individual employers’ conduct. Workman’s compensation statutes provide a lien against any third-party recovery, which means that employers (and their insurers) will be rewarded for their negligence if injured employees can frame liability suits against third-parties, such as suppliers of raw materials to the employers.

For the most part, organized labor and management reached their great compromise over occupational injury litigation back from about 1911 through the early 1930s. Before the passage of the various compensation acts, employees had common law negligence actions against employers for deviations from reasonable care. In some part of the country, juries were extremely sympathetic to injured workers, and equally hostile to employers. At the same time, employers had powerful defenses in the form of contributory negligence, which barred claims by workers who were the least bit careless for their own safety. The fellow-worker rule, assumption of risk, and statutes of limitations further diminished workers’ likelihood of success in pursuing tort claims. One option that was not on the table in the negotiations was to open up liability of remote vendors to employers as a way to mitigate the hardships of the common law tort system. Remote suppliers had even more potent defenses in the form of privity of contract, intervening and superseding negligence of the employers and employees, and all the other defenses that employers enjoyed. More important, however, the interlocutors realized that employers controlled the workplace, and had the greatest opportunity to prevent industrial injuries and occupational disease. When the workman’s compensation bargain was struck, labor knew that the scheduled awards would be workers’ sole or main source of compensation.

Worker’s compensation statutes made recovery for most injuries a certainty, with schedules of damages that were deeply discounted from what might be had in a jury trial. In return for well-nigh absolute liability, employers gained certainty of outcome, reduction of administrative costs, and immunity to tort liability for all but intentional harms. The remedial compensation statutes gave employers immunity, but they did not eradicate the basic common law bases for suits against employers. But for the worker’s compensation statutes, employees would have rights of action against employers. Gaps in the compensation acts translated into gaps in immunity, and reversion to the common law of negligence.

The predicate for the “deal” began to disintegrate after World War II. For one thing, changes in tort law diminished the defenses that employers had exercised so effectively before the deal. Contributory negligence gave way to comparative negligence.  Assumption of risk defenses were curtailed, and the fellow-servant rule was severely modified or abandoned.

Just when Labor might have been feeling consumed by buyer’s remorse over its deal, strict liability principles began to replace privity doctrines. In 1965, the American Law Institute adopted § 402A which provided for “Special Liability of Seller of Product for Physical Harm to User or Consumer,” based upon concerns of unequal knowledge of defects and latent hazards of products sold to consumers. Liability followed for harm caused by a product irrespective of privity of contract or warranty, and even if “the seller has exercised all possible care in the preparation and sale of his product.” Restatement (Second), Torts § 402A (2)(a),(b) (1965).

Section 402 became the vehicle for injured workers to ditch their capped damages in worker’s compensation court, and to put their cases back in front of juries, with the prospect of unlimited awards for non-economic damages. Although instigated by the perceived imbalance of knowledge between manufacturers and buyers with respect to design and manufacturing defects, strict liability doctrine quickly became a vehicle for redressing inadequacies in the workman’s compensation systems. What was problematic, however, was that there was often no inequality of knowledge between seller and purchaser, or hidden or latent hazard in the product or material.

There are exceptions to the exclusivity of workman’s compensation remedies against employers. One exception, available in most states, is for intentional torts committed by employers. The scienter requirement for intentional torts allowed only very few cases to proceed against employers in tort. A bigger gap in immunity, however, was opened in Pennsylvania, where workers regained their common law right to sue employers for negligence and other torts, for occupational diseases that manifest more than 300 weeks after last employment. Section 301(c)(2) of the Pennsylvania’s Workman’s Compensation Act, 77 P.S. § 411(2) removes these delayed manifested occupational disease claims from the scope of Pennsylvania’s Act. The Pennsylvania Supreme Court filled in the obvious logical gap: if the Act did not apply, then the employer had no immunity against a common law cause of action, which was never abolished, and was unavailable only when there was a statutory remedy under the Act. Tooey v. AK Steel Corp., 81 A.3d 851 (2013); “Pennsylvania Workers Regain Their Right of Action in Tort against Employers for Latent Occupational Diseases” (Feb. 14, 2014). See also Gidley v. W.R. Grace Co., 717 P.2d 21(Mont. 1986)).

The Tooey decision has the potential to open an important door for plaintiffs and defendants alike. With employer immunity erased, the employer’s duty of reasonable care to protect the health and safety of its employees can once again be harnessed to improve the lot of workers, without concocting Rube-Goldberg theories of liability against remote suppliers and premise owners. Juries will see the entire evidentiary case, including the actions and omissions of employers, which will tend to exculpate remote suppliers. Employers will be given incentives to train employees in workplace safety, and to document their efforts. Employers will assert comparative negligence and assumption of risk defenses, which will give the lie to the plaintiffs’ claims of inadequate warnings from the remote suppliers.  Tooey, and the prospect of employer liability, has the potential to improve the truth finding ability of juries in tort cases.

Folta v. Ferro Engineering, 2014 IL App (1st) 123219.

In June of last year, the Illinois intermediate appellate court followed the Pennsylvania Supreme Court’s lead in Tooey, and decided to allow a direct action against an employer when the employee’s claim was not within the scope of the Illinois workers’ compensation act. Folta v. Ferro Eng’g , 14 N.E.3d 717, 729 (Ill. App. Ct.), appeal allowed (Ill. S. Ct. Sept. 24, 2014). See Steven Sellers, “Workers’ Compensation System Threatened By Illinois Asbestos Decision, Companies Say,” 43 Product Safety & Liability Reporter (Jan. 8, 2015).

James Folta developed mesothelioma 41 years after leaving his employment with Ferro Engineering, a latency that put his claim outside the Illinois Workers’ Compensation Act and Workers’ Occupational Diseases Act. The panel of the intermediate appellate court held that the same latency that denied Mr. Folta coverage, also worked to deny the employer immunity from common law suit. Mr. Folta’s asbestos exposure occurred at his Ferro workplace, from 1966 to 1970, during which time raw asbestos and many finished asbestos product suppliers provided warnings about the dangers of asbestos inhalation.

The BNA reporter, Mr. Sellers, quoted Mark Behrens, of Shook, Hardy & Bacon, as stating that:

“This case is part of an emerging national attack on state workers’ compensation systems by the personal injury bar.”

Id. Perhaps true, but the systems have been under critical attack from the public health community, legal reformers, labor, and industry, for some time. No one seems very happy with the system except employers in the specific moment and circumstance of asserting their immunity in tort actions. The regime of worker compensation immunity for employers has failed to foster worker safety and health, and it has worked to shift liability unfairly to remote suppliers who are generally not in a position to redress communication lapses in the workplace.

The Illinois Supreme Court has allowed Ferro Engineering to appeal the Folta case. Not surprisingly, the American Insurance Association, the Property Casualty Insurers Association of America and the Travelers Indemnity Company have filed an amicus brief in support of Ferro. Various companies — Caterpillar, Inc., Aurora Pump Co., Innophos, Inc., Rockwell Automation, Inc., United States Steel Corp., F.H. Leinweber Co., Inc., Driv-Lok, Inc., Ford Motor Co., and ExxonMobil Oil Corp. — have also banded together to file an amicus brief in support of Ferro. Ironically, many of these companies would benefit from abandoning employer immunity in occupational disease litigation. Taking the short view, the defense amicus brief argues that the Illinois Appellate Court’s decision distorts the “delicate balancing of competing interests,” and will lead to a flood of asbestos litigation in Illinois. The defense amicus further argues that the intermediate appellate court’s decision is “the first step towards unraveling the quid pro quo embodied in the acts.”

