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

The Slemp Case, Part I – Jury Verdict for Plaintiff – 10 Initial Observations

May 13th, 2017

While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgment of the Department of Justice that you are not able to effectively lead the Bureau.”

Letter from Donald Trump to James Comey (May 9, 2017) (emphasis added)

Just as a President’s poor diction does not define or guide good English grammar, a lay civil jury’s verdict on scientific issues does not resolve open scientific questions of causation between exogenous exposures and cancer or other chronic disease outcomes. Last week, a jury in St. Louis returned a substantial verdict for compensatory and punitive damages against Johnson & Johnson, and others, for supposedly causing Lois Slemp to develop ovarian cancer. From some of the media coverage, readers might infer that Ms. Slemp’s attorneys’ had presented a credible case of causation between perineal talc use and ovarian cancer. See, e.g., Daniel Siegal, “J&J Hit With $110M Verdict In Latest Mo. Talc Cancer Trial,” Law360 (May 4, 2017). The cause of this verdict requires close scrutiny of the scientific evidence, the jury and juries generally, the lawyering from both sides, and the judicial management of the trial. 

Hit.” Hit? When did comic-book language invade legal journalism? Why not “slammed,” “zapped,” or “kapow”?

The case, which has gained this recent notoriety is Lois Slemp v. Johnson & Johnson, case no. 1422-CC09326-01, 22nd Judicial Circuit Court of Missouri. The jury awarded Ms. Slemp $5.4 million in compensation, and $66 million against Johnson & Johnson, $39 million against Johnson & Johnson Consumer, and $50,000 against Imerys (the talc miner and supplier), in punitive damages. On the compensatory award, the jury ascribed 99 percent of fault to the two J & J companies, and 1 percent to Imerys. Id.

The truth is that the Slemp verdict, as is the case for most civil jury verdicts, does not represent a valid scientific judgment. Nonetheless, the verdict requires explanation. If talc does not cause ovarian cancer, we may well ask whether the case was poorly defended, whether the court system failed to serve as a gatekeeper, and whether the scientific case was beyond the comprehension of the lay jury.

The verdict of course also raises serious questions about our civil justice system. The law of products liability typically states that a manufacturer or seller is held to the level of an expert in knowing the harmful aspects of its products. If this knowledge is widely known about consumers, then the seller will generally have an obligation to warn about the latent harm. But what happens when there is no knowledge of a causal relationship? Or what happens when experts legitimately disagree? How can a manufacturer or seller be charged with outrageous misconduct, let alone negligence, when experts sincerely and legitimately disavow a causal relationship?

David H. Schwartz, Ph.D. of Innovative Science Solutions LLC, and I posted a preliminary, big-picture overview of the Slemp case at the Courtroom View Network’s website. See Schwartz & Schachtman, “10 Key Scientific Takeaways From Recent $110M Talc Powder Verdict,” Courtroom View Network Blog (May 12, 2017). Thanks to the generosity of Courtroom View, David and I were able to view the video of the Slemp trial, and to evaluate the legal process of presenting a complicated scientific case to a lay jury. There is much to be said about that process, what went right and what went wrong, but for now, I will simply repeat, below, what we said on CVN’s blog. I hope in subsequent posts to look more closely at specific issues, especially with respect to the presentation of statistical and epidemiologic evidence, by all parties.

* * * * *

The following is a republication (with minor formatting changes) of the original post, by David H. Schwartz and Nathan Schachtman. 

Establishing a rigorous and reliable causal inference between an exposure and an adverse health outcome is one of the most difficult things to do in the health sciences. However, it is sometimes even more difficult to effectively and appropriately demonstrate that a causal relationship does not exist.

The difficulty of this task was illustrated in the most recent talcum powder trial in St. Louis, Missouri. As was widely reported, Johnson & Johnson and talc raw material producer Imerys received the third (and largest) plaintiff verdict in their four recent talc trials (3 plaintiff verdicts and one defense verdict). Having the enviable opportunity to watch the trial (in real time or on demand) on Courtroom View Network’s website provides an invaluable opportunity to review and learn from an important ongoing mass tort action.

At this trial, the defense put up a single expert witness, Dr. Huh, a clinician who defended the aggressive and wide-ranging scientific claims advanced by plaintiff’s expert witnesses in a number of scientific disciplines, including epidemiology, clinical medicine, and pathology. Dr. Huh, a skilled and experienced ObGyn and a clinical gynecological oncologist, attempted to neutralize plaintiff’s scientific allegations made by putting the clinical characteristics of the patient into context, while dismissing the many statistically significant epidemiological studies touted by plaintiffs as adequately establishing a causal inference for talcum powder and ovarian cancer.

In his cross examination, plaintiff counsel continuously barraged Dr. Huh with technical observations relating to the large body of epidemiologic studies that plaintiff expert witnesses claimed demonstrated that talc exposure caused ovarian cancer. From the perspective of a scientist who has consulted with many product manufacturers alleged to cause cancer and other chronic diseases, and a lawyer who has tried many science-based cases over the past 32 years, this most recent trial illustrates some important and emblematic issues that arise in pharmaceutical, medical device, and toxic tort cases. We provide 10 such observations below.

1. Provide overall context of Bradford Hill criteria

Unlike other legal cases where there is a paucity of epidemiologic data showing statistically significant associations between an exposure and a disease endpoint, in this case there are many epidemiologic studies – and even some meta-analyses – that invite plaintiffs to make the claim that the available scientific evidence meets the Bradford Hill criteria. Therefore, it is critical to provide the jury with a lucid understanding of why the Bradford Hill criteria are utilized and how they should appropriately be applied. Indeed, the Bradford Hill criteria were developed for a situation exactly like the talc litigation; that is, a relatively weak association is reported and scientists want to determine whether that association should validly and reliably be considered causal.

