TORTINI

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

Judicial Notice of Untruths

March 3rd, 2014

Judicial notice is a procedure for admitting facts the truth of which are beyond dispute. A special kind of magically thinking occurs when judges take judicial notice of falsehoods, myths, or lies.

In the federal judicial system, Federal Rule of Evidence 201 addresses judicial notice of adjudicative facts, and provides:

(b) Kinds of Facts That May Be Judicially Noticed. The court may judicially notice a fact that is not subject to reasonable dispute because it:

(1) is generally known within the trial court’s territorial jurisdiction; or

(2) can be accurately and readily determined from sources whose accuracy cannot reasonably be questioned.

Procedurally, Rule 201 provides that a court must take judicial upon the request of a party who has supplied any needed basis for the fact to be noticed.  A court may take notice sua sponte.  Rule 201(c)(1), (2).

In the Chantix litigation, counsel for Pfizer challenged plaintiffs’ expert witness, Curt Furberg, on Rule 702 grounds.  According the MDL judge, the Hon. Inge Prytz Johnson, Pfizer asserted that Furberg’s proferred testimony because the FDA approved Chantix as safe and effective. In re Chantix (Varenicline) Prods. Liab. Litig., 889 F. Supp. 2d 1272, 1285 n.8 (N.D. Ala. 2012).  Citing no authority or text, Judge Johnson announced that “[a]pproval by the FDA is not evidence of the safety of a medication.” Id.

To be sure, safety issue can sometimes arise after initial approval, but before the FDA or the manufacturer and sponsor of the medication can react to the new safety data.  The sweeping statement, however, that the FDA’s approval is not any evidence of safety seems bereft of factual support and common sense.

Judge Johnson went on, however, to invent supporting evidence out of thin air:

“The court takes judicial notice of such things as that at one time, thalidomide was used for morning sickness in pregnant women. Unfortunately, 10,000 children were born with birth defects from it before it was banned. And 50  years elapsed before doctors understood why thalidomide caused limbs to disappear. See e.g. http://www.nytimes.com/2010/03/16/science/16limb.html?pagewanted=all. Similarly, the fact that the FDA at one time approved Vioxx did not prevent the same being removed from the market due to growing concerns that it increased the risk of heart attacks and strokes. http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm103420.htm. Hence, initial approval by the FDA is not proof of the safety of a medication.”

The point about the FDA’s approval not constituting evidence of safety may simply be sloppy writing and reasoning.  In the quote above, perhaps Her Honor merely meant to say that initial approval is not evidence that a medication is safe in view of later obtained data that were not available to the FDA on its review of the new drug application.  If so, fair enough, but the sweeping statement that the initial approval is no evidence of safety ignores the considerable time, cost, and energy that goes into the FDA’s review of safety before agency approves marketing.

More egregious, however, is Judge Johnson’s taking judicial notice of the marketing of thalidomide as though it had some relevancy and probative value for her claim about the inefficacy of the FDA’s safety reviews.[1]  Consider the recent review of the FDA’s handling of thalidomide by Margaret Hamburg, M.D., Commissioner of the U. S. Food and Drug Administration:

“Fifty years ago, the vigilance of FDA medical officer Dr. Frances Kelsey prevented a public health tragedy of enormous proportion by ensuring that the sedative thalidomide was never approved in the United States.  As many remember, in the early 1960’s, reports were coming in from around the world of countless women who were giving birth to children with extremely deformed limbs and other severe birth defects.  They had taken thalidomide. Although it was being used in many countries, Dr. Kelsey discovered that it hadn’t even been tested on pregnant animals.”

Margaret Hamburg, “50 Years after Thalidomide: Why Regulation Matters” (Feb. 7, 2012).

Judge Johnson took judicial notice of a non-fact. The FDA never approved thalidomide for use in the United States, back in the 1950s or 1960s.[2]



[1] Judge Johnson’s fantastical history of the FDA was recently cited by plaintiffs’ counsel in the Zoloft birth defects litigation.  See Plaintiffs’ Opposition to Defendants’ Motion to Exclude the Testimony of Anick Berard, Ph.D., at 13 (Filed Feb. 24, 2014), in In re Zoloft (sertraline hydrochloride) Prods. Liab. Litig., Case 2:12-md-02342-CMR Document 713.

[2] Judge Johnson’s errant history may have resulted from her European perspective of the thalidomide tragedy.  Judge Inge Prytz Johnson immigrated from Denmark, where she was born and educated. She became a U.S. citizen in 1978, and a state court judge one year later.  In 1998, she was nominated by President Clinton to the Northern District of Alabama.  In October 2012, Judge Johnson assumed senior status. See Kent Faulk, “U.S. District Judge Inge Johnson goes into semi-retirement” (Oct. 19, 2012) (quoting Judge Johnson as saying that “One thing I like about my job is I don’t have to take sides.”)

The Historical Intersection of Law and Epidemiology: Miller v National Cabinet (NY Court of Appeals 1960)

January 3rd, 2014

The history of statistics, epidemiology, and products liability are intertwined in ways that call for greater attention.  The 1950s and 1960s witnessed increasingly sophisticated statistical approaches to epidemiologic evidence. Starting in 1950, and continuing throughout the 1950s, Sir Richard Doll and Sir Austin Bradford Hill began their epidemiologic exploration of lung cancer among smokers. See, e.g., Richard Doll & A. Bradford Hill, “Smoking and Carcinoma of the Lung,” 2 Br. Med. J. 739 (1950); Richard Doll & A. Bradford Hill, “The mortality of doctors in relation to their smoking habits; a preliminary report,” 1 Br. Med. J. 1451 (1954).  In 1955, Sir Richard Doll published his important paper that suggested an association between asbestosis and lung cancer.  Richard Doll, “Mortality from Lung Cancer in Asbestos Workers,”  12 Br. J. Indus. Med. 81 (1955).  No disparity between observed and expected rates of lung cancer was observed among workers without asbestosis. Measures of p-values were used to assess the strength of the evidence against a null hypothesis of no association. As important an advance as was Doll’s paper, and as careful an investigator as he was, it is remarkable that Doll neglected to consider the potential role of smoking in producing the excess lung cancer rates among the factory workers with asbestosis. 

Starting in the 1960s, Dr. Irving Selikoff began publishing his epidemiologic studies of American asbestos insulators. See, e.g., Irving J. Selikoff , Jacob Churg,  and E. Cuyler Hammond, “Asbestos exposure and neoplasia,” 188 J. Am. Med. Ass’n 22 (1964). Selikoff neglected to stratify his observational data by the presence or absence of clinical asbestosis (although his later studies suggested that there was a very high prevalence of asbestosis after 20 years from first employment).  In addition, these insulator studies used crude measures of smoking, which lumped the very rare non-smoking insulators in with those who “never smoked regularly.”

In 1965, Sir Austin Bradford Hill published his lecture to the Royal Society of Medicine, in which he gave a spirited defense of inferring causality from observational epidemiologic studies. Austin Bradford Hill, “The Environment and Disease: Association or Causation?” 58 Proc. Royal Soc’y Med. 295 (1965). Hill was justly proud of the success of observational epidemiology, at least for very large effect sizes that made residual confounding and bias unlikely.

The same years as Hill’s lecture, the American Law Institute published the Restatement (Second) of Torts, with its controversial Section 402A. Before 1965, employee-plaintiff lawsuits against remote suppliers of raw materials and products to employers were a rarity in American law.  Bradford Hill’s lecture on causal assessments of “clear-cut” statistical associations came just as epidemiologic, statistical evidence was working its way into tort cases involving smoking and lung cancer.  Not surprisingly, some of the first uses of epidemiologic evidence occurred in cases involving claims that tobacco caused lung cancer. See, e.g., Lartigue v. R.J. Reynolds Tobacco Co., 317 F.2d 19 (1963) (affirming defense verdict in case noted for plaintiffs’ use of epidemiologic evidence) (“The plaintiff contends that the jury’s verdict was contrary to the manifest weight of the evidence. … The jury had the benefit of chemical studies, epidemiological studies, reports of animal experiments, pathological evidence, reports of clinical observations, and the testimony of renowned doctors. The plaintiff made a convincing case, in general, for the causal connection between tobacco and cancer and, in particular, for the causal connection between Lartigue’s smoking and his cancer. The defendants made a convincing case for the lack of any causal connection.”), cert. denied, 375 U.S. 865 (1963), and cert. denied, 379 U.S. 869 (1964).

Epidemiologic and statistical evidence in tort cases has become a commonplace, even when it is distorted and abused by litigants and judges. Recent decisions involving claims that benzene caused various cancers are illustrative.  See, e.g., Milward v. Acuity Specialty Products Group, Inc., 664 F.Supp. 2d 137 (D. Mass. 2009) (granting motion to exclude opinions that substantially distorted epidemiologic evidence under the vague rubric of “weight of the evidence”), rev’d, 639 F.3d 11 (1st Cir. 2011) (closing off scrutiny of expert witness’s abuse of epidemiologic evidence in one of the most controversial, reactionary decisions involving federal gatekeeping decisions of recent years), cert. denied, U.S. Steel Corp. v. Milward, ___ U.S. ___, 2012 WL 33303 (2012). See also David E. Bernstein, “The Misbegotten Judicial Resistance to the Daubert Revolution,” 89 Notre Dame L. Rev. 27 (2013); “WOE-fully Inadequate Methodology – An Ipse Dixit By Another Name” (Sept. 2, 2011); “Milward — Unhinging the Courthouse Door to Dubious Scientific Evidence” (Sept. 2, 2011)

Given the problematic Milward decision, we might wonder what challenges to benzene-leukemia cases looked like just before Hill’s defense of inferring causality from observational studies began to infuse the witches’ brew of Rule 402A. What did statistical evidence look like before Hill’s paper?  In court cases, typically, statistical evidence was presented crudely or not at all.