The problem with the defense position is that there already a flood of asbestos litigation in Illinois and elsewhere, and the problem lies not in damming the flood, but ensuring its equitable resolution. Divining what a legislature intended is always a risky business, but it seems unlikely it had any clear understanding of diseases with latencies in excess of 25 years. And while the Ferro decision has the potential to unravel the defense’s understanding of employer immunity in long-latency occupational disease cases, the real issue is whether bringing the employer to the table in civil litigation over occupational diseases will result in more equitable allocation of responsibility for the harms alleged. Even a “wrong” decision by the Illinois Supreme Court will have the advantage of inciting the Illinois legislature to clarify what it meant, and perhaps to recalibrate tort law to acknowledge the primary role of employers in providing safe workplaces.

Posted in Learned and sophisticated intermediary, Sophisticated User | Comments Off on The Erosion of Employer Immunity in Tort Litigation

The Rhetoric of Playing Dumb on Statistical Significance – Further Comments on Oreskes

January 17th, 2015

As a matter of policy, I leave the comment field turned off on this blog. I don’t have the time or patience to moderate discussions, but that is not to say that I don’t value feedback. Many readers have written, with compliments, concurrences, criticisms, and corrections. Some correspondents have given me valuable suggestions and materials. I believe I can say that aside from a few scurrilous emails, the feedback generally has been constructive, and welcomed.

My last post was on Naomi Oreskes’ opinion piece in the Sunday New York Times[1]. Professor Deborah Mayo asked me for permission to re-post the substance of this post, and to link to the original[2]. Mayo’s blog does allow for comments, and much to my surprise, the posts drew a great deal of attention, links, comment, and twittering. The number and intensity of the comments, as well as the other blog posts and tweets, seemed out of proportion to the point I was trying to make about misinterpreting confidence intervals and other statistical concepts. I suspect that some climate skeptics received my criticisms of Oreskes with a degree of schadenfreude, and that some who criticized me did so because they fear any challenge to Oreskes as a climate-change advocate. So be it. As I made clear in my post, I was not seeking to engage Oreskes on climate change or her judgments on that issue. What I saw in Oreskes’ article was the same rhetorical move made in the courtroom, and in scientific publications, in which plaintiffs environmentalists attempt to claim a scientific imprimatur for their conclusions without adhering to the rigor required for scientific judgments[3].

Some of the comments about Professor Oreskes caused me to take a look at her recent book, Naomi Oreskes & Erik M. Conway, Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming (N.Y. 2010). Interestingly, much of the substance of Oreskes’ newspaper article comes directly from this book. In the context of reporting on the dispute over the EPA’s meta-analysis of studies on passive smoking and lung cancer, Oreskes addressed the 95 percent issue:

“There’s nothing magic about 95 percent. It could be 80 percent. It could be 51 percent. In Vegas if you play a game with 51 percent odds in your favor, you’ll still come out ahead if you play long enough. The 95 percent confidence level is a social convention, a value judgment. And the value it reflects is one that says that the worst mistake a scientist can make is to fool herself: to think an effect is real when it is not. Statisticians call this a type I error. You can think of it as being gullible, naive, or having undue faith in your own ideas.89 To avoid it, scientists place the burden of proof on the person claiming a cause and effect. But there’s another kind of error-type 2-where you miss effects that are really there. You can think of that as being excessively skeptical or overly cautious. Conventional statistics is set up to be skeptical and avoid type I errors. The 95 percent confidence standard means that there is only 1 chance in 20 that you believe something that isn’t true. That is a very high bar. It reflects a scientific worldview in which skepticism is a virtue, credulity is not.90 As one Web site puts it, ‘A type I error is often considered to be more serious, and therefore more important to avoid, than a type II error’.91 In fact, some statisticians claim that type 2 errors aren’t really errors at all,  just missed opportunities.92”

Id. at 156-57 (emphasis added). Oreskes’ statement of the confidence interval, from her book, advances more ambiguity by not specifying what the “something” you don’t believe to be true. Of course, if it is the assumed parameter, then she has made the same error as she did in the Times. Oreskes’ further discussion of the EPA environmental tobacco smoke meta-analysis issue makes her meaning clearer, and her interpretation of statistical significance, less defensible:

“Even if 90 percent is less stringent than 95 percent, it still means that there is a 9 in 10 chance that the observed results did not occur by chance. Think of it this way. If you were nine-tenths sure about a crossword puzzle answer, wouldn’t you write it in?94”

Id.  Throughout her discussion, Oreskes fails to acknowledge that the p-value assumes the correctness of the null hypothesis in order to assess the strength of the specific data as evidence against the null. As I have pointed out elsewhere, this misinterpretation of significance testing is a rhetorical strategy to evade significance testing, as well as to obscure the role of bias and confounding in accounting for data that differs from an expected value.

Oreskes also continues to maintain that a failure to reject the null is playing “dumb” and placing:

“the burden of proof on the victim, rather than, for example, the manufacturer of a harmful product-and we may fail to protect some people who are really getting hurt.”

Id. So again, the same petitio principii as we saw in the Times. Victimhood is exactly what remains to be established. Oreskes cannot assume it, and then criticize time-tested methods that fail to deliver a confirmatory judgment.

There are endnotes in her book, but the authors fail to cite any serious statistics text. The only reference of dubious relevance is another University of Michigan book, Stephen T. Ziliak & Deidre N. McCloskey, The Cult of Statistical Significance (2008). Enough said[4].

With a little digging, I learned that Oreskes and Conway are science fiction writers, and perhaps we should judge them by literary rather than scientific standards. See Naomi Oreskes & Erik M. Conway, “The Collapse of Western Civilization: A View from the Future,” 142 Dædalus 41 (2013). I do not imply any pejorative judgment of Oreskes for advancing her apocalyptic vision of the future of Earth’s environment as a work of fiction. Her literary work is a worthy thought experiment that has the potential to lead us to accept her precautionary judgments; and at least her publication, in Dædalus, is clearly labeled science fiction.

Oreskes’ future fantasy is, not surprisingly, exactly what Oreskes, the historian of science, now predicts in terms of catastrophic environmental change. Looking back from the future, the science fiction authors attempt to explore the historical origins of the catastrophe, only to discover that it is the fault of everyone who disagreed with Naomi Oreskes in the early 21st century. Heavy blame is laid at the feet of the ancestor scientists (Oreskes’ contemporaries) who insisted upon scientific and statistical standards for inferring conclusions from observational data. Implicit in the science fiction tale is the welcome acknowledgment that science should make accurate predictions.

In Oreskes’ science fiction, these scientists of yesteryear, today’s adversaries of climate-change advocates, were “almost childlike,” in their felt-need to adopt “strict” standards, and their adherence to severe tests derived from their ancestors’ religious asceticism. In other words, significance testing is a form of self-flagellation. Lest you think, I exaggerate, consider the actual words of Oreskes and Conway:

“In an almost childlike attempt to demarcate their practices from those of older explanatory traditions, scientists felt it necessary to prove to themselves and the world how strict they were in their intellectual standards. Thus, they placed the burden of proof on novel claims, including those about climate. Some scientists in the early twenty-first century, for example, had recognized that hurricanes were intensifying, but they backed down from this conclusion under pressure from their scientific colleagues. Much of the argument surrounded the concept of statistical significance. Given what we now know about the dominance of nonlinear systems and the distribution of stochastic processes, the then-dominant notion of a 95 percent confidence limit is hard to fathom. Yet overwhelming evidence suggests that twentieth-century scientists believed that a claim could be accepted only if, by the standards of Fisherian statistics, the possibility that an observed event could have happened by chance was less than 1 in 20. Many phenomena whose causal mechanisms were physically, chemically, or biologically linked to warmer temperatures were dismissed as “unproven” because they did not adhere to this standard of demonstration.

