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Differential Diagnosis in Milward v. Acuity Specialty Products Group

September 26th, 2013

Graffiti on the bathroom wall in the building that housed my undergraduate college’s philosophy department:

How does a philosopher treat constipation?

By using iterative disjunctive syllogism.

The joke is that this variety of syllogism is nothing other than reasoning by the process of elimination.

A or B or C

~A

B or C

~B

∴C

The syllogism works as a valid form of argument if the premises are all true.  So, if we start with three possible causes, A, B, and C, and we know that one or more of them caused an outcome, then we might proceed by the process of elimination to show that we can rule out all the others but the alleged cause.  The first line of the syllogism is true if at least one of the disjuncts is true.  As we rule out particular disjuncts upon learning that they are in fact false, we are left we a smaller set of disjuncts.  If we can proceed until we are left with the disjunct of interest, we may actually have succeeded in identifying a cause in fact of the particular case.

In the syllogistic argument above, we must be able to show that A and B are false before we can then conclude that C is true.

In differential etiology, we start with known causes, exposures or conditions that are known to be capable of causing a disease or disorder.  We do not know whether the potential causes were actually in play in a given case.  If we can use this syllogistic reasoning to conclude that the defendant’s product was a cause of the of the plaintiff’s harm, we might actually have shown specific causation in a reliable fashion.  If, however, we cannot proceed to a conclusion that unequivocally includes the defendant’s product, we are left with an indeterminate outcome, and the plaintiff must take nothing.

The Milward case was recently back in the news.  On remand from the First Circuit, the district judge, now the Hon. Douglas Woodlock, faced a renewed Rule 702 motion directed to Milward’s specific causation expert witnesses.  Milward v. Acuity Specialty Products Group, Inc., Civil Action No. 07–11944–DPW, 2013 WL 4812425 (D. Mass. Sept. 6, 2013).

Judge Woodlock wryly commented upon the First Circuit’s ignoring the statutory mandate of Rule 702, by its embracing caselaw that predated the 2000 statutory amendment of the Rule:

“While a 2000 amendment to Fed.R.Evid. 702 codified a rigorous reliability test, the Daubert line of cases has been read by the First Circuit as “demand[ing] only that the proponent of the evidence show that the expert’s conclusion has been arrived at in a scientifically sound and methodologically reliable fashion.” Ruiz–Troche v. Pepsi Cola of Puerto Rico Bottling Co., 161 F.3d 77, 85 (1st Cir.1998). “So long as an expert’s scientific testimony rests upon good grounds based on what is known, it should be tested by the adversarial process, rather than excluded for fear that jurors will not be able to handle the scientific complexities.” Milward, 639 F.3d at 15 (internal quotation and citation omitted).”

Milward, at *3.  After noting the statute’s “rigorous reliability test,” and the First Circuit’s having  diluted the statutory standard by drawing from pre-statute caselaw, Judge Woodlock got down to the business of gatekeeping, by examining the facts of record before him.

The defense’s first challenge was to Milward’s industrial hygienist’s opinion that quantified his benzene exposure.  The industrial hygienist, James Stewart, estimated Milward’s benzene exposure, both total and from individual products.  The defense challenge was interesting, given that plaintiffs have challenged defendants’ use of similar exposure recreations to advance apportionments that will defeat joint and several liability.  The district court denied the defense challenge, and turned its attention to the specific causation issue, which proved to be a good example of patho-epistemology .

The plaintiffs relied upon Dr. Sheila Butler, who was board certified in occupational medicine, pathology, and hematology, to opine that Brian Milward’s exposure was responsible for causing his Acute Promyelocytic Leukemia (“APL”), a rare subtype of Acute Myeloid Leukemia (“AML”). Butler’s opinion was simple if not simpistic:

“there is a ‘reasonable medical probability that there is a direct causal association between Mr. Milward’s APL and his excessive occupational exposure to benzene containing substances’ based primarily on

(1) the fact that his exposure to benzene preceded his development of APL, and

(2) a survey of studies showing increased AML risk following low average dose exposures to benzene.”

Milward at *6.

Simplistic and simply wrong. Butler had equated exposure and some risk, unquantified, with specific causation, an empty and unsupported assertion.  Judge Woodlock did not dignify this subjective opinion with further discussion, but turned his attention to Butler’s “differential diagnosis” analysis by which Butler claimed to have eliminated other potential causes of Milward’s APL such that she could say that benzene was a specific cause.

The district court started from the premise that so-called differential diagnosis is useful and accepted for assessing causation. Id. at *7 (citing Baker v. Dalkon Shield Claimants Trust, 156 F.3d 248, 253 (1st Cir.1998).  For some reason, however, the court emphasized that the differential etiology was particularly appropriate when the expert witness’s opinion lacks a foundation of epidemiologic studies or a “well-established threshold exposure levels at which disease occurs.”  The district court did not explain what it possibly could have meant by this emphasis, and I doubt that there is any basis for the court’s statement.

The real issue in Milward, on remand, was whether Dr. Butler applied the differential etiology in a reliable manner.  The defense argued that Dr. Butler failed to rule out competing risk factors, Milward’s prior smoking, and his morbid obesity, as causes of Milward’s APL.  The court dismissed this challenge with the recognition that plaintiffs might still prevail if Milward’s disease resulted from either benzene and smoking or benzene, smoking, and obesity. Sadly, the court did not address the quality or quantity of the evidence for smoking, or for obesity, and APL; nor did it address the magnitude of the associations that were being claimed by the defense, or by the plaintiffs.  The court did not explore the evidentiary base for the defense assertion that smoking or obesity causes APL such that it should be in the first line of the iterative disjunctive syllogism.

The problem, of course, was not the plaintiffs’ failure to rule out obesity or smoking, but their failure to rule out the unknown factors, which account for the solid majority of APL cases.  Indeed, in the first round of Rule 702 briefings and hearings, plaintiffs’ expert witness, Dr. Martin Smith, opined that between 70 and 80 percent of APL cases are idiopathic; that is, they have no known cause.  Id. at *7.  The syllogism thus becomes very difficult because one proposition in the first line of the argument is that the cause is unknown, and the plaintiff cannot arrive at the conclusion that his APL was caused by benzene unless and until he provides reliable evidence that more likely than not, his APL disease was not caused by one or more of the unknown causes.  In other words, plaintiffs must show that the APL was not a background case that would have occurred regardless of occupational benzene exposure, and perhaps regardless of occupational exposure with obesity and smoking.  Judge Woodlock, relying heavily upon the Restatement (Third) of Torts expressed the matter this way:

“When a disease has a discrete set of causes, eliminating some number of them significantly raises the probability that the remaining option or options were the cause-in-fact of the disease.  Restatement (Third) of Torts: Phys. & Emot. Harm § 28, cmt. c(4) (2010) (‘The underlying premise [of differential etiology] is that each of the[] known causes is independently responsible for some proportion of the disease in a given population.  Eliminating one or more of these as a possible cause for a specific plaintiff’s disease increases the probability that the agent in question was responsible for that plaintiff’s disease.’). The same cannot be said when eliminating a few possible causes leaves not only fewer possible causes but also a high probability that a cause cannot be identified. Id. (‘When the causes of a disease are largely unknown … differential etiology is of little assistance’.).”

In the face of this irrefutable logic of this part of comment c, Butler argued that she had “ruled out” idiopathic APL by “ruling in” benzene.  Of course, benzene had to be postulated as a general cause in order for it to be placed into the first line of the syllogism, but Butler’s assertion about ruling in benzene as a specific cause is truly an ipse dixit, a non sequitur, and a petitio principii, all rolled into one opinion.  After all, the APL case may have arisen out of benzene exposure and the unknown causes, or only the unknown (idiopathic) causes.  Butler cannot rule in benzene until she rules out idiopathic causes as the sole specific causes in this case. To be fair, the prevalence of idiopathic cases cited by Martyn Smith might be lower in a population with heavy benzene exposure, assuming Smith’s general causation were true, but again, such an acknowledgment would only raise the question of what the prevalence of idiopathic cases is in a population of exposure that looked like Mr. Milward’s.