2. Build solid foundation for “correlation does not equal causation” argument

Multiple studies assert an association between talc and ovarian cancer. However, the defense position is that the studies used to make this assertion suffer from bias and confounding, making them unreliable. Relying upon multiple flawed or biased studies to demonstrate a relationship between two factors does not make the two factors causally related. For example, it does not matter how many times one shows that wearing work boots is associated with back injury, it does not make wearing work boots a cause of back injury. (The two factors are associated, but not causally so.) It is critical for the defense to make it crystal clear (as many times as he is questioned) that “correlation does not equal causation.”

3. Develop a genetic defense

Knowledge of the role of genetic data related to ovarian cancer is moving at breakneck speed. Indeed, a study was published in March identifying nine new susceptibility loci for different epithelial ovarian cancer histotypes. While these data may or may not have been relevant to the individual patient in the Slemp trial, there is no way to know unless the defense had a full genome sequence of the plaintiff’s germline. Such information could conceivably be aligned with newly published data to demonstrate that her genetic profile was consistent with the development of ovarian cancer.

4. Hone the lack of consistency argument

Not surprisingly, in his cross examination of Dr. Huh, plaintiff counsel repeatedly referred to the many case-control studies that reported statistically significant associations between talc and ovarian cancer to support the view that the Hill criterion of “consistency” was met. Dr. Huh repeatedly attempted to rebut this assertion, but failed to make a clear argument as to why these multiple studies failed to support the criterion of consistency. He did refer to the fact that the cohort studies disagreed with the case control studies, but failed to clearly articulate his interpretation of that discrepancy.

At the end of the day, it is not at all surprising that multiple confounded and biased studies all demonstrate the same association. To truly demonstrate the criterion of consistency, one must show that the same results are obtained when using different study methods. Indeed, when a different study design is utilized (cohort studies), the association vanishes. One can posit methodological flaws in the cohort studies (misclassification bias as was repeatedly stated by plaintiff counsel), but flaws can also be posited for the case control studies (recall bias and confounding). The point is that repeating the same poorly conceived study design over and over does not constitute consistency and that the criterion of consistency is therefore not met in this data set.

An example, such as the strong relationship between Vitamin A and cancer prevention might have helped. In observational studies, Vitamin A is clearly associated with a reduction of lung cancer rates based on multiple observational studies. When the claim was tested in randomized clinical trials, the claim failed miserably; indeed, Vitamin A might even increase the rate of lung malignancies in those who took supplements. Similarly, hormone replacement therapy (HRT) was once thought to decrease the risk of cardiovascular disease based on multiple observational studies. It was not until a large randomized controlled trial was conducted that the putative association between HRT and cardiovascular benefit was discredited.

5. Do not let conflict of interest arguments cloud the causal inference assessment

Alleged conflicts of interest were raised repeatedly in accusatory tones, suggesting that any research that J & J funded could not be trusted. Furthermore, suggestions were made that J & J controlled where funding was allocated through their contributions to the National Institutes of Health. These arguments must be addressed aggressively and should not be allowed to hang in the air without response.

6. Pathological evidence must be confronted by someone who studied the pathology slides

Plaintiff counsel confronted Dr. Huh with allegations by plaintiff’s pathologist about the type of cancer from which plaintiff suffered. Because Dr. Huh is not a pathologist and because he did not look at plaintiff’s pathology sides, he attempted to use his clinical impressions and medical records to counter the pathological evidence offered by the plaintiff’s expert witness in pathology. The defense seemed enamored of a “less is more” strategy, but forcing expert witnesses into testimony beyond their expertise requires fortitude and perhaps luck.

7. Put “authoritative”statements into appropriate context

Throughout his cross examination, plaintiff’s counsel confronted Dr. Huh with statements from web sites and textbooks suggesting that talc caused ovarian cancer or where talc is listed as a risk factor for ovarian cancer. Many times, such statements referred to a putative association as opposed to a causal relationship. It is critical to point out their inherent weaknesses, including the fact that they have been cherry picked and to counter with other authoritative sources where talc is not listed as a risk factor and/or the causal link has been questioned. It is also important to be ready with other risk factors that could be equally likely to be linked to ovarian cancer and to emphasize that focusing on talc is arbitrary. The plaintiff is this recent trial was morbidly obese, an undisputed risk factor for ovarian cancer.

As with the lack of consistency argument (#3, above), rebuttal of this contention would be effectively guided using specific examples. For instance, many textbooks and other authoritative sources stated that HRT had cardiovascular benefits based on multiple observational studies. The fact is that these statements were wrong.

8. Concede that cohort studies are not always better than case-control studies

The talc defense strongly asserted the view that cohort studies are necessarily better than case control studies. While this contention is generally true (all factors being equal), it is not always true and it leads to some effective cross examination (e.g., the general assertion that cohort studies may suffer, in some instances, from misclassification bias). As one of us (NAS) stated in a recent post related to the California Science Day hearings, there is no reason to make the blanket statement that cohort studies are always better than case control studies.

Rather, the general point can be made that each study type has its appropriate use and that in this case, the findings from studies using the two different methodologies do not agree with each other. Clearly, the role of differential recall is just as likely to bias a case control study as the role of misclassification is to bias a cohort study. This leaves the evidence at a draw at best.