Historians have long argued about why this standard was accepted, given that it had no substantive mathematical basis. We have come to understand the 95 percent confidence limit as a social convention rooted in scientists’ desire to demonstrate their disciplinary severity. Just as religious orders of prior centuries had demonstrated moral rigor through extreme practices of asceticism in dress, lodging, behavior, and food–in essence, practices of physical self-denial–so, too, did natural scientists of the twentieth century attempt to demonstrate their intellectual rigor through intellectual self-denial.14 This practice led scientists to demand an excessively stringent standard for accepting claims of any kind, even those involving imminent threats.”

142 Dædalus at 44.

The science fiction piece in Dædalus has now morphed into a short book, which is billed within as a “haunting, provocative work of science-based fiction.” Naomi Oreskes & Erik M. Conway, The Collapse of Western Civilization: A View from the Future (N.Y. 2014). Under the cover of fiction, Oreskes and Conway provide their idiosyncratic, fictional definition of statistical significance, in a “Lexicon of Archaic Terms,” at the back of the book:

“statistical significance  The archaic concept that an observed phenomenon could only be accepted as true if the odds of it happening by chance were very small, typically taken to be no more than 1 in 20.”

Id. at 61-62. Of course, in writing fiction, you can make up anything you like. Caveat lector.

 

[1] See “Playing Dumb on Statistical Significance” (Jan. 4, 2015).

[2] See “Significance Levels are Made a Whipping Boy on Climate Change Evidence: Is .05 Too Strict? (Schachtman on Oreskes)” (Jan. 4, 2015).

[3] See “Rhetorical Strategy in Characterizing Scientific Burdens of Proof” (Nov. 15, 2014).

[4] See “The Will to Ummph” (Jan. 10, 2012).

Posted in Scientific Evidence, statistical evidence | Comments Off on The Rhetoric of Playing Dumb on Statistical Significance – Further Comments on Oreskes

Playing Dumb on Statistical Significance

January 4th, 2015

For the last decade, at least, researchers have written to document, explain, and correct, a high rate of false-positive research findings in biomedical research[1]. And yet, there are some authors who complain that the traditional standard of statistical significance is too stringent. The best explanation for this paradox appears to lie in these authors’ rhetorical strategy of protecting their “scientific conclusions,” based upon weak and uncertain research findings, from criticisms. The strategy includes mischaracterizing significance probability as a burden of proof, and then speciously claiming that the standard for significance in the significance probability is too high as a threshold for posterior probabilities of scientific claims. See “Rhetorical Strategy in Characterizing Scientific Burdens of Proof” (Nov. 15, 2014).

Naomi Oreskes is a professor of the history of science in Harvard University. Her writings on the history of geology are well respected; her writings on climate change tend to be more adversarial, rhetorical, and ad hominem. See, e.g., Naomi Oreskes, Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming (N.Y. 2010). Oreskes’ abuse of the meaning of significance probability for her own rhetorical ends is on display in today’s New York Times. Naomi Oreskes, “Playing Dumb on Climate Change,” N.Y. Times Sunday Rev. at 2 (Jan. 4, 2015).

Oreskes wants her readers to believe that those who are resisting her conclusions about climate change are hiding behind an unreasonably high burden of proof, which follows from the conventional standard of significance in significance probability. In presenting her argument, Oreskes consistently misrepresents the meaning of statistical significance and confidence intervals to be about the overall burden of proof for a scientific claim:

“Typically, scientists apply a 95 percent confidence limit, meaning that they will accept a causal claim only if they can show that the odds of the relationship’s occurring by chance are no more than one in 20. But it also means that if there’s more than even a scant 5 percent possibility that an event occurred by chance, scientists will reject the causal claim. It’s like not gambling in Las Vegas even though you had a nearly 95 percent chance of winning.”

Although the confidence interval is related to the pre-specified Type I error rate, alpha, and so a conventional alpha of 5% does lead to a coefficient of confidence of 95%, Oreskes has misstated the confidence interval to be a burden of proof consisting of a 95% posterior probability. The “relationship” is either true or not; the p-value or confidence interval provides a probability for the sample statistic, or one more extreme, on the assumption that the null hypothesis is correct. The 95% probability of confidence intervals derives from the long-term frequency that 95% of all confidence intervals, based upon samples of the same size, will contain the true parameter of interest.

Oreskes is an historian, but her history of statistical significance appears equally ill considered. Here is how she describes the “severe” standard of the 95% confidence interval:

“Where does this severe standard come from? The 95 percent confidence level is generally credited to the British statistician R. A. Fisher, who was interested in the problem of how to be sure an observed effect of an experiment was not just the result of chance. While there have been enormous arguments among statisticians about what a 95 percent confidence level really means, working scientists routinely use it.”

First, Oreskes, the historian, gets the history wrong. The confidence interval is due to Jerzy Neyman, not to Sir Ronald A. Fisher. Jerzy Neyman, “Outline of a theory of statistical estimation based on the classical theory of probability,” 236 Philos. Trans. Royal Soc’y Lond. Ser. A 333 (1937). Second, although statisticians have debated the meaning of the confidence interval, they have not wandered from its essential use as an estimation of the parameter (based upon the use of an unbiased, consistent sample statistic) and a measure of random error (not systematic error) about the sample statistic. Oreskes provides a fallacious history, with a false and misleading statistics tutorial.

Oreskes, however, goes on to misidentify the 95% coefficient of confidence with the legal standard known as “beyond a reasonable doubt”:

“But the 95 percent level has no actual basis in nature. It is a convention, a value judgment. The value it reflects is one that says that the worst mistake a scientist can make is to think an effect is real when it is not. This is the familiar “Type 1 error.” You can think of it as being gullible, fooling yourself, or having undue faith in your own ideas. To avoid it, scientists place the burden of proof on the person making an affirmative claim. But this means that science is prone to ‘Type 2 errors’: being too conservative and missing causes and effects that are really there.

Is a Type 1 error worse than a Type 2? It depends on your point of view, and on the risks inherent in getting the answer wrong. The fear of the Type 1 error asks us to play dumb; in effect, to start from scratch and act as if we know nothing. That makes sense when we really don’t know what’s going on, as in the early stages of a scientific investigation. It also makes sense in a court of law, where we presume innocence to protect ourselves from government tyranny and overzealous prosecutors — but there are no doubt prosecutors who would argue for a lower standard to protect society from crime.

When applied to evaluating environmental hazards, the fear of gullibility can lead us to understate threats. It places the burden of proof on the victim rather than, for example, on the manufacturer of a harmful product. The consequence is that we may fail to protect people who are really getting hurt.”

The truth of climate change opinions do not turn on sampling error, but rather on the desire to draw an inference from messy, incomplete, non-random, and inaccurate measurements, fed into models of uncertain validity. Oreskes suggests that significance probability is keeping us from acknowledging a scientific fact, but the climate change data sets are amply large to rule out sampling error if that were a problem. And Oreskes’ suggestion that somehow statistical significance is placing a burden upon the “victim,” is simply assuming what she hopes to prove; namely, that there is a victim (and a perpetrator).