Dr. Butler argued that Martyn Smith had previously ruled in benzene, but that was only as a general cause that can then be represented as one disjunct in the first line of the syllogism.  Here Judge Woodlock identified another gap between Smith’s general causation opinion and Dr. Butler’s attempt to use Smith’s opinion to place benzene into the differential etiology for Mr. Milward.  On this remand, the plaintiffs had to show that “the levels of exposure that are hazardous to human beings generally as well as the plaintiff’s actual level of exposure.” Id. (citing Westberry v. Gislaved Gummi AB, 178 F.3d 257, 263-64 (4th Cir.1999) (talcum powder undisputedly could cause sinus problems, and plaintiff was exposed at levels known to be causative).  The court suggested that Milward had not yet shown that exposure at the levels he experienced could cause APL.  Of course, even if Milward sustained cumulative exposures capable of causing APL, this fact sufficed only to place benzene into the differential diagnosis, and it did not advance the iterative disjunctive syllogism to a conclusion of either a single or multiple disjuncts that included benzene.

Judge Woodlock did a good job of saving the First Circuit from the notoriety of its general causation decision in the Milward case. The new trial court decision is a strong reminder that risk does not equal causation.  Differential etiology cannot rule out idiopathic cause(s) as the sole specific cause of a plaintiff’s disease unless there is a fingerprint of causation that makes the risk identifiable as a cause in a specific case.  Such a fingerprint or biomarker was apparently absent in the Milward case.  Similarly, the differential etiology might rule out putative specific causes on a probabilistic basis if the idiopathic cases made up a small number of all the cases in relation to the number of cases that arise from the exposure that is the subject of the litigation.

The Milward decision joins other soundly decided differential diagnosis cases coming out of the First Circuit.  See, e.g., Plourde v. Gladstone, 190 F. Supp. 2d 708, 722-723 (D. Vt. 2002) (excluding testimony where expert failed to rule out causes of plaintiff’s illness other than exposure to herbicides); Whiting v. Boston Edison Co., 891 F. Supp. 12, 21 n.41 (D. Mass. 1995) (noting that differential diagnosis cannot be used to support conclusion of specific causation when 90% disease cases are idiopathic).

But lest anyone get too comfortable with the notion that this issue has been mastered by the federal judiciary, keep in mind that there are some really poorly reasoned cases out there. See, e.g., Allen v. Martin Surfacing, 263 F.R.D. 47, 56 (D. Mass. 2008) (admitting general and specific causation testimony to be tested by adversary process, rather than excluded altogether, despite paucity of epidemiologic evidence and general acceptance that there are no known causes of amyotrophic lateral sclerosis).

The limits of the “process of elimination” approach has been addressed by some scientific organizations, such as the Teratology Society, in the particularly demanding context of determining a cause for a child’s congenital malformation:

“Biologic plausibility includes a consideration of alternative explanations for the outcome in an individual plaintiff. For example, if a plaintiff has a birth defect syndrome caused by a known genetic disorder, chemical exposure becomes implausible as a cause of the abnormality in that particular individual. The consideration of alternative explanations is sometimes misused by expert witnesses to mean that failure to find an alternative explanation for an outcome is proof that the exposure at issue must have caused the outcome. A conclusion that an exposure caused an outcome is, however, based on positive evidence rather than on lack of an alternative explanation.”

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).

A brief, partial survey of differential etiology cases is set out below.

SECOND CIRCUIT

McCullock v. H.B. Fuller Co., 61 F.3d 1038, 1044 (2d Cir. 1995) (defining differential etiology as an analysis “which requires listing possible causes, then eliminating all causes but one”)

Prohaska v. Sofamor, S.N.C., 138 F. Supp. 2d 422, 439 (W.D.N.Y. 2001) (excluding expert’s opinion and granting summary judgment where expert “was unable to rule out, to a reasonable degree of medical certainty, [plaintiff’s] pre-existing condition, scoliosis, as a current cause of her pain”)

Zwillinger v. Garfield Slope Hous. Corp., 1998 WL 623589, at *20 (E.D.N.Y. Aug. 17, 1998) (excluding testimony and granting summary judgment where expert failed to rule out alternative causes of plaintiff’s immunotoxicity syndrome)

THIRD CIRCUIT

Magistrini v. One Hour Martinizing Dry Cleaning, 180 F. Supp. 2d 584, 608-610 (D.N.J. 2002) (excluding testimony of expert who sought to testify that dry cleaning fluid caused leukemia, but failed to rule out smoking as an alternative cause), aff’d, 68 F. App’x 356 (3d Cir. 2003)

In re Paoli R.R. Yard PCB Litig., 2000 WL 274262, at *5 (E.D. Pa. March 1, 2000) (expert’s opinion should be excluded “because she failed to rule out alternative causes” of plaintiff’s injuries)

Kent v. Howell Elec. Motors, 1999 WL 517106, at * 5 (E.D. Pa. July 20, 1999) (excluding expert testimony and granting summary judgment because expert could “not rule out reasonable alternative theories of what caused the retaining ring to fail”);

O’Brien v. Sofamor, 1999 WL 239414, at *5 (E.D. Pa. Mar. 30, 1999) (excluding expert’s testimony and granting summary judgment where plaintiff “offer[ed] no evidence that [plaintiff’s experts] performed a differential diagnosis, or even considered other potential causes” of plaintiff’s back condition)

Schmerling v. Danek Med., Inc., 1999 WL 712591, at *9 (E.D. Pa. Sept. 10, 1999) (excluding expert’s testimony and granting summary judgment on the grounds that expert’s failure to rule out alternative causes “alone warrants a determination that the expert’s methodology is unreliable”);

Turbe v. Lynch Trucking Inc., 1999 WL 1087026, at *6 (D.V.I. Oct. 7, 1999) (excluding expert’s testimony where expert “expressed awareness of obvious alternative causes” yet “did not investigate any other possible causes”);

Reiff v. Convergent Technologies, 957 F. Supp. 573, 582-83 (D.N. J. 1997) (excluding expert’s testimony and granting summary judgment where expert failed to rule out alternative causes of plaintiff’s carpal tunnel syndrome)

Rutigliano v. Valley Bus. Forms, 929 F. Supp. 779, 787 (D.N.J. 1996) (excluding expert’s testimony and granting summary judgment where the “record is replete with evidence, including [the expert’s] own admissions, that [plaintiff’s] symptoms could be attributable to medical conditions other than formaldehyde sensitization”)

Diaz v. Matthey, Inc., 893 F. Supp. 358, 376-377 (D.N.J. 1995) (excluding testimony and granting summary judgment where expert failed to rule out alternative causes for plaintiff’s asthma) (Irenas, J.)

Wade-Greaux v. Whitehall Labs., Inc., 874 F. Supp. 1441 (D.V. I.), aff’d, 46 F.3d 1120 (3d Cir. 1994) (excluding testimony of expert who failed to rule out alternative causes of plaintiff’s birth defects)

FOURTH CIRCUIT

Westberry v. Gislaved Gummi AB, 178 F.3d 257, 262-263 (4th Cir. 1999) (“Differential diagnosis, or differential etiology, is a standard scientific technique of identifying the cause of a medical problem by eliminating the likely causes until the most probable one is isolated”)

Shreve v. Sears, Robuck & Co., 166 F. Supp. 2d 378, 397-98 (D. Md. 2001) (excluding testimony where expert failed to rule out other causes of plaintiff’s injury other than an alleged defect in snow thrower)

Fitzerald v. Smith & Nephew Richards, Inc., 1999 WL 1489199 (D. Md. Dec. 30, 1999) (excluding expert’s testimony and granting summary judgment where expert “failed to rule out what could have been another cause of [plaintiff’s] condition”)

Aldridge v. Goodyear Tire & Rubber Co., 34 F. Supp. 2d 1010, 1024 (D. Md. 1999), vacated on other grounds, 223 F.3d 263 (4th Cir. 2000) (excluding testimony of plaintiffs’ experts where they “failed to adequately address possible alternative causes of plaintiffs’ illnesses”)