In 1960, there was little opportunity to challenge causation opinions on admissibility grounds; rather sufficiency of the evidence to support a verdict or judgment was the primary means to gain review of an adverse decision.  Case reports of leukemia in workers very heavily exposed to benzene appeared in the 1920s, but it was not until the 1960s that analytical epidemiologic evidence (case-control and cohort studies) of association between leukemia and benzene were published. See generally Deborah Glass, Christopher Gray, Damien Jolley, Carl Gibbons, and Malcolm Sim, “The health watch case – control study of leukemia and benzene: the story so far,” 1076 Ann. N.Y. Acad. Sci. 80-89 (2006).  Thus, when the New York Court of Appeals decided a case involving a claim of benzene-induced leukemia, in 1960, the judicial decision was driven largely by the absence of specific quantification of risk of leukemia among workers occupationally exposed to benzene.[1]  Miller v. National Cabinet Co., 8 N.Y.2d 277, 281, 168 N.E.2d 811, 813, 204 N.Y.S.2d 129, 132, modified on other grounds, 8 N.Y.2d 1025, 70 N.E.2d 214, 206 N.Y.S.2d 795 (1960). The New York high court wrestled with the formalistic aspects of the expert witnesses’ testimony, including whether they expressed themselves in terms of “possibilities” or “probabilities.” Miller, 8 N.Y.2d at 284, 168 N.E.2d  at 814-15, 204 N.Y.S.2d at 134.

Focusing in one of the more knowledgeable of plaintiffs’ expert witnesses, Dr. Reznikoff, the Miller court was impressed that this witness disclaimed any intent to support an inference, from statistical analyses, to the plaintiff’s decedent.  Id. at 283. Furthermore, the court suggested that Reznikoff’s evidence might have been sufficient were it not for concession:

“I am sorry I can’t give you any statistics, but we don’t have them.”

Id. at 283.  The court appeared also to be concerned that Reznikoff’s approach provided no mechanistic insight or understanding into why many cases of  leukemia followed benzene exposure. Id.  

Reznikoff’s qualifications to speak to the subject were not dispositive of the question; the court was looking for data that were not available in the 1950s, when the case was tried:

“Not every supposition of a witness concerning what might be has the force of evidence, even though he has been licensed to practice medicine. If the witness is unfamiliar with any statistical data in the medical literature or in his own practice to give an inkling either to himself or to the court or board of how high the incidence of these cases is in situations of this kind, then the doctor’s assumption that it is ‘quite high’ is without significance. The lack of any kind of statistical data, which in the absence of scientific understanding is all that there would be to go on, is the more inexplicable if the claim is well founded in view of the large number of persons who die of leukemia and of workers in industry who are exposed to benzol. If there were any observed correlation between the two, it is certain that a physician of Dr. Reznikoff’s standing would be in possession of the information.”

Id. at 283-84. The court did not excuse the claimant’s evidentiary display with the indulgent, “this was the best evidence available,” when the evidence was inadequate.  Nor did the court engage in soothsaying that causality would someday be demonstrated.  We might feel some frustration today, looking back, that the court missed this opportunity, but case reports, and even case reports and epidemiologic studies, have generated many false-positive associations.  Clearly, more is required, and the New York Court of Appeals recognized the necessity for more.

Traumatic Cancers Distinguished

In 1960, the courts still indulged the proto-scientific opinion that traumatic injury caused cancer.[2]  Some medical writers supported this opinion, but by 1960, the opinion was already falling out of favor due to an improved understanding of carcinogenesis.

There is much irony, therefore, in the Miller court drawing’s an invidious distinction between Reznikoff’s proto-epidemiologic evidence and traumatic cancer cases that were still prevalent in the 1960s.  Id. at 285-86. In the traumatic cancer cases, in the 1960s, and even in the 1970s, courts sustained verdicts for cancer claimants who had shown that their cancers were diagnosed very shortly after a traumatic blow to the precise portion of the body where cancer manifested. The Miller court referred to these traumatic cancer cases as presenting the kind of causal inferences that could be understood and made by judges and juries.  Today, 40 years later, we see those causal inferences as mostly rubbish, based upon incorrect, inadequate, and discarded theories of carcinogenesis.

The prospect of cancer cases sustained by epidemiologic (statistical) evidence clearly troubled the New York court:

“The courts have been confronted before with cancer cases, and this is not likely to be the last. This is not an isolated situation. Questions of causation are common to actions based on warranty, tort or workmen’s compensation proceedings. Would, for example, evidence that there are 4 to 11 times as many cases of lung cancer among cigarette smokers as among nonsmokers be sufficient to establish a cause of action for breach of warranty in the sale of cigarettes? … There appear to be no decisions upholding causation in so complex a variety of the disease as leukemia. The cancer decisions in the courts where recovery has been allowed have dealt almost entirely with trauma, and there only in instances where the trauma occurred in the spot in the body where the pre-existing cancer was and the symptoms of its aggravation were immediately apparent … . In all of those cases the immediacy of the symptoms of aggravation of the cancer by a traumatic injury suffered in the area where the cancer was located was accepted as a substitute for scientific evidence or understanding of cause and effect. Absent that, damage claims of this nature have been dismissed on the law for lack of evidence of causation.”

Id. at 285-86 (internal citations omitted). The Miller court went on to note that New York law required that the cancer must develop at the exact location of the injury.  Furthermore, latency between the traumatic blow and the clinical recognition of the cancer was fatal to the claim, even in the face of opinion testimony that a plaintiff’s cancer was a “very slow growing” tumor.  Today, we understand that latency between first-exposure and clinical manifestation is necessitated by the length of induction periods and the doubling time of solid tumor cancers.  As a result of the Miller court’s reliance upon some dodgy notions of cancer causation, it held that Mr. Miller’s latency period disqualified the case from the immediate impact rule of traumatic cancer cases. Id. at 287-88 (distinguishing Hagy v. Allied Chemical & Dye Corp., 122 Cal. App. 2d 361, 265 P.2d 86 (1953), which involved a diagnosis of laryngeal cancer following immediately upon exposure to sulfuric acid mists).

The majority in Miller further expressed its concern that the understanding of cancer causation was marked by such uncertainty that the mere possibilities of chemical carcinogenesis should not be tolerated in this and similar cases:

“… [F]or so long as the causes of a disease — like cancer — are unknown to science, everyone contracting the disease could secure medical testimony that it is ‘possible’ that the disease is contracted from a wide variety of causes, choosing in each instance the particular possibility having the greatest promise of holding liable some responsible defendant. Any cancer expert could readily state that cancer could be caused by virus infection or by exposure to automobile exhaust fumes, sunlight, radiation, smog, smoking, hormone imbalance or according to any other theory which has been entertained by researchers or specialists as a possibility. Is a malpractice suit pending against some doctor who has given cortisone or ACTH as medicine? Then appears a medical witness who testifies that possibly cancer is caused by hormone imbalance induced thereby. Is it an action for breach of an implied warranty in the sale of cigarettes? Then the medical witness will testify that cigarettes could be a cause of lung cancer. Is it X ray or working in a garage where there have been exhaust fumes? Then the ‘possibility’ doctrine is adapted to creating questions of fact in those fields — and the same with benzol exposure and leukemia. Such a doctrine would overturn the rule that the burden is on the party asserting that a disease is based on actionable facts to prove causation. It would mean that, wherever such a cause is possible, the burden rests on the opposite party to prove that the disease resulted from something else. Consequently, for so long as the causes of the disease are unknown to medical science, the claimant or plaintiff can always recover — if the trier of the fact is favorably disposed — since no one can prove that the disease had other causes. This is a perversion of the normal rule that the disease must have resulted from the occupation and that the burden of proving causation is upon the party asserting it. The law does not intend that the less that is known about a disease the greater shall be the opportunity of recovery in court.”

Id. at 289.

The Miller decision provoked a dissent, mostly on formalistic grounds.  Id. at 290. The dissenting judges asserted, without much analysis, that there was substantial evidence to support causality. Given that qualified expert witnesses showed up for the claimant seemed sufficient on this score for the dissenters.  To the extent that the claimant’s expert witnesses expressed themselves in terms of possibilities, the dissenters opined that possibilities are sufficient, especially in the context of workman’s compensation cases, in which the burden of proof standards are lower than in common law civil liability cases.

The majority opinion stands as an eloquent expression of concern about the need for quantitative evidence of statistical risk in chemical exposure cancer cases. The court also presciently saw what would become a plague of litigation involving claims of cancer causation.  In 1960, for benzene and leukemia, the evidence was clearly, even by the standards of the day, inadequate, and the claimant’s expert witnesses were appropriately modest about what inferences could be drawn both with respect to general and specific causation.  The 1970s would witness a growing immodesty among available expert witnesses, as well as an explosive growth in the techniques and applications of analytical epidemiology to many problems, including the relationship between benzene and leukemia.