Oreskes’ solution seems to have a Bayesian ring to it. She urges that we should start with our a priori beliefs, intuitions, and pre-existing studies, and allow them to lower our threshold for significance probability:

“And what if we aren’t dumb? What if we have evidence to support a cause-and-effect relationship? Let’s say you know how a particular chemical is harmful; for example, that it has been shown to interfere with cell function in laboratory mice. Then it might be reasonable to accept a lower statistical threshold when examining effects in people, because you already have reason to believe that the observed effect is not just chance.

This is what the United States government argued in the case of secondhand smoke. Since bystanders inhaled the same chemicals as smokers, and those chemicals were known to be carcinogenic, it stood to reason that secondhand smoke would be carcinogenic, too. That is why the Environmental Protection Agency accepted a (slightly) lower burden of proof: 90 percent instead of 95 percent.”

Oreskes’ rhetoric misstates key aspects of scientific method. The demonstration of causality in mice, or only some perturbation of cell function in non-human animals, does not warrant lowering our standard for studies in human beings. Mice and rats are, for many purposes, poor predictors of human health effects. All medications developed for human use are tested in animals first, for safety and efficacy. A large majority of such medications, efficacious in rodents, fail to satisfy the conventional standards of significance probability in randomized clinical trials. And that standard is not lowered because the drug sponsor had previously demonstrated efficacy in mice, or some other furry rodent.

The EPA meta-analysis of passive smoking and lung cancer is a good example of how not to conduct science. The protocol for the EPA meta-analysis called for a 95% confidence interval, but the agency scientists manipulated their results by altering the pre-specified coefficient confidence in their final report. Perhaps even more disgraceful was the selectivity of included studies for the meta-analysis, which biased the agency’s result in a way not reflected in p-values or confidence intervals. See “EPA Cherry Picking (WOE) – EPA 1992 Meta-Analysis of ETA & Lung Cancer – Part 1” (Dec. 2, 2012); “EPA Post Hoc Statistical Tests – One Tail vs Two” (Dec. 2, 2012).

Of course, the scientists preparing for and conducting a meta-analysis on environmental tobacco smoke began with a well-justified belief that active smoking causes lung cancer. Passive smoking, however, involves very different exposure levels and raises serious issues of the human body’s defensive mechanisms to protect against low-level exposure. Insisting on a reasonable quality meta-analysis for passive smoking and lung cancer was not a matter of “playing dumb”; it was a recognition of our actual ignorance and uncertainty about the claim being made for low-exposure effects. The shifty confidence intervals and slippery methodology exemplifies how agency scientists assume their probandum to be true, and then manipulate or adjust their methods to provide the result they had assumed all along.

Oreskes then analogizes not playing dumb on environmental tobacco smoke to not playing dumb on climate change:

“In the case of climate change, we are not dumb at all. We know that carbon dioxide is a greenhouse gas, we know that its concentration in the atmosphere has increased by about 40 percent since the industrial revolution, and we know the mechanism by which it warms the planet.

WHY don’t scientists pick the standard that is appropriate to the case at hand, instead of adhering to an absolutist one? The answer can be found in a surprising place: the history of science in relation to religion. The 95 percent confidence limit reflects a long tradition in the history of science that valorizes skepticism as an antidote to religious faith.”

I will leave substance of the climate change issue to others, but Oreskes’ methodological misidentification of the 95% coefficient of confidence with burden of proof is wrong. Regardless of motive, the error obscures the real debate, which is about data quality. More disturbing is that Oreskes’ error confuses significance and posterior probabilities, and distorts the meaning of burden of proof. To be sure, the article by Oreskes is labeled opinion, and Oreskes is entitled to her opinions about climate change and whatever.  To the extent that her opinions, however, are based upon obvious factual errors about statistical methodology, they are entitled to no weight at all.

 

[1] See, e.g., John P. A. Ioannidis, “How to Make More Published Research True,” 11 PLoS Medicine e1001747 (2014); John P. A. Ioannidis, “Why Most Published Research Findings Are False” 2 PLoS Medicine e124 (2005); John P. A. Ioannidis, Anna-Bettina Haidich, and Joseph Lau, “Any casualties in the clash of randomised and observational evidence?” 322 Brit. Med. J. 879 (2001).

 

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More Antic Proposals for Expert Witness Testimony – Including My Own Antic Proposals

December 30th, 2014

The late Professor Margaret Berger epitomized a person you could like and even admire, while finding many of her ideas erroneous, incoherent, and even dangerous. Berger was frequently on the losing side of expert witness admissibility issues, and she fell under the influence of the plaintiffs’ bar, holding conferences with their walking-around money, laundered through SKAPP, The Project on Scientific Knowledge and Public Policy.[1] In appellate cases, Berger often lent the credibility of her scholarship to support plaintiffs’ efforts to strip away admissibility criteria for expert witness causation opinion.[2] Still, she was always polite and respectful in debate. When Judge Weinstein appointed her to chair a committee to search for appropriate court-appointed expert witnesses in the silicone gel breast implant litigation, Professor Berger proved a careful, impartial listener to all the parties involved.

In 2009, before the publication of the Third Edition of the Reference Manual on Scientific Evidence, Professor Berger gave a presentation for an American Law Institute continuing legal education program, in which she aired her antipathy toward gatekeeping.[3] With her sights set primarily on defense expert witnesses, Berger opined that a monetary relationship between an expert witness and the defendant could be grounds for a Rule 702 exclusion. While the jingle of coin doth soothe the hurt that conscience must feel (for some expert witnesses), the focus of the Rule 702 inquiry is properly on relevance, reliability, and validity. Judge Shira Scheindlin, who sat on the same panel as Professor Berger, diplomatically pointed out that employee expert witnesses are offered all the time, and any bias is a subject for cross-examination, not disqualification. Remarkably, neither Professor Berger nor Judge Scheindlin acknowledged that conflicts of interest, actual or potential, are not relevant to the Daubert or Rule 702 factors that guide admissibility. If Berger’s radical position of identifying conflict of interest with unreliability were correct, we might dismiss her views without any consideration[4], given her conflicts of interest from her association with SKAPP, and her several amicus briefs filed on behalf of plaintiffs, seeking to avoid the exacting requirements of expert witness evidence gatekeeping.

In her ALI-CLE lecture, Professor Berger waxed enthusiastically about what was then a recent federal trial court decision in Allen v. Martin Surfacing, 263 F.R.D. 47 (D. Mass. 2009). Berger asserted that the case was unpublished and that the case, like many other “Daubert” cases was hidden from view. Berger thought that Allen’s obscurity was unfortunate because the decision was “fabulous” and was based upon astute opinions of “outstanding” experts[5]. Berger was wrong on every point, from the chemical involved, to the unavailability of the opinion, to the quality of the expert witnesses (who were not ALS experts, but frequent, willing testifiers), and to the carefulness of the exposure and causation opinions offered.[6] See James L. Bernat & Richard Beresford, Ethical and Legal Issues in Neurology 59-60 (Amsterdam 2013) (discussing Allen and characterizing the court’s decision to admit plaintiffs’ expert witnesses’ opinions as based upon plausibility without more).

