The Daubert case arose from claims of teratogenicity of Bendectin. The history of the evolving scientific record has not been kind to those claims. See “Bendectin, Diclegis & The Philosophy of Science” (Oct. 26, 2013); Gideon Koren, “The Return to the USA of the Doxylamine-Pyridoxine Delayed Release Combination (Diclegis®) for Morning Sickness — A New Morning for American Women,” 20 J. Popul. Ther. Clin. Pharmacol. e161 (2013). Twenty years later, the decisions in the Daubert appeals look sound, even if the reasoning was at times shaky. How have other notable Rule 702 exclusions stood up to evolving scientific records?
A recent publication of an epidemiologic study on lung cancer among workers exposed to polychlorinated biphenyls (PCBs) raised an interested question about a gap in so-called Daubert scholarship. Clearly, there are some cases, like General Electric v. Joiner[1], in which plaintiffs lack sufficient, valid evidence to make out their causal claims. But are there cases of Type II injustices, for which, in the fullness of time, the insufficiency or invalidity of the available evidentiary display is “cured” by subsequently published studies?
In Joiner, Chief Justice Rehnquist noted that the district court had carefully analyzed the four epidemiologic studies claimed by plaintiff to support the association between PCB exposure and lung cancer. The first such study[2] involved workers at an Italian capacitor plant who had been exposed to PCBs.
The Chief Justice reported that the authors of the Italian capacitor study had noted that lung cancer deaths among former employees were more numerous than expected (without reporting whether there was any assessment of random error), but that they concluded that “there were apparently no grounds for associating lung cancer deaths (although increased above expectations) and exposure in the plant.”[3] The court frowned at the hired expert witnesses’ willingness to draw a causal inference when the authors of the Bertazzi study would not. As others have noted, this disapproval was beside the point of the Rule 702 inquiry. It might well be the case that Bertazzi and his co-authors could not or did not conduct a causal analysis, but that does not mean that the study’s evidence could not be part of a larger effort to synthesize the available evidence. In any event, the Bertazzi study was small and uninformative. Although all cancer mortality was increased (14 observed vs. 5.5 expected, based upon national rates; SMR = 253; 95% CI 144-415), the study was too small to be meaningful for lung cancer outcomes.
The second cited study[4], from an unpublished report, followed workers at a Monsanto PCB production facility. The authors of the Monsanto study reported that the lung cancer mortality rate among exposed workers “somewhat” higher than expected, but that the “increase, however, was not statistically significant and the authors of the study did not suggest a link between the increase in lung cancer deaths and the exposure to PCBs.” Again, the Court’s emphasis on what the authors stated is unfortunate. What is important is obscured because the Court never reproduced the data from this unpublished study.
The third study[5] cited by plaintiff’s hired expert witnesses was of “no help,” in that the study followed workers exposed to mineral oil, without any known exposure to PCBs. Although the workers exposed to this particular mineral oil had a statistically significantly elevated lung cancer mortality, the study made no reference to PCBs.
The fourth study[6] cited by plaintiffs’ expert witnesses followed a Japanese PCB-exposed group, which had a “statistically significant increase in lung cancer deaths.” The Court, however, was properly concerned that the cohort was exposed to numerous other potential carcinogens, including toxic rice oil by ingestion.
The paucity of this evidence led the Court to observe:
“Trained experts commonly extrapolate from existing data. But nothing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence which is connected to existing data only by the ipse dixit of the expert. A court may conclude that there is simply too great an analytical gap between the data and the opinion proffered. … That is what the District Court did here, and we hold that it did not abuse its discretion in so doing.”
Joiner, 522 U.S. at 146 (1997).
Interestingly omitted from the Supreme Court’s discussion was why the plaintiffs’ expert witnesses failed to rely upon all the available epidemiology. The excluded witnesses relied upon an unpublished Monsanto study, but apparently ignored an unpublished investigation by NIOSH researchers, who found that there were “no excess deaths from cancers of the … the lung,” among PCB-exposed workers at a Westinghouse Electric manufacturing facility[7]. Actually, NIOSH reported a statistically non-significant decrease in lung cancer rate, with fairly a narrow confidence interval.