Oglesby v. General Motors Corp., 190 F.3d 244, 250 (4th Cir. 1999) (affirming exclusion of testimony where “as a matter of logic, [the expert witness] could not eliminate other equally plausible causes” of cracked plastic inlet);

Driggers v. Sofamor, S.N.C., 44 F. Supp. 2d 760, 765 (M.D.N.C. 1998) (excluding expert’s testimony and granting summary judgment where “expert failed to rule out other possible causes of [plaintiff’s back] pain”);

Higgins v. Diversey Corp., 998 F. Supp. 598, 603 (D. Md. 1997), aff’d, 135 F.2d 769 (4th Cir. 1998) (excluding expert’s testimony that the accidental inhalation of a bleach caused plaintiff’s injuries, where expert “admit[ted] that he [could] not rule out several other possible causes”)

FIFTH CIRCUIT

Michaels v. Avitech, Inc., 202 F.3d 746, 753 (5th Cir. 2000) (excluding testimony when “plaintiff’s experts wholly fail[ed] to address and rule out the numerous other potential causes” of an aircraft disaster)

Black v Food Lion, Inc, 171 F3d 308 (5th Cir 1999) (expert witness, purporting to use a differential diagnosis, testified that plaintiff’s slip in the supermarket caused fibromyalgia, which is largely idiopathic) (“This analysis amounts to saying that because [the physician] thought she had eliminated other possible causes of fibromyalgia, even though she does not know the real ‘cause,’ it had to be the fall at Food Lion. This is not an exercise in scientific logic but in the fallacy of post-hoc propter-hoc reasoning, which is as unacceptable in science as in law.”)

Conger v. Danek Med., Inc., 1998 WL 1041331, at *5-6 (N.D. Tex. Dec. 14, 1998) (excluding expert’s testimony and granting summary judgment when expert “had not attempted to rule out [other potential sources] as causes for [plaintiff’s back] pain”);

Leigh v. Danek Med., Inc., 1998 WL 1041329, at *4-5 (N.D. Tex. Dec. 14, 1998) (excluding expert’s testimony and granting summary judgment where expert failed to rule out alternative causes of plaintiff’s back pain)

Bennett v. PRC Public Sector, 931 F. Supp. 484, 492 (S.D. Tex. 1996) (excluding testimony of expert who failed to consider and rule out alternative causes of plaintiff’s repetitive motion disorders)

SIXTH CIRCUIT

Nelson v. Tennessee Gas Pipeline Co., 1998 WL 1297690, at *6 (W.D. Tenn. Aug. 1, 1998) (excluding testimony of expert who “failed to engage in adequate techniques to rule out alternative causes and offers no good explanation as to why his opinion is nevertheless reliable in light of other potential causes of the alleged injuries”);

Downs v. Perstorp Components, 126 F. Supp. 2d 1090, 1127 (E.D. Tenn. 1999) (excluding expert testimony as to whether exposure to chemicals caused plaintiff’s injuries where expert failed to rule out alternative causes)

EIGHTH CIRCUIT

Jisa Farms, Inc. v. Farmland Indus., No. 4:99CV3294, 2001 U.S. Dist. LEXIS 26084 (D. Neb. 2001)

Thurman v. Missouri Gas Energy, 107 F. Supp. 2d 1046, 1058 (W.D. Mo. 2000) (expert’s opinion “that the pipeline failed because of corrosion” was excluded and summary judgment granted where expert reached the conclusion “without eliminating other causes”)

Bruzer v. Danek Med., Inc., 1999 WL 613329, at *8 (D. Minn. Mar. 8, 1999) (excluding expert’s testimony and granting summary judgment where expert did “not attempt to rule out any alternative potential causes for [plaintiff’s] continuing and increasing [back] pain”)

National Bank of Commerce v. Assoc. Milk Producers, 22 F. Supp. 2d 942, 963 (E.D. Ark. 1998), aff’d, 191 F.3d 858 (8th Cir.1999) (excluding testimony and granting summary judgment where expert did “not successfully rule out other possible alternative causes” for cancer)

TENTH CIRCUIT

In re Breast Implant Lit., 11 F. Supp. 2d 1217, 1234 (D. Colo. 1998) (excluding expert testimony where expert failed to “explain what alternative causes he considered, or how he ruled out other possible causes” of plaintiffs’ auto- immune disease)

Stover v. Eagle Products, 1996 WL 172972, at *11 (D. Kan. Mar. 19, 1996) (excluding testimony of expert who “[did] not explain in any meaningful detail how he [was] able to exclude the numerous multiple alternative causes” of injury to plaintiff’s dogs)

ELEVENTH CIRCUIT

Rink v. Cheminova, Inc., 400 F.3d 1286, 1295 (11th Cir. 2005) (“[I]n the context of summary judgment . . . differential diagnosis evidence by itself does not suffice for proof of causation.”)

STATE COURT CASES

Blanchard v. Goodyear Tire & Rubber Co.,  2011 Vt. 85, 30 A.3d 1271 (2011) (holding that plaintiff’s claim that his NHL was caused by benzene was not reliably supported by differential diagnosis when a large percentage of NHL cases have no known cause)

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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).

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Conflicts of Interest in Asbestos Studies – the Plaintiffs’ Double Standard

September 18th, 2013

Conflicts of interest disclosures have become the stuff of “criminal” accusations.  In Weitz & Luxenberg P.C. v. Georgia–Pacific LLC, 2013 WL 2435565 (N.Y. App. Div., 1st Dep’t June 6, 2013), the court recited a defense expert witness’s failure to disclose his expert witness status in articles as part of a determination that a prima facie showing of “crime-fraud” had been made to justify the trial court’s in camera review of materials claimed to be protected from discovery under the attorney-client privilege:

“Nor did the articles reveal that Dr. Bernstein has been disclosed as a GP expert witness in NYCAL since 2009, that he had testified as a defense expert for Union Carbide Corporation in asbestos litigation, or that he had been paid by, and spoken on behalf of, the Chrysotile Institute, the lobbying arm of the Quebec chrysotile mining industry.”

Id. at *2. In “A Cautionary Tale on How Not to Sponsor a Scientific Study for Litigation,” I wrote about how the First Department of the New York Appellate Division went off the rails in considering the crime-fraud exception without first determining that the privilege applied in the first place.  The appellate court’s reasoning as to why the trial court should look for an exception was equally vacuous.  If failure to disclose consulting or testifying for attorneys is a “crime” or a “fraud,” then the playing field should be level and the indictment should apply to all sides.

Steve Markowitz is a physician with Queens College, City University of New York.  Dr. Markowitz testifies for plaintiffs, both here in New York City, and abroad, in asbestos personal injury cases.  See, e.g., Wannall v. Honeywell International Inc., 2013 WL 1966060 (D.D.C. May 14, 2013) (excluding Markowitz’ testimony as unreliable).  So the plaintiffs’ bar, which would equate failure to disclose consulting with “crime” or “fraud,” should be on the alert that Dr. Markowitz does not disclose his consulting arrangements in publications that bear on the issues covered by his testimony.

I blogged previously about an in-press version of Markowitz’s publication of an update of the epidemiologic study of North American insulators. See “The Mt. Sinai Catechism” (June 7, 2013). The paper is now out in final form, although behind a paywall.  Steven B. Markowitz, Steven M. Levin, Albert A. Miller, and Alfred Morabia, “Asbestos, asbestosis, smoking, and lung cancer. New findings from the North American insulator cohort,” 188 Am. J. Respir. Crit. Care Med. 90 (2013).  What is publicly available, however, are the disclosure statements for each of the authors. Lo, and behold, Dr. Markowitz declared no consultations that could be a potential conflict of interest.

This is a remarkable double standard.  Consulting for a defendant is a “crime,” if not disclosed, but plaintiffs’ testifying expert witnesses do not feel the need to disclose their consultancies at all.  What is more remarkable, however, is that the authors of this article strained and stretched their data to try to save their synergy theory.  Even the editorial that accompanied the article, while generally reciting the Mt. Sinai catechism, noted that the synergistic, multiplicative interaction was no longer so clear: “asbestos exposure and smoking together are associated with an at least additive increased risk.  …” John R. Balmes, “Asbestos and Lung Cancer: What We Know,” 188 Am. J. Respir. Crit. Care Med. 8,9 (2013).