Implicit in Berger’s errors, however, may be the beginnings of some concrete suggestions for improving the gatekeeping process. After all, Berger thought that no one would likely find and read the Allen decision.  She may have thus believed that she had some freedom from scrutiny when she praised the decision and the expert witnesses involved. Just as there is a groundswell of support for greater disclosure of underlying data to accompany scientific publications, there should be support for wide dissemination of the underlying materials behind Rule 702 opinions. Most judges cannot or will not write sufficiently comprehensive opinions describing and supporting their decisions to admit or exclude expert witness opinion to permit vigorous public scrutiny. Some judges fail to cite to the underlying studies or data that are the bases of the challenged opinions. As a result, the “Daubert” scholarship suffers because it frequently lacks access to the actual reports, testimony, studies, and data themselves. Often the methodological flaws discussed in judicial opinions are just the tip of the iceberg, with flaws running all the way to the bottom.

And while I am on “antic proposals” of my own, courts should consider requiring all parties to file proposed findings of fact and conclusions of law, with record cites, to support their litigation positions. Lawyers on both sides of the “v.” have proven themselves cavalier and careless in their descriptions and characterizations of scientific evidence, inference, and analysis. Proposed findings would permit reviewing courts, scientists, and scholars to identify errors for the benefit of appellate courts and later trial courts.

 

[1] SKAPP claimed to have aimed at promoting transparent decision making, but deceived the public with its disclosure of having been supported by the “Common Benefit Trust, a fund established pursuant to a court order in the Silicone Gel Breast Implant Products Liability litigation.” Somehow SKAPP forgot to disclose that this court order simply created a common-benefit fund for plaintiffs’ lawyers to pursue their litigation goals. How money from the silicone gel breast implant MDL was diverted for advocated anti-Daubert policies is a mystery that no amount of transparent decision making has to date uncovered. Fortunately, for the commonweal, SKAPP appears to have been dissolved. The SKAPP website lists those who guided and supported SKAPP’s attempts to subvert expert witness validity requirements; not surprisingly, the SKAPP supporters were mostly plaintiffs’ expert witnesses:

Eula Bingham, PhD
Les Boden, PhD
Richard Clapp, DSc, MPH
Polly Hoppin, ScD
Sheldon Krimsky, PhD
David Michaels, PhD, MPH
David Ozonoff, MD, MPH
Anthony Robbins, MD, MPA

[2] See, e.g., Parker v. Mobil Oil Corp., N.Y. Ct. App., Brief Amicus Curiae of Profs. Margaret A. Berger, Edward J. Imwinkelried, Sheila Jasanoff, and Stephen A. Saltzburg (July 28, 2006) (represented by Anthony Z. Roisman, of the National Legal Scholars Law Firm).

[3] Berger, “Evidence, Procedure, and Trial Update: How You Can Win (Or Lose) Your Case (Expert Witnesses, Sanctions, Spoliation, Daubert, and More)” (Mar. 27, 2009).

Berger, “Evidence, Procedure, and Trial Update: How You Can Win (Or Lose) Your Case (Expert Witnesses, Sanctions, Spoliation, Daubert, and More)” (Mar. 27, 2009).

[4] We can see this position carried to its natural, probable, and extreme endpoint in Elizabeth Laposata, Richard Barnes, and Stanton Glantz, “Tobacco Industry Influence on the American Law Institute’s Restatements of Torts and Implications for Its Conflict of Interest Policies,” 98 Iowa Law Rev. 1 (2012), where the sanctimonious authors, all anti-tobacco advocates criticize the American Law Institute for permitting the participation of lawyers who represent tobacco industry. The authors fail to recognize that ALI members include lawyers representing plaintiffs in tobacco litigation, and that it is possible, contrary to their ideological worldview, to discuss and debate an issue without reference to ad hominem “conflicts” issues. The authors might be surprised by the degree to which the plaintiffs’ bar has lobbied (successfully) for many provisions in various Restatements.

[5] Including Richard Clapp, who served as an advisor to SKAPP, which lavished money on Professor Berger’s conferences.

[6] See “Bad Gatekeeping or Missed Opportunity – Allen v. Martin Surfacing” (Nov. 30, 2012); “Gatekeeping in Allen v. Martin Surfacing — Postscript” (April 11, 2013).

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New Standard for Scientific Evidence – The Mob

December 27th, 2014

A few years ago, a law student published a Note that argued for the dismantling of judicial gatekeeping.  Note, “Admitting Doubt: A New Standards for Scientific Evidence,” 123 Harvard Law Review 2021 (2010).  The anonymous Harvard law student asserted that juries are at least as good, if not better, at handling technical questions than are “gatekeeping” federal trial judges. The empirical evidence for such a suggestion is slim, and ignores the geographic variability in jury pools.

To be sure, some jurors have much greater scientific and mathematical aptitude than some judges, but the law student’s run at Rule 702 ignores some important institutional differences between judges and juries, including that judicial errors are subject to scrutiny and review, and public comment based upon written judicial opinions. Most judges have 20 years of schooling and 10 years of job experience, which should account for some superiority.

Misplaced Sovereignty

Another student this year has published a much more sophisticated version of the Harvard student’s Note, an antic proposal with a similar policy agenda that would overthrow the regime of judicial scrutiny and gatekeeping of expert witness opinion testimony. Krista M. Pikus, “We the People: Juries, Not Judges, Should be the Gatekeepers of Expert Evidence,” 90 Notre Dame L. Rev. 453 (2014). This more recent publication, while conceding that judges may be no better than juries at evaluating scientific evidence, asserts that jury involvement is required by a political commitment to popular sovereignty. Ms. Pikus begins with the simplistic notion that:

“[o]ur system of government is based on the idea that the people are sovereign.”

Id. at 470. Since juries are made up of people, jury determinations are required to implement popular sovereignty.

This notion of sovereignty is really quite foreign to our Constitution and our system of government. “We, the People” generally do not make laws or apply them, with the exception of grand and petit jury factual determinations. The vast legislative and decision making processes are entrusted to Congress, the Executive, and the ever-expanding system of administrative agencies. The Constitution was indeed motivated to prevent governmental tyranny, but mob rule was not an acceptable alternative. For the founders, juries were a bulwark of liberty, and a shield against an overbearing Crown. Jurors were white men who owned property.

Pikus argues that judges somehow lack the political authority to serve as fact finders because they are not elected, but in some states judges are elected, and in other states and in the federal system, judges are appointed and confirmed by elected officials. Juries are, of course, not elected, and with many jurisdictions permitting juries of six persons or fewer, juries are hardly representative of the “popular sovereign.” The systematic exclusion of intelligent and well-educated jurors by plaintiffs’ counsel, along with the aversion to jury service by self-employed and busy citizens, helps ensure that juries fail to represent a fair cross-section of the population. Curiously, Pikus asserts that the “right to a trial by one’s peers is an integral part of our legal system,” but the peerage concept is nowhere in the Constitution. If it were, defendants in complicated tort cases might well have a right to juries composed of scientists or engineers.

The Right to Trial by Jury

There is, of course, a federal constitutional right to trial by jury, guaranteed by the Seventh Amendment:

“In Suits at common law … the right of trial by jury shall be preserved, and no fact tried by a jury shall be otherwise reexamined in any Court of the United States, than according to the rules of the common law.”

A strict textualist might hold that federal courts could dispense with juries in cases brought under statutory tort legislation, such as the New Jersey Products Liability Act, or for claims or defenses that were not available at the time the Seventh Amendment was enacted. Even the textualist might hold that the change in complexity of fact-finding endeavors, over two centuries, might mean that both the language and the spirit of the Seventh Amendment point away from maintaining the jury in cases of sufficient complexity.