9. Provide a multi-disciplinary defense

In a case involving so many complex disciplines, it does not seem tenable to address all of them with a single expert, even one as well qualified and experienced as Dr. Huh. Many defense lawyers firmly believe in the “less is more” strategy, but complex scientific data sets such as these necessitate a complete presentation of the exculpatory evidence. Although it is easy in hindsight to criticize trial strategy, forcing a clinical oncologist to address pathology, toxicology, and epidemiology places an unfair burden on the lone witness. Certainly, a jury may be more prone to view an expert witness, who is willing to testify outside his area of expertise, as a hired gun advocate.

10. Careful and consistent use of terminology

Because of the nuanced nature of the defense case (i.e., statistically significant associations demonstrated in observational studies may not be causal in nature), it is critical to use terms consistently and carefully. Terms such as “association,” “link,” “causal inference,” and “causation” must be carefully defined and utilized judiciously and with clear intent.


Of course, looking at testimony in hind-sight is always 20/20. As stated at the outset of this piece defending the assertion that an exposure is not causally related to a clearly defined injury is one of the most difficult things to do in the courtroom, especially when this is attempted through a single expert witness and there are numerous studies purporting to make such a link. Nevertheless, some extremely critical lessons can be learned from this experience to guide future cases.

Talc Litigation Supported by Slippery Expert Witness

April 25th, 2017

Another day, another talc trial in Missouri. This one involves Lois Slemp, who sued Johnson & Johnson and its talc supplier, Imerys Talc America Inc., on her claim that her long-term use of talc caused her to develop borderline ovarian cancer.

To support her causal claim, Slemp’s lawyers called upon Dr. Daniel Cramer, a gynecologist and epidemiologist, from Harvard, to testify. See Daniel Siegal, “J & J’s Talc Caused Woman’s Cancer, Harvard MD Tells Jury,” Law360 (April 24, 2017) [cited as Siegel]. At first blush, counsel’s retention of Dr. Cramer seems like a brilliant choice. Cramer is a Professor of Epidemiology, at Harvard University’s T.H. Chan School Of Public Health, and a Professor of Obstetrics, Gynecology and Reproductive Biology, at Harvard Medical School. For over 30 years, Cramer has published primary studies, reviews, and commentary pieces in which he has addressed the epidemiologic and biological evidence involving talc and ovarian cancer.1

Cramer, as both a physician and an epidemiologist, addressed both general and specific causation in the Slemp case. Notwithstanding Slemp’s risk factors of family history of cancer and obesity, Cramer asserted with “reasonable degree of medical and scientific certainty” that talc was “the major contributing cause and substantial cause in the development of her serious borderline tumor.” Siegel, supra.

Somehow this physician epidemiologist has taken a putative risk factor and converted it into the cause. This conversion would perhaps make sense if the risk factor were necessary or sufficient to cause the outcome, but the evidence involving talc and ovarian cancer does not even remotely resemble such a situation. The epidemiologic evidence is weak and inconsistent, but if causation were assumed on the basis of cherry-picked studies, the relative risk for ovarian cancer would be somewhere around 1.2. Somewhat like the magic grits in My Cousin Vinny, Dr. Cramer has found a putative risk factor that blocks out all other risk factors, including the idiopathic, baseline risks that afflict all women in the age range of Ms. Slemp.

On cross-examination, Cramer was confronted with his failure to have asserted general causation in his professional, peer-reviewed publications on talc and ovarian cancer. Defense counsel Orlando Richmond drew the jury’s attention to an invidious comparison between Cramer’s courtroom assertions and his epistemically more modest conclusions and qualifications in the scientific literature, in which he never claimed a causal relationship between talc use and ovarian cancer:

Q. “Nowhere in the published scientific literature, did you or your colleagues, ever publish, ever publish, that genital talc use causes serious borderline tumors, the disease Ms. Slemp has. Isn’t that a correct statement, sir?”

A. “We certainly made a powerful case for there being an association. We may not have used the word ‘causal,’ if I had known how important that word was, I would have used it a long time ago.”


Wow! A Harvard professor of medicine and epidemiology, who teaches at the Harvard School of Public Health, and who labored in the field of epidemiology for over three decades, was unaware until earlier this week, when he darkened the doorway of a Missouri courtroom, that there was an important distinction between association and causation, and this distinction was crucial to discussions and debates in science and public policy.

Now that is slipperier than the most lubricious talc dusting. Why would such an accomplished physician scientist equivocate so? Perhaps Cramer refrained from drawing a causal conclusion because uncertainty favored obtaining future grants to study the same issue. Maybe he refrained from drawing a causal conclusion because doing so would have made him subject to criticism, ridicule, and rebuttal from his professional colleagues. I cannot think of a flattering reason for Cramer’s timidity in expressing himself clearly to his professional peers over the course of 34 years of researching the issues.

Previously, I have called attention to “white hat” bias in the courtroom, which occurs when scientists enter the fray based upon their distorted perceptions of siding with the “little guy” in a misguided quest for social justice. Cramer’s participation in the litigation process illustrates another kind of bias in play in courtrooms. After 30 years of publishing on talc and ovarian cancer, Cramer has failed to obtain acceptance of a claim for causality from the scientific community, but the courtroom is a venue where he can obtain the approving judgment of a scientifically naïve jury or judge and thus gain some vindication for his work that has gone unappreciated by professional colleagues and policy makers.