Two Swedish studies[8] were perhaps too small to add much to the mix of evidence, but lung cancer rates were not apparently increased in a North American study[9].
Joiner thus represents not only an analytical gap case, but also a cherry picking case, as well. The Supreme Court was eminently correct to affirm the shoddy evidence proffered in the Joiner case.
But has the District Judge’s exclusion of Joiner’s expert witnesses (Dr. Arnold Schecter and Dr. (Rabbi) Daniel Teitelbaum) stood up to the evolving scientific record?
A couple of weeks ago, researchers published a large, updated cohort study, funded by General Electric, on the mortality experience of workers in a plant that manufactured capacitors with PCBs[10]. Although the Lobby and the Occupational Medicine Zealots will whine about the funding source, the study is a much stronger study than anything relied upon by Mr. Joiner’s expert witnesses, and its results are consistent with the NIOSH study available to, but ignored by, Joiner’s expert witnesses. And the results are not uniformly good for General Electric, but on the end point of lung cancer for men, the standardized mortality ratio was 81 (95% C.I., 68 – 96), nominally statistically significantly below the expected SMR of 100.
[1] General Electric v. Joiner, 522 U.S. 136 (1997).
[2] Bertazzi, Riboldi, Pesatori, Radice, & Zocchetti, “Cancer Mortality of Capacitor Manufacturing Workers, 11 Am. J. Indus. Med. 165 (1987).
[3] Id. at 172.
[4] J. Zack & D. Munsch, Mortality of PCB Workers at the Monsanto Plant in Sauget, Illinois (Dec. 14, 1979) (unpublished report), 3 Rec., Doc. No. 11.
[5] Ronneberg, Andersen, Skyberg, “Mortality and Incidence of Cancer Among Oil-Exposed Workers in a Norwegian Cable Manufacturing Company,” 45 Br. J. Indus. Med. 595 (1988).
[6] Kuratsune, Nakamura, Ikeda, & Hirohata, “Analysis of Deaths Seen Among Patients with Yusho – A Preliminary Report,” 16 Chemosphere 2085 (1987).
[7] Thomas Sinks, Alexander B. Smith, Robert Rinsky, M. Kathy Watkins, and Ruth Shults, Health Hazard Evaluation Report, HETA 89-116-209 (Jan. 1991) (reporting lung cancer SMR = 0.7 (95%CI, 0.4 – 1.2). This unpublished study was published by the time the Joiner case was litigated. Thomas Sinks, G. Steele, Alexander B. Smith, and Ruth Shults, “Mortality among workers exposed to polychlorinated biphenyls,” 136 Am. J. Epidemiol. 389 (1992). A follow-up on this unpublished study confirmed the paucity of lung cancer in the cohort. See Avima M. Ruder, Misty J. Hein, Nancy Nilsen, Martha A. Waters, Patricia Laber, Karen Davis-King, Mary M. Prince, and Elizabeth Whelan, “Mortality among Workers Exposed to Polychlorinated Biphenyls (PCBs) in an Electrical Capacitor Manufacturing Plant in Indiana: An Update,” 114 Environmental Health Perspect. 18 (2006).
[8] P. Gustavsson, C. Hogstedt, and C. Rappe, “Short-term mortality and cancer incidence in capacitor manufacturing workers exposed to polychlorinated biphenyls (PCBs),” 10 Am. J. Indus. Med. 341 (1986); P. Gustavsson & C. Hogstedt, “A cohort study of Swedish capacitor manufacturing workers exposed to polychlorinated biphenyls (PCBs),” 32 Am. J. Indus. Med. 234 (1997) (cancer incidence for entire cohort, SIR = 86, 95%; CI 51-137).
[9] David P. Brown, “Mortality of workers exposed to polychlorinated biphenyls–an update,” 42 Arch. Envt’l Health 333 (1987)
[10] See Renate D. Kimbrough, Constantine A. Krouskas, Wenjing Xu, and Peter G. Shields, “Mortality among capacitor workers exposed to polychlorinated biphenyls (PCBs), a long-term update,” 88 Internat’l Arch. Occup. & Envt’l Health 85 (2015).