Judges versus Juries

The fact is that judges and juries can, and do, act tyrannically, in deciding factual issues, including scientific and technical issues. Ms. Pikus would push the entire responsibility for ensuring accuracy in scientific fact finding to the least reviewable entity, the petit jury. Juries can ignore facts, decide emotively or irrationally, without fear of personal scrutiny or criticism. Pikus worries that judges “insert their policy opinions into their decisions,” which they have been known to do, but she fails to explain why we should tolerate the same from unelected, unreviewable juries. Id. at 472.

Inconsistently, Pikus acknowledges that “many can agree that some cases might be better suited for a judge instead of a jury,” such as “patent, bankruptcy, or tax” cases that “typically require additional expertise.” Id. at 471 & n. 185. To this list, we could add family law, probate, and equity matters, but the real question is what is it about a tax case that makes it more intractable to a jury than a products case. State power is much more likely to be abused or at issue in a tax case than in a modern products liability case, with a greater need for a “bulwark of liberty”. And the products liability case is much more likely to require scientific and technical expertise than a tax case.

The law of evidence, in federal and in most state courts, permits expert witnesses to present conclusory opinions, without having to account for the methodological correctness of their relied-upon studies, data, and analyses. Jurors, who are poorly paid, and pulled away from their occupations and professions, do not have the aptitude, patience, time, or interest to explore the full range of inferences and analyses performed by expert witnesses. Without some form of gatekeeping, trial outcomes are reduced to juror assessment of weak, inaccurate proxies for scientific determinations.

Pikus claims that juries, and only juries, should assess the reliability of an expert witness’s testimony. Id. at 455. As incompetent as some judges may be in adjudicating scientific issues, their errors are on display for all to see, whereas the jury’s determinations are opaque and devoid of public explanation. Judges can be singled out for technical competency, with appropriate case assignments, and they can be required to participate in professional legal education, including training in statistics, epidemiology, toxicology, genetics, and other subjects. It is difficult to imagine a world in which the jurors are sent home with the Reference Manual on Scientific Evidence, before being allowed to sit on a case. Nor is it feasible to have lay jurors serve on an extended trial that includes a close assessment of the expert witnesses’ opinions, as well as all the facts and data underlying those opinions.

Pikus criticizes the so-called “Daubert” regime as a manifestation of judicial activism, but she ignores that Daubert has been subsumed into an Act of Congress, in the form of a revised and expanded Federal Rules of Evidence.

In the end, this Note, like so much of the anti-Daubert law review literature is a complaint against removing popular, political, and emotive fact finding from technical and scientific issues in litigation. To the critics, science has no criteria of validity which the law is bound to respect. And yet, as John Adams argued before the Revolution:

“Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence[1].”

Due process requires more than the enemies of Daubert would allow.

[1] John Adams, “Argument in Defense of the Soldiers in the Boston Massacre Trials” (Dec. 1770)

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When is a Treating Physician Not a Treating Physician?

December 25th, 2014

When the so-called treating physician is handpicked by an attorney to advance his client’s lawsuit. See Daniel E. Cummins, “Did Your Attorney Refer You to that Doctor?” (Dec. 17, 2014).

Treating physicians are a powerful weapon in health-effects litigation because they can deliver what appears to opinions untainted by “litigation bias.” Jurors and judges, challenged by difficult medical causation issues, find the caring attitude of treating physicians as a powerful proxy for the truth, which alleviates the need to think critically and carefully about epidemiology, statistics, toxicology, and the like. Of course, some treating physicians are biased by their care and treatment of the patient, especially when their treatment did not go so well. Physicians who were not able to cure or ameliorate their patients’ conditions may welcome the opportunity to advocate for their patients to give them, or their survivors, to make up for their failure to help through the healing arts. Patient-advocacy bias, however, is more difficult to appreciate than hired-expert witness bias.

Plaintiffs’ counsel often base their litigation strategy upon using treating physicians on causation or damages issues to take advantage of jurors’ and judges’ perceptions of treating physicians as motivated by beneficence rather than lucre[1]. Of course, there are dangers in these tactics. For one thing, the treating physicians, as in Tamraz v. Lincoln Elec. Co., may not really be up to the task of delivering a causation opinion, and the plaintiffs’ counsel’s cynical tactic will make a weaker case weaker still in the eyes of the jury. And then the treating physician may not subscribe fully to the plaintiffs’ lawyer’s litigation goals and theories[2]. See “Politics of Expert Witnesses – The Treating Physician” (June 7, 2012).

Plaintiffs’ counsel may attempt to avoid the weaknesses of their treating physician strategy by selecting a carefully screened physician, ready to endorse plaintiffs’ litigation theories, and then to refer the claimant to this physician under cover of an asserted attorney-client privilege. A recent trial court in Pennsylvania, however, dealt a serious blow to this covert strategy by holding that the lawyer’s directing of his client’s medical care is not within the scope of the attorney-client relationship, and thus not a privileged communication. English v. Stepchin, No. CP-23-CV-786-2014, 101 Del. 424 (C.P. Del. Cty. Nov. 12, 2014 Kenney, P.J.). In English, plaintiff’s counsel asserted the privilege and objected to defense counsel’s deposition question whether plaintiff’s counsel had referred plaintiff to her treating physician.

On motion to compel discovery, Delaware County President Judge Chad F. Kenney overruled the objection, and held that “whether counsel referred Plaintiff to her treating physicians does not constitute legal assistance so as to justify properly invoking the attorney-client privilege.” As Judge Kenney explained:

“Clearly, whether counsel referred Plaintiff to her treating physicians is not a communication involved in either rendering a legal opinion or securing legal services. Furthermore, we conclude that the communication of such information does not constitute assistance in a legal matter so as to properly invoke the attorney-client privilege.

* * *

The disclosure of such information is not of a nature as would discourage trust or candid communication between a lawyer and a client and we are of the opinion that it does not outweigh the interest in the accessibility of material evidence to further the truth determining process.”

Id. at 425. The assertion of the attorney-client privilege was thus rejected, and the plaintiff was required to provide details as to how she came to go to her so-called treating physician.

The English decision represents a symmetrical paring of the attorney-client privilege to match the limitations imposed by other recent decisions on defense counsel. See, e.g., In re Vioxx Prods. Liab. Litig., 501 F. Supp. 2d 789, 800, 802 (E.D.La. 2007)(“We could not see the legal significance of these comments…” by in-house counsel on “scientific reports, articles accepted for publication in noted journals, and research proposals”); Weitz & Luxenberg P.C. v. Georgia-Pacific LLC, 2013 WL 2435565, 2013 NY Slip Op 04127 (June 6, 2013).

[1] See, e.g., Simmons v. Novartis Pharm. Corp., 2012 WL 2016246, *2, *7 (6th Cir. 2012) (affirming exclusion of retained expert witness, as well as a treating physician who relied solely upon a limited selection of medical studies given to him by plaintiffs’ counsel); Tamraz v. BOC Group Inc., No. 1:04-CV-18948, 2008 WL 2796726 (N.D.Ohio July 18, 2008)(denying Rule 702 challenge to treating physician’s causation opinion), rev’d sub nom. Tamraz v. Lincoln Elec. Co., 620 F.3d 665 (6th Cir. 2010) (carefully reviewing record of trial testimony of plaintiffs’ treating physician; reversing judgment for plaintiff based in substantial part upon treating physician’s speculative causal assessment created by plaintiffs’ counsel), cert. denied, 131 S. Ct. 2454 (2011).  See generally Robert Ambrogi, “A ‘Masterly’ Opinion on Expert Testimony,” Bullseye: October 2010; David Walk, “A masterly Daubert opinion” (Sept. 15, 2010);  Ellen Melville, “Comment, Gating the Gatekeeper: Tamraz v. Lincoln Electric Co. and the Expansion of Daubert Reviewing Authority,” 53 B.C. L. Rev. 195 (2012) (student review that mistakenly equates current Rule 702 law with the Supreme Court’s 1993 Daubert decision, while ignoring subsequent precedent and revision of Rule 702).