[1] A decade or two later, the scientific community recognized high levels of exposure to benzene as a cause of certain kinds of leukemia, by virtue of epidemiologic studies. See, e.g., Fusun Yaris, Mustafa Dikici, Turhan Akbulut, Ersin Yaris, Hilmi Sabuncu, “Story of benzene and leukemia: epidemiologic approach of Muzaffer Aksoy,” 46 J. Occup. Health 244 (2004); Abdul Khalade, Maritta S Jaakkola, Eero Pukkala and Jouni JK Jaakkola, “Exposure to benzene at work and the risk of leukemia: a systematic review and meta-analysis,” 9 Envt’l Health 31 (2010).  See also Michael D. Green, The Paradox of Statutes of Limitations in Toxic Substances Litigation, 76 Cal. L. Rev. 965, 974 (1988).

[2] William B. Coley & Norman L. Higinbotham, “Injury as a Causative Factor in the Development of Malignant Tumors,” 98 Annals of Surgery 991 (1933); Shields Warren, “Minimal Criteria Required to Prove Causation of Traumatic or Occupational Neoplasms,” 117 Annals of Surgery 585 (April 1943); Shields Warren, “Criteria Required to Prove Causation of Occupational or Traumatic Tumors,” 10 U. Chi. L. Rev. 313, 318-20 (1943); Russell & Clark, “Medico-Legal Considerations of Trauma and Other External Influences in Relationship to Cancer,” 6 Vand. L. Rev. 868, 875 (1953); Arden R. Hedge, “Can a Single Injury Cause Cancer?” 90 California Medicine 55 (1959); Auster, “The Role of Trauma in Oncogenesis: A Juridical Consideration,” 175 J. Am. Med. Ass’n 940, 949 (1961); Comment, “Sufficiency of Proof in Traumatic Cancer Cases,” 46 Cornell L.Q. 581, 581-82 (1961); Comment, “Sufficiency of Proof in Traumatic Cancer: A Medico-Legal Quandary,” 16 Arkansas L. Rev. 243, 256 67 (1962); Dyke, “Traumatic Cancer,” 15 Clev.Mar. L. Rev 472, 484-94 (1977).  See also Comment, “Judicial Attitudes Towards Legal and Scientific Proof of Cancer Causation,” 3 Columbia J. Envt’l L. 344, 354-68 (1977).

 

Gastwirth on the Wells Case

December 27th, 2013

One of the high points of 2013 for me was the Practicing Law Institute seminar on expert witness gatekeeping.  I am indebted to my co-chair David Cohen, and the talented participants, Dr. David Garabrant, Joe Cecil, Mary Wells, and Mike Williams.  I learned a great deal from all of them, even when we disagreed.

At the seminar, which addressed the slippage in the federal judiciary’s fidelity to Rule 702 text and principles, Joe Cecil kindly reminded me of Professor Gastwirth’s contribution on the Wells v. Ortho Pharmaceutical Corp., 615 F. Supp. 262, 298 (N.D. Ga. 1985), aff’d and rev’d in part on other grounds, 788 F.2d 741 (11th Cir.), cert. denied, 479 U.S.950 (1986).  Joseph L. Gastwirth, “The need for careful evaluation of epidemiological evidence in product liablility cases: a reexamination of Wells v. Ortho and Key Pharmaceuticals,” 2 Law, Probability and Risk 151 (2003).

The Supreme Court recently reinvigorated the Wells case, and like Frankenstein’s monster, it walks again.  Matrixx Initiatives, Inc. v. Siracusano, 131 S. Ct. 1309 (2011).  See alsoMatrixx Unloaded.”  As a result of the Matrixx decision, I revisited the untoward Wells decision several times this year. SeeWells v. Ortho Pharmaceutical Corp. Reconsidered – Part 1”; and here, here, here, here, and here.  Joe’s reminder, however, provoked me to look one more time at Wells, through the lens of Gastwirth’s review.

Gastwirth is a well-known statistician, not a lawyer.  His article undertakes some interesting sensitivity analyses of the potential role of one known confounder in the epidemiologic studies of spermicides and birth defects, cited by witnesses in Wells. Not surprisingly, Gastwirth confuses important legal concepts, when he contends that science and law have different goals because science has the luxury of waiting for additional studies to resolve indeterminate datasets.  Gastwirth at 154. Gastwirth suggests that in law, causality determinations turn on fairness, but in science, they turn on the truth.  Gastwirth offers no support for his assertion, and there is much law to the contrary.  Federal Rule of Evidence 102, for instance, explains the “Purpose” of the Federal Rules and how they should be construed:

“These rules should be construed so as to administer every proceeding fairly, eliminate unjustifiable expense and delay, and promote the development of evidence law, to the end of ascertaining the truth and securing a just determination.”

Truth does count, at least in some courts, and it is hard to imagine a case in which the goals of truth and justice are bifurcated. Gastwirth sees law courts as unable to avoid judgment when the evidentiary display is weakly developed or not replicated, but he is wrong.  Courts can, do, and should avoid permitting judgments based upon indeterminate datasets.

Gastwirth also contends that the duty to warn in tort is based upon a possibility of causation, and he opines that this is perfectly satisfactory.  Gastwirth at 155.  Gastwirth cites the Restatement (Third) a/Torts for his view, but the Restatement does not couch the duty to warn as predicated upon merely possible risk:

“A defendant will not be liable under an implied warranty of merchantability for failure to warn about risks that were not reasonably foreseeable at the time of sale or could not have been discovered by way of reasonable testing prior to marketing the product. A manufacturer will be held to the standard of knowledge of an expert in the appropriate field, and will remain subject to a continuing duty to warn of risks discovered following the sale of the product at issue.”

Id. (emphasis added).  Gastwirth fails to explain why the epistemic standard of the Restatement should be diluted to include merely possible risks; nor does he explain why the law should impose a duty because a minority of so-called experts claim knowledge of the existence of a risk, whether potential or known.

Risks are based upon known causal relationships, viewed ex ante rather than post hoc.  Gastwirth attempts to defend the Wells decision on the basis that the trial judge, Judge Shoob, could have correctly found a possible risk, but this was not then or now the standard for imposing a duty to warn.  Even if possibilities were the basis for a duty to warn, the courts in Wells had to find sufficient evidence of cause in fact between the spermicidal jelly and the birth defect present in the infant plaintiff.  No merely possible risk could have satisfied this burden, and Gastwirth avoids this important issue in his review.  Ultimately, Gastwirth fails to come to grips with how the Wells courts artificially distinguished two causation standards – warning-harm and product-harm.  Gastwirth at 184.

When courts are required to work with an epistemic standard for evaluating opinions about causal claims, they will often confront sincere beliefs supported by “putative” justifications, but which turn out to be untrue.  The obvious implication is that the causal opinions were not “true” when offered, and the asserted, putative justification was no justification at all.  Twenty years post-Daubert should have made our courts more sensitive to the pathology of claiming, or pathoepistemology, as I call it.

Although Gastwirth is intent to show that the district and circuit court decisions in Wells were reasonable given the record evidence at the time of their decisions, Gastwirth’s defense is tepid at best. Gastwirth concedes that the plaintiffs’ evidence in the Wells case was not very convincing, and he is quick to point out that he does not conclude that spermicides cause limb reduction defects (although he does believe that the data were sufficient for his idiosyncratic diluted duty-to-warn legal standard:

 “The epidemiological evidence in the Wells case surely was not very convincing and it is understandable that scientists and legal scholars might desire stronger scientific evidence before holding a defendant liable. What seems unfortunate is the lack of discussion of the part of the record most supportive of the legal decisions from the published criticisms.201 While it is reasonable to ask how much evidence should be required before a warning is required, is it fair to rely on studies that were published after the time of exposure to assess the producer’s duty at the time?”

Gastwirth at 184-85.  The equivocation in this passage between assessing causation for a duty to warn and for product harm is typical of Gastwirth’s confusion throughout this article.  As noted, Gastwirth appears to believe it is sufficient to show the plausibility of the causal relationship such that the trial court’s findings of a duty to warn, and a breach of that duty, were reasonably supported:

“It should be stressed that our examination of the studies does not conclude that exposure to spermicides causes limb reduction defects. 202 Indeed, the studies published in the 1980s are sensitive to the potential effect of unmeasured known potential risk factors that were not controlled for in the analysis. Many studies observed that it is difficult to rule out small but meaningful risks given their sample size or that more studies including potential confounding variables be carried out before a scientific conclusion can be reached.203

Gastwirth at 185 & n.202.  So small increased risks were difficult to rule in or rule out, but then how can a judgment for plaintiffs be sustained unless, as I have shown elsewhere, Judge Shoob improperly placed the burden of proof upon the defendant?  The studies published in the 1980s may have been sensitive to the potential effect of unmeasured and uncontrolled known potential risks, but Judge Shoob clearly was not sensitive to the problem at all.

Other problems abound. The studies involved in the Wells case not only failed to account for the few known confounders at the time, but they could not and did not sort out the residual confounding.  Gastwirth concedes the point in a footnote, in which he cites a paper by Professor Gary Shaw on the role of multivitamin use in preventing birth defects. See Gastwirth at 185 & n. 202 (citing Shaw et al., “Maternal Periconceptional Use of Multivitamins and Reduced Risk for Conotruncal Heart Defects and Limb Deficiencies Among Offspring,” 59 Am. J. Med. Genetics 536 (1995) (showing that children of mothers who had taken vitamins and folic acid had a 30-35% lower risk of limb defects).  Gastwirth sees the discovery of causes not previously controlled for in the spermicide/birth defect studies of the 1980s as example of the differences between scientific and legal judgments.  Another way to look at such discoveries is to impose some standard of intellectual modesty upon courts in basing their findings upon speculative causal claims.