1 See, e.g., Daniel W. Cramer, et al., “The Association Between Talc Use and Ovarian Cancer: A Retrospective Case-Control Study in Two U.S. States,” 27 Epidemiology 334 (2016); Daniel W. Cramer, “The epidemiology of endometrial and ovarian cancer,” 26 Hematol. Oncol. 1 (2012); M. A. Gates, Daniel W. Cramer, et al., “Talc use, variants of the GSTM1, GSTT1, and NAT2 genes, and risk of epithelial ovarian cancer,” 17 Cancer Epidemiol. Biomarkers Prevention 2436 (2008); Joshua Muscat, M. Huncharek, and Daniel W. Cramer, “Talc and anti-MUC1 antibodies,” 14 Cancer Epidemiol Biomarkers Prevention 2679 (2005); Daniel W. Cramer, et al., “Presence of talc in pelvic lymph nodes of a woman with ovarian cancer and long-term genital exposure to cosmetic talc,” 110 Obstet. & Gynecol. 498 (2007); D. M. Gertig, Daniel W. Cramer, Graham A. Colditz, et al., “Prospective study of talc use and ovarian cancer,” 92 J. Nat’l Cancer Inst. 249 (2000); Daniel W. Cramer, “Perineal talc exposure and subsequent epithelial ovarian cancer: a case-control study,” 94 Obstet. & Gynecol. 160 (1999); Daniel W. Cramer, et al., “Genital talc exposure and risk of ovarian cancer,” 81 Internat’l J. Cancer 351 (1999); Bernard L. Harlow, Daniel W. Cramer, et al., “Perineal exposure to talc and ovarian cancer risk,” 80 Obstet. & Gynecol. 19 (1992); Daniel W. Cramer, et al., “Ovarian cancer and talc: a case-control study, 50 Cancer 372 (1982).

Science Day Should Be Every Day in Our Courtrooms — Part II

March 24th, 2017

This post and the previous one are an expansion upon a post that I wrote with Dr. David Schwartz, of Innovative Science Solutions, LLC. Dr. Schwartz is a talented scientist with whom I had the privilege and pleasure to work at McCarter & English, before he left to become an independent scientific consultant. Dr. Schwartz is one of the founding partners of his firm, which focuses on helping lawyers with the scientific issues in complex health effects litigation. Our earlier post can be found on the Courtroom View Network’s website. “Guest Analysis: Key Takeaways from Recent Talc Powder ‘Science Day’ Hearing in California,” Courtroom View Network (Mar 24, 2017).


Talc Science Goes Bicoastal

This year, two trial judges have entertained Science Days in talc cases, on both coasts of the United States. In the federal talc litigation, MDL 2738,1 Judge Freda L. Wolfson conducted a Science Day on January 26, 2017. In the coordinated California state court talc cases, Judge Maren E. Nelson, of the Superior Court of California, Los Angeles County, conducted a Science Day, on March 7, 2017.2

Federal Talc MDL 2738

In the federal cases, Johnson & Johnson, one of the defendants, initiated the Science Day, in November 2016, when it asked Judge Wolfson to set aside a day in “which the parties and their experts can outline their positions/arguments regarding the medical and science issues at play.”3 In Case Management Order No. 1 (Jan. 23, 2017), Judge Wolfson apparently agreed, and the parties had their talc Science Day on January 26, 2017.4 The Science Day took up over five hours of presentations to Judge Freda L. Wolfson, and Judge Lois H. Goodman.5

California Coordinated Docket

In the California cases,6 plaintiffs’ counsel filed a formal motion, in early December 2016, to request a Science Day tutorial. The plaintiffs’ motion requested that each side be permitted two hours to present their views of the scientific evidence in support of their litigation positions on causation and liability in talc ovarian cancer cases. The plaintiffs argued that a Science Day would be “significant benefit to the Court and the parties.”7 Judge Nelson granted the request, and held Science Day on March 7, 2017.

Courtroom View Network (CVN)

The proceedings in California were recorded videographically, and are available through Courtroom View Network (CVN). Johnson & Johnson opposed televising the Science Day proceedings, on the procedural ground that CVN had not filed and served the appropriate motion. Johnson & Johnson also argued a substantive ground that the proceedings were not a formal trial, and that televising “would not confer any benefit on the public, the parties, or the Court, let alone one that outweighs the significant concerns posed by such a broadcast.”8

Whatever the merits of J & J’s procedural ground, its substantive grounds seem dubious. The importance of the Science Day proceedings transcends the pecuniary interests of the parties to the litigation. First, the presentations provide the empirical bases for other courts and lawyer to evaluate the procedures employed. Second, lawyers and judges generally, outside the talc litigation, can learn a great deal from the strengths, weaknesses, and mistakes made by the participants in the televised proceedings. Many of the scientific issues that pervade the talc litigation recur frequently in other mass tort litigations in the United States and abroad. Finally, and perhaps most important, the talc litigation involves litigation claims of huge import to the public generally. For better or worse, litigation has become an adjunct to regulation in the United States. If the plaintiffs’ claims are true, then there has been a serious failure of national and international regulatory agencies and scientific organizations in evaluating the evidentiary record. If the defendants’ claims are true, then the plaintiffs’ lawyers have misunderstood and distorted the basic process of synthesizing evidence and arriving at conclusions of causation. More important, it behooves the public to understand why one side is wrong.

Evaluation of the California Talc Litigation Science Day

Plaintiffs’ Presentations

The presentation by the plaintiff lawyers was eerily reminiscent of the scientific case made by plaintiffs in the silicone breast implant ligation. Their arguments ranged from highlighting anecdotal evidence to emphasizing the implicit sinister nature of talc migration from the vaginal opening to the ovaries. Plaintiff counsel focused heavily on the alleged role of talc in the inflammatory process and strong (unsubstantiated) implications that anything that enhances inflammation must necessarily cause cancer.