[2] In the welding fume litigation, inspired by the money and tactics of ex-convict Richard Scruggs, plaintiffs’ counsel adopted a dual strategy of co-opting a local treating physician, and alternatively, having their ready, willing, and able retained expert witness, Dr. Paul Nausieda, claim that he had created a physician-patient relationship with the claimant.

 

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First Amendment Rights of the Litigation Industry

December 21st, 2014

When a Wall Street Journal opinion piece stated that “the plaintiffs bar is all but running the Senate[1],” Frederick Martin (“Fred”) Baron, former president of the litigation industry’s Association of Trial Lawyers of America (ATLA), reportedly quipped that “I really, strongly disagree with that. Particularly the ‘all but’.” Baron, affectionately known as “Robber Baron” for his aggressive advocacy for uninjured asbestos claimants and questionable deposition coaching tactics, was the ultimate Democratic party insider. He was the finance chair of John Edwards’ ill-fated presidential campaign, and the sugar daddy for Rielle Hunter, the mother of Edwards’ out-of-wedlock child. You cannot get more “inside” than that.

Robber Baron died in 2008, but his legacy is a reminder of the hypocrisy of those who decry the Citizens United[2] opinion, which held that corporations and unions have first amendment rights to speak in ways that might influence the outcomes of elections. While many fuss over “corporate” speech, the litigation industry has operated largely without constraint. Last year, for example, plaintiffs’ counsel, Edward F. Blizzard, and representatives of the litigation industry’s ATLA, now operating under the self-serving name, American Association for Justice (AAJ), met with Food and Drug Administration officials to influence agency policy on generic medication warnings. This week, the Times featured front-page coverage of how the litigation industry has co-opted the policies and agendas of the States’ attorneys general, and directed their targeting of corporations. See Eric Lipton, “Lawyers Create Big Paydays by Coaxing Attorneys General to Sue,” New York Times (Dec. 18, 2014).

The litigation industry makes its presence felt in many ways, sometimes as an omnipresent threat that influences business and professional judgments. President Obama criticized Sony’s decision to pull down The Interview, as an undue concession to terrorists. See “Sony’s Decision to Pull Movie Is a ‘Mistake,’ Obama Says.” Obama went so far as to express his wish that “they’d spoken to me first.” But would Obama, or anyone, have been able to control the litigation industry’s second-guessing of Sony’s or any individual theater owner’s decision to show the movie?

Lipton’s article is a vivid reminder that the plaintiffs’ trial bar remains the largest rent-seeking lobby in the United States.

[1] John Fund, “Have You Registered to Sue?” Wall Street Journal (Nov. 6, 2002).

[2] Citizens United v. Federal Election Comm’n, 558 U.S. 310 (2010).

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Showing Causation in the Absence of Controlled Studies

December 17th, 2014

The Federal Judicial Center’s Reference Manual on Scientific Evidence has avoided any clear, consistent guidance on the issue of case reports. The Second Edition waffled:

“Case reports lack controls and thus do not provide as much information as controlled epidemiological studies do. However, case reports are often all that is available on a particular subject because they usually do not require substantial, if any, funding to accomplish, and human exposure may be rare and difficult to study. Causal attribution based on case studies must be regarded with caution. However, such studies may be carefully considered in light of other information available, including toxicological data.”

F.J.C. Reference Manual on Scientific Evidence at 474-75 (2d ed. 2000). Note the complete lack of discussion of base-line risk, prevalence of exposure, and external validity of the “toxicological data.”

The second edition’s more analytically acute and rigorous chapter on statistics generally acknowledged the unreliability of anecdotal evidence of causation. See David Kaye & David Freedman, “Reference Guide on Statistics,” in F.J.C. Reference Manual on Scientific Evidence 91 – 92 (2d ed. 2000).

The Third Edition of the Reference Manual is even less coherent. Professor Berger’s introductory chapter[1] begrudgingly acknowledges, without approval, that:

“[s]ome courts have explicitly stated that certain types of evidence proffered to prove causation have no probative value and therefore cannot be reliable.59”

The chapter on statistical evidence, which had been relatively clear in the second edition, now states that controlled studies may be better but case reports can be helpful:

“When causation is the issue, anecdotal evidence can be brought to bear. So can observational studies or controlled experiments. Anecdotal reports may be of value, but they are ordinarily more helpful in generating lines of inquiry than in proving causation.14”

Reference Manual at 217 (3d ed. 2011). The “generally” is given no context or contour for readers. These authors fail to provide any guidance on what will come from anecdotal evidence, or when and why anecdotal reports may do more than merely generating “lines of inquiry.”

In Matrixx Initiatives Inc. v. Siracusano, 131 S. Ct. 1309 (2011), the Supreme Court went out of its way, way out of its way, to suggest that statistical significance was not always necessary to support conclusions of causation in medicine. Id. at 1319. The Court cited three Circuit court decisions to support its suggestion, but two of three involved specific causation inferences from so-called differential etiologies. General causation was assumed in those two cases, and not at issue[2]. The third case, the notorious Wells v. Ortho Pharmaceutical Corp., 788 F. 2d 741, 744–745 (11th Cir. 1986), was also cited in support of the suggestion that statistical significance was not necessary, but in Wells, the plaintiffs’ expert witnesses actually relied upon studies that claimed at least nominal statistical significance. Wells was and remains representative of what is possible and results when trial judges ignore the constraints of study validity. The Supreme Court, in any event, abjured any intent to specify “whether the expert testimony was properly admitted in those cases [Wells and others],” and the Court made no “attempt to define here what constitutes reliable evidence of causation.” 131 S. Ct. at 1319.

The causal claim in Siracusano involved anosmia, loss of the sense of smell, from the use of Zicam, zinc gluconate. The case arose from a motion to dismiss the complaint; no evidence was ever presented or admitted. No baseline risk of anosmia was pleaded; nor did plaintiffs allege that any controlled study demonstrated an increased risk of anosmia from nasal instillation of zinc gluconate. There were, however, clinical trials conducted in the 1930s, with zinc sulfate for poliomyelitis prophylaxis, which showed a substantial incidence of anosmia in the treated children[3]. Matrixx tried to argue that this evidence was unreliable, in part because it involved a different compound, but this argument (1) in turn demonstrated a factual issue that required discovery and perhaps a trial, and (2) traded on a clear error in asserting that the zinc in zinc sulfate and zinc gluconate were different, when in fact they are both ionic compounds that result in zinc ion exposure, as the active constituent.

The position stridently staked out in Matrixx Initiatives is not uncommon among defense counsel in tort cases. Certainly, similar, unqualified statements, rejecting the use of case reports for supporting causal conclusions, can be found in the medical literature[4].