Gastwirth’s casual dismissiveness of the need for replication in a legal standard of causation is difficult to square with his acknowledgment that early studies often prove misleading about the existence of a true risk.  Gastwirth, for instance, acknowledges that later publications quite commonly do not support initial hypotheses.  Gastwirth at 179, 184 (citing Michael B. Bracken, “Spermicidal Contraceptives and Poor Reproductive Outcomes: The Epidemiologic Evidence Against an Association,” 151 Am. J. Obstet. & Gyncecol. 552, 555 (1985)).  Gastwirth channels the anti-manufacturer Zeitgeist for his claim that “firms” may not report studies that show risk, but he ignores the pervasive, prevalent practice of academic and advocacy scientists’ not publishing negative studies in the first place, and even later in the natural history of scientific controversies.

Ultimately, however, Gastwirth’s own judgment is a self-fulfilling prophecy of how the law and science should part company over false-positive assertions of causality.  Fortunately, the law has evolved in a different direction, towards convergence of scientific and legal modes of assessing causal claims.  Now judges must evolve as well.

Pennsylvania Superior Court Takes The Bite Out of Fixodent Claims

December 12th, 2013

In the spring of 2012, Judge Sandra Mazer Moss granted summary judgment to Proctor & Gamble, after excluding, on Frye grounds, plaintiff’s expert witnesses who opined that plaintiff suffered zinc neurotoxicity from his use of FixodentJacoby v. Rite Aid Corp., 2012 Phila. Ct. Com. Pl. LEXIS 208 (2012).  SeePhiladelphia Plaintiff’s Claims Against Fixodent Prove Toothless” (May 2, 2012).  Judge Moss’s exclusion of plaintiff’s expert witnesses involved a careful analysis of the evasive, hand-waving tactics of the witnesses.  Among the plaintiff’s team of expert witnesses was Dr. Martyn Smith, the chief hand waver and obscurantist in Milward v. Acuity Specialty Products Group, Inc., 664 F.Supp. 2d 137 (D. Mass. 2009), rev’d, 639 F.3d 11 (1st Cir. 2011), cert. denied, U.S. Steel Corp. v. Milward, ___ U.S. ___, 2012 WL 33303 (2012).

On Monday, December 9, 2013, after a careful review, the Pennsylvania Superior Court affirmed summary judgment for Proctor & Gamble in the Jacoby case. Jacoby v. Rite Aid Corp., Pa. Super. Ct. No. 1508 EDA 2012 (Dec. 9, 2013) [Slip op.]  The Superior Court panel, consisting of Judges Stevens, Lazarus, and Colville, largely adopted Judge Moss’s analysis and affirmed in a signed, but unpublished, opinion by Judge Lazarus. 

Like Judge Moss before them, the Panel saw through the attempt to pass off “Weight of the Evidence” (WOE) and “Totality of the Evidence” (TOE) as scientific methodologies.  The witnesses, Martyn Smith and others, failed to specify what evidence they weighed, how they weighed the evidence, and what the weights supposedly were.  Another expert witness vaguely pointed to the “Naranjo scale” in support of interpreting case reports to show causal association, but this scale was similarly incompetent other than as a crude “plausibility” scale for assessing case reports.

The Superior Court’s decision in Jacoby is noteworthy on several important issues. There was no material issue as to whether zinc at some dose and duration of exposure can cause neuropathies.  The Court saw, however, that the important issue was whether zinc in the form, dose, and duration ingested by plaintiff can cause the outcome he experienced, and whether his exposure to zinc in Fix-o-dent actually caused his alleged injury.  The Superior Court re-affirmed Pennsylvania’s case law that makes extrapolation from different doses, different durations, and different biological circumstances, a “novel” claim that is subject to the gatekeeping by the so-called Frye standard. Slip op. at 11.

The Superior Court’s opinion astutely observed that the issue was not whether WOE and TOE are accepted scientific methodologies, but whether expert witness Martyn Smith can “evade a reasoned Frye inquiry merely by making reference to accepted methods in the abstract.”  Id. at 12 (citing Betz, at 58).  When pressed, Martyn Smith’s invocation of WOE amounted to little more than a distortion and abridgment of the Bradford Hill factors.  The Superior Court recognized, however, that the Bradford Hill guidelines provide an evaluative process to consider whether an association, after first being shown to be clear cut and not attributable to chance, is causal or spurious.  Id. at 13.  As Bradford Hill postulated the question that arises before his famous nine factors come into the analysis:

“Disregarding then any such problem in semantics we have this situation. Our observations reveal an association between two variables, perfectly clear-cut and beyond what we would care to attribute to the play of chance. What aspects of that association should we especially consider before deciding that the most likely interpretation of it is causation?”

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

In this case, Smith never got off the dime with his evasive tactics.  He did not identify a quantified association that could be assessed for the play of random variation, or bias and confounding.  Smith tried to suggest that a mere possibility of an association was sufficient to invoke the Bradford Hill guidelines, but the Superior Court rejected this attempt to invent a new-age scientific method. Slip op. at 13.

The Superior Court acknowledged that the scientific literature describes WOE as varying from nothing more than “seat-of-the-pants qualitative assessment” to “aggregating diverse modalities.”  Id. at 14.  In Smith’s hands, WOE was little more than a personal, subjective opinion, an ipse dixit dressed as a scientific opinion.  Smith never defined his WOE approach, and the other witnesses never defined their TOE approach.  The plaintiffs’ witnesses in Jacoby failed to offer an accepted methodology when they failed to identify the forms of evidence they considered, and how they went about weighing the evidence upon which they had relied.  Id. at 15.

In a brief discussion, the Panel also embraced another basic evidentiary principle to dismiss a common tactic in specious claiming. The plaintiffs’ challenged defendants’ pharmokinetic study and tried to suggest that their deconstruction counted as affirmative evidence to support their own theory of biological fate and distribution. Id. at 16.  The Superior Court saw through the ruse; the plaintiffs had not created affirmative evidence for their theory by arguing that the defendants’ study was flawed. 

The Superior Court squarely confronted the limitations and inadequacy of relying upon descriptive, anecdotal case reports. Case reports provide a narrative and temporal history of events with respect to exposure and outcome, but they cannot fully account for confounding by known and unknown factors.  Case reports represent post hoc assessments that were not planned, and therefore lack data that would permit distinguishing coincidence from causality.  Id. at 17 (citing Dr. Lorene Nelson’s report).  See In re Denture Cream Prods. Liab. Litig., 795 F. Supp. 2d 1345 (S.D. Fla.2011).

Proctor & Gamble had the good fortunate to have obtained a good ruling in the MDL litigation in the Southern District of Florida, which no doubt helped focus the gatekeeping process in Pennsylvania state court. Unfortunately, the Superior Court Panel chose not to publish its decision.  This decision is regrettable for its inconsistency with the transparency and due process expected of all courts.  See Erica Weisgerber, “Unpublished Opinions: A Convenient Means to an Unconstitutional End,” 97 Georgetown L.J. 621 (2009).

Rockefeller and McCarthy — The Rush from Responsibility

December 4th, 2013

William Rockefeller was the engineer who operated the Metro-North Railroad train at 83 mph around the Spuyten Dyvel curve, in the Bronx.  The general speed limit is 70 mph, and the speed limit going into the curve is 30 mph.  The train derailed, killing four passengers and injuring many more, some very seriously.  Rockefeller told investigators that he had become “dazed,” whatever that means in the absence of some “dazing” event.  Matt Flegenheimer & William K. Rashbaum, “Train Engineer Was Dazed Before Crash, Lawyer Says” (Dec. 3, 2013 ). George Orwell would have appreciated the slippery and soul-less use of the passive voice.  Who did the dazing?

Jeffrey P. Chartier, Rockefeller’s lawyer, described his client as suffering from “highway hypnosis.”  Chartier, testifying for his client, claimed that Rockefeller had lost concentration only momentarily, and that he was “extremely remorseful.” Metro-North trains are pretty substantial trains, not the sort that can accelerate momentarily from 30 to 82 mph.

Rockefeller is a member of the Association of Commuter Rail Employees, and so, of course, his union representative, Anthony Bottalico, had to weigh in on the issue. Bottalico casually mentioned that Rockefeller had described himself as having nodded off before the derailment.  When pressed, Bottaclico realized his error in acknowledging responsibility, and he quickly changed up:

“People use the word ‘zoned out,’ ‘nod,’ ‘fell asleep,’ … I’m not a sleep expert.”

Bottalico’s indiscretion, in speaking to the media about a pending investigation (and trying to spin the facts to exculpate the union engineer) led the safety board to remove the union as a party to the investigation.

The search for responsibility is part of our human condition.  Legal categories often drive the search.  In occupational exposure cases, employers have tort immunity by virtue of workman’s compensation immunity.  The Depression-era bargain between labor and management on workplace injuries pushes our legal system, and the litigation industry, to place responsibility on remote vendors of products and raw materials to the workplace, despite their lack of control over the dissemination of information on the job.  In most so-called sophisticated intermediary cases, the accident or injury would not have occurred at all had the employer and the employees done their respective jobs with respect to providing a safe workplace.

In the Spuyten Duyvil crash, Rockefeller’s lawyer and rail safety pundits suggest that automatic systems might have prevented the derailment.  The hard fact remains, however, that Rockefeller was the most important link in the causal chain.  He was the “least expensive” means to avoid the disaster because it was his job and his responsibility to do so.  Had Rockefeller simply done his job, four people killed in the crash would be alive today.  And many more would not be crippled and in pain.