The only reason that I harp on conflicts is that the Third Edition of the Reference Manual on Scientific Evidence (2011) improvidently started down this road, as have several federal district and state court judges, including the judges who sat on the First Department panel, which decided Weitz & Luxenberg P.C. v. Georgia–Pacific LLC.  I believe that the focus should be on the data and the analysis, not on the speaker.  If the courts insist upon creating this toxic environment for scientists who “consult,” then the toxicity should be visited on all parties’ expert witnesses equally.

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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. See “Debunking 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.

Posted in Causation, Rule 702, Scientific Evidence | Comments Off on Do English Judges Diss Epidemiology?

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.

Posted in Rule 702, Scientific Evidence | Comments Off on Daubert Bewigged

Urging Review and Reversal, Scientists File Amicus Brief in the Harkonen Case

September 7th, 2013

Earlier this week, Professors Kenneth Rothman and Timothy Lash, and I, filed our Brief by Scientists And Academics as Amici Curiae, in the case, Harkonen v. United States.  As noted previously, Dr. Harkonen has petitioned the Supreme Court for review of the Ninth Circuit’s affirmance of his conviction for Wire Fraud.  Other amici will likely file on Monday, September 9, 2013.

Posted in statistical evidence | Comments Off on Urging Review and Reversal, Scientists File Amicus Brief in the Harkonen Case

Aaron Kesselheim’s Presentation on FDA Regulation of Manufacturer Speech

September 3rd, 2013

On August 5, 2013, Dr. Scott Harkonen filed his petition for a writ of certiorari with the United States Supreme Court. As noted in some previous posts, Dr. Harkonen was acquitted of misbranding, but convicted of wire fraud, for his role in issuing a press release about the results of a clinical trial of interferon gamma 1b, in patients with idiopathic pulmonary fibrosis.  (See Multiplicity versus Duplicity – The Harkonen Conviction; The Matrixx Motion in U.S. v. Harkonen; The (Clinical) Trial by Franz Kafka).

Dr. Harkonen’s petition presents two questions:

“1. Whether a conclusion about the meaning of scientific data, one on which scientists may reasonably disagree, satisfies the element of a “false or fraudulent” statement under the wire fraud statute, 18 U.S.C. § 1343?

2. Whether applying 18 U.S.C. § 1343 to scientific conclusions drawn from accurate data violates the First Amendment’s proscription against viewpoint discrimination, or renders the statute, as applied , unconstitutionally vague.”

Both questions are important given that the government has conceded that Dr. Harkonen’s press release accurately presented the raw data and calculated p-values.  The crime, if crime it be, lay in Dr. Harkonen’s drawing a causal inference from a subgroup, p = 0.004, which was not prespecified, in a specified secondary endpoint of survival (p = 0.08), when the subgroup was clearly based upon the goals of the trials, and there was other corroborative evidence in the form of two previous trials, clinical practice, and strong mechanistic evidence.

The government argued that NO inferences could be drawn from a trial that “failed” on its primary endpoint.  The government’s embrace of this statistical orthodoxy greatly misrepresented scientific practice to the courts below.  The only “failed” trial is one that is not conducted.

There are many who would go to great lengths to distort the facts of the Harkonen case in order to demonize the pharmaceutical industry, or to arm the Justice Department with a weapon that can shut down scientific speech about pharmaceutical interventions.  The expansion of the Wire Fraud Act, seen in the Harkonen case, to achieve these political goals will not only affect pharmaceutical company scientists, but also government and academic scientists.  The standard for falsity, drawn from an out-dated, tendentious, and overly rigid conception of hypothesis testing will apply equally to non-industry scientists in False Claim Act cases.  Perhaps in future posts, I can provide some good examples, on condition that any qui tam relators share their bounty with me.

Back in May, Aaron Kesselheim presented (by video) a paper, written with Michelle Mello, of the Harvard School of Public Health, on “The Prospect of Continued FDA Regulation of Manufacturer Promotion in an Era of Expanding Commercial Speech.”  Kesselheim went out of his way to misrepresent the facts of the Harkonen case, as part of his brief against off-market promotion.

By way of background, Aaron S. Kesselheim is a physician and a lawyer, and an Assistant Professor of Medicine at Harvard Medical School.  He is also a faculty member in the Division of Pharmacoepidemiology and Pharmacoeconomics in the Department of Medicine at Brigham and Women’s Hospital.   Given his position and his training in two professions, as well as the extraordinary stakes involved in allowing the government to prosecute scientists for drawing allegedly false conclusions about facts that the government concedes are accurate, Dr. Kesselheim should have exercised much greater care in checking his own assertions more closely.

Dr. Kesselheim focused primarily on the Second Circuit’s recent decision in United States v. Caronia, 703 F.3d 149 (2d Cir. 2012) , which reversed a judgment of conviction for off-label promotion, on First Amendment grounds.  About nine minutes into his presentation, Kesselheim turned to alternative strategies for the government to use to squelch off-label promotion.  One of his suggestions was to follow the model of the Harkonen prosecution, and to prosecute off-label promotion as false and misleading speech.

In his discussion of his suggested strategy, Kesselheim suggested that Dr. Harkonen had made misleading “conclusory, unsubstantiated claims for efficacy,“ and “without reference to supporting evidence.”  It is Kesselheim, however, who seriously mislead his listeners and readers by stating that Dr. Harkonen had made “conclusory, unsubstantiated claims for efficacy.”  The Press Release that was the subject of the government’s indictment set out accurately actual count data and calculated p-values.  No data were fabricated or falsified.  Within the limited space and the informal context of a Press Release, Dr. Harkonen had provided a substantial account of the data from InterMune’s clinical trial, as well as citing a previous, independent clinical trial and its extension, clinical experience, and mechanism research on the action of interferon γ-1b.  Unfortunately, it is Kesselheim who is speaking in conclusory sound bites when he ignores the context and content of the actual Press Release at issue.

Kesselheim went on to suggest that Harkonen’s statement was refuted by a “company-sponsored clinical trial showing that the drug was not effective.” This statement is not only false, but shows a flagrant disregard for statistical analysis and the data in the Harkonen case.  Kesselheim implies that a clinical trial that fails to show treatment efficacy thereby shows that the treatment was not effective.  His statement commits the fundamental error of equating a failure to reject the null hypothesis at a specified level of attained significance with acceptance of the null hypothesis.  This reasoning is fallacious and fundamentally flawed.

To be sure, the prespecified secondary survival endpoint in InterMune’s clinical trial did not meet the 0.05 cutoff (it was 0.08), although the per-protocol analysis for this endpoint came up at 0.055, on a preliminary analysis of the data. When the clinical trial was fully analyzed and written up for publication in the New England Journal of Medicine, the treatment-adherent analysis for survival in the entire clinical trial was 0.02, with a statistically significant hazard ratio for survival, favoring the therapy:

“Analysis of the treatment-adherent cohort of patients showed an absolute reduction in the risk of death of 9 percent in the interferon gamma-1b group, as compared with the placebo group, and a relative reduction in the risk of 66 percent (5 percent of 126 patients in the interferon gamma-1b group and 14 percent of 143 patients in the placebo group died, P=0.02). The 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).”

Ganesh Raghu, Kevin K. Brown, Williamson Z. Bradford, Karen Starko, Paul W. Noble, David A. Schwartz, and Talmadge E. King, Jr., for the Idiopathic Pulmonary Fibrosis Study Group, “A Placebo-Controlled Trial of Interferon Gamma-1b in Patients with Idiopathic Pulmonary Fibrosis,” 350 New Engl. Med. J. 125, 129-30 (2004).