As one would expect, plaintiff counsel placed strong emphasis on the published epidemiological studies linking talc exposure to ovarian cancer. It is important to highlight that the majority of the studies showing an association between talc and ovarian cancer came from case-control studies by design (as opposed to a cohort design). Plaintiff counsel offered very little distinction between these two study designs and, instead tried to make the case that the sheer volume of studies made their argument..

Finally, it should be noted that at many times throughout the plaintiff presentations, the presenter veered off into non-scientific, ad hominem attacks against the industry and/or activities that they tried to paint as venal or unseemly. Defense counsel made objections throughout that seemed to be based upon first amendment protections for the defendants’ ability to speak to agencies about the scientific evidence. For example, the last presenter for the plaintiffs described alleged industry “lobbying” efforts at NTP. Defense counsel objected on first amendment grounds, and the judge semi-sustained the objection on the basis that it had little or nothing to do with the science. The plaintiffs’ emphasis on “lobbying” contained no examples of misrepresentations of scientific data. See Talc Litigation in Missouri – Show Me the Law and the Evidence” (Feb. 24, 2017).

Defendants’ Presentations

In general, the defense presentations were more structured, coherent, substantial, and rigorously scientific. For example, unlike the plaintiffs’ graphics, many of the defense slides could stand on their own in a scientific or medical society presentation. The defense lawyers attempted to provide a solid foundation for the judge on the different types of ovarian cancer as well as the myriad uncertainties that exist in terms of the known causes of the condition. Many of the slides contained direct quotes from notable scientists and regulators on topics that were directly relevant to answering critical questions in the litigation.

Epidemiology and Specific Causation

Nevertheless, the defense presentations were not without their problems. Consider the following quote from an article by Graham Colditz, used in one of the defense powerpoint slides:9

The fundamental object of epidemiology is to estimate the population average risk of the disease. Risk is a population measure, not an individual disease measure.”

Colditz has served as an expert witness on epidemiology for plaintiffs in talc and other litigations, and the defense no doubt believed that they could make their point in a rhetorically powerful way by quoting him. The problem starts with the quote’s failure to make the defense’s point. Risk is a measure or relative proportions in the sample, to be used to estimate the population measure. To say that it is a group measure, however, does not mean that there are no reasonable inferences from the group measure to the individual member of the sample or population.

The defense seems to want to argue that even there were an increased risk not explained by chance, bias, or confounding, that measure of risk does not tell us anything about what caused an individual claimant’s ovarian cancer.

A fuller quotation might even have helped the defense because Colditz seems intent on undermining not just the use of group measures of risk as an individual variable, but also the use of the measure to support an inference about individuals:

The fundamental object of epidemiology is to estimate the population average risk of disease. Risk is a population measure, not an individual measure. Epidemiology does not estimate individual levels of risk, nor does it perfectly predict individual likelihood of disease. As noted by Rose, epidemiology does not describe why an individual case of cancer arises in the population but rather the population burden of cancer.14 In his article in this issue of the Journal, Begg ignores this principle and uses the term “risk” as an individual-level variable.15

The fuller quotation points to a disagreement in which another epidemiologist was willing to use risk to describe individual attribute, but more to the point is that Colditz’s assertion is that risk is a group measure.

Colditz, at least in this article, does not claim that the group measure of risk was irrelevant to prospective individual predictions or retrospective individual attributions. Interestingly, Graham Colditz has elsewhere asserted that an increased risk of disease cannot be translated into the “but-for” standard of causation10:

Knowledge that a factor is associated with increased risk of disease does not translate into the premise that a case of disease will be prevented if a specific individual eliminates exposure to that risk factor. Disease pathogenesis at the individual level is extremely complex.”

Defense may have wanted to highlight this assertion even recognizing that it is controversial, and quite dependent upon the magnitude of the measured risk.

In attempting to make their point with a quote from plaintiffs’ own expert (Dr. Graham Colditz), the defense oversimplified a much more complex issue. While increased or relative risk is indeed a measure or incidence rates used to estimate rates in the broader population, this aspect of relative risk as a measure does not mean that there are no reasonable inferences that can be made from the group measure to the individual member of the sample or population. The defense seems to want to make the seemingly unreasonable point that even if an increased risk were appropriately demonstrated by the epidemiology, that that measure of risk does not tell us anything about what caused an individual claimant’s ovarian cancer. This point might be correct when the magnitude of the increased risk is small (as is alleged in the talc ovarian cancer litigation), but the sweeping generality of the defense’s assertion is jarring.

Back in the 1960s and 1970s, tobacco companies attempted to rebut inferences of individual causation, despite scientific consensus on general causation, and relative risks of 20 to 30, and more for lung cancer in smoking versus non-smoking groups. The tobacco companies’ claim of the irrelevancy of epidemiology to inferring specific causation was not particularly credible when the population attributable risk was 95 percent and greater.

Even at lower relative risks, measures of risks in epidemiologic studies and clinical trials are used to predict individual responses to treatments, to life style interventions, and to life style and other risk factors. Of course, there is always potential heterogeneity in the sample and in the population, which should be acknowledged, but when the studies are multivariate, with inclusion of the known causes and potential risk factors, then scientists and physicians routinely use these measures of risks and benefits in groups to make predictions about individuals.

Consider a man, seriously overweight, who goes to see his internist. His physician tells him,

look in populations of overweight men, just like yourself, more men die of heart attack and stroke, and they die of these diseases at an early age, and suffer more morbidity and disability from them, then in groups of men who are not overweight, but don’t worry, that has NOTHING to do with you. We don’t know your risk, so go right on eating candy bars for breakfast, and studiously avoiding exercise.”