In today’s New York Times, Joe Nocera muses about how Long Island Congresswoman Carolyn McCarthy, was diagnosed with lung cancer. McCarthy, who is 69 years old, was a life-long cigarette smoker, yet in her court filings she refers to her lung cancer as her asbestos disease. Joe Nocera, “The Asbestos Scam” N.Y. Times (Dec. 3, 2013). We live in a free country (well, sort of free) and people should be free to deceive themselves and indulge their superstitions.  But surely we can draw the line at deceiving others with such nonsense.  McCarthy was never an asbestos insulator or an asbestos-exposed tradesperson.  McCarthy’s lawyer, supposedly told The New York Post that “it has been conclusively proven that cigarette smoking and asbestos exposure act synergistically to cause lung cancer.”

Nocera points out that in fact it has not.  Even Selikoff himself, who did so much to perpetuate a theory of multiplicative, synergistic reactivity, wrote that his insulator cohort synergistic risk estimates could not be extrapolated to other exposures (such as the evanescent household exposures alleged by Congresswoman McCarthy):

“These particular figures apply to the particular groups of asbestos workers in this study.  The net synergistic effect would not have been the same if their smoking habits had been different; and it probably would have been different if their lapsed time from first exposure to asbestos dust had been different or if the amount of asbestos dust they had inhaled had been different.”

Selikoff, et al., “Asbestos Exposure, Cigarette Smoking and Death Rates,” 330 Ann. N.Y. Acad. Sci. at 487 (1979). Despite Selikoff’s atypical care, his colleagues who carried the Mt. Sinai banner into courtrooms all around this country, glibly ignored his qualification.  See alsoIrving Selikoff and the Right to Peaceful Dissembling.”  Of course, when Selikoff’s heirs updated his insulator study, they did not find evidence of interaction even for insulators who lacked sufficiently heavy exposure to cause asbestosis.  Steve Markowitz, Stephen Levin, Albert Miller, and Alfredo Morabia, “Asbestos, Asbestosis, Smoking and Lung Cancer: New Findings from the North American Insulator Cohort,” Am. J. Respir. & Critical Care Med. (2013). SeeThe Mt. Sinai Catechism” (June 7, 2013).  I doubt that these qualifications will find their way into the reporting of The New York Post.

Ultimately, Irving Selikoff and his heirs helped create a litigation industry that has placed responsibility for asbestos disease on vendors, not employers, and completely out of proportion to any realistic appraisal of traditional tort law. Rockefeller and McCarthy, and Selikoff (and the litigation industry he helped to start) all illustrate the misallocation of responsibility for avoidable human suffering.  Denialism is where you find it.

Christopher Bryson and the Problem of Political Science

October 12th, 2013

Fluoridation of water has long been a “political science” issue, with radical libertarians and anarchists viewing fluoridation as the high-water mark of state paternalism.  The motive to misstate and misrepresent the science may at times be obvious, but individual statements, standing alone, may be difficult to judge.

Fluorine chemistry and toxicology are sufficiently advanced that misrepresentations should be easy to detect.  Fluorine is a halogen; the lightest in the series.  As a gas, fluorine is extremely reactive and toxic, as are other halogen gases, such as chlorine.  Fluorine gas was used for uranium enrichment in the Manhattan project, and project scientists conducted research on fluorine toxicity to help them set exposure limits in a new manufacturing process.

As devotees of Breaking Bad no doubt have learned, hydrogen fluoride is extremely toxic and corrosive.  Other halogen-based acids are, of course, toxic and corrosive, such as hydrogen chloride.

Compounds of fluorine are generically fluorides, and the properties of the salts and compounds varies considerably with the cation and the chemical structures involved.  Many modern medications, such as atorvastatin and fluoxetine contain fluorine in their chemical structures.  The toxicology of the fluorine compounds must, therefore, take into account the variability of structure and function of fluorine.  Toxicity of fluorine gas or of hydrogen fluoride cannot be “extrapolated” to a simple sodium salt, and more than the toxicity of chlorine gas can be imply the toxicity or ordinary table salt, sodium chloride.  The allergenicity of a compound such as potassium aluminumtetrafluoride cannot be the basis for asserting the immunogenicity of a simple alkali salt.

Recently, I came across a YouTube video of a journalist, Christopher Bryson, holding forth on his perception of a vast conspiracy to poison people by the fluoridation of drinking water.  Bryson’s passion and selectivity in making his case resembles the deep flaws of our tort system, which allows lawyers and expert witnesses to overwhelm judges and juries with emotion, selectivity, and overstatement.  Bryson refers to all fluorine chemicals, whether the elemental gas, the acid, or the many complex and variable salts as “fluoride.”  Occupational and environmental exposures to hydrogen fluoride are equated with micromolar levels of sodium fluoride in drinking water. Never once does he actually quantitate the exposures he labels as “toxic.” Largely, Bryson proceeds by ad hominems, ad nauseam.  If scientists have industry connections, they are bad, and their science is corrupt.  If a scientist has ever done something productive (e.g., George L. Waldbott), and he opines that water fluoridation is bad, then that scientist must be correct.  Apparently, Bryson has never heard of Linus Pauling and his Vitamin C fiasco.  See K. Frank Austen, M. Dworetzky, Richard S. Farr, G.B. Logan, S. Malkiel, E. Middleton Jr., M.M. Miller, Roy Patterson, C.E. Reed, S.C. Siegel, and P.P. Van Arsdel Jr., “A statement on the question of allergy to fluoride as used in the fluoridation of community water supplies,” 47 J. Allergy & Clinical Immunology 347 (1971) (“no”).

Bryson makes for an interesting case study in hysteria.  He is also very much a public example of the tone and substance of many of the plaintiffs’ theories that clog the civil dockets of our court system.  Bryson’s passion and intensity — heat without illumination  — are reminiscent of the courtroom antics in many a so-called “toxic tort” case.  Bryson’s video is thus a good place to start to try to understand science in the courtroom, and the need for strong gatekeeping.  The potential for inflammatory advocacy, distortion, and misrepresentation have always been part of legal proceedings, but when it comes to advocacy about claims that turn on “scientific” evidence, there is a difference.  Juries in common law cases, in 1789, were not confronted with the abuses of the sort that Bryson so well exemplifies.

The Bryson video led me to look at Bryson’s book, The Fluoride Deception.  The book starts with “Notes on Terminology,” which warns that

“THE TERMS fluorine and fluoride should not be confused in a book about chemical toxicity.”

* * *

“In these pages I’ve tried to be clear when I’m referring to the element fluorine or to a compound, a fluoride. And because different fluoride compounds often have unique toxicities, where relevant or possible, I have also given the compound’s specific name.”

So far so good, but then Bryson, having baited, switches:

“Mostly, however, for simplicity’s sake, I have followed convention and used the shorthand fluoride when referring to the element and its multiple manifestations, a procedure approved and used by the U.S. National Academy of Sciences.”

Christopher Bryson, The Fluoride Deception at xi (2004).

Fluoride deception indeed Mr. Bryson.  The cited source for the indiscriminate use of fluoride makes clear that it uses “fluoride” as a general term when differentiation is not necessary for its discussion.  It is not, however, a basis for conflating or confusing the toxicities of fluorine species or doses.  National Research Council, Biological Effects of Atmospheric Pollutants: Fluorides 3 (1971).  Bryson provides an apt example of how science communication works in politicized contexts, such as the courtroom or the legislature.

Harkonen’s Appeal Updated

October 9th, 2013

The Solicitor General’s office has obtained yet another extension in which to file its opposition to Dr. Harkonen’s petition for a writ of certiorari. The new due date is November 8, 2013.

This week, Nature published a news article on the Harkonen case. See Ewen Callaway, “Uncertainty on trial,” 502 Nature 17 (2013).  Mr. Calloway’s story accurately recounts that Thomas Fleming, a biostatistician at the University of Washington, chaired the data safety monitoring board for the InterMune trial, and that he had told Dr. Harkonen and others at InterMune that he, Fleming, believed that the press release was misleading.   But this “fact” simply represents that Fleming disagreed with the causal inference of efficacy.  His opinion might well have been correct, but it did not make Dr. Harkonen’s press release “demonstrably” false.  Overstating confidence in a conclusion may be the occasion for disputing the evidentiary warrant for the conclusion, but it does not make the speaker a liar.

Calloway also reports that the government believed that documents suggested that there had been off-label promotion of interferon γ-1b, but of course, the jury acquitted Dr. Harkonen of mislabeling.  Calloway’s recitation of  these discredited allegations, however, provide important context for why the federal government continues to overreach by pressing its opposition to Dr. Harkonen’s appeal on the conviction for criminal wire fraud.

Mr. Calloway notes that there were “statisticians, clinical researchers and legal scholars” who criticized the judgment of conviction on grounds that it rested upon misinterpretations and misunderstandings of statistics, and that it could criminalize much expert witness testimony, grant applications, and article submissions. But Mr. Calloway’s presentation is subtly biased.  He fails to identify those “statisticians, clinical researchers and legal scholars,” other than a few whom he then impugns as having been “compensated” by the defense.

He quotes Stanford Professor Steven Goodman as filing a brief stating that:

“You don’t want to have on the books a conviction for a practice that many scientists do, and in fact think is critical to medical research… .”