Dr. Harkonen, in his Press Release, did focus on what seems like an eminently sensible subgroup, within the survival secondary endpoint, of mild- and moderate-cases, which, a priori, were believed to be the patients mostly likely to benefit from the interferon γ-1b therapy.  (What was not known before the trial was at what point in disease progression might patients no longer respond with greater survival, and hence the difficulty in setting the boundary between moderate and severe cases.)  Kesselheim might argue that the interferon γ-1b clinical trial, standing alone, was inconclusive, but he certainly cannot argue truthfully that the trial showed that the biological product to be ineffective.  Clinical trials do not neatly divide the world of possible results into demonstrations of efficacy and demonstrations of inefficacy.  Not only does the evidence come in degrees, but there is a range of “inconclusiveness” in between the two extremes. Given his background, training, and experience, Kesselheim certainly should know this, and he should apologize for his inaccurate statements.

Kesselheim might well have stopped there, but he went on to acknowledge that the company-sponsored clinical trial at issue did find, in post-hoc analyses, a non-significant trend of benefit in a subset of patients.  Talk of misleading speech!  The p-value at issue was 0.004, uncorrected for multiple comparisons, but no one, not Kesslheim, not the government or anyone else, has offered any appropriate adjustment for multiple comparisons that would inflate that 0.004 to over 0.05.  Kesselheim has no warrant for branding the subgroup finding “non-significant,” until he shows that the p = 0.004, when appropriately modified (if it can be), exceeds 0.05.

Kesselheim mangles other, less technical facts.  He claims that the company saw a ten-fold increase in sales of interferon γ-1b for idiopathic pulmonary fibrosis.  No such fact was ever, or could ever, be established in the Harkonen case.  Kesselheim claims that Dr. Harkonen admitted, in emails, that he did not really believe that the trial “demonstrated” benefit; no such emails were ever adduced at trial, and this seems to be part of a fictional narrative that Dr. Kesselheim has manufactured.  Finally, Kesselheim harrumphs that FDA declined to approve drug.  The company never filed a new drug application for the idiopathic pulmonary fibrosis indication; there was no application to reject.  Perhaps more important is that the Press Release was issued before InterMune had made any formal submission of data to the FDA, an event that did not take place until the following year.

Kesselheim sighs that the Harkonen prosecution will be a difficult act to follow because it requires a case-by-case showing of falsity, with the necessity of expert testimony, and heavy cognitive demands on lay jurors. How ironic that Kesselheim, a lawyer and a physician, and a Harvard Medical School faculty member, buckled under the cognitive demands of his topic. Indeed, Kesselheim’s confusion is a strong argument for why the Supreme Court should put a stop to the practice of asking jurors to second guess whether a scientist has incorrectly inferred causation from accurately presented facts.

Let’s hope Dr. Harkonen gets a fair hearing in the Supreme Court.

Posted in Scientific Evidence, statistical evidence | Comments Off on Aaron Kesselheim’s Presentation on FDA Regulation of Manufacturer Speech

Woodside & Davis on the Bradford Hill Considerations

August 23rd, 2013

Dr. Frank Woodside and Allison Davis have published an article on the so-called Bradford Hill criteria.  Frank C. Woodside, III & Allison G. Davis, “The Bradford Hill Criteria: The Forgotten Predicate,” 35 Thomas Jefferson L. Rev. 103 (2013).

Their short paper may be of interest to Rule 702 geeks, and students of how the law parses causal factors in litigation.

The authors argue that a “predicate” to applying the Hill criteria consists of:

  • ascertaining a clear-cut association,
  • determining the studies establishing the association are valid, and
  • satisfying the Daubert [1][sic] requirements.

Id. at 107.  Parties contending for a causal association often try to flyblow the need for statistical significance at any level, and argue that Bradford Hill did not insist upon statistical testing.  Woodside and Davis remind us that Bradford Hill was quite firm in insisting upon the need to rule out random variability as an explanation for an association:

“Our observations reveal an association between two variables, perfectly clear-cut and beyond what we would care to attribute to the play of chance.”

Id. at 105; see Hill, Austin Bradford Hill, “The Environment and Disease: Association or Causation?” 58 Proc. Royal Soc’y Med. 295 (1965).  The authors correctly note that the need for study validity is fairly implied by Bradford Hill’s casual expression about “perfectly clear-cut.”

Woodside and Davis appear to acquiesce in the plaintiffs’ tortured interpretation of Bradford Hill’s speech, on which statistical significance supposedly is unimportant.  Woodside & Davis at 105 & n.7 (suggesting that Bradford Hill “seemingly negates the second [the requirement of statistical significance] when he discounts the value of significance testing, citing Bradford Hill at 299).

Woodside and Davis, however, miss the heavy emphasis that Bradford Hill actually placed upon “tests of significance”:

“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.  Bradford Hill never says that statistical tests contribute nothing to proving an hypothesis; rather, his emphasis is on the insufficiency of statistical tests alone to establish causality.  Bradford Hill’s “beyond that” language clearly stakes out the preliminary, but necessary importance of ruling out the play of chance before proceeding to consider the causal factors.

Passing beyond their exegetical fumble, Woodside and Davis proceed to discuss the individual Bradford Hill considerations and how they have fared in the crucible of Rule 702.  Their discussion may be helpful to lawyers who want to track the individual considerations, and how they have treated, or dismissed, by trial courts charged with gatekeeping expert witness opinion testimony.

There is another serious problem in the Woodside and Davis paper.  The authors describe risk ratios and the notion of “confidence intervals”:

“A confidence interval provides both the relative risk found in the study and a range (interval) within which the risk would likely fall if the study were repeated numerous times.32 … As such, risk measures used in conjunction with confidence intervals are critical in establishing a perfectly clear-cut association when it comes to examining the results of a single study.35”

Woodside & Davis at 110.  The authors cite to the Reference Manual on Scientific Evidence (3d 2011), but they fail to catch important nuances of the definition of a confidence interval.  The obtained interval from a given study is not the interval within which the “risk would likely fall if the study were repeated… .”  Rather it is 95% of the many intervals, from the many repeated studies done on the same population, with the same sample size, which would capture the true risk.  As for the obtained interval, the true risk is either within it, or not, and no probability value attaches to the likelihood that the true value lies within the obtained interval.

It is a mystery why lawyers would bother to define something like the confidence interval, and then do it incorrectly.  Here is how Professors Finkelstein and Levin define the confidence interval in their textbook on statistics:

“A confidence interval for a population proportion P is a range of values around the proportion observed in a sample with the property that no value in the interval would be considered unacceptable as a possible value for P in light of the sample data.”

Michael Finkelstein & Bruce Levin, Statistics for Lawyers 166-67 (2d ed. 2001).   This text explains why and where Woodside and Davis went astray:

“It is the confidence limits PL and PU that are random variables based on the sample data. Thus, a confidence interval (PL, PU) is a random interval, which may or may not contain the population parameter P. The term “confidence” derives from the fundamental property that, whatever the true value of P, the 95% confidence interval will contain P within its limits 95% of the time, or with 95% probability. This statement is made only with reference to the general property of confidence intervals and not to a probabilistic evaluation of its truth in any particular instance with realized values of PL and PU.”

Id. at 167-71.

[1] Surely the time has come to stop referring to the Daubert factors and acknowledge that the Daubert case was just one small step in the maturation of evidence law.  The maturation consisted of three additional Supreme Court cases, many lower court cases, and a statutory revision to Federal Rule of Evidence 702, in 2000.  The Daubert factors hardly give due consideration to the depth and breadth of the law in this area.

Posted in Causation, Rule 702, statistical evidence | Comments Off on Woodside & Davis on the Bradford Hill Considerations

Second Circuit Hands down a Marvel Opinion on Historian Expert Testimony

August 17th, 2013

“What will history say?  History, sir, will tell lies as usual.”
George Bernard Shaw, The Devil’s Disciple (1901)

 * * * * *

Parties to products liability litigation have for some time resorted to the ruse of using historians as rhetoricians and advocates to argue partisan litigation positions to the jury, in the evidentiary phase of trials.  The obvious opening for this ruse has come in advancing party positions on “state of the art” to claim or defend against negligence.  When plaintiffs use this tactic, they seek not only to introduce evidence of pre-sale belief or knowledge of hazards, but also to disparage any challenges to, or doubts about, hazards as unreasonable, biased, or malicious.  When defendants use this tactic, they of course seek to return the favor, by employing their expert witnesses as advocates on crucial issues of historical knowledge.