Of course, no sane, competent physician would advise the obese patient in this manner. Now, I understand rhetorically why the defense might want to capitalize on Colditz’ statement, but the end result appears to mislead the intended audience. The rejection of probabilistic inferences is still occasionally sanctioned by courts11, but more typically, such inferences are permitted when not conjectural.

Defense’s Misleading Claim that Case-Control Studies are Smaller than Cohort Studies

In its Science Day presentation, the defense asserted that a disadvantage of case-control studies is, among other things, their “small size.” In the same vein, the defense claimed that an advantage of cohort studies is their “large size.” The defense provided no supporting citations for its contention about the relative size of the two kinds of analytical epidemiologic studies.12

In his oral comments, the defense presenter notes the size disparity between the case-control and the cohort studies as a reason to distrust the results of the case-control studies on talc exposure and ovarian cancer. The presenter leans in and says that the cohort studies are huge, some with hundreds of thousands of women.

Now there are important qualitative differences between case-control and cohort studies, with respect to recall bias and the validity of control groups. To be sure, and fair, the defense made these points accurately. The defense’s invidious comparison of size of the two types of studies ignores that case-control studies are statistically much more efficient.

As the defense presented the matter, case-control studies are placed lower on the “hierarchy of evidence” than cohort studies. For this point, the defense did present a supporting citation13, and their claim is generally correct, but epidemiologists recognize that a well-conducted case-control study may well trump a cohort study. Case-control studies are often ranked below cohort studies because of greater potential for systematic bias, the inherent difficulty in selecting appropriate controls, and because the measure of risk in the form of an odds ratio is at best an estimate of the relative risk. The sizes of the “cases” group in a case-control study and the cohort in a cohort study are not a valid comparison.

A case-control study may be based upon hundreds of cases of ovarian cancer, a size that would require a huge cohort study. Furthermore, the size of the cohort study can be highly misleading because recruitment and inception into the cohort often takes place at a young age, when the rate of ovarian cancer is very low. The efficiency of the case-control study design is reflected in the narrow confidence intervals seen in many of the published papers. Some of these confidence intervals are as narrow as those generated by analysis of data from “larger” cohort studies.14 The size is ultimately related to the precision of the various studies’ point estimates of measured risk, not to the accuracy of their measurements. The statistical efficiency of the ovarian cancer talc case-control studies becomes an important when rare disease subtypes are considered, or when the interaction between genotype, exposure, and cancer outcomes needs to be considered.

Synthesis of Evidence for Judgments of Causation

Finally, it seems that neither the defense nor the plaintiffs adequately incorporated into their presentations the important concept of causal inference (or how evidence from disparate sources is synthesized into a judgment of causation, or into a rejection of such a claim). Specifically, counsel never explicitly set forth the importance of the Bradford Hill factors, or the techniques of proper and rigorous systematic review methodologies. The defense did touch upon many of the key considerations of the Bradford Hill factors as they applied to the relevant data, but there was no discussion of how these factors are considered after the identification of an association that is not likely the result of bias and that is beyond the play of chance. With respect to meta-analysis, both sides provided no guidance or insight into the problems that arise in conducting, reporting, and interpreting quantitative syntheses of a body of epidemiologic studies.

The Trial Court’s Role

Most trial judges, sadly, come to cases such as the talc ovarian cancer cases without any training in statistics, epidemiology, toxicology, or an adequate understanding of the role that clinical medicine plays (or does not play) in assessing important questions of causation. Judge Nelsen seemed to listen carefully, but asked few questions to suggest that Her Honor understood the discrepancy in statements made in the parties’ presentation.

Perhaps a starting point for Science Day should be an Order that sets out the procedures for the Day, as well as a statement: “The Court has read and studied the relevant chapters in the Reference Manual on Scientific Evidence (3d ed. 2011), and all materials submitted by the parties. The parties should not recreate a tutorial that covers material in the Reference Manual, unless they wish to contest its contents. Specific references to the Manual, in connection with the parties’ presentation would be very helpful to the Court.”

1  In re Johnson & Johnson Talcum Powder Products Marketing, Sales Practices & Prods. Liab. Litig., No. 16-2738 (D.N.J.)

2 Johnson & Johnson Talcum Powder Cases, No. JCCP4872 (Calif. Super. Ct., Los Angeles Cty.).

3  “Johnson & Johnson Files Status Report in MDL Docket, Requests ‘Science Day’ to Address Causation in Talc Cases,” HarrisMartin’s Talcum Powder Litigation Report (Nov. 16, 2016).

4  “Parties in Federal Talcum Powder MDL Hold ‘Science Day’,” HarrisMartin’s Talcum Powder Litig. Report (Jan. 26, 2017).

5  Id.

6  Johnson & Johnson Talcum Powder Cases, No. JCCP4872 (Calif. Super. Ct., Los Angeles Cty.).

7  “Plaintiffs Ask Court to Hold ‘Science Day’ in California Coordinated Talcum Powder Docket,” HarrisMartin’s Talcum Powder Litig. Report (Dec. 7, 2016).

8  See “Calif. Court Oversees ‘Science Day’ in Talcum Powder Docket One Day After J&J Opposes Broadcast of Hearing,” HarrisMartin’s Talcum Powder Litig. Report (Mar. 8, 2017).

9 “Defense Slide 129. “Epidemiology Estimates Risk in the Population, Not in Individuals,” quoting from Graham Colditz, “Cancer Culture: Epidemics, Human Behavior, and the Dubious Search for New Risk Factors,” 91 Am. J. Pub. Health 357, 357 (2001).

10 Graham A. Colditz, “From epidemiology to cancer prevention: implications for the 21st Century,” 18 Cancer Causes Control 117, 118 (2007).