Calloway errs in suggesting that Professor Goodman was a brief writer rather than an affiant.  Dr. Zibrak, a pulmonary physician is quoted, with the note that he was compensated to tell other physicians about his clinical experience with interferon γ-1b in patients with idiopathic pulmonary fibrosis.  By playing the “compensation card,” Calloway tries to diminish the force of Goodman’s and Zibrak’s substantive arguments.  This sly attempt, however, is blunted by the significant number of legal scholars and scientists who filed amicus briefs without compensation.  More important, the attempt is irrelevant to the issues in the case.

MISLEADING REPORTING

Calloway described the trial as showing that only “slightly fewer” patients had died on interferon γ-1b than on placebo, but that the difference was not statistically significant “because the probability that it was not due to the drug was greater than 5%, a widely accepted statistical threshold.”  Well, the p-value was 0.08 on the intent-to-treat analysis, and 0.055 on the per-protocol analysis.  When the investigators published a more sophisticated time-to-event analysis in the New England Journal of Medicine, their reported “hazard ratio for death in the interferon gamma-1b group, as compared with the placebo group, was 0.3 (95 percent confidence interval, 0.1 to 0.9).” Raghu et al. N. Engl. J. Med. 350, 125–133; 2004 (for the entire trial, not the “controversial” subgroup).  Calloway notes the publication of the results, but fails to inform the Nature readers of this hazard ratio or the confidence interval.  Some might say that Mr. Calloway misled readers by inaptly describing this hazard ratio as “slightly fewer” deaths on interferon γ-1b than placebo, and by failing to provide all the pertinent information.

Oh; wait. Is failure to present all the facts, fraud???

TRANSPOSITION FALLACY

Perhaps more ironic was that Mr. Calloway’s interpretation of statistical significance is wrong. The p-value is not the “probability that it was not due to the drug” or the probability that the null hypothesis is true.  Good thing that Mr. Calloway does not live in the United States where statistical errors of this sort can be a criminal offense.

The Nature news story quoted Gordon Guyatt, from McMaster University, who thinks that Dr. Harkonen skewed the findings:

“This guy gave a very unbalanced presentation; whether it is sufficiently unbalanced that you should send him to jail, I don’t know… .”

But the data were all accurately presented; it was the use of the verb “demonstrate,” which triggered the prosecution.  And it was hardly a “presentation”; it was a press release, which clearly communicated that a presentation was forthcoming within a couple of weeks at a scientific conference.

The story also cites Patricia Zettler, a former FDA attorney, who now teaches at Stanford Law School, for her doubts that the case will matter to most scientists.  See also Zettle, “U.S. v. Harkonen: Should Scientists Worry About Being Prosecuted for How They Interpret Their Research Results?” (Oct. 7, 2013).  If her prediction is correct, then this is a sad commentary on the scientific community.  Ms. Zettler suggests that the Supreme Court is likely to deny the petition, and leave Dr. Harkonen’s conviction in place, and that this denial will not seriously affect scientific discourse.  If this suggestion is true, then courts will have acquiesced in a very selective prosecution, given the widespread prevalence of the statistical reporting practices that were on trial here.

As much as everyone would like to see editors, scientists, governments, companies, and universities held to higher standards in science reporting, criminalizing the commonplace because the speaker is an unpopular scientist who has a commercial, as well as a scientific, interest is profoundly disturbing.  Ultimately, all scientists, from private or public sectors, from academic or non-academic institutions, have financial or reputational interests to be advanced in their communication of scientific results.

The irony is that many federal judges would not exclude an expert witness who would testify under oath to a conclusion based upon much weaker evidence than Dr. Harkonen presented in a press release, and which announced a much fuller discussion at an upcoming scientific conference in a couple of weeks.  If Ms. Zettler is correct, it will be much more difficult for federal and state trial judges to reject challenges to expert witness testimony based upon statistically “non-significant” results, with the old “goes to the weight, not the admissibility” excuse.

Bradford Hill on Statistical Methods

September 24th, 2013

I am indebted to the article by Dr. Frank Woodside and Allison Davis on the so-called Bradford Hill criteria, for reminding me about the distorted view that some plaintiffs’ counsel advance in litigation about Bradford Hill’s view of statistical testing.  Frank C. Woodside, III & Allison G. Davis, “The Bradford Hill Criteria: The Forgotten Predicate,” 35 Thomas Jefferson L. Rev. 103 (2013).  Dr. David Schwartz has also written an insightful blog post on Bradford Hill.  See David Schwartz, “5 Reasons to Apply the Bradford Hill Criteria in Your Next Case” (Sept. 20, 2013).

Here is where Bradford Hill postulates the position of a research question before his famous nine factors come into the analysis:

“Disregarding then any such problem in semantics we have this situation. Our observations reveal an association between two variables, perfectly clear-cut and beyond what we would care to attribute to the play of chance. What aspects of that association should we especially consider before deciding that the most likely interpretation of it is causation?”

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

The starting point, before the Bradford Hill nine factors come into play, requires a “clear-cut” association, which is “beyond what we would care to attribute to the play of chance.”  What is “clear-cut” association?  The most reasonable interpretation of Bradford Hill is that the starting point is an association that is not the result of chance, bias, or confounding.

I parted company with Woodside and Davis over whether Bradford Hill was somehow dismissive of the role of assessing chance in explaining an association.  In acknowledging any validity in the plaintiffs’ interpretation of Bradford Hill’s 1965 paper, Woodside and Davis, do an injustice, in my view, to Bradford Hill’s careful articulation of his position.

The starting position, quoted above, seems very clear, but Woodside and Davis note that later on in his speech, Bradford Hill suggested that tests of significance do not contribute to proof of the hypothesis.  Bradford Hill’s actual words are, however, fairly precise:

“No formal tests of significance can answer those questions. Such tests can, and should, remind us of the effects that the play of chance can create, and they will instruct us in the likely magnitude of those effects. Beyond that they contribute nothing to the ‘proof’ of our hypothesis.”

Bradford Hill at 299.

Plaintiffs’ counsel sometimes argue that this passage means that significance testing contributes “nothing” to proving the hypothesis, but this ignores two key points.  First, the argument ignores where in the text the passage occurs:  after Bradford Hill’s discussion of the nine factors.  Bradford Hill’s statement can be understood only as a reflection back on the nine factors.  The phrase “those questions” refers back to the nine factors, and this is the limitation that Bradford Hill is placing upon “formal tests of significance.” The starting point, before the nine factors are examined, is, after all, a “clear-cut” association, “beyond what we would care to attribute to the play of chance.”

Second, plaintiffs’ counsel’s argument ignores the clear meaning of the “[b]eyond that” phrase.  Beyond what?  Well, the limited role is nothing other than quantifying the play of chance in the observed results.  This role is hugely important, and of course, is incorporated into the starting point before the nine factors are examined.  In modern analyses, the role of random variability would actually be explored in the analysis of the exposure-outcome gradient, and perhaps in some of the other nine factors as well.  Bradford Hill implied that a statistically significant association was a preliminary step, after which the really hard work began.

It would be unfair to Bradford Hill to read into his statement much about “strict” testing versus a more flexible inferential approach in selecting or interpreting a Type I error rate.  By the time he presented his Presidential Address to the Royal Society of Medicine in 1965, much fur had flown in the disputes between Neyman and Fisher.  Resolving Bradford Hill’s view on the dispute is not a pressing issue because on either account, the quantification of the p-value is an extremely important step in evaluating scientific data.

In his textbook on medical statistics, Bradford Hill expands on the role of statistical analysis in medicine:

“Are simple methods of the interpretation of figures only a synonym for common sense or do they involve an art or knowledge which can be imparted? Familiarity with medical statistics leads inevitably to the conclusion that common sense is not enough. Mistakes which when pointed out look extremely foolish are quite frequently made by intelligent persons, and the same mistakes, or types of mistakes, crop up again and again. There is often lacking what has been called a ‘statistical tact, which is rather more than simple good sense’. That tact the majority of persons must acquire (with a minority it is undoubtedly innate) by a study of the basic principles of statistical method.”

Austin Bradford Hill, Principles of Medical Statistics at 2 (4th ed. 1948) (emphasis in original).

Even in this early work though, Bradford Hill acknowledges the limits of statistical methods:

“It is a serious mistake to rely upon the statistical method to eliminate disturbing factors at the completion of the work.  No statistical method can compensate for a badly planned experiment.”

Id. at 4 (emphasis in original).  That statistical method cannot save a poorly planned experiment (or observational study) does not, however, imply that statistical methods are not needed to interpret a properly planned experiment or study.

In the summary section of the first chapter, Bradford Hill removes any doubt about his view of the importance, and the necessity, of statistical methods:

“The statistical method is required in the interpretation of figures which are at the mercy of numerous influences, and its object is to determine whether individual influences can be isolated and their effects measured.”

Id. at 10 (emphasis added).

Do English Judges Diss Epidemiology?

September 13th, 2013

As noted the other day, Claire McIvor, a senior lecturer, at the Birmingham Law School, has published an interesting U.K. perspective on the use of epidemiologic and statistical evidence in health-outcome litigation. SeeDebunking some judicial myths about epidemiology and its relevance to UK tort law,” in 21 Med. Law Rev. (2013), in press.

Ms. McIvor criticizes one case in particular for what she argues is an inappropriate dismissal of epidemiologic evidence as presented by an epidemiologist. Novartis Grimsby Ltd. v. Cookson, [2007] EWCA Civ 1261.