Two historian gladiators, David Rosner and Gerald Markowitz, have served as capable arguers in silica, asbestos, lead, and vinyl chloride litigation.  Indeed, you might well expect to meet them at the Argument Clinic, although more recently, they starred in an appearance in a California lead paint case, currently on trial.  See CA Lead Paint Trial: Same old Rosner, Markowitz show (Aug. 07, 2013); Howard Mintz, “Hazardous lead paint: Legal battle comes to trial in California” (July 16, 2013) (quoting Rosner’s email exchange with reporter in which he previews his partisan opinions on lead paint in advance of his testimony).

We can find no clearer statement of judicial antipathy to expert witness advocacy than the famous copyright decision by Judge Learned Hand in Nichols v. Universal Pictures Corp., 45 F.2d 119 (2d Cir. 1930).  Both sides in Nichols presented expert testimony on “dramatic writing” in an effort to prove or disprove a claim that one screenplay infringed upon another. Deprecating the lengthy, argumentative testimony from both sides’ experts, Judge Hand declared that

“[i]t ought not be allowed at all. . . .”

Id. at 123. Judge Hand explained with his usual magisterial authority:

“Argument is argument whether in the box or at the bar, and its proper place is the last.”

Id.

Other areas of expertise, besides historical scholarship, fail to satisfy the basic requirements of expert witness testimony. For instance, Judge Hand’s complaints about the “literary critic” expert witnesses in Nichols, have been relodged against “ethics” witnesses. In GST v. Telecommunications, Inc., 192 F.R.D. 109 (S.D.N.Y. 2000), both parties offered expert witness on the ethics of the conduct of corporate officers. Invoking the helpfulness criterion of Federal Rule of Evidence 702, the Court found the proffered testimony would not aid the jury:

“It is evident that the contentious advocacy of the experts – illustrated by conclusions on the credibility of explanations regarding the business judgment of the board of directors . . . in clearly expressed, biased viewpoints – do little to aid the triers of fact on the underlying transactions.”

Id. at 110. The trial court discerned a serious danger that expert testimony on ethics would usurp the jury’s role in applying the law to the facts found in the case. Id. Permitting such testimony would allow expert witnesses to attempt to substitute their judgment for the jury’s. Id.; see, e.g., Pan American World Airways, Inc. v. Aetna Casualty & Surety, 505 F.2d 989, 998 (2d Cir. 1974) (noting disapprovingly that, evidence consisted “largely of hearsay, propaganda, speculation, and conjecture”). See also Imwinkelreid, “Expert Testimony by Ethicists: What Should Be the Norm?” 76 Temple L. Rev. 91, 114, 128 (2003) (noting that normative testimony will virtually always be inadmissible).

Of course, the substitution of an expert witness’s judgment for the jury’s is precisely what many trial lawyers hope to accomplish. Lawyers can select and present expert witnesses based upon their opinions and conclusions, whereas the conclusions of juries are all too unpredictable.  Trial courts must be vigilant to police expert witness opinion testimony in the area of history as much as, if not more than, in the area of scientific testimony. Rule 702’s requirement of knowledge that will assist the trier of fact is designed to prevent expert witnesses from testifying about matters within the common understanding of the jury, and about which the jurors can reason without help from an expert witness. In the Rezulin Multidistrict Litigation (MDL), testimony that was “a narrative of the case which a juror is equally capable of constructing” was precluded.  In re Rezulin Products Liability Litig., 309 F.Supp. 2d 531, 541 (S.D.N.Y. 2004).  Judge Kaplan explained that expert witnesses were not the appropriate conduit for a narrative of events, meetings, regulations, and documents, when they were not percipient witnesses. Such testimony was within the jury’s lay understanding, and the law prohibited the attempt to have expert witnesses “supplant the role of counsel in making argument at trial, and the role of the jury in interpreting the evidence.” Id. at 551.  See generally “Narratives & Historians for Hire”; and “How Testifying Historians Are Like Lawn-Mowing Dogs.”

In Marvel Characters, Inc. v. Kirby, 2013 WL 4016875 (2d Cir. Aug. 8, 2013), the Second Circuit reaffirmed Learned Hand’s jaundiced view of expert witness advocates in the form of historian testimony. Jack Kirby was among the artists responsible for creating comic strip characters of X-Men, the Hulk, Captain America, Thor, and the Fantastic Four. Kirby’s heirs claimed that the intellectual property rights in these characters passed to them.  Marvel Characters, Inc., sought a declaratory judgment that the characters were “works for hire,” now owned by Marvel Entertainment, a subsidiary of corporate oligarch, Walt Disney Co.

The district court rejected the claims of Kirby’s heirs, and the Second Circuit affirmed. Marvel Worldwide, Inc. v. Kirby, 777 F. Supp. 2d 720 (S.D.N.Y. 2011), aff’d, 2013 WL 4016875 (2d Cir. 2013).  In ruling on Marvel’s motion for judgment, the district evaluated and excluded the proffered expert witness testimony of John Morrow and Mark Evanier, who would have testified on the history of the relationship between Marvel and Jack Kirby. 777 F. Supp. 2d 720, 729-30 (S.D.N.Y. 2011). The Second Circuit held that the district court had clearly not abused its discretion in these exclusionary rulings.  Marvel Characters, Inc. v. Kirby, slip op. at 36.

In affirming the rejection of these historians’ proffered opinions, the Circuit waxed  historiosophical:

“We have no doubt that a historian’s ‘specialized knowledge’ could potentially aid a trier of fact in some cases. A historian could, for example, help to identify, gauge the reliability of, and interpret evidence that would otherwise elude, mislead, or remain opaque to a layperson. He or she might helpfully synthesize dense or voluminous historical texts. Or such a witness might offer background knowledge or context that illuminates or places in perspective past events.”

Slip op. at 34 (internal citations omitted).

Morrow and Evanier wandered far outside the permissible boundaries of historian expert testimony.  They sought to marshal opinions based largely upon hearsay statements of various artists, uttered in a variety of settings, about how Marvel treated artists back in the day. From these statements, the aspiring litigation historians speculated about intentions, understandings, and motivations of the historical actors at Marvel, and of Jack Kirby.  Id. at 35.

The appellate court recognized the serious danger of using historian expert witnesses as

“a conduit for introducing hearsay under the guise that the testifying expert used the hearsay as the basis of his testimony.”

Id. (internal citations omitted).  The Circuit recognized that implicit in Rule 703 is something akin to a “best evidence” rule, which relegated the historians to clearly less than best:

“The appropriate way to adduce factual details of specific past events is, where possible, through persons who witnessed those events. And the jobs of judging these witnesses’ credibility and drawing inferences from their testimony belong to the factfinder.”

Id. at 37.  The Circuit also noted that the expert opinion testimony from historians was beset a serious evidentiary challenges. In addition to relevance, legal and logical, and Rule 702, historian opinions raises basic issues about the source of the opinions.

Applying these principles, the appellate court recognized that the heirs’ witnesses were not using specialized knowledge or offering helpful historian insights, but they were marshalling hearsay:

“But Morrow and Evanier do not bring their expertise to bear in any such way. As the district court recognized, their reports are by and large undergirded by hearsay statements, made by freelance artists in both formal and informal settings, concerning Marvel’s general practices towards its artists during the relevant time period.  Drawing from these statements, they then speculate as to the motivations and intentions of certain parties… .”

Id. at 36 (internal citations omitted).

The Second Circuit’s decision is timely.  Perhaps the California trial court pondering the claims against the paint industry will heed the Marvel opinion.  The Marvel Characters opinion should close the door on the use of Rosner and Markowitz’ historical argument, as well as that of other would-be testifying historians in other cases.  In products liability cases, many of the proffered witnesses seek to testify about hearsay statements, and argue inferences about intentions, understandings, and motivations of the historical actors.  Like Morrow and Evanier, they should be excluded from the litigation process.