11 See, e.g., Smith v. Ortho Pharmaceutical Corp., 770 F. Supp. 1561, 1573 (N.D. Ga. 1991) (“However, in an individual case, epidemiology cannot conclusively prove causation; at best, it can only establish a certain probability that a randomly selected case of disease was one that would not have occurred absent exposure, or the ‘relative risk’ of the exposed population. Epidemiology, therefore, involves evidence on causation derived from group-based information, rather than specific conclusions regarding causation in an individual case.”).

12  See Defense Slide 134, “Disadvantages of Case-Control Studies,” which sets out in bullet points, “Recall Bias, Confounding, Small Size.” And in Defense Slide 135, “Epidemiologic Studies on Talc and Ovarian Cancer: Three Types Large Prospective Cohort Studies,” the defense touts advantages of cohort studies to include “No Recall Bias” and “Large Size.” The slides contained no supporting citation for the contention about size.

13 See Defense Slide 136, “Epidemiology Studies on Talc and Ovarian Cancer: Three Types,” where the defense places case-control studies lower on the “hierarchy of evidence” than cohort studies, citing Trisha Greenhalgh, “How to Read a Paper,” 315 Brit. Med. J. 241 (1997).

14 See Wera Berge, Kenneth Mundt, Hung Luu & Paolo Boffetta, “Genital use of talc and risk of ovarian cancer: a meta-analysis,” European J. Cancer Prevention (2017), in press, DOI: 10.1097/CEJ.0000000000000340.


American Bar Association’s “Civil Trial Practice Standards” (August 2007).

7. Use of Tutorials to Assist the Court

a. Pretrial Use of Tutorials. In cases involving complex technology or other complex subject matter which may be especially difficult for non-specialists to comprehend, the court may permit or require the use of tutorials to educate the court. Tutorials are intended to provide the court with background information to assist the court in understanding the technology or other complex subject matter involved in the case. Tutorials may, but need not, seek to explain the contentions or arguments made by each party with respect to the technology or complex subject matter.

b. Selection of Type of Tutorial.

i. In any case in which the court believes one or more tutorials might be useful in assisting it in understanding the complex technology or other complex subject matter, the court should invite the parties to express their views on the desirability of one or more tutorials.

ii. Once the court decides to permit or require one or more tutorials, it should invite the parties to suggest the subject matter and format of each tutorial.

iii. If the parties cannot agree on the subject matter and format, the court should invite each party to submit a description of any tutorial it proposes and to explain how that tutorial will assist the court and why it is preferable to the tutorial proposed by another party. The court may approve one or more tutorials proposed by the parties, or the court may fashion its own tutorial after providing the parties with an opportunity to comment on the court’s proposed subject matter and format.

c. Procedures for Presentation. A court may consider the following procedures for the presentation of tutorials:

i. An in-court or recorded presentation by an expert jointly selected by the parties.

ii. An in-court or recorded presentation by one or more experts on behalf of each party.

iii. An in-court or recorded presentation by counsel for each party.

iv. A combined in-court or recorded presentation by counsel and one or more experts on behalf of each party.

v. An in-court or recorded presentation by an expert appointed by the court, which may include cross-examination by counsel for each party.

vi. Recorded presentations that have been prepared for generic use in particular kinds of cases by reliable sources such as the Federal Judicial Center.

d. Trial Use of Tutorials. In cases involving complex technology or other complex subject matter which may be especially difficult for non-specialists to comprehend, the court may permit or require the use of tutorials to educate the court or jury during one or more stages of the trial. Trial tutorials are intended to provide the court or jury with background information to assist in understanding the technology or other complex subject matter involved in the case. Tutorials may, but need not, seek to explain the contentions or arguments made by each party with respect to the technology or complex subject matter.

e. Selection of Type of Tutorial. The court should use the process set forth in 7.b. above.

f. Procedures for Presentation.

i. In a bench trial, the court may consider using any of the procedures set forth in 7.b. above.

ii. In a jury trial, the court should consider the use of tutorials in connection with interim statements and arguments as provided in

Standard 9.

iii. In both bench and jury trials, the court should provide parties with a full opportunity to present admissible evidence in support of their cases that may differ from or quarrel with information presented in a tutorial and to argue that the information presented in a tutorial should be rejected by the court or jury.

Science Day Should Be Every Day in Our Courtrooms — Part I

March 24th, 2017

The following post and its sequel are an expansion upon a post that I wrote with Dr. David Schwartz, of Innovative Science Solutions, LLC. Dr. Schwartz is a talented scientist with whom I had the privilege and pleasure to work at McCarter & English, before he left to become an independent scientific consultant. Dr. Schwartz is one of the founding partners of his firm, which focuses on helping lawyers with the scientific issues in complex health effects litigation. Our earlier post can be found on the Courtroom View Network’s website. “Guest Analysis: Key Takeaways from Recent Talc Powder ‘Science Day’ Hearing in California,” Courtroom View Network (Mar 24, 2017).


Every February 28th, India celebrates National Science Day in honor the Indian physicist Sir Chandrashekhara Venkata Raman, who discovered the Raman effect. The United States has no equivalent celebration, but “Science Days” have become a commonplace in complex state and federal Litigations, around the country.


The major impetus for science tutorials seems to have come from the United States Supreme Court’s decision in Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993). The holding of Daubert, now incorporated into, and extended by Federal Rule of Evidence 702, requires trial judges to act as gatekeepers of the relevance and reliability of expert witness opinion testimony in their courtrooms. One of the first tests of the judiciary’s performance to perform this role came in the silicone gel breast implant litigation. The federal silicone cases were consolidated before Judge Pointer Sam C. Pointer, Jr., in MDL 926. Judge Pointer believed that trial judges in the transferor courts should conduct whatever review of expert witness opinion was needed to satisfy the then recent Daubert decision.