The pursuer, Cookson, worked for Novartis Grimsby, at its factory that manufactured dyes, including azo dyes, from 1964, until 2001, when he developed bladder cancer.  Cookson also chose to be exposed to various carcinogens as a personal lifestyle; he smoked cigarettes, 1/2 to one pack per day, for about 20 years, before quitting around 1980.

Cookson sued Novartis on allegations that he was overexposed to various aromatic amines[1], some of which are known to cause bladder cancer.  Novartis had previously paid such claims, but it contested Mr. Cookson’s case because of its belief that his workplace exposures had not been excessive, and that his past smoking habit more likely explained his cancer.  Both sides called physician expert witnesses, urologists, who both agreed that smoking and the aromatic amines could cause bladder cancer, but disagreed as to what caused Mr. Cookson’s disease.

Given the contest on causation, the two urologists agreed that the input of an epidemiologist, jointly instructed, would be helpful.  Now how quaint is that, for both sides to agree upon an expert witness?  Most lawyers in the United States would think it malpractice to engage in such a practice.

Professor Ray Cartwright, an epidemiologist who had published on the causes of bladder cancer, was the jointly instructed witness. A PubMed search for articles written by Cartwright on bladder cancer is set out below, and suggests that he was an appropriate choice, ex ante, at any rate.

Cartwright reviewed the epidemiologic literature, including some of his own studies. Cartwright’s report disappointed the plaintiff, however, when he opined that the workplace aromatic amine exposure was slight and posed only a low risk compared to the smoking. In assessing Cookson’s workplace exposure, Cartwright relied upon the exposure estimates of the parties’ industrial hygienists, and based his causal attribution upon an assessment that exposures were low.  Later, when plaintiff’s counsel showed that Cartwright misinterpreted some of the exposure data, Cartwright revised his report, but maintained that Cookson’s cancer was caused by smoking.

Professor Cartwright’s misstep on exposure probably diminished the strength of his opinion in the eyes of the trial judge, who ruled for the plaintiff.  Ms. McIvor seems to believe that this ruling improperly elevated clinical testimony over epidemiologic testimony, and credited “personalized probabilities” of the plaintiff’s testifying urologist, who attributed the cancer 20–25% to smoking, versus 70–75% to workplace exposures, and who opined that the workplace more than doubled the risk level that Cookson would have had had he never worked at the Novartis factory.  Novartis Grimsby Ltd. at 48.

Novartis appealed, on grounds that included an allegation of error in equating fact of exposure with causation of the bladder cancer.  Speaking for a unanimous England and Wales Court of Appeal, Lady Justice Smith dismissed the appeal, including its challenge to the medical causation issues.  Contrary to Ms. McIvor, however, the appellate court’s decision gave due weight to the epidemiologist, but found that the epidemiologic evidence was accessible to, and interpretable by, the clinicians. Although neither the appellate decision nor McIvor reviewed the actual epidemiologic evidence, several studies suggest that the relative risks for benzidine-derived dyes are greater than for smoking, and especially the risk for former smokers.  The judicial decision flowed not from improvidently dismissing epidemiologic evidence, or testimony by an epidemiologist, but from relying upon epidemiologic evidence marshaled by the plaintiff, through his urologist.[2]

Both sides agreed that smoking could cause bladder cancer, but they also had to agree that the risk of bladder cancer wanes after smoking cessation. Unfortunately, the Court of Appeal did not review the evidence, but the Surgeon General’s Reports note that cessation reduces risk by half after only a few years.  Wynder and Stellman (1977) and Wynder and Goldsmith (1977) suggest that the risk returns to baseline after 15 years of abstinence.  A study by Cartwright himself suggested the return to baseline in six years, although other studies (by Iscovich; Howe; Vineis; Hartge; and Burch) suggested an initial decline, followed by a persistent increased risk even beyond 15 years of abstinence.

Lady Justice Smith declared herself perplexed by these data, which seemed to be at odds with the notion that bladder cancer develops after 20 or more years latency:

“I myself have found it hard to understand how the passage of time after stopping smoking could result in a reduced risk of developing the disease if the aetiology of the disease is that the cancer begins at the time of exposure but does not manifest itself until later. However, as I have said, this issue was not fully explored in evidence and both experts agreed that the risk of developing bladder cancer from smoking decreased after smoking ceased.”

Novartis Grimsby Ltd. at 45.

Clearly though, it was not helpful to have Cartwright contradicted by the data in his own study.  Although the higher aromatic amine exposures occurred early in the plaintiff’s work career, Cookson continued to have some exposure up until the time of his diagnosis in 2001.  Professor Cartwright may well have been further undermined by the lack of any “time windows” in the occupational epidemiology, which would have supported a similar argument of declining risk from the more intense occupational exposure in the 1960’s.  The absence of such evidence for benzidine, compared with the evidence of latency and post-cessation declining risk for smoking, clearly hurt the employer’s case.  This imbalance in the evidence clearly helps to explain and support the courts’ rejection of Cartwright’s testimony.

Given the epidemiologic evidence, it is not at all clear that the plaintiff’s testifying urologist’s opinion that smoking contributed 25%-30%, whereas aromatic amines contributed 70%-75%, was merely a subjective or personal probability.  Smoking is associated with a two- to three-fold increase in risk in prospective studies, but Cookson was 20 years post-cessation.  His aromatic amine dyestuff exposure, which carries a much higher relative risk for bladder cancer, continued through till the end of his work tenure.  See “Dyes metabolized to benzidine,” in IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 100F (WHO 2012).

Cookson’s bladder cancer might have been a “background” case, or a result of both smoking and aromatic amine exposure, or a result of one or the other contested causes.  There appeared to be no serious evidence of synergy.  Given the studies at issue, the plaintiff’s testifying urologist’s opinion may well have been a reasoned analysis of the epidemiologic evidence.  The epidemiologist’s opinion, on the other hand, was clearly undermined by the facts of smoking cessation, and an initial error in exposure estimation.  Novartis’ counsel argued that Cartwright was the “real expert” on the issue of attribution, but Cartwright’s opinion was lacking important foundational facts, and there was no argument that Mr. Barnard, the plaintiff’s urologist, had erred in interpreting the epidemiologic data.  Novartis Grimsby Ltd. at 56.  The real “expert” was in the data, and there was no showing (at least in the published opinion) that the clinician, Mr. Barnard, misunderstood or distorted the epidemiologic data.  In this respect, the Novartis Grimsby case is very different from the Milward case, in which a plaintiff’s toxicologist mistreated, misanalyzed, and misrepresented epidemiologic studies on benzene.

Lady Justice Smith rejected the appellant’s criticism of the trial judge’s weighting Mr. Barnard’s opinion over Professor Cartwright’s:

“The proposition that a clinician is not capable of fully understanding the published epidemiological literature on the causation of a condition within his own specialty seems unsustainable and would, I think, surprise many clinicians and epidemiologists. In my view, it was clear from his detailed reports on causation that Mr. Barnard was familiar with the published work and he was also able to discuss it intelligently when giving evidence. The Recorder was plainly of that view. As for the suggestion that Mr. Barnard was too ready to assume that working for the appellant created an increased risk, this was a good ‘jury point’ but, if it did not appeal to the Recorder, that was an end to it.”

Novartis Grimsby Ltd. at 57.

Although Ms. McIvor is correct to be concerned with the court’s eager over-generalization about the ability of clinicians to understanding of epidemiologic studies, there was little suggestion that Mr. Barnard had tripped up, and there was a good deal to suggest that Professor Cartwright’s opinion was lacking on essential issues.  Admittedly, this impression may have been created by selective reporting by the Court of Appeal.  I have not seen the record or the briefs, but Ms. McIvor has not cited anything from those sources.

Mr. Barnard, the plaintiff’s urologist, further testified that the “occupational exposure had more than doubled the risk due to smoking.”  Novartis Grimsby Ltd. at 53.  The Court of Appeal thus found it easy to affirm the verdict that Cookson had shown that his workplace exposure was the “but for” cause of his cancer.  Of course, the Court of Appeal here accepted evidence of risk and relative risk as showing causation, a dubious proposition. Novartis Grimsby Ltd. at 67. And the Court of Appeal, distinguishing a pneumoconiosis case, further pronounced that the bladder cancer injury was “indivisible,” and thus not capable of an apportionment because neither exposure could be said to make the disease more severe.  The Court could have said, if it yielded to its own risk as causation rationale, that both exposures made the cancer more likely, and the occupational exposure contributed to this overall risk three times as much as the plaintiff’s smoking.  In Justice Lady Smith’s words:

“The natural inference to draw from the finding of fact that the occupational exposure was 70% of the total is that, if it had not been for the occupational exposure, the respondent would not have developed bladder cancer. In terms of risk, if occupational exposure more than doubles the risk due to smoking, it must, as a matter of logic, be probable that the disease was caused by the former.”

Novartis Grimsby Ltd. at 74.

The Court of Appeal’s opinion was thus consistent with its own commitment to the conflation of risk with causation, a conflation that may well be objectionable, but does not seem to be the basis for Ms. McIvor’s objections to the Novartis decision.  Of course, a remand with directions to apportion would have a perfectly logical and consistent result with the insistence that risk be substituted for causation in supporting the verdict below.


Publications of Professor Cartwright on Bladder Cancer from National Library of Medicine Database

1: Subramonian K, Cartwright RA, Harnden P, Harrison SC. Bladder cancer in patients with spinal cord injuries. BJU Int. 2004 Apr;93(6):739-43. PubMed PMID: 15049983.

2: Cartwright RA. Bladder cancer screening in the United Kingdom. J Occup Med. 1990 Sep;32(9):878-80. PubMed PMID: 2074512.