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The Rhetoric and Challenge of Conflicts of Interest

July 30th, 2013

The Challenge

Critics and anti-industry zealots have argued that industry-sponsored science is vitiated by conflicts of interest.  The critics of industry research have supported their attack with studies that claim to show that industry studies disproportionately report outcomes favorable to their sponsors.

The potential conflicts posed by industry-sponsored research studies are fairly obvious.  Industries that make or sell products, raw materials, or chemicals have an interest in having toxicological and epidemiologic studies support claims of safety.  Research that suggests an industry’s product causes harm may hurt the industry’s financial interests directly by inhibiting sales, or indirectly by undermining the industry’s position in litigation, or by leading to greater regulatory scrutiny and control.  If the harm evidenced by the research is sufficiently severe, the research may lead to product recall or bans, again with serious economic consequences for the industry.  Evidence of harm may require heightened warnings or instructions, which may limit sales or encourage sales of competing, less hazardous products.

The Response.

The answer to the anti-industry challenge lies in a reality more complicated and nuanced that the simplistic views of the critics.  Industry often must conduct or sponsor research to live up to its common law or regulatory duties to test its products.  At other times, industry sponsors research in response to emerging scientific papers that claim that the industry product is harmful in ways not previously known.  While on occasion, industry might be accused of “manufacturing doubt[1],” there are scientists equally intent upon “manufacturing certainty,” whether from dodgy data or iffy inferences.

The motives and interests of scientists intent on manufacturing a faux certainty are harder to discern than the potential conflicts of industry and scientists who are funded by industry.  Many scientists purport to have only the lofty goals of science or the public interest at heart in pursuing their research, but a close look shows that there are several potential conflicts of interest prevalent in the research community, and that these interests help shape science into anti-industry positions.

1.  White Hat Bias

Over 20 years ago, a science journalist published an account of how dire predictions of asbestos deaths had not come to pass.  Tom Reynolds, “Asbestos-Linked Cancer Rates Up Less Than Predicted,” 84 J. Nat’l Cancer Instit. 560 (1992).  In trying to understand why the earlier predictions had been disconfirmed by later data, Reynolds quoted one scientist as saying that:

“the government’s exaggeration of the asbestos danger reflects a 1970s’ Zeitgeist that developed partly in response to revelations of industry misdeeds.  ‘It was sort of the “in” thing to exaggerate … [because] that would be good for the environmental movement’….  ‘At the time it looked like you were wearing a white hat if you made these wild estimates. But I wasn’t sure whoever did that was doing all that much good.”

Id. at 562.  Reynolds captured the essence of “white-hat” bias, a form of political correctness applied to issues that really depend upon scientific method and data for their resolution.

More recently, David Allison and Mark Cope, two public health researchers described[2] white-hat bias as a prevalent cognitive bias in how research is reported and interpreted.  They described white-hat bias as a “bias leading to the distortion of information in the service of what may be perceived to be righteous ends.” Perhaps the temptation to overstate the evidence against a toxic substance is unavoidable, but it diminishes the authority and credibility of regulators entrusted with promulgating and enforcing protective measures.  And error is still error, regardless of its origin.  Allison and Cope give examples of white-hat bias in how papers are cited, with “exonerative” studies cited less often than those than claim harmful outcomes.  And when positive papers were cited, they were often interpreted misleadingly to overstate the harms previously reported.

2. Other “Interested” Actors Who Sponsor and Conduct Scientific Research

The discussion and debate surrounding industry sponsorship of scientific research often ignores the activities of other, intensely interested sponsors and researchers.  Labor unions, for instance, have sponsored research on occupational hazards.  Evidence of harm often becomes potent ammunition in labor-management negotiations over work conditions and wages.  Environmental groups have sponsored studies with sympathetic researchers who are openly eager to embarrass industrial interests and support increasing regulatory restrictions or bans on chemicals or products.  Plaintiffs’ counsel may well be the largest rent-seeking group in the United States, and they have sponsored studies with the implicit or explicit goal of supporting their claims for compensation.  Disease support groups, often aligned with plaintiffs’ counsel, have sponsored research, to support their claims for compensation and fees, the more, the better.  Scientists and physicians who serve as expert witnesses for plaintiffs’ counsel have undertaken research to advance and support their testimonial enterprise in the litigation brought by the counsel who engaged them to testify.

3.  Regulatory Biases

Many scientists are funded by regulatory agencies intent upon showing harm from particularly exposures or industrial processes.  The agencies may be motivated by their desire to expand their regulatory control under their statutory mandate by having scientific evidence that fits their political and regulatory goals.  Some scientists may be politically aligned, or simply believe that the public interest requires the sought after enhanced regulation.

4.  Publication Bias

“Null” studies, studies that do not find a statistical significant increased risk of harm from exposure, do not sell.  More to the point, null studies do not routinely get published.  Spending substantial amounts of time on a study without obtaining an outcome that will make the study publishable is a sure-fire way to sideline one’s academic career.  Publications are the measurable units of success in academic circles.  Publications beget future grants and funding, which further enhance academic reputation and careers.

The pressure on researchers to find some untoward outcome from research on a potential toxic material or product is great.  As John Ioannides and others have shown, prevalent research methods encourage technique that will lead to some findings.  For instance, an epidemiologic cohort study will compare a group with and without exposure, but will look at multiple health outcomes.  Perhaps there was an a priori hunch that lung cancer rates would be increased among the exposed group, but the researchers also looked at a 100 other cancers, and perhaps another 100 other non-malignant diseases, in the study.  Chance alone would have led to several statistically significant findings of increased disease outcomes among the exposed group, and researchers can publish these findings that encourages readers to believe that they were the subject of the research all along.

Similarly, case-control studies can collect cases of a disease of interest and compare them with non-diseased controls in terms of dozens if not hundreds of prior exposures and life-style variables.  Again, the researchers can report the exposures and variables statistically significantly associated with the disease, and neglect to report all those not associated.[3]

5. Biased Studies with Biased Outcomes, Making Biased Claims

The critics of industry-sponsored studies have themselves conducted “studies of studies,” to assess whether sponsorship correlated with outcomes favorable to the sponsor.  These studies of studies claim to find that industry studies invariably or disproportionately favor their sponsors’ interests, but these studies of studies are themselves critically flawed by selection bias.[4]

To understand the selection bias involved, we need only pay attention to the conditions that lead industry to conduct the study.  In connection with potential toxicities of chemicals or products, industry  often is responding to an emerging scientific literature that claims the industrial materials cause harm.  If the studies that claim harm are clearly valid, there is likely to be no counter-study undertaken.  In this scenario, the anti-industry critics will find no industry study for inclusion in their analysis of whether industry studies are correlated with a favorable outcome.

Studies with doubtful data or overstretched conclusions are more likely to provoke an industrial concern into sponsoring research, and given the inciting condition, we should not be surprised that outcome is more favorable to industry than the previously published studies.    Studies ultimately favorable to the defense are thus counted in the “studies of studies,” but given the circumstances that led to the sponsorship, the imbalance in the results is exactly what we should expect to see. Of course, if the study somehow supports the prior findings, the critics of industry will claim that the industry-sponsored study is an “admission” of harm.  Inconclusive or exonerative studies will be dismissed by these critics as uninformative or vitiated by conflicts of interest.

There are many examples of how this selection bias plays out. In the early days of the silicone gel breast implant litigation, ostensibly neutral researchers published papers that claimed an association between silicone implants and scleroderma.  See Harry Spiera, “Scleroderma After Silicone Augmentation Mammoplasty,” 260 J. Am. Med. Ass’n 236 (1988).  These papers led to an FDA-imposed moratorium, which in turn instigated a litigation tsunami.  The then current and former manufacturers of silicone implants sponsored several epidemiologic studies.  Although the companies engaged reputable researchers from the leading medical research centers in the United States, public-interest advocates such as Sidney Wolfe decried the “biased” industry-financed research that came out.  Not surprisingly, the sponsored studies mostly exonerated any causal role of silicone in producing autoimmune diseases.