When the disease outcome has an expected value, a baseline rate, in the exposed population, then case reports simply confirm what we already know: cases of the disease happen in people regardless of their exposure status. For this reason, medical societies, such as the Teratology Society, have issued guidances that generally downplay or dismiss the role that case reports may have in the assessment and determination of causality for birth defects:

“5. A single case report by itself is not evidence of a causal relationship between an exposure and an outcome.  Combinations of both exposures and adverse developmental outcomes frequently occur by chance. Common exposures and developmental abnormalities often occur together when there is no causal link at all. Multiple case reports may be appropriate as evidence of causation if the exposures and outcomes are both well-defined and low in incidence in the general population. The use of multiple case reports as evidence of causation is analogous to the use of historical population controls: the co-occurrence of thalidomide ingestion in pregnancy and phocomelia in the offspring was evidence of causation because both thalidomide use and phocomelia were highly unusual in the population prior to the period of interest. Given how common exposures may be, and how common adverse pregnancy outcome is, reliance on multiple case reports as the sole evidence for causation is unsatisfactory.”

The Public Affairs Committee of the Teratology Society, “Teratology Society Public Affairs Committee Position Paper Causation in Teratology-Related Litigation,” 73 Birth Defects Research (Part A) 421, 423 (2005).

When the base rate for the outcome is near zero, and other circumstantial evidence is present, some commentators insist that causality may be inferred from well-documented case reports:

“However, we propose that some adverse drug reactions are so convincing, even without traditional chronological causal criteria such as challenge tests, that a well documented anecdotal report can provide convincing evidence of a causal association and further verification is not needed.”

Jeffrey K. Aronson & Manfred Hauben, “Drug safety: Anecdotes that provide definitive evidence,” 333 Brit. Med. J. 1267, 1267 (2006) (Dr. Hauben was medical director of risk management strategy for Pfizer, in New York, at the time of publication). But which ones are convincing, and why?

        *        *        *        *        *        *        *        *        *

Dr. David Schwartz, in a recent blog post, picked up on some of my discussion of the gadolinium case reports (see here and there), and posited the ultimate question: when are case reports sufficient to show causation? David Schwartz, “8 Examples of Causal Inference Without Data from Controlled Studies” (Dec. 14, 2014).

Dr. Schwartz discusses several causal claims, all of which gave rise to litigation at some point, in which case reports or case series played an important, if not dispositive, role:

  1.      Gadolinium-based contrast agents and NSF
  2.      Amphibole asbestos and malignant mesothelioma
  3.      Ionizing radiation and multiple cancers
  4.      Thalidomide and teratogenicity
  5.      Rezulin and acute liver failure
  6.      DES and clear cell vaginal adenocarcinoma
  7.      Vinyl chloride and angiosarcoma
  8.      Manganese exposure and manganism

Dr. Schwartz’s discussion is well worth reading in its entirety, but I wanted to emphasize some of Dr. Schwartz’s caveats. Most of the exposures are rare, as are the outcomes. In some cases, the outcomes occur almost exclusively with the identified exposures. All eight examples pose some danger of misinterpretation. Gadolinium-based contrast agents appear to create a risk of NSF only in the presence of chronic renal failure. Amphibole asbestos, and most importantly, crocidolite causes malignant mesothelioma after a very lengthy latency period. Ionizing radiation causes some cancers that are all-too common, but the presence of multiple cancers in the same person, after a suitable latency period, is distinctly uncommon, as is the level of radiation needed to overwhelm bodily defenses and induce cancers. Thalidomide was associated by case reports fairly quickly with phocomelia, which has an extremely low baseline risk. Other birth defects were not convincingly demonstrated by the case series. Rezulin, an oral antidiabetic medication, was undoubtedly causally responsible for rare cases of acute liver failure. Chronic liver disease, however, which is common among type 2 diabetic patients, required epidemiologic evidence, which never materialized[5].

Manganism, by definition, is the cause of manganism, but extremely high levels of manganese exposure, and specific speciation of the manganese, are essential to the causal connection. Manganism raises another issue often seen in so-called signature diseases: diagnostic accuracy. Unless the diagnostic criteria have perfect (100%) specificity, with no false-positive diagnoses, then once again, we expect false-positive cases to appear when the criteria are applied to large numbers of people. In the welding fume litigation, where plaintiffs’ counsel and physicians engaged in widespread, if not wanton, medico-legal screenings, it was not surprising that they might find occasional cases that appeared to satisfy their criteria. Of course, the more the criteria are diluted to accommodate litigation goals, the more likely there will be false positive cases.[6]

Dr. Schwartz identifies some common themes and important factors in identifying the bases for inferring causality from uncontrolled evidence:

“(a) low or no background rate of the disease condition;

(b) low background rate of the exposure;

(c) a clear understanding of the mechanism of action.”

These factors and perhaps others should not be confused with strict criteria here. The exemplar cases suggest a family resemblance of overlapping factors that help support the inference, even against the most robust skepticism.

In litigation, defense counsel typically argue that analytical epidemiology is always necessary, and plaintiffs’ counsel claim epidemiology is never needed. The truth is more nuanced and conditional, but the great majority of litigated cases do require epidemiology for health effects because the claimed harms are outcomes that have an expected incidence or prevalence in the exposed population irrespective of exposure.

[1] Reference Manual on Scientific Evidence at 23 (3d ed. 2011) (citing “Cloud v. Pfizer Inc., 198 F. Supp. 2d 1118, 1133 (D. Ariz. 2001) (stating that case reports were merely compilations of occurrences and have been rejected as reliable scientific evidence supporting an expert opinion that Daubert requires); Haggerty v. Upjohn Co., 950 F. Supp. 1160, 1164 (S.D. Fla. 1996), aff’d, 158 F.3d 588 (11th Cir. 1998) (“scientifically valid cause and effect determinations depend on controlled clinical trials and epidemiological studies”); Wade-Greaux v. Whitehall Labs., Inc., 874 F. Supp. 1441, 1454 (D.V.I. 1994), aff’d, 46 F.3d 1120 (3d Cir. 1994) (stating there is a need for consistent epidemiological studies showing statistically significant increased risks).”)

[2] 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).

[3] There may have been a better argument for Matrixx in distinguishing the method and place of delivery of the zinc sulfate in the polio trials of the 1930s, but when Matrixx’s counsel was challenged at oral argument, he asserted simply, and wrongly, that the two compounds were different.

[4] Johnston & Hauser, “The value of a case report,” 62 Ann. Neurology A11 (2007) (“No matter how compelling a vignette may seem, one must always be concerned about the reliability of inference from an “n of one.” No statistics are possible in case reports. Inference is entirely dependent, then, on subjective judgment. For a case meant to suggest that agent A leads to event B, the association of these two occurrences in the case must be compared to the likelihood that the two conditions could co-occur by chance alone …. Such a subjective judgment is further complicated by the fact that case reports are selected from a vast universe of cases.”); David A. Grimes & Kenneth F. Schulz, “Descriptive studies: what they can and cannot do,” 359 Lancet 145, 145, 148 (2002) (“A frequent error in reports of descriptive studies is overstepping the data: studies without a comparison group allow no inferences to be drawn about associations, causal or otherwise.”) (“Common pitfalls of descriptive reports include an absence of a clear, specific, and reproducible case definition, and interpretations that overstep the data. Studies without a comparison group do not allow conclusions about cause and disease.”); Troyen A. Brennan, “Untangling Causation Issues in Law and Medicine: Hazardous Substance Litigation,” 107 Ann. Intern. Med. 741, 746 (1987) (recommending that testifying physicans “[a]void anecdotal evidence; clearly state the opposing side is relying on anecdotal evidence and why that is not good science.”).

[5] See In re Rezulin, 2004 WL 2884327, at *3 (S.D.N.Y. 2004).

[6] This gaming of diagnostic criteria has been a major invitation to diagnostic invalidity in litigation over asbestosis and silicosis in the United States.

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