3: Cuzick J, Babiker A, De Stavola BL, McCance D, Cartwright R, Glashan RW. Palmar keratoses in family members of individuals with bladder cancer. J Clin Epidemiol. 1990;43(12):1421-6. PubMed PMID: 2147716.

4: Philip PA, Fitzgerald DL, Cartwright RA, Peake MD, Rogers HJ. Polymorphic N-acetylation capacity in lung cancer. Carcinogenesis. 1988 Mar;9(3):491-3. PubMed PMID: 3345587.

5: Cartwright RA. Screening workers exposed to suspect bladder carcinogens. J Occup Med. 1986 Oct;28(10):1017-9. PubMed PMID: 3772536.

6: Boyko RW, Cartwright RA, Glashan RW. Bladder cancer in dye manufacturing workers. J Occup Med. 1985 Nov;27(11):799-803. PubMed PMID: 4067684.

7: Cartwright RA, Philip PA, Rogers HJ, Glashan RW. Genetically determined debrisoquine oxidation capacity in bladder cancer. Carcinogenesis. 1984 Sep;5(9):1191-2. PubMed PMID: 6467507.

8: Cartwright RA, Glashan RW. Palmar keratoses and bladder cancer. Lancet. 1984 Mar 10;1(8376):563. PubMed PMID: 6142276.

9: Cartwright RA, Adib R, Appleyard I, Glashan RW, Gray B, Hamilton-Stewart PA, Robinson M, Barham-Hall D. Cigarette smoking and bladder cancer: an epidemiological inquiry in West Yorkshire. J Epidemiol Community Health. 1983

Dec;37(4):256-63. PubMed PMID: 6655413; PubMed Central PMCID: PMC1052920.

10: Cartwright RA, Adib R, Appleyard I, Glashan RW, Richards B, Robinson MR, Sunderland E, Barham-Hall D. ABO, MNSs and rhesus blood groups in bladder cancer. Br J Urol. 1983 Aug;55(4):377-81. PubMed PMID: 6411162.

11: Cartwright RA, Adib R, Appleyard I, Coxon JG, Glashan RW, Richards B, Robinson MR, Sunderland E, Barham-Hall D. Ten genetic polymorphisms in bladder cancer. J Med Genet. 1983 Apr;20(2):112-6. PubMed PMID: 6221102; PubMed Central PMCID: PMC1049011.

12: Cartwright RA. Historical and modern epidemiological studies on populations exposed to N-substituted aryl compounds. Environ Health Perspect. 1983 Mar;49:13-9. PubMed PMID: 6339220; PubMed Central PMCID: PMC1569142.

13: Cartwright RA, Robinson MR, Glashan RW, Gray BK, Hamilton-Stewart P, Cartwright SC, Barham-Hall D. Does the use of stained maggots present a risk of bladder cancer to coarse fishermen? Carcinogenesis. 1983;4(1):111-3. PubMed PMID: 6821882.

14: Cartwright RA, Glashan RW, Rogers HJ, Ahmad RA, Barham-Hall D, Higgins E, Kahn MA. Role of N-acetyltransferase phenotypes in bladder carcinogenesis: a pharmacogenetic epidemiological approach to bladder cancer. Lancet. 1982 Oct 16;2(8303):842-5. PubMed PMID: 6126711.

15: Garner RC, Mould AJ, Lindsay-Smith V, Cartwright RA, Richards B. Mutagenic urine from bladder cancer patients. Lancet. 1982 Aug 14;2(8294):389. PubMed PMID: 6124790.

16: Cartwright R. Occupational bladder cancer and cigarette smoking in West Yorkshire. Scand J Work Environ Health. 1982;8 Suppl 1:79-82. PubMed PMID: 7100861.

17: Glashan RW, Cartwright RA. Occupational bladder cancer and cigarette smoking  in West Yorkshire. Br J Urol. 1981 Dec;53(6):602-4. PubMed PMID: 7317749.

18: Cartwright RA, Gadian T, Garland JB, Bernard SM. The influence of malignant cell cytology screening on the survival of industrial bladder cancer cases. J Epidemiol Community Health. 1981 Mar;35(1):35-8. PubMed PMID: 7264531; PubMed Central PMCID: PMC1052117.

19: Cartwright RA, Adib R, Glashan R, Gray BK. The epidemiology of bladder cancer in West Yorkshire. A preliminary report on non-occupational aetiologies. Carcinogenesis. 1981;2(4):343-7. PubMed PMID: 7273315.

20: Cartwright RA, Glashan RW, Gray B. Survival of transitional cell carcinoma cases in 2 Yorkshire centres. Br J Urol. 1980 Dec;52(6):497-9. PubMed PMID: 7459578.

21: Cartwright RA, Bernard SM, Glashan RW, Gray BK. Bladder cancer amongst dye users. Lancet. 1979 Nov 17;2(8151):1073-4. PubMed PMID: 91807.

22: Cartwright RA. Genetic association with bladder cancer. Br Med J. 1979 Sep 29;2(6193):798. PubMed PMID: 519209; PubMed Central PMCID: PMC1596415.

23: Williams DR, Cartwright RA. The esterase D polymorphism in patients with diabetes or carcinoma of the bladder and a matched sample of non-dono. Ann Hum Biol. 1978 May;5(3):281-4. PubMed PMID: 686669.


[1] α-naphthylamine, some of which was contaminated with β-napthylamine, benzidine, dianisidine and o-tolidine

[2] There was a suggestion that the plaintiff’s urologist had invoked his clinical experience in treating men from the factory with bladder cancer, but the courts did not seem to give dispositive weight to this irrelevant argument for causation. Novartis Grimsby Ltd. at 56.

Daubert Bewigged

September 11th, 2013

Claire McIvor, a senior lecturer, at the Birmingham Law School, has published an interesting U.K. perspective on the use of epidemiologic and statistical evidence in health-outcome litigation. See “Debunking some judicial myths about epidemiology and its relevance to UK tort law,” in 21 Med. Law Rev. (2013), in press.

McIvor argues that British judges have failed to engage with epidemiologic evidence, and have relegated epidemiologic evidence to a status inferior to clinical evidence, even when testifying clinicians have little to offer the fact finder.  If the be-wigged judges have done this shame on them, but McIvor suggests that a pre-trial hearing is necessary to address the proper (and improper) range of methodologies and inferences:

“The very fact that methodologically problematic evidence can end up before a trial court is indicative of the need for a pre-trial admissibility test for scientific evidence in UK civil law. Such a test would afford the court an opportunity to evaluate the scientific reliability of any epidemiological evidence that the parties wish to introduce at trial.”

McIvor at 22.  In advancing this recommendation, McIvor expands upon a recent Law Commission recommendation for what she describes as “a pre-trial admissibility test for scientific evidence in criminal litigation, similar to that which is used in the USA.”  McIvor at 32 (citing Law Commission, Expert Evidence in Criminal Proceedings in England and Wales (Law Comm’n No. 325, 2011)).

This recommendation and discussion, however, are confusing and perhaps confused.  The test in the United States is not a pre-trial test, although a party may ask for a determination in advance, either in conjunction with a motion for summary judgment, or to limit the evidentiary display at trial.   Nonetheless, objections to expert witness opinion testimony can certainly be made at trial.  Indeed, if the pre-trial motion is denied, the moving party may well have to renew its objection at trial in any event.

MacIvor’s recommendation is puzzling for other reasons.  First, most civil cases are tried to the bench, and the need to challenge the expert opinion pre-trial is certainly less pressing.  Lengthy, methodological challenges are virtually impossible before a jury but they would be made in front of the presiding judge, in any event.  Second, having recommended the pre-trial procedure, and the substantive standard for reliability and validity, McIvor proceeds to tell us that it [the Daubert standard] has “proven to be a rather controversial test in practice.”  Id. at 32 n.84 (citing no less of an authority than Carl Cranor, Toxic Torts: Science, Law and the Possibility of Justice 62-90 ( 2006)).  Cranor is hardly an unbiased, reliable source, but if McIvor accepts his pronouncements, her recommendation is hard to understand.  Third, McIvor gives us an example of a class of cases, which at first blush, suggest that judges on the other side of the Atlantic just do not understand science.  In McTear v. Imperial Tobacco, [2005] 2 SC 1, the trial judge, Lord Nimmo Smith, ruled in favor of a tobacco company in a lung cancer personal injury case.  His ruling was largely based upon a rejection of the epidemiologic evidence, which McIvor suggests is unreasonable, but then tells us that the rejection might have resulted from the plaintiffs’ reliance upon reports without the benefit of an epidemiologist to explain and teach the trial judge about the meaning of the evidence.

Indeed, McIvor tells us that Lord Nimmo Smith complained in his opinion that he had not been:

“‘sufficiently instructed by the expert evidence about this discipline’ to be able to form his own judgment of the evidence. This was not an unreasonable point, at least as regards the issue of individual causation.”

McIvor at 32 (quoting Lord Nimmo Smith).  Well, it does suggest that the good Lord may have been a stubborn Scot, who was not going to give any weight to the common wisdom, but rather insist that the plaintiff make his case in court.  Even McIvor goes on to characterize the plaintiff’s counsel’s strategy as “unwise, in hindsight.”  Id.

Rule 702 is an extremely important part of the law of evidence in federal courts, and in many state courts.  The U.K. would do well to adopt it, with allowance for the very different role of judges in civil cases on the other side of the Atlantic.