Some of the first federal silicone lawsuits remanded from the MDL went to Judge Robert Jones in Portland Oregon. These cases involved complex issues of immunology, clinical rheumatology, epidemiology, toxicology, surgery, and polymer and analytical chemistry. At the outset of his case management of the remanded cases, plaintiffs’ counsel requested that Judge Jones schedule an all-day tutorial for counsel to present on these scientific issues. The parties’ tutorials, along with an avalanche of defense Daubert motions, persuaded Judge Jones to take the unusual step of appointing technical advisors to assist him in assessing the scientific evidence, inferences and claims in the silicone litigation. See Hall v. Baxter Healthcare Corp., 947 F. Supp. 1387, 1415 (D. Ore. 1996).1 Judge Jones’s technical advisors attended court throughout the Daubert hearings conducted in Portland, and they delivered advisory reports to Judge Jones to assist him in his gatekeeping function. Judge Jones ultimately granted the defense motions to exclude the plaintiffs’ expert witnesses’ claims of silicone causation of connective tissue diseases.

In large measure because of Judge Jones’s case management and exclusion of expert witness testimony, the silicone MDL court appointed a panel of neutral expert witnesses, in the fields of epidemiology, rheumatology, immunology, and toxicology.2

One of the first requests received from the Science Panel in MDL 926 was for what turned out to be a series of Science Days in which the parties’ expert witnesses would present to them, and explain their interpretation of the vast array of evidence, from different disciplines. Each presenting party expert witness was allowed 15 to 20 minutes to present. The lawyers were not entirely reduced to potted plants; they had a chance to conduct a short cross-examination. Given that the primary audience was a panel of four distinguished scientists, there was an emphasis for most of the lawyers, for the plaintiffs and the defendants, to ask pertinent, substantive questions.

The Science Panel was not entirely satisfied with the party expert witnesses, and requested a second Science Day, at which the Panel could call its own slate of scientists to address the scientific claims made in the litigation. The proceedings took place at the National Academies of Science, in Washington, D.C.

These proceedings, along with extensive submissions of articles and briefings from the parties led to the Report of National Science Panel, on November 30, 1998.

Every Day is Science Day, Somewhere

Since the breast implant litigation, many MDL and other courts have faced complex causation claims in litigation involving pharmaceutical products, medical devices, consumer products and a host of chemical exposures. Appointment of independent, neutral expert witnesses remains unusual, but trial judges have welcomed tutorials in the form of “Science Days,” to help them learn the methodologies and vocabularies of the scientific disciplines that are involved in the litigations before them. For some reason, the parties, the judges, and the legal media often reference Science Days in scare quotes, signaling that perhaps other Science takes place in these proceedings. Whether the scare quotes are warranted remains to be determined.

Science Days” have become a tradition in mass tort litigation.3 In the last few years, there is a Science Day somewhere, in some courtroom, going on, perhaps not daily, but with sufficient frequency that the phenomenon should receive more critical attention. Federal judges with multi-district litigation, or state judges with multi-county cases, set aside time to permit the parties a chance to educate them about the scientific and technical aspects of the litigations before them. Judges know that Daubert and Rule 702, or their state analogues, require them to act as gatekeepers. Furthermore, myriad motions in the discovery and trial phases of a case will require judges to make nuanced but accurate decisions about scope and content of discovery, and admissibility of documents and testimony,

Science Day – Have It Your Way

John Milton: We negotiating?

Kevin Lomax: Always.4

The Devil’s Advocate (1997).

There are no federal or state rules that set out procedures for science tutorials for judges or their appointed expert. The form and substance of Science Days depend upon a three-say negotiation among the plaintiffs, defendants, and the trial judge. Although the parties are often left to work out a plan for science day, most courts tend to weigh in by imposing time limits, and they may even rule in or rule out live witness testimony.

In 2007, the American Bar Association set out Civil Trial Practice Standards,5 which included an entire section on the use of tutorials to assist the court. [The relevant standards for tutorials is set out at the end of Part II of this post, as an appendix.]

1 See Laural L. Hooper, Joe S. Cecil, and Thomas E. Willging, “Neutral Science Panels: Two Examples of Panels of Court-Appointed Experts in the Breast Implants Product Liability Litigation,” at 9 (Federal Judicial Center 2001).

2 MDL 926 Order 31 (May 31, 1996) (order to show cause why a national Science Panel should not be appointed under Federal Rule of Evidence 706); MDL 926 Order No. 31C (Aug. 23, 1996) (appointing Drs. Barbara S. Hulka, Peter Tugwell, and Betty A. Diamond); Order No. 31D (Sept. 17, 1996) (appointing Dr. Nancy I. Kerkvliet).

3 See, e.g., Barbara J. Rothstein & Catherine R. Borden, Managing Multidistrict Litigation in Products Liability Cases: A Pocket Guide for Transferee Judges at 39 & n. 54 (Fed. Jud. Ctr. 2011); Sean Wajert, “‘Science Day’ In Mass Torts,” Mass Tort Defense (Oct. 20, 2008); Lisa M. Martin, “Using Science Day to Your Advantage,” 2(4) Pro Te: Solutio 9 (2009).

4 From the screenplay of the movie, directed by Taylor Hackford, written by Jonathan Lemkin and Tony Gilroy, and based on a novel by Andrew Neiderman.

5 American Bar Association’s “Civil Trial Practice Standards” (August 2007 & 2011 Update).