The biases of the physicians who supported the alleged causal association were much more difficult to ferret out.  Many of the physicians adopted pro-causation views to attract patients from the many support “victim” support groups, and many of the scientists who advocated pro-causation opinions sought to market test kits that would identify biomarkers of a unique silicone-induced disease.  The house of cards created by the support groups and plaintiffs’ counsel ultimately collapsed when court-appointed expert witnesses and the Institute of Medicine examined the evidence closely.  Today, the entire episode can be chalked up mostly to litigation fraud.  See Hon. Judge Jack B. Weinstein, “Preliminary Reflections on Administration of Complex Litigation.” Cardozo Law Review DeNovo 1, 14 (2009) (“[t]he breast implant litigation was largely based on a litigation fraud. …  Claims—supported by medical charlatans—that enormous damages to women’s systems resulted could not be supported.”).

Another example is provided by the welding fume litigation.  In 2001, Dr. Brad Racette published a case series that he erroneously called a case-control study, which purported to find an earlier age of onset for Parkinson’s disease among welders.  In 2005, working in cooperation with plaintiffs’ counsel, Racette transmuted litigation screenings into a cross-sectional study, which purported to find an increased prevalence ratio of “parkinsonism” among welders.  Both studies were seriously flawed, but the plaintiffs’ counsels’ use of Racette’s studies created an incentive for industry to sponsor several studies.  The plaintiffs’ counsel blasted the industry defendants for “manufacturing doubt,” but in fact, the industry-sponsored studies were valid scientific efforts, conducted by respected epidemiologists.  The industry sponsored studies were corroborated several times over by governmentally sponsored studies, conducted in the United States and abroad.  A meta-analysis published last year by well-regarded neuroepidemiologists ultimately vindicated the industry position, as well as the industry-sponsored studies.  See James Mortimer, Amy Borenstein, and Lorene Nelson, “Associations of welding and manganese exposure with Parkinson disease: Review and meta-analysis,” 79 Neurology 1174 (2012) (reporting a statistically significant decreased risk of Parkinson’s disease among welding tradesmen).

In the pharmaceutical industry, publications will invariably show outcomes favorable to drug sponsors.  New drugs that fail to show efficacy in clinical trials will not likely be written about because the sponsor will not file an application for regulatory approval.  Writing up the clinical trials for publication typically is part of the process of seeking regulatory approval, and the publication effort is not undertaken unless there is a reasonable chance of approval.  Unremarkably, the published papers describing these clinical trials disproportionately show efficacy and manageable side effects.

 

6. Hypocrisy Over Conflicts of Interest

The persistence in ignoring non-financial conflict of interests is not innocent.  By elevating financial conflicts of interest, public advocates attempt to silence industry and discount industry-sponsored studies.  The single-minded focus on financial conflicts of interest misdirects attention away from the existence of other sorts of biases, and the distortions they create.[5]

Conflicts of interest have thus largely and incorrectly been reduced to financial conflicts.  For instance, in 2011, the National Institutes of Health (NIH) addressed only financial issues when it promulgated rules for managing conflicts of interest in the field of medical research.[6]  Several commentators advocated regulation of non-financial COI, but the agency refused to include such conflicts within its rules.[7] The Institute of Medicine (IOM), in a monograph on conflicts of interest in medicine, similarly gave almost exclusive priority to financial ties.[8]

The focus on economic conflicts of interest is dangerous because it instills complacency about non-financial interests, and provides a false sense of assurance that the most serious biases are disclosed or eliminated.  One need only consider the many examples of retractions, frauds, and ethical lapses in biomedical research to understand that non-financial interests, such as friendships and alliances, institutional hierarchies, intellectual biases and commitments, beneficence, “white-hat” advocacy, as well as the drive for professional achievement, recognition, and rewards, all have the potential to complicate, distort, and sometimes undermine scientific research in myriad ways. The failure to recognize and regulate non-economic conflicts and biases endangers the validity of science.  Not only are these non-financial threats ignored, but financial interests receive undue attention, resulting in the erosion of public trust in scientific research that is sound.

 

The Cure

1. Push Back Against the Rhetoric of Conflicts of Interest

Industry should not be cowed by the anti-industry attack on industry-sponsored studies.  Twenty years ago, one of the leading epidemiologists, Professor Kenneth Rothman, referred to the anti-industry bias as “new McCarthyism in science.[9]”  This intolerance toward corporate sponsorship has been going on for some time, fueled by one-sided accounts of industry-sponsored studies.  As noted by one of the leading 20th century epidemiologists, “an opinion should be evaluated on the basis of its contents, not on the interests or credentials of the individuals who hold it.[10]”  Courageously, some scientists have fought for science to be judged on its merits.[11]

Professor Stossel and others created an organization, ACRE – The Association of Clinical Researchers and Educators, to defend legitimate interactions between Physicians and Industry. ACRE has spoken out against the lopsided demonization of the pharmaceutical industry, and the lionizing of the industry’s critics.  A few years ago, a scientist working for the pharmaceutical industry, joined Professor Rothman, to cry out against the unfairness and partiality of journals’ conflict-of-interest rules and policies.[12]  Dr. Hirsch published a strongly worded commentary that journals’ concerns are often poorly disguised prejudices against industry.  Many of the journals in question rarely or never fuss over the obvious conflicts of interest created by the “profit motive” of researchers who want to climb the academic ladder, increase their salaries, enlarge their budgets, extend their influence, travel to organizational conferences, bolster their prestige, win more grants, enhance their reputations, or advance their political goals or ideologies.

The medical profession, the courts, and the public are seriously misled by the obsession with conflicts of interest, on either side.  The obsession allows a disclosed or undisclosed conflict of interest to substitute for the much harder work of considering the merits of a study.


[1] David Michaels, Doubt is Their Product (2008).

[2] Mark B. Cope and David B. Allison, “White hat bias: examples of its presence in obesity research and a call for renewed commitment to faithfulness in research reporting,” 34 Internat’l J. Obesity 84 (2010).

[3] The works of John Ioannides explore the problem of false discovery rate and publication practices that encourage error.  See N. S. Young, J. P. Ioannidis and O. Al-Ubaydli, 2008. Why current publication practices may distort science. PLoS Medicine, 5, e20.

[4] Miquel Porta, Sander Greenland, and John M. Last, eds., A Dictionary of Epidemiology 225-26 (5th ed. 2008).

[5] Richard S. Saver, “Is It Really All About The Money? Reconsidering Non-Financial Interests In Medical Research,” 40 J. L. Med. & Ethics 467 (2012).

[6] Department of Health and Human Services, “Responsibility of Applicants for Promoting Objectivity in Research for Which Public Health Service Funding is Sought and Responsible Prospective Contractors,” 76 Fed. Reg. 53256 (Aug. 25, 2011).

[7] Id. at 53258.

[8] Institute of Medicine, Conflict of Interest in Medical Research, Education, and Practice (Washington, D.C.: The National Academies Press, 2009).

[9] Kenneth J. Rothman, “Conflict of interest: the new McCarthyism in science,” 269 J. Am. Med. Ass’n 2782 (1993).

[10] Brian MacMahon, “Epidemiology:  another perspective,” 37 Internat’l J. Epidem. 1192, 1192 (2008).

[11] See Thomas P. Stossel, “Has the hunt for conflicts of interest gone too far?” 336 Brit. Med. J. 476 (2008); Nature Publishing Group, “Nothing to see here: based on one company’s past poor publishing practices, a top-tier medical journal misguidedly stigmatizes any paper from industry,” 26 Nature Biotechnol. 476 (2008); Kenneth J. Rothman & S. Evans, “Extra scrutiny for industry funded trials: JAMA’s demand for an additional hurdle is unfair–and absurd, 331 Brit. Med. J. 1350 (2005), and 332 Brit. Med. J. 151 (2006) (erratum).

[12] Laurence J. Hirsch, “Conflicts of Interest, Authorship, and Disclosures in Industry-Related Scientific Publications: The Tort Bar and Editorial Oversight of Medical Journals,” 84 Mayo Clin. Proc. 811 (2